Duel: P-38J lightning vs Do335-A1

[Double T]

Both twin engined, single-seat fighters. How would these two have matched-up in a dog-fight?
The Do335 was a bit larger and heavier. Max-weight was 25,800lbs compared to 20,300lbs for the P-38J.
Max-speed was 402mph for the P-38 and 477mph at emergency war-power for the Do335 Arrow.
Ceiling was 40,000ft for the P-38 and 37,400 for the Arrow.
Armament for the Do335 was a 30mm cannon in prop-hub, and two-20mm in the nose firing through the prop. (The B1 version added one 30mm cannon in each wing.) For the P-38: four .50cal machine-guns and one 20mm cannon.

FIRE AWAY.

[Ricky]

Sad to say, I think the Lightning may be a good bet. The J model was the pinnace of the series, with most of the initial faults/problems ironed out, and quite a formidable fighter.
The D0335 seems to have an armament configured towards bomber interception, and maybe therefore at a disadvantage against more nimble opponants.
The D0335 does have a great speed though...

[Red Admiral]

The Do-335 is a power fighter. All it has to do is use its superior speed and extremely heavy armament in a series of high speed passes without trying to excessively maneuver which bleeds the speed off.

[Romantic Technofreak]

I think this is a very one-sided comparison. The title goes clearly to the Do 335. The tandem-engine concept, rejected by Kelly Johnson when he outlined the P-38, is simply superior. 75 mph speed difference are talking unambigously. With its short wings, some sources tell the Do 335 even to have a superior maneuverability compared to other heavy fighters. The Do 335 was the only piston-engined fighter that had the potential to keep up with contemporary jets, while the P-38 was already widely relegated to the fighter-bomber role.

There are some troubles remaining: The heavy fighter concept, at the end of the war, seemed not to show advantages over light ones because of the range performance of the Mustang. Kurt Tank wanted to have the Do 335 dropped in favour of his Ta 152, because it showed no range advantage and the latter needed one engine less. And the rear engine of the Do 335, like in other similar designs, was difficult to cool.

Anyway, a longer time ago we had the topic, everybody to choose 10 favourite aicraft types. I took the chance for to create my own air force, consisting of the best aircraft of every class (I could not include naval planes because of the limitation of 10). Although, in reality, Germany´s contribution to the use of heavy fighters was a joke, the Do 335 won her class, in my eyes the only German plane to do so.

[DoBravery]

All I'm going to say is that the P-38J wasn't the fastest P-38. But I guess if a Do 335 were to have come across a P-38 it would have been a J.

BTW I've got the J's top speed at 414mph (666kph) at 25,000ft (7,620m).

I think altitude will play a big factor in this matchup.
(I guess I said a bit more):)

[Double T]

DoBravery:
I wanted the matchup to be against the P-38L but I couldn't put my hands on the specs as I prepared the thread.
I think it's a fairly-even match-up determined ultimately by the skill of the pilot in the cockpit and tactics employed.
Hmmmm. I'll take the P-38. But I do like the Do335 single-seater. A lot.

Tim

[GregP]

The P-38J had a power loading of 6.8 pounds per HP while the Do-335 was 5.6 pounds per HP. Advantage 335.

The P-38J had a wing loading of 65.8 pounds per HP wjile the Do335 was 52.7 pounds per HP. Advantage 335.

These numbers are at NORMAL gross weight, not "best combat weight," nor at "maximum weight."

It looks like the Do-335 was better in both categories, but looks can be deceiving. We KNOW the P-38J could turn on a dime, but we don;t really know about the Do-335. The P-38J had the ability to use the flaps for tighter turns and the Do-335 didn't. The P-38J had hydraulic ailerons and the Do-335 didn't. It could be that the weight at the extreme ends of the Do-335 airframe affected the turning circle or the stability in a turn ... we don't know.

I tend to lean toward the Do-335 based on the numbers, but if the Do-335 HAD ever encountered a P-38J, it very well might have encountered 8, 12, or more at one time. There never WERE very many Do335s in service, so we don't really know.

Still, unless proven otherwise, and that would be HARD to do today, I'd say the Dornier Do-335 was the better mount. It HAD to have had a better cabin heater! Even an empty house had a better heater!

[ickysdad]

I think both the J & L versions of the P-38 hit around 414 MPH on Military Power but at full boost the P-38J tagged at about 430 MPH ,the L hit 440+ .

[Wuzak]

I would think that the P38 has it all over the 335 in terms of manoueverability.

I guess the 335 would have to use its superior speed to be able to combat the P38.

I thought that the 335 was not completely sorted when it entered service either. That it had problems with porpoising.


Where is Lighning? He'll have the definitive list on why the P38 wins.

[Lightning]

Hi Wuzak,

I have been on a "leave-of-absence" for a while. Mrs. Lightning ("Sparky") had a pretty serious operation, and I have been spending quite a bit of time at the hospital lately. Things are improving.

Back to the subject at hand:

I have done some reading about the Do 335A-1. Quite a few references have conflicting specifications, especially with regards to speed and weight. Speed is quoted anywhere from less than 450 mph up to 475 mph; weight figures vary between about 21,000 lbs up to 25,800 lbs. I'll base my comments on the following specifications:

Speed: 460 mph @ 23,300 ft
Initial Climb: 4600 fpm
Ceiling: 37,400 ft
Range: 1280 mi on internal; 2330 mi with huge drop tank
Armament: One 30mm (70 rds); two 15mm (200 rds/gun)
Bombload: One 1100 lb bomb on the center line and "light ordnance" on wing mounts

Based on these figures, the P-38J was about 20 mph slower (both at War Emergency Power). This speed advantage is somewhat offset by the poor handling qualities of the '335 at high speed--it had a tendency to "porpois" and "snake" at these speeds; the P-38 did not.

At low-to-medium speeds, the Lightning was far more maneuverable thanks to its maneuvering flap, its boosted ailerons, and its ability to use asymmetrical engine thrust (as it did in the Pacific against the far-more-agile Japanese fighters). Another important factor here is the Lightning's lower fighting weight.

The P-38J was equal to, or better than the Pfeil in its initial climb rate. I believe its (the P-38) had a better sustained rate due to its lighter weight and better high-altitude performance.

A comment was made earlier that the '335 could employ "boom-and-zoom" tactics against the Lightning. I don't think so. The Pfeil had a ceiling of 37,400 ft against the Lightning's 44,000 ft. If anything, the P-38J could better use this tactic, based on its climb and altitude performance.

Continued by Edit:

By virtue of the "dive flap" on the P-38J-25 (and all "L"s), the Lightning, as far as I can see, could out-dive the "335. It would have a steeper diving angle, would not accelerate through its critical Mach number, and would not have the compressibility problems as in early models. The dive flaps also extended the allowed diving speed by 20 mph.

The '335A-1 had much heavier guns than the Lightning, but it also had a much lower rate-of-fire and carried far less ammunition--470 rounds vs.the Lightning's 2150 rounds. It's two 15mm guns had the added disadvantage of being synchronized to fire through the propeller.

As to the placement of their engines, as long as both engines were running, the P-38 would have the advantage because of the pilot's ability to use engine manipulation to enhance maneuverability (as stated earlier). In an engine-out situation, the advantage would shift to the '335.

Another advantage that the Lightning had, although not associated with performance, was far better pilot visability. In, and especially before, a dogfight, this is very important.

Aside from the actual plane-on-plane combat comparison of these two planes, the Lightning was a better choice as a multirole fighter. It's range was as good; it could fly much higher; it carried over three times the bombload; its armament was concentrated in the nose without the need for rate-of-fire-reducing synchronization. These attributes made it a better interceptor (because of its sustained climb and higher altitude--not its firepower) and a better fighter bomber/ground-attack aircraft.

And remember, the P-38 was a proven design in actual combat operations in all kinds of conditions all over the world. Who knows what problems would have been encountered by the Do 335 under like conditions.

For the above reasons, I think the P-38J Lightning would win the dogfight with the Do 335A-1 Pfeil.

Regards,
Lightning

[Ricky]

Off-topic - I'm sorry to hear that Mrs Lightning is unwell, but glad that she is improving.
Best wishes to you both,
Ricky

[Double T]

Lightning:
Best wishes to the Missus for a speedy recovery. Will keep ya'll in my thoughts and prayers.

Tim

[Lightning]

Thanks, Guys!!! Your good wishes mean a lot to me. It's strange to have friends all over the world that one will probably never meet in person. Friends nonetheless.

Plese go back and read my added lines re: P-38J vs Do 335. I got "bumped" off the computer before I could finish my thoughts, so I finished them by edit.

Thanks again for the kind words.

Respectfully,
Lightning

[Tony Williams]

You will of course expect me to mention the De Havilland Hornet, which made for a better comparison with the Do 335 as it was developed over much the same period - the Lightning was an earlier design.

My money would have been on the Hornet, which was not only very fast (472mph in service trim) and had better anti-fighter armament but also enjoyed superb handling.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Wuzak]

Thanks for the reply Lightning.

Best wishes for you wife too. Hope all will be well.

By the time the Do335 entered service the Lightning had been through many combat experiences, improved immeasurably, and was thoroughly sorted.

The Do335 was on the beginning of the development curve.

I wonder, how would the Do335 compare against a P47?

[ickysdad]

Which P-47?????

[Kutscha]

quote:Originally posted by ickysdad

Which P-47?????

The P-47N [?]. There was also the XP-72, which was basically a P-47 with a P&W R-4360 engine but was 'killed' because of the new jets.

[ickysdad]

What about the P-47 J or M ???? The P-47J was basically an interceptor version of the P-47 ,it had searing performance but being an interceptor didn't have range so it fell by the wayside. The "M" IMHO was every bit the equal of the P-51H and actually seen service in WW2 pity any axis aircraft like the TA-152 ,FW-190D-9, Do. 335 that mistook it for say an earlier "D" model(which wouldn't have been an easy kill anyways). As far as the D0. 335 verse the P-38 ,what about comparing the German aircraft to the P-38K (which could have been in production in mid-43) ?

[andyo2000]

The P-47N was designed specifically for the Pacific. By the end of 1944, only 24 of them had been delivered anyway. Since the Do-335 only left Europe after it was captured by the US, these two planes would never have met. If they had battled, I would have to give the win to the Do-335. Though they were alike in many technical details, the 335 had more speed and better climbing power.

The P-47M, of which 134 were produced or converted to, was a special high-speed model designed to counter German jets and flying bombs. Note the high-speed, because that means its range was atrocious. (Only 560 miles at cruising speed). The Do-335 still maintained a slight speed advantage. To top it all of, the 47M had engine problems that meant it did not fly a combat mission until a few weeks before V-E day. I don't think these planes met either, although it's not impossible.

And the P-47J. Here is a plane that could probably have fought and defeated a Do-335. In mid-1944, it set a new speed record of 504 mph, which is about 30mph faster than the Do-335's max. All of the P-47s had a lower wing area and span, so it's possible the Allies could have won a turning contest. The Do-335's only hope, it seems, was to have climbed out of harm's way. No P-47 could stay with the Do-335 there. However, like the last two match-ups, this one never happened. The P-47J was cancelled soon after its contract was signed, mainly due to the new P-72. Only a few were made.

Onto the P-38K. This is a very sneaky little plane, and I couldn't find much. I did find that had average increases of 40mph over the P-38L max speeds. That means it was about even with the 335. However, since no 38Ks were produced, this a moot point.

All four of these planes were nice, yes. But none of them could have scrapped a Do-335, either because there weren't any to do so or because they just weren't good enough.

[ickysdad]

How is the Do. 335 faster if it had porpoising problems? It's top speed was what??? 460-470 MPH???? Lightning indicated it may have been as low as 450 MPH and it had problems in handling high speeds. The P-47N could definately hit 460-470 MPH, the P-47M about 480-almost 500 MPH(it's engine problems were due I think to wrong spark ollugs being shiipped),the P-38K and maybe even the L(and probably the P-47J too) could outclimb the "335" . Let's look at the P-38L it's top speed was 440+ MPH on 100 octane fuel(not the later 150 octane fuel ,this goes for the other planes too) and it had no problems hitting this speed,the Do.335 suposedly hit 450?, 460?, 470? 477???? but had severe problems doing so . I think Lightning summed it up nicely. These links will give some specs on the P-47M,P-47J, P-47N,P-38K, and P-38L .Some of my info I also got from Francis Dean's "America's 100,000".
http://www.geocities.com/pentagon/quarters/9485/P-47M.html

http://home.att.net/~C.C.Jordan/index.html

[andyo2000]

The max speed of the Do-335 was 474 mph. Yes, there were a few problems at higher speeds, but we know it could go that fast, if only for a little while. I don't know the extent of those problems, so I left them out.

The P-47N had a max speed of 460 at 30,000 ft. With WEP, I'm sure it could go much faster. The P-47M could go 470mph at 30,000 ft. The engine problems did stop them, but I believe the specifications we got were done with engines in good order. The engine problems were solved by the end of the war.

The P-38J couldn't top 440 mph. That's at 30,000 ft. And the K was only 14 mph faster than the J at 29,000 ft, which works out to about 444 mph there. The L topped out at 414 mph at 25,000 ft.

The L also could climb to 10,000 ft. in 4 minutes or 20,000 ft. in 7 minutes. The Do-335 could get to 3,280 ft. in 55 seconds and to 26,245 ft. in 14.5 minutes. It's hard to compare this data, being so different. It seems like the Do-335 gets off to an early lead if the L has an average beginning rate of climb of 2500 ft/minute. However, the 335 takes an extra 7.5 minutes to climb just 6200 extra feet after 20000, which may give the lead to the P-38. It would seem like the P-38L would win this contest though.

Lastly, fuel shouldn't be an issue. Remember, by the end of the war German planes might as well have been hand-cranked. If we can speculate about what the P-38 might have been capable of with better fuel, than the same goes for the Do-335. My guess is 500mph+ if the porpoising problems could be kept under control, but it's anyone's guess.

So let's compare speeds sans WEP, at around 25,000 ft.

Do-335 - 474mph at 21,350 ft.
P-47M - 453mph at 25,000 ft.
P-47N - 448mph at 25,000 ft.
P-38K - 444mph at 29,000 ft.
P-38L - 414mph at 25,000 ft.
P-38J - 406mph at 20,000 ft.

Keeping in mind that speed increases with altitude, the Do-335 is clearly the faster plane. On WEP, the P-47s might have been able to catch up, but just maybe. Note that the 474mph speed of the Do-335 is at 21,350 ft, which puts it a disadvantage in this speed comparison.

[ickysdad]

What are your sources? Mine are the website I posted and Francis Dean's "America's 100,000" . Eric Brown in his book "Wings of the Luftwaffe" says the Do.335 hit 360 MPH at SL & 430 one time at 18,000' while achieving a very,very top speed of 455 MPH with boost at 23,395' also 437 MPH at 21,665'. He also clearly states all the problems the Germans had weith this aircraft. Both clearly state the P-47N ,P-47M , P-38L(yes it(the "L" did hit over 440 MPH the J a tad over 430 MPH). Figures for top speeds of USAAF aircraft are around 470 MPH for P-47N, 480-490 for the P-47M, 440+ for the P-38L,all on 100/120 octane fuels much less the 150 octane fuel the USAAF had at the end of the war. Fuel is an issue because the US researched into developing it and thier engines were designed to be able to use over boost,the German engines it didn't matter if they had the extra high grade fuel because thier engines were designed around 87/90 octane fuel. Pouring high octane fuel (i.e 150 octane) into an engine designed for lower octane(87/90 octane) will not give it higher performance. To show what going from 100 octane fuel to 150 octane can do just look at the P-51 it normally pulled 61" om Military Power & 67" on WEP(achieving 380 MPH at SL) but with 150 octane & pulling 77" in USAAF planes, 81" on RAF models it would hit 410 MPH(USAAF models), 420 MPH (RAF midels) both at SL. Now imagine the speeds of the aircraft mentioned above(P-47M, P-47N, P-38L) with over-boost along with 150 octane fuel.
If we're going to give the Do. 335 the benefit of the doubt about porpoising then we have to give the P-47M the benefit of the doubt about it's engine problems.

Go to this website and see what these guys say about the P-38L hitting over 440 MPH .
http://groups.google.com/group/soc.history.war.world-war-ii/browse_frm/thread/24885f5ec7fbefc4/aee3a685ad4427d3?tvc

[Lightning]

Hi andyo2000,

Your quote: quote:Keeping in mind that speed increases with altitude, the Do-335 is clearly the faster plane.

This is not so. Speed increases with altitude only up to a certain point. At altitudes higher than this, speed drops off. That's why the maximum speed for an airplane is always stated at a given altitude.

As altitude increases, drag decreases, but so does engine power. Supercharging delays this effect, but it can only do so much. There comes a point where the drag/power combination is at its optimum. It is at this altitude that maximum speed is attained. Go higher or lower, and maximum speed will be less. There are also some aerodynamic considerations, such as changes in angle-of-attack due to thinner air, but I'm not well-enough versed on these to provide meaningful comment.

As regards rate of climb, this too depends on altitude. You can't extrapolate the time-to-30,000-ft from the time-to-20,000-ft. Neither can you use the initial climb rate to estimate the time to 20- or 30- thousand ft. That first 10,000 ft is attained far quicker than the last 10,000 ft. Remember, "service ceiling" is defined as the altitude at which the airplane's rate of climb has dropped to 100 fpm!

Regards,
Lightning

[Lightning]

Hi Tony Williams,

While it's true that the Hornet and Do 335 were being developed at roughly the same time, the '335 flew a little earlier, was in limited production before war's end, and was actually engaged in combat (only about 20 aircraft) whereas the Hornet wasn't. Some early production Hornets may have flown in early 1945, but deliveries and deployment to squadrons were not until 1946.

I would not, therefore, consider the Hornet to be a WWII fighter. This being the case, it is not appropriate to the present topic.

Regards,
Lightning

[Kutscha]

With a sky filled with Allied a/c, attacking every LW they saw, in the air and on the ground, how can one say that Do335s on test flights were 'in combat'. WNrs ran from 240101-123 plus 240161-163 and not all of these were completed. Some even crashed during testing. None flew true combat missions.

If the DB603L engines had been installed, the Do335 topped out at 490mph at 32,800ft. Every Do335 was over 410mph above 13,000ft. At 19,700ft, they were doing a minimum of 440mph. This from Dornier flight test data.

Lightning you misunderstood, me thinks.

"Keeping in mind that speed increases with altitude, the Do-335 is clearly the faster plane."

I don't think anyone was claiming that speed would keep increasing, for ever, with increasing altitude.

The only reason you want to dis-allow the Hornet is because it is so much better than the P-38.:D[:p]

[simon]

When debating a "What if...?" topic it is always difficult because different people have differing ideas about what are reasonable presumptions. To me the Hornet would be a fair alternative candidate since it was more the contemporary of the Do335, in terms of development and projected squadron service.

The Do335 may have flown and may have seen combat (My books say that it didn't, however Lightning is usually more knowledgable than me) but it did not see operational service and was not delivered to squadrons.

If the Do335 can be considered a WWII aircraft given that it did not make operational service and never made squadron deliveries (If it did see combat I cannot imagine that it was intentional), so can the Hornet.

Off Topic, I was sorry to hear that Mrs Lightning was unwell, I hope she is getting better or at the very least feeling better. I hope it was nothing too serious.

[ickysdad]

Simon,
Operational service is the keyword for me in regards to the Do.335 verse various USAAF aircraft . It's very obious the plane had severe problems ALOT of the so-caled German secret weapons did whench if they were put unto mass production there would have been ALOT of problems.

Kutschka,
You said that "if" the uprated engines were installed the Do. 335 hit 490 MPH . Is there any info that they actually were? Eric Brown in " Wings of the Luftwaffe" states that the Germans claimed 470 MPH as the top speed(i.e. he does indicate he finds that credible) however he goes on to say that they had more trouble getting that plane fit to fly for thier tests post-war then any other former Luftwaffe aircraft. Captain Brown also brings up the problems the plane had even in obtaining 450 MPH because of high speed handling problems. I hate to think what would have happened at 490 or even just 470 MPH.

Lightning,
IMHO the Hornet maybe more appropiate since it's a later aircraft than the P-38 ,the fact that the P-38 seems more than capable verse the Do. 335 despite it being a much earlier aircraft is testimony to it's superb design.

[Wuzak]

quote:Originally posted by Kutscha

The only reason you want to dis-allow the Hornet is because it is so much better than the P-38.:D[:p]


Thems fighting words...........[:p]

[andyo2000]

Lightning - you are correct. I am a little too unexperienced to really make sense of that data. If anyone else can, I would welcome them to try.

The Do-335 may have not seen the war. However, the P-47 J and N never saw the Do-335 either, and neither did the P-38K. The P-47M was also very unlikely to get in a dogfight with anything, as only a handful were delivered before war's end. I think that's why we're discussing this anyway - if the planes had met we'd know how they fared against each other and there wouldn't be as much of an argument. (Although we can discuss just about anything [:p])

And for you ickysdad, my sources are here. And i did not know that about the octane capabilities of engines, thank you.

http://aeroflt.users.netlink.co.uk/profile/d335top.htm
http://p-38online.com/
http://home.att.net/~jbaugher1/p47.html

[Lightning]

Hi Kutscha,

Your quote: quote:The only reason you want to dis-allow the Hornet is because it is so much better than the P-38.

That all depends on what "better" means. The Hornet was faster. Ranges were comparable (lots of ambiguous data on this one). The P-38L had a 6500-ft ceiling advantage. The P-38L had twice the bombload. Rates of climb were comparable (although I don't know the time-to-20,000 ft for the Hornet--it might be better).

In terms of versatility, the Lightning was clearly superior. The Hornet was designed mainly with the coming island-hopping campaign against the Japanese in mind. It was primarily to be used as a long-range fighter/escort. In terms of speed and range, it was optimized, but this was at the expense of its being a rugged all-around warplane a la the Lightning.

Also, how did the Hornet compare with the P-38L in dog-fighting ability (especially at low speed/altitude) and maneuverability? Please don't just give me your opinion on this--cite some reliable information. I truthfully haven't been able to find this out about the Hornet, but I do know that, in this respect, the Lightning had no peers among twin-engined fighters of the war.

The status of the Do-335 notwithstanding, The Hornet was not a WWII fighter! It was never truly battle tested (except in a few post-war minor operations involving British forces against third-world opposition to her empire). The Lightning was a first-line warplane from beginning to end, in every theater and climate, in every role asked of it, and against the very best the enemy had.

DeHavilland had the whole of WWII to develop the Hornet. The great success and qualities of the Mosquito were drawn upon, and its shortcomings were avoided in the new design. I would have been very surprised had the Hornet not been a stellar perfomer.

By the very nature of the Hornet's design goals, by its given specifications, and by the somewhat delicate configuration it presents, I feel very confident in saying that it would not have been as effective in bringing overall destruction to the enemy as was the P-38 Lightning.

Better?

And great perfomance does not guarantee greatness. The Hornet was faster, longer ranged, could carry a much-heavier load, had superior firepower, and had far more power than any variant of the Spitfire. Was the Hornet a better fighter than the Spitfire? Was it as great?

Regards,
Lightning

[Red Admiral]

quote:In terms of versatility, the Lightning was clearly superior. The Hornet was designed mainly with the coming island-hopping campaign against the Japanese in mind. It was primarily to be used as a long-range fighter/escort. In terms of speed and range, it was optimized, but this was at the expense of its being a rugged all-around warplane a la the Lightning.

Whereas the Lightning was designed as a long-range fighter, then pressed into service as ground attack aircraft/interdictor from lack of anything better. Was it really that good at ground attack? Not really compared to other types such as the Hawker Typhoon. The Lightning suffered mainly from a lack of armament in this role, as well as limited ammunition for its single 20mm cannon. It could carry rockets and bombs as well, but so could other planes. The Lightning is only rugged because of two-engined reliability. In reality the complex turbocharging pipes were quite vulnerable to damage. Being of metal construction, it was harder to repair than wooden construction like the Mosquito/Hornet.

The Lightning had less range than the Hornet. The -L had 424gal of internal fuel. The Hornet had 540gal. Both could carry underwing tanks of c. 500gal.

Personally, I don't like the Lightning, and never will. It could never really match a single-engined fighter for pure fighter skills. It was never going to match bombers/interdictors because of a lack of space, weight constraints, and fighter performance would suffer also. And, like just about all US aircraft, it suffered from a lack of armament.

[ickysdad]

Well in fact it was pressed into ground attack because of the arrival of the Mustang.
The P-38 not able to match single engined fighters? Not according to quite a few Luftwaffe fighter pilot accounts. Most of the problems of this aircraft was due to the early models all of which could have been fixed if not for the unreasonable decision of the USAAF to interrupt production even just slightly. The P-38 J/L's were just as fast as either the Spitfire XIV or P-51D for all practical purposes. In climb it wasn't that inferior to the XIV but was a better zoom climber,it was superior in this regard to the P-51(i.e. sustained climb) though the Mustang was the superior zoom climber. It could outdive the XIV though in turn it was outdived by the Mustang. I wouldn't say that USAAF/USN fighters lacked armament.

[Lightning]

Hi Red Admiral,

Let's take your comments in turn:

* The P-38 was not originally designed as a long-range fighter; it was designed as a high-altitude interceptor. In fact, the reason for the limited internal fuel capacity of the early models was that the Army specification required that all performance figures be met with internal fuel only--no drop tanks. A large internal fuel load would have been detrimental to quick take-off and climb to altitude and to high speed performance when it got there. These attributes are an interceptor's stock-in-trade.

* Lack of armament? The Lightning had four 50-cal machine guns with 500 rpg, and one 20mm with 150 rds. That's five guns, all concentrated in the nose, with 2150 available rounds. How does that compare with the Typhoon's wing guns? And while we're on the subject of the Typhoon, it was mainly designed as a fighter bomber. It never really distinguished itself in this role nor as a fighter.

* Yes, other fighters/fighter bombers carried bombs and rockets. How did they compare to this:

Bombs--two two-thousand pound bombs (That's 4000 pounds--for a fighter!)

Rockets-- Either 14 or 10, depending on launcher arrangement. The more successful of the two was the "Chrismas tree" launchers for 10 rockets.

Torpedos-- Although never used in combat, the P-38 actually demonstrated the ability to launch two two-thousand pound torpedos. There are photographs of the drop.

* As to ease of repair, sheet metal is easier to repair than wood. It took special craftsmen to both fabricate and repair wooden airplane structures. Also, when metal is overstessed (as in the case of a wing spar), it "takes a set" i.e. it deforms but doesn't break. An overstessed wooden structural component will bend only so far before it suffers total failure. This relieves the woodworkers of the task of making any repairs.

* The Lightning's fighter performance suffered? The P-38 shot down more Japanese aicraft (mostly fighters) than any Allied fighter except the F6F Hellcat. If you add in the kills of other Axis aircraft, I'm not sure how the Lightning and Hellcat compare. Both were stellar.

The two top American aces both flew exclusively Lightnings. I think three of the top 10 flew P-38s.

If I remember correctly, up until early 1945, a P-38 group (the 82nd, I believe) was the top-scoring fighter group against the Germans/Italians. It was finally surpassed by a P-51 group in the last days of the war. Not bad when you consider the number of Lightnings vs Mustangs in those theaters, and that the Lightnings were doing much more air-to-ground work than the Mustangs at the end.

Some added comments:

When it comes to versatility, how do other fighters of WWII stack-up against the Lightning?

Only the P-51 had its long-range capability, with the possible exception of the P-47N, which was tremendously modified to the point that, when loaded with fuel, it was so heavy for a single-engine fighter that it was not much good for anything but long-range escort work.

The P-47 was more resistant to ground fire, but it could not compare to the P-38 in terms of ordnance delivery. Its eight 50-cal wing guns were no more effective than the P-38's concentrated firepower (see above).

The Spitfire was a superb air-to-air, point-defense fighter, but it was far outclassed by the Lightning in the long-range escort role, the fighter bomber/close-air-support role, the night fighter role (although the P-38M only saw very limited use because of the war's end), the strategic bombing ("Droopsnoot") role, and the photo/recon role (the PR Spits were very fast, but their camera arrays and placement were inferior to those of the F-5--especially the F-5G).

In overall versatility and effectiveness (not only in the fighter bomber role), the Tempest/Typhoon fighters were far behind the Lightning. Compare their contribution to victory, in all theaters, to that of the P-38.

You may not like the Lightning, Red Admiral, but you are seriously underestimating it.

Regards,
Lightning

[DoBravery]

quote:
It could never really match a single-engined fighter for pure fighter skills. It was never going to match bombers/interdictors because of a lack of space, weight constraints, and fighter performance would suffer also. And, like just about all US aircraft, it suffered from a lack of armament.


More often than not, the Lightning's speed gave it the choice of withdrawing from or pursuing an engagement. That is probably one of the most important assets to have. The Japenese produced great aircraft in terms of pure fighting skills, but cleary that wasn't enough.

US aircraft were perfectly armed for their mission of clearing the skies of German and Japanese light aircraft. The US never had to go up against a significant heavy bomber force from the Axis to warrant armament upgrades. The only reason the German fighters were dripping with 30mm and gun pods by war's end was because of the Allied bombers. In terms of having the best pure fighter attributes, I would say the lightly armed 'F' model was maybe the best ME109 variant. For a higher altitude bomber killer, the Germans had to BEEF-UP the 109.

I thing the biggest strike against the P-38 is that it was more complex to build than a single seat aircraft.

Red Admiral--You pointed out one of the best qualities about the Fork Tailed Devil. How many aircraft can you think of that could be compared to fighters in one sentance, then bombers in the next.

[Red Admiral]

By the same token, you seriously over-estimate the Lightning.

An armament of 4x0.5" and 1x20mm cannon is poor compared to others. The armament weight was 429kg and can fire 2320 in 5.3s. 4xHispano Mk.II can fire 2320 in 2.9s for a weight of 344kg. So the 4x20mm cannon give about 80% more firepower than the mix, for less weight. Go on to the Tempest with the Mk.V and the disparity increases to over 100%. The Typhoon was designed as a replacement for the Hurricane. It lacked high-level performance but was an excellent ground-attack aircraft.

http://www.quarry.nildram.co.uk/WW2guneffect.htm

How often did the Lightning carry 2x2000lb bombs? It would be seriously detrimental to performance, carrying this load. Rockets don't really weigh much, or have an effect on the aircraft to a great extent. I don't know why the RAF used mainly batteries of 6-8. The Fw-190, G.55 and Firebrand can all drop Torpedoes as well.

When metal is overstressed it either fractures or it permanently deforms. It can take far stress again before fracturing.

The problem of citing shoot-downs is that it neglects; huge numbers and pilot quality in favour of the US, especially towards the end of the war.

quote:When it comes to versatility, how do other fighters of WWII stack-up against the Lightning?

Most of its contemporaries have a similar range on internal fuel to the Lightning. Roughly 1300km or so. It isn't hard to fit external fuel tanks onto aircraft. This boosted the range of all aircraft.

8x0.5" are more effective than 4x0.5" and 1x20mm.

quote:In overall versatility and effectiveness (not only in the fighter bomber role), the Tempest/Typhoon fighters were far behind the Lightning.

Why? Apart from carrying 4000lb of bombs, there is little difference in capabilities. The Tempest is a superior fighter to the P-38. Why weren't their PR variants of both? Because the RAF had the Mosquito and Spitfire for high and low-level rec already.

The Fork-Tailed devil thing is myth. In reality, the LW pilots had a good opinion for most of the allied fighters, apart from the P-38 which they thought was inferior.

[DoBravery]

I find it quite a complement for the P-38 that whenever someone critiques it, they must cite 4 to 6 different aircraft to cover all of the Lightning's attributes.

[simon]

I am far from a big fan of weight of fire as a measure of effectiveness, if nothing else weapon placement must also be considered. If one is to go by Galland's assessment that a gun in the nose is worth two in the wings when considering weight of fire (Double the Lightning's weight as all its weapons were nose mounted) does that not place the Lightning ahead?

[Ricky]

quote:Originally posted by DoBravery

US aircraft were perfectly armed for their mission of clearing the skies of German and Japanese light aircraft. The US never had to go up against a significant heavy bomber force from the Axis to warrant armament upgrades. The only reason the German fighters were dripping with 30mm and gun pods by war's end was because of the Allied bombers. In terms of having the best pure fighter attributes, I would say the lightly armed 'F' model was maybe the best ME109 variant. For a higher altitude bomber killer, the Germans had to BEEF-UP the 109.

Well, here we are again!:D

[ickysdad]

Red Admiral,
Alot of Luftwaffe pilots had a very healthy respect for the P-38, at least the sources I read do. I wouldn't say the Tempest is that superior to say the "L" version of the P-38 both of which have similar timeframes. The P-38 in Europe had problems with it's intercoolers mainly because of improperly blended fuel which lead to engine failure . The aircraft flew in the Aleutions and didn't have this problem so evidently it wasn't the cold weather in Europe.

[andyo2000]

I didn't know much on ickysdad's point that the Luftwaffe pilots did respect the P-38. So I looked up a little bit and here's what I found.

The P-38 was deployed to all 3 theaters. The bomber and transport pilots were terrified of the P-38. For example, on October 9, 1943, two P-38 pilots knocked off 12 Ju-87s. On two days in April of that year, 67 Ju-52s and 13 fighters were knocked off by P-38s alone.

Fighter pilots still respected the P-38. By the end of the war they knew how to exploit the '38s problems, but stayed clear of its concentrated nose firepower. That supports simon's comment on the P-38's firepower.

Also, I found more on ickysdad's comment on P-38 problems in the ETO.
Short summary - there were many.
In the PTO and MTO, P-38s were flown at low to mid-altitudes. In the ETO, they were flown much higher. Engines literally fell apart under those conditions. Superchargers failed under sustained use and also occasionally froze. Fuel was an issue as well. British fuel is believed to have been improperly blended - and anti-knock compound came out of solution and settled at the bottom of gas tanks. Oil coolers and intercoolers also worked too efficiently and froze engines. To top it all off, inadequate cockpit heating resulted in frostbite and pilot error.

To read more on P-38s in the ETO, go to http://home.att.net/~ww2aviation/P-38.html (not all my info was from there but it's very interesting)

[ickysdad]

Andy,
Well the problems tended to be in the early pre-J models and could have been rectified but for the stubborness of the USAAF. Alot of my info on the Luftwaffe's respect for the P-38 comes from "
Luftwaffe Fighter Planes & Aces" .

[Kutscha]

In the ETO, the major problem was with the turbo charger's waste gates. Moisture froze in the sense lines for the regulator. The turbo would runaway, often exploding. This was also a problem on the B-17s and B-24s.

This fuel problem. Did the P-38s use PEP fuel? Afaik there was no problem with 100 grade British fuel which was the standard British fuel from mid '40.

[ChrisMcD]

Hi Guys,

We appear to be wrestling with beliefs and intagibles here, despite all the facts quoted!

Just some comments

Tempest/Typhoon
Hawkers were criminaly late in discovering commpressibility. The Typhoon had much too thick a wing for most of the onterceptor roles it was designed to replace the Hurricane for. It was the low level 'hit and run' raids on the UK south coast by Fw190's in 1942/3 that kept it from being abandoned. At low level the sheer brute power of the Sabre made it the only Allied fighter that could catch the Fw 190 low down (even if it's tail kept falling off).

Camm was not stupid and rapidly redesigned a thinner elliptical wing version (as he commented "If the RAF will only by soemthing that looks like a Spitfire that's what we'll make!). But both were designed as interceptors but had to take up alternative trades- the Typhoon just happened to be able to carry huge loads on that barn door of a wing and the Tempest was a bit short of alternatives in 1945.

ETO Lightnings
We have discussed the poor performance of P38's in Europe before. But, remember that the P51 had a poor start as well, but managed to get through it. You wonder it it was a combination of personalites (I am guessing here) and the fact that the Mustang airframe and the Merlin had built up a huge reservoir of expertise and reputation in the UK before the Merlin models turned up - so that there was a greater determination to make it work (I will avoid a digression onto the RAF's experience with castrated P38's and who was to blame - but it cannot have helped!)

There is no doubt that the P38 did well in the Aleutians (but as I remember the attrition rate was horrendous) still if I was flying in perpetual fog over the North Pacific I would appreciate two engines. Also, the Allison did have a good reputation as an economical engine, but getting the best out of it was a specialised technique was it not (best taught by Lindberg!) Presumably the Allison would only give its best results when maintained perfectly and handled by experts.

Another point is that the Americans had developed dive and zoom tactics to cope with Japanes fighters well before the P38 got to the PTO, so that the plane perfectly fitted existing experience and preferences.

Getting back to the Do335 - I am with Kurt Tank - what could it do that the Ta152 couldn't do better on one engine - including beating up P38's!

[andyo2000]

Kustcha -

The problem was not with the actual fuel. The Lightnings used 91 Grade and 100/130 Grade on different occasions. British fuel wasn't inherently the problem. However, the Brits did add something called TEL to their fuel, tetraethyl lead. It condensed inside the P-38 engines because its superchargers were overly effective. After it came out of solution it caused pinging, or early detonation. This can be fatal for any engine, including car engines.

The US put TEL in commercial fuel but I don't believe it was added to aviation fuel. Major Doolittle had pushed for high-octane fuel in the mid-1930s, so apparently our fuel needed no new compounds to safeguard against knocking. Did we, anyone?

[Kutscha]

Andy,

Sam Heron put TEL in American fuel (8cc/gal) at Wright Field in 1931 and tested it in a Wright R-1340. Even testing in 1922 by the US Army, at McCook, found that adding TEL was advantageous. Whether the Americans went ahead and used it in military engines, I can't say, but would conclude they did, as 100 was shipped to the UK for British use. (most of the British 100 came from the USA)

How many inches of boost is 18lb boost? The Merlin ran this boost without problems, afaik, but there was some problems when the boost went to 25lb. WEP on the P-38L was 60", though it is said that it went to 70", or so, in late 1944.

I think you are referring to the lead deposits that appeared with the lean running of the engine to get extra range with the use of 100/150 fuel. The P-51 had this problem, solved by increasing the rpm of the engine every so often.

[ickysdad]

quote:Originally posted by ChrisMcD

Hi Guys

ETO Lightnings
We have discussed the poor performance of P38's in Europe before. But, remember that the P51 had a poor start as well, but managed to get through it. You wonder it it was a combination of personalites (I am guessing here) and the fact that the Mustang airframe and the Merlin had built up a huge reservoir of expertise and reputation in the UK before the Merlin models turned up - so that there was a greater determination to make it work (I will avoid a digression onto the RAF's experience with castrated P38's and who was to blame - but it cannot have helped!)

There is no doubt that the P38 did well in the Aleutians (but as I remember the attrition rate was horrendous) still if I was flying in perpetual fog over the North Pacific I would appreciate two engines. Also, the Allison did have a good reputation as an economical engine, but getting the best out of it was a specialised technique was it not (best taught by Lindberg!) Presumably the Allison would only give its best results when maintained perfectly and handled by experts.

Another point is that the Americans had developed dive and zoom tactics to cope with Japanes fighters well before the P38 got to the PTO, so that the plane perfectly fitted existing experience and preferences.

Getting back to the Do335 - I am with Kurt Tank - what could it do that the Ta152 couldn't do better on one engine - including beating up P38's!

A couple of points here Chris.....Alot of what you say is true on maintaining the Allison if I remember correctly most of the expierenced ground crews went to the MED leving the 8th. AF with the inexpierenced ones whench some of the reasons for some of the engine problems . As far as the Aleutions well attrition was high on all aircraft in that region.As far as the D0.335 not being any better than the TA152 I agree,the Do. 335 just had too many problems and it's performance figures seem to be all over the place ,i.e. topspeed anywhere from 450 to 490 MPH. Though the TA-152 had it's structural problems also

[ChrisMcD]

Hi Guys,

I do not claim to be an expert on petrol, but this is another discussion we have had before.

Rod Banks was instrumental in getting the RAF to use 100 octane petrol with TEL after his experience in the Schneider trophy races.

All the early Allied 100 octane petrols were based on aromatic blends derived from Caribean oilfields. The Americans were first to switch, but the RAF were close behind and had stockpiled enough by 1940. Aromatic petrol is high grade but prone to pre-detonation (knocking)

TEL is a marvelous product and does a lot more than just allow a higher octane level by reducing pre-detonation (ie. it lubricates valve stems), but it does have the effect of building up on the spark plugs at long range settings.

Kutsha is right in that there is a routine for for dealing with it. To get maximum range you need to maximise boost and retard ignition, but this leads to lead being deposited on the spark gap of the plug and shorting it out, leading to engines cutting out.

Pilots had to be taught to rev up every so often to burn the lead off the plugs to avoid this (that man Lindberg).

The Allison was famous for its lean efficiency, but did make demands on the pilot to achieve this.

The Merlin has the reputation of being idiot proof, but the only pilot I ever spoke to who was able to give an expert opinion (at one time he was one of only three Lancaster instructors left in the RAF), told me that he always felt that it's oil supply was not perfect - "If you saw the pressure gauge start to flicker, switch it off immediatly! Give me a Lancaster Mk II every time!). Shades of the Vulture

Hi Ickysdad - does this tie in with your experience?

The Do332 is a great idea, but Focke Wulf built better fighters.

[Wuzak]

quote:Originally posted by Kutscha

How many inches of boost is 18lb boost? The Merlin ran this boost without problems, afaik, but there was some problems when the boost went to 25lb. WEP on the P-38L was 60", though it is said that it went to 70", or so, in late 1944.


18psi is equivalent to 36.7in of Mercury, if my calculations are correct.

60in of Mercury equates to 29.5psi. Roughly 2 atmospheres (1 atmosphere is equivalent to standard pressure at standard temp, which is 101.3kPa/14.7psi).

btw, just quoting the boost pressure isn't really enough. You really ought to know what the compression ratio for the engine was. As it is the pressure inside the combustion chamber which determines whether or not knocking will occur. And that is determined by the boost and compression ratio.

Unsupercharged engines run more (static) compression than do boosted engines. And boosted engines vary in the CR depending on the boost levels. High boost engines tend to have lower CRs than low boost engines.

[Wuzak]

quote:Originally posted by ChrisMcD

TEL is a marvelous product and does a lot more than just allow a higher octane level by reducing pre-detonation (ie. it lubricates valve stems), but it does have the effect of building up on the spark plugs at long range settings.

I'm not sure that TEL qualifies as a "marvellous" product!

The company that developed TEL was bought by GM in the late '20s/early '30s. It was GM, using all their influence and money, that pushed TEL into common use in fuels for automobiles. Despite that it was already known that TEL was carcinogenic!

There were alternatives to TEL in the '30s too. The best of them was alcohol.

When TEl was removed from fuels in Australia in the mid '80s there were many arguments against because of TEL's lubricating qualities. When it was introduced, however, it was purely for boosting the octane of the fuel, and enabling more compression to be used.

[ChrisMcD]

Hi Wuzak,

Sorry, I should have qualified that 'marvelous'

Any organic lead compound is bad news for the environment and TEL is one of the worst.

It was the classic 'quick and dirty' solution to a specific problem that had much wider unforseen consquences.

Over the last 20 years it is noteworth that organic compounds of mercury, lead and tin have all been gradualy withdrawn. Hence the toxicologist catechism; "everything is either illegal, immoral, fattening or causes cancer in white rats"

But I still think that twin engined fighters are only suited for use over water.

[Kutscha]

Allison V-1710 and RR Merlin/1650 ran 6.00:1 CRs. The extra performance came from boost increases.

Key Specifications (Prior to racing modifications)

Model V-1710 G6R/L (V-1710-143/-145)
Application All models: Major production included P-37, P-38, P-39, P-40, P-46, P-47, P-51A, P-63, P-82
Engine Type V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material Aluminum heads, water jacket, crankcase; Steel cylinder liners; Forged aluminum alloy pistons; Magnesium oil pan
Bore x Stroke 5.5" x 6.0"
Compression Ratio 6.00:1
Supercharger type Two stage engine driven supercharger, 10.25" engine impeller, 12.1875" auxiliary impeller
Supercharger Ratio 7.48 engine stage, 8.087 (R) and 8.03 (L) auxiliary stage
Anti-detonation 50:50 water-methanol injection anti-detonation injection (ADI)
Fuel System Bendix-Stromberg SD-400D3 speed/density injection
Weight 1,595 lbs
Power 2,250 hp war emergency rating (WER) at 3,200 RPM & 101" Hg (35 psig) boost "wet" (w/ADI) and 115/145 PN fuel
Performance 325 psi BMEP (brake mean effective pressure)
Max. Piston Speed: 3,200 ft/min
Firing Order RH turning: 1L-2R-5L-4R-3L-1R-6L-5R-2L-3R-4L-6R
LH turning: 1L-6R-5L-2R-3L-4R-6L-1R-2L-5R-4L-3R
Timing Ignition: Intake fires 28° BTDC, Exhaust 34° BTDC, Sparkplug gap = 0.012-0.015"
Intake: Valve opens 48° BTDC, Closes 62° ABDC, 0.015" clearance (cold), 0.533" lift
Exhaust: Valve opens 76° BBDC, Closes 26° ATDC, 0.020" clearance (cold), 0.533" lift

http://www.unlimitedexcitement.com/Miss%20US/Allison%20V1710%20Engine.htm

Key Specifications (Prior to racing modifications)

Model V-1650-9
Application All models:
Engine Type V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material Aluminum heads, water jacket, crankcase; Steel cylinder liners; Forged aluminum alloy pistons
Bore x Stroke 5.4" x 6.0"
Compression Ratio 6.00:1
Supercharger type Two stage engine driven supercharger, 12.0" first stage, 10.1" second stage
Supercharger Ratio 6.391 (low blower), 8.095 (high blower)
Anti-detonation 50:50 water-methanol injection anti-detonation injection (ADI)
Fuel System Bendix-Stromberg PD18, Type G-9 pump, 9 psi idling, 12-16 psi operating
Weight 1,690 lbs
Power 1735 bhp @ 3000 rpm 66" boost
Rotation: CCW crankshaft rotation when viewed from supercharger end
Cylinder ID Bank: Right - A, Left - B when viewed from supercharger; "A" has oil regulator; 1-propeller end, 6-supercharger end
Firing Order 1A-6B-4A-3B-2A-5B-6A-1B-3A-4B-5A-2B,
Spark Plug 14mm thread, 0.011-0.014" gap
Magneto BTH C6SE12S/2 (Ex: AN SF 12RG-P-3 or SF 12RA-P-3, In: AN SF 12 LG-P-3 or SF 12LA-P-3)
Northeast (Ex: AN SF 12RA-P-4, In: AN SF 12LA-P-4)
Magneto Direction Exhaust Side -- CW, Intake Side -- CCW, viewed from driving end
Spark timing Fully Advanced: Intake 45° btc, Exhaust 50° btc, Magneto breaker gap 0.011-0.014
Cam Timing
(crank degrees) Intake: Valve opens 31° BTDC, Closes 52° ABDC, 0.015" clearance (cold), 0.590" max lift -- Note: Time w/0.020
Exhaust: Valve opens 72° BBDC, Closes 12° ATDC, 0.020" clearance (cold), 0.590" max lift
263° intake duration, 264° exhaust duration
Note: Tappet clearance for timing -- 0.020"

http://www.unlimitedexcitement.com/Pride%20of%20Pay%20n%20Pak/Rolls-Royce%20Merlin%20V-1650%20Engine.htm

[Wuzak]

quote:Originally posted by ChrisMcD

Any organic lead compound is bad news for the environment and TEL is one of the worst.

It was the classic 'quick and dirty' solution to a specific problem that had much wider unforseen consquences.


Problem is that they knew many of the problems associated with TEL BEFORE they introduced it widely.

[Wuzak]

Thanks Kutscha.

Some interesting numbers.

Interesting that the Allison made over 2000hp in WE. IIRC, none were normally rated at more than 1500hp in WW2.

Which compares with the later Merlin (RR versions at least) which were rated at around 2000hp.

[Kutscha]

Wuzak,

That is the engine used in the P-82.

Zeno's site has some P-38 info. http://www.zenoswarbirdvideos.com/More_P-38_Stuff.html

On the engine chart, it gives 1600hp @ 60"

Another site, but on the P-40, with some interesting Allison info. http://www.raafwarbirds.org.au/targetvraaf/p40_archive/p40_archive.htm

[Lightning]

Hi Red Admiral,

First of all, let me take a hit: My quote: quote:And while we're on the subject of the Typhoon, it was mainly designed as a fighter bomber. It never really distinguished itself in this role nor as a fighter.

In reality, the Typhoon WAS a great fighter bomber. It carried a great offensive ordnance load for a single-engine fighter--to include two 1000-lb bombs at the end. It DID distinguish itself as a fighter bomber.

I also was wrong when I said that the Typhoon was originally designed as a fighter bomber. That's not true--it was designed as an interceptor.

I like to keep things straight.

Typhoon vs Lightning?
The P-38 had better speed, had a higher climb rate, could dive faster, had greater range, had a higher ceiling, could carry twice the bombload, and carried more rockets than the Typhoon. It was a better air-to-air fighter than the Typhoon, especially at high altitudes. It was a better night fighter (in fact, the Typhoon was a failure in its attempted use as a night fighter). The Lightning was also astronomically beter as a photo/recon plane.
The Lightning was a better interceptor (although not often used as such). (Again, the Typhoon failed here.) As a long-range bomber escort fighter, the Typhoon doesn't even come into the picture.

The only role in which the Typhoon compares favorably with the Lightning is that of fighter bomber, and even there the P-38 had more potential. The Typhoon could never have carried out the long-range raid on the Ploiesti oil refineries that the P-38 did, nor could it have performed the Lightning's long-range missions against ground targets and shipping in the Pacific.

As to your latest comments:

It's not how many rounds that are fired that counts but how many hit their target. My point was the greater concentration of the Lightning's firepower as opposed to the Typhoon's wing-mounted guns. Also, my question was how many rounds were carried by the Typhoon as compared with the P-38's basic load of 2150? You never addressed that. In fact, you never addressed most of the points I made in my last posting.

Your comments regarding wood vs metal structures are wrong. Many aircraft having metal structural components returned to base with deformed skins and structures, such as spars, during the war. This damage was caused by overloading, exceeding design limits, or both. Once a wooden spar reaches this point, it fails completely--there is no taking a "set".

Regarding the Tempest, It made its mark against low-flying, unmaned V-1 "Buzzbombs" and low-flying Fw-190 fighter bombers (which were not the equivalent of first-line fighters). They did, it's true, shoot down a total of 20 Me-262s, but other fighters also defeated these jets. There were very few encounters between the P-38 and the '262, so the Lightning, as far as I know, never scored against them.

Down low, the Tempest was a very good fighter, but take the fight to much above 15,000 feet, and the late-model P-38 was better. I'll also repeat myself in stating that at low-to-medium altitude, the P-38J-25 and the P-38L, with their maneuvering flaps, dive flaps, and use of asymmetrical engine thrust were very maneuverable. I think they could at least hold their own against the Tempest in a slow-speed dogfight.

In terms of versatility, the above comments pertaining to the Typhoon basically apply.

With due respect, I believe I have effectively made the point for the P-38 over the Typhoon/Tempest. Of course you'll disagree, but then you're as biased against the Lightning as I am for it.

Regards,
Lightning

[Ricky]

quote:Originally posted by Lightning

With due respect, I believe I have effectively made the point for the P-38 over the Typhoon/Tempest. Of course you'll disagree, but then you're as biased against the Lightning as I am for it.
I can see when something makes sense:)

One question - would the P-38 have been better in combatting the low-level Fw-190s?

[Lightning]

Hi Ricky,

quote:One question - would the P-38 have been better in combatting the low-level Fw-190s?

The Tempest was at its best down low. The intruding Fw-190 fighter bombers were optimized for low-level attacks. In this scenario, i.e. a high-speed, low-level interception, the Tempest was in its element; it was probably the best choice for this task of all available fighters at that time. The P-38 would, therefore, not have been as good.

Regards,
Lightning

[Red Admiral]

quote:Your comments regarding wood vs metal structures are wrong. Many aircraft having metal structural components returned to base with deformed skins and structures, such as spars, during the war. This damage was caused by overloading, exceeding design limits, or both. Once a wooden spar reaches this point, it fails completely--there is no taking a "set".

But after having returned to base, the aircraft are essentially scrap because if excessive force is applied again, they'll break. It depends mainly on stresses that the wood laminate of the Mosquito can take. Luckily, I found a section drawing of fuselage and wings, along with materials. Mainly spruce being used for load-bearing. However it would require a lot of study to actually tell what would happen.

I started reading The Aeronautical Journal at the weekend, somehow got onto a paper about WWII aircraft. It cited the Lightning as being especially prone to compressibility effects due to its thick wing. Have you heard about this previously? I've seen it mentioned in regards to Thunderbolts and a few other types, but not the Lightning before.

[Kutscha]

What Lightning fails to remember is that even if the metal a/c does not reach its limits, the metal is still 'worked'. Each time the metal is 'worked', the limit is decreased unlike wood. A wooden a/c can reach [u]near</u> it limits many more times than a metal a/c.

edit: added 'near'

[simon]

Yes, but wood can only reach a set limit once then it will snap metal can bend many times before it fatigues.

[Ricky]

Dang, sorry Lightning - I meant the Typhoon![B)]

quote:Originally posted by Lightning

The Tempest...

[Wuzak]

quote:Originally posted by simon

Yes, but wood can only reach a set limit once then it will snap metal can bend many times before it fatigues.


Trees have been known to sway in the wind for a couple of hundred years.........

[simon]

...and to snap with a single gust when only a few years old. You can't compare a living tree blowing in the wind to a dead wooden spar that is bent so much it snaps.

[Wuzak]

quote:Originally posted by Lightning

As to ease of repair, sheet metal is easier to repair than wood. It took special craftsmen to both fabricate and repair wooden airplane structures. Also, when metal is overstessed (as in the case of a wing spar), it "takes a set" i.e. it deforms but doesn't break. An overstessed wooden structural component will bend only so far before it suffers total failure. This relieves the woodworkers of the task of making any repairs.


I pondered what you meant by "taking a set" before deciding that what you are talking about is the metal being taken beyond its yield point.

Up until its yield point a metal will return back to its original shape and size when unloaded. This is the "elastic" range of the metal. The relationship between stress and strain (a measure of how the material stretches) is quite linear.

Beyond the yield point the metal enters its "plastic" state. The relationship between stress and tsrain is no longer linear. Once it enters this state it no longer will return to its original state. It becomes permanently deformed.

And is practically useless....

The fatigue life of the metal is reduced very substationally, and aircraft structures, particularly wings, go through a lot of cycles during flight.

The material than has a distinct breaking point - termed Ultimate Tensile Stress.

Different metals have different stress/strain relationships. Basic steel alloys have clear yield points, whilst, from memory, basical aluminium has a less clear yield point. High strength alloys do perform differently to basic grades, and I think Aluminium alloys would become more brittle.

I don't know much about wood structures, but I dare say that failure would be more progressive due to the fibres. It would be an order of magnitude of strength lower than metal, though.

[Wuzak]

quote:Originally posted by Kutscha

Allison V-1710 and RR Merlin/1650 ran 6.00:1 CRs. The extra performance came from boost increases.

Key Specifications (Prior to racing modifications)

Model V-1710 G6R/L (V-1710-143/-145)
Application All models: Major production included P-37, P-38, P-39, P-40, P-46, P-47, P-51A, P-63, P-82
Engine Type V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material Aluminum heads, water jacket, crankcase; Steel cylinder liners; Forged aluminum alloy pistons; Magnesium oil pan
Bore x Stroke 5.5" x 6.0"
Compression Ratio 6.00:1
Supercharger type Two stage engine driven supercharger, 10.25" engine impeller, 12.1875" auxiliary impeller
Supercharger Ratio 7.48 engine stage, 8.087 (R) and 8.03 (L) auxiliary stage
Anti-detonation 50:50 water-methanol injection anti-detonation injection (ADI)
Fuel System Bendix-Stromberg SD-400D3 speed/density injection
Weight 1,595 lbs
Power 2,250 hp war emergency rating (WER) at 3,200 RPM & 101" Hg (35 psig) boost "wet" (w/ADI) and 115/145 PN fuel
Performance 325 psi BMEP (brake mean effective pressure)
Max. Piston Speed: 3,200 ft/min
Firing Order RH turning: 1L-2R-5L-4R-3L-1R-6L-5R-2L-3R-4L-6R
LH turning: 1L-6R-5L-2R-3L-4R-6L-1R-2L-5R-4L-3R
Timing Ignition: Intake fires 28° BTDC, Exhaust 34° BTDC, Sparkplug gap = 0.012-0.015"
Intake: Valve opens 48° BTDC, Closes 62° ABDC, 0.015" clearance (cold), 0.533" lift
Exhaust: Valve opens 76° BBDC, Closes 26° ATDC, 0.020" clearance (cold), 0.533" lift

http://www.unlimitedexcitement.com/Miss%20US/Allison%20V1710%20Engine.htm

Key Specifications (Prior to racing modifications)

Model V-1650-9
Application All models:
Engine Type V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material Aluminum heads, water jacket, crankcase; Steel cylinder liners; Forged aluminum alloy pistons
Bore x Stroke 5.4" x 6.0"
Compression Ratio 6.00:1
Supercharger type Two stage engine driven supercharger, 12.0" first stage, 10.1" second stage
Supercharger Ratio 6.391 (low blower), 8.095 (high blower)
Anti-detonation 50:50 water-methanol injection anti-detonation injection (ADI)
Fuel System Bendix-Stromberg PD18, Type G-9 pump, 9 psi idling, 12-16 psi operating
Weight 1,690 lbs
Power 1735 bhp @ 3000 rpm 66" boost
Rotation: CCW crankshaft rotation when viewed from supercharger end
Cylinder ID Bank: Right - A, Left - B when viewed from supercharger; "A" has oil regulator; 1-propeller end, 6-supercharger end
Firing Order 1A-6B-4A-3B-2A-5B-6A-1B-3A-4B-5A-2B,
Spark Plug 14mm thread, 0.011-0.014" gap
Magneto BTH C6SE12S/2 (Ex: AN SF 12RG-P-3 or SF 12RA-P-3, In: AN SF 12 LG-P-3 or SF 12LA-P-3)
Northeast (Ex: AN SF 12RA-P-4, In: AN SF 12LA-P-4)
Magneto Direction Exhaust Side -- CW, Intake Side -- CCW, viewed from driving end
Spark timing Fully Advanced: Intake 45° btc, Exhaust 50° btc, Magneto breaker gap 0.011-0.014
Cam Timing
(crank degrees) Intake: Valve opens 31° BTDC, Closes 52° ABDC, 0.015" clearance (cold), 0.590" max lift -- Note: Time w/0.020
Exhaust: Valve opens 72° BBDC, Closes 12° ATDC, 0.020" clearance (cold), 0.590" max lift
263° intake duration, 264° exhaust duration
Note: Tappet clearance for timing -- 0.020"

http://www.unlimitedexcitement.com/Pride%20of%20Pay%20n%20Pak/Rolls-Royce%20Merlin%20V-1650%20Engine.htm


Came across some numbers for gas turbines the other day.

One was a GE engine that was first used in 1950s, produced 1350hp for 400lb (182kg) dry weight! I haven't been able to find the same engine again, however....

The stats for the CT7-5A2 Turboshaft:

Physical Stats
Compressor Stages: 6
Low Pressure Turbine/High Pressure Turbine: 2/2
Maximum Diameter : 737mm / 29"
Length: 2438mm / 96"
Dry Weight: 356 / 783lb
Power Specifications
Specific Fuel Consumption at Max Power: 0.29kg/kW/hr / 0.476lb/hp/hr
Max Power at Sea Level: 1294kW / 1735shp
Overall Pressure Ratio at Max Power: 17

[Wuzak]

quote:Originally posted by simon

...and to snap with a single gust when only a few years old. You can't compare a living tree blowing in the wind to a dead wooden spar that is bent so much it snaps.


True that living trees are more flexible than dead ones.

But metal also snaps when it is bent too far. Some metals take less bending than others.

But the engineers take into account the material properties and design accordingly. Whether it is wood or aluminium.

And it doesn't matter if it is wood or aluminium - if it is overstressed it is not long for this world.

[Lightning]

Hi Red Admiral,

Your quote: quote:But after having returned to base, the aircraft are essentially scrap because if excessive force is applied again, they'll break.

The point here is that an over-stressed metal structure, such as a wing spar, although it has been deformed, still has a very good chance of returning to base to be scrapped. This capability is far reduced with wooden structures.

Your Quote: quote:I started reading The Aeronautical Journal at the weekend, somehow got onto a paper about WWII aircraft. It cited the Lightning as being especially prone to compressibility effects due to its thick wing. Have you heard about this previously? I've seen it mentioned in regards to Thunderbolts and a few other types, but not the Lightning before.

I certainly have. This was a well-known problem with the P-38's controlability as it accelerated to near its critical mach number.

The thick wing was, however, not a drawback in all respects. It allowed for more internal fuel; it provided the great strength to carry the heavy loads that were a hallmark of the Lightning; it was one of the reasons for the P-38's high rate of climb to altitude.

Since we have been discussing the Hawker Typhoon, it is timely to mention here that a thick wing was responsible for limiting its speed. The later Tempest had a thinner wing and was faster.

Regards,
Lightning

[Lightning]

Hi Kutscha,

Your quote; quote:What Lightning fails to remember is that even if the metal a/c does not reach its limits, the metal is still 'worked'. Each time the metal is 'worked', the limit is decreased unlike wood. A wooden a/c can reach near it limits many more times than a metal a/c.

This is not true (at least not in any practical sense). Take, for example, a steel spring. As long as it is not stretched or bent to the point where it "takes a set", it will always return to its original configuration of size and shape. It will always have the same elasticity no matter how many times it is exercised. If this were not true, the springs used in clocks, scales, and automobile suspensions (not to mention the ubiquitous Cessna landing-gear strut) would be wothless. How else could you explain how the mainspring in a fine old clock can last 100 years and still be perform flawlessly?

What you're referring to is only true if the metal is stressed beyond its limit. This can be demonstrated by one simple example. If you take a piece of metal wire and flex it without causing it to "kink", you can go on bending it indefinitely without its breaking. If, however, you bend it at one point to where it deforms, or kinks, (i.e. "takes a set"), and then keep bending it back-and-forth, it will weaken with every cycle until it breaks. You'll also probably burn your fingers with the heat generated.

Regards,
Lightning

[Lightning]

Hi Ricky,

Your quote: quote:Dang, sorry Lightning - I meant the Typhoon

In that case, I'll take the Lightning to make the interception, although the Fw-190 variant in question was probably faster at low level.

Without stretching this out needlessly, I'll give four reasons for my choice:

1) The Lightning was designed as an interceptor, and, although it was not used all that much in that capacity, it was a successful design as such. The Typhoon, on the other hand, was designed as an interceptor but failed significantly in that role.

2) The P-38 was faster than the Typhoon.

3) The P-38 could get to the necessary altitude quicker than the Typhoon.

4) The Fw-190 would be carrying a bombload at intercption, thereby offsetting much of its low-level advantage.

Regards,
Lightning

[Wuzak]

quote:Originally posted by Lightning

This is not true (at least not in any practical sense). Take, for example, a steel spring. As long as it is not stretched or bent to the point where it "takes a set", it will always return to its original configuration of size and shape. It will always have the same elasticity no matter how many times it is exercised. If this were not true, the springs used in clocks, scales, and automobile suspensions (not to mention the ubiquitous Cessna landing-gear strut) would be wothless. How else could you explain how the mainspring in a fine old clock can last 100 years and still be perform flawlessly?

What you're referring to is only true if the metal is stressed beyond its limit. This can be demonstrated by one simple example. If you take a piece of metal wire and flex it without causing it to "kink", you can go on bending it indefinitely without its breaking. If, however, you bend it at one point to where it deforms, or kinks, (i.e. "takes a set"), and then keep bending it back-and-forth, it will weaken with every cycle until it breaks. You'll also probably burn your fingers with the heat generated.


For springs to last for a long time they are made from special spring steel alloys and are usually not taken to anywhere near yield point.

Spring steels tend to have a higher yield point than ordinary steel grades as well.

As for your wire example, you are showing that the fatigue life of the material is much less when taken beyond its yield point (takes a set). Metals can still be fatigued into failure without going beyond yield point. The difference is that it will take millions of cycles to fail, rather than tens.

And you'd want to be bending the wire pretty damn quick if you want to generate the heat required to burn your fingers!

[GregP]

Hey guys, this is basic mechanics of materials.

Metal cannot go on "flexing forever." It has a fatigue life. many metal aircraft have airframe lives of about 10,000 to 15,000 hours, and this the fatigue life. Even if not overstressed, the metal will fail.

Wood can be much better than metal and much worse at the same time. If a wodd spar is made right, sealed right, and is kept in the same weather for its entire lifetime, it can significantly outperform metal. But, if you build it in a wet place and then move it to a dry place, and if it is not properly sealed, then it will fail very much sooner than it otherwise would have.

Look at it this way. There is only one sport for which the main intent is to stress the crap out of an aircraft, and that is competive aerobatics. Up until recently, most "unlimited" aerobatic craft have been made of wood, not metal. The best aerobatics propellers are still wood (German MT Propeller). Recently, carbon fiber has made a large showing. Carbon Fiber, when combined with metal OR wood, significantly increase strength.

I look at as follows:

If you want to leave you aircraft out in the weather, make it of metal. If you hanger it, then use whichever material results in the best aircraft. Many times, that is wood, many times that is metal. Neither is inherently "better" or "worse" than the other. Wood has its pitfalls, so does metal. Just try joining two dissimilar metals with rivets of a 3rd dissimilar metal. It'll break VERY quickly. Try using non-AN grade metal bolts and the same will happen.

Wood has similar "gtoochas," try asking Setve Whittman who perished in his own-design wood plane that was improperly made and sealed 25+ years before it failed. It withstood a lot before failing, but the fault was in contruction, not in the wood. A metal plane may or may not have lasted as long or longer if improperly made to start with.

[DoBravery]

I remember watching a biography on Thomas McGuire the 2nd US P-38 ace (38 kills) in the Pacific. He was known for pushing his P-38 into extreme manuevers. His mechanic said he was constantly dealing with stressed metal. He died while pulling his plane into a sharp turn to engage a Japanese Ki-43 Oscar. His P-38 flipped into an uncontrollable spin and crashed. Many in his group felt he pushed it too hard one time too many.

I know this happens to all sorts of aircraft, I just thought this story was relevant.

[andyo2000]

while we're talking about wood and metal -

we all know wood was just about the only material in WWI aircraft. By 1920, however, new aircraft of metal created excitement, and many people called for an end to wooden planes. By 1924 the US military was fully on board. Points like metal being harder to work with, heavier, and sometime more fault-prone were ignored for the most part.

Practicality outweighed public opinion, and by 1930 there were still only 5% of aircraft being of metal construction. Around this time, stressed-skin metal began to be used. This was much more aerodynamic and sometimes stronger, but would compress much easier. The solution to this, reinforcing the skin, made metal planes much more expensive than wooden ones. Furthermore, the metals used then were mostly derivatives of Duralumin, an aluminum alloy that could spontaneously corrode and fail in flight.

After new aluminum alloys were discovered metal planes began to take the lead. Though wooden planes occasionally make comebacks, like the Mosquito, they were done for.

[Lightning]

Hi Wuzak,

quote:
For springs to last for a long time they are made from special spring steel alloys and are usually not taken to anywhere near yield point.

Spring steels tend to have a higher yield point than ordinary steel grades as well.

As for your wire example, you are showing that the fatigue life of the material is much less when taken beyond its yield point (takes a set). Metals can still be fatigued into failure without going beyond yield point. The difference is that it will take millions of cycles to fail, rather than tens.

And you'd want to be bending the wire pretty damn quick if you want to generate the heat required to burn your fingers!

Whether we are talking about special spring steel or not, it is only a matter of the quality and purpose of the metal; i.e. it is only a matter of degree, not principle.

Remember my use of the phrase "at least not in any practical sense". Your phrase: "...it will take millions of cycles to fail..." 'Nuff said... Point made.

It doesn't matter how fast you flex the wire, the same amount of heat will be generated. Temperature is a measure of the concentration, not the amount, of heat. Spread out the time over which the heat is generated, and the temperature will be lower. The only real difference here is that failure of the kinked wire will be hastened by the elevated temperature, but failure will occur regardless.

REgards,
Lightning

[Lightning]

Hi Greg P,

quote:
Look at it this way. There is only one sport for which the main intent is to stress the crap out of an aircraft, and that is competive aerobatics. Up until recently, most "unlimited" aerobatic craft have been made of wood, not metal. The best aerobatics propellers are still wood (German MT Propeller). Recently, carbon fiber has made a large showing. Carbon Fiber, when combined with metal OR wood, significantly increase strength.

One of the main reasons for this is how the airframe, wings, and propeller respond and react to the stresses involved--not because wood is stronger or less failure prone than metal. Wooden baseball bats are preferred to metal ones for the same reason, not because they are stronger; the same goes for longbows; the same goes for bowling pins; the same goes for violins; the same goes for skis; etc.; etc.; etc.

Regards,
Lightning

[Lightning]

Hi DoBravery,

quote:I remember watching a biography on Thomas McGuire the 2nd US P-38 ace (38 kills) in the Pacific. He was known for pushing his P-38 into extreme manuevers. His mechanic said he was constantly dealing with stressed metal. He died while pulling his plane into a sharp turn to engage a Japanese Ki-43 Oscar. His P-38 flipped into an uncontrollable spin and crashed. Many in his group felt he pushed it too hard one time too many.

What you say about McGuire is true; he often overstressed his P-38s. That was not the reason, however, that he was killed. He was trying to take the Japanese fighter off his wingman's tail when he violated his own oft-repeated rules for aerial combat. He (1) let his airspeed drop, (2) tried to turn steeply at low altitude, and (3) didn't drop his external tanks. He stalled in the turn and fell inverted into the jungle of Los Negros Island. Thus ended the "ace race" between him and Dick Bong.

Regards,
Lightning

[Double T]

Lightning:
Your recollections of Tommy McGuire's death are spot-on with possibly one-exception:
I've read one account which stated that Tommy had actually righted his plane just as he ran-out of altitude and crashed.

Tim

[Wuzak]

quote:Originally posted by Lightning

Whether we are talking about special spring steel or not, it is only a matter of the quality and purpose of the metal; i.e. it is only a matter of degree, not principle.

Remember my use of the phrase "at least not in any practical sense". Your phrase: "...it will take millions of cycles to fail..." 'Nuff said... Point made.


Yes, on this point we agree.

However, components in an airframe are continuously being stressed and unstressed in flight.

And springs can and do fail from fatigue. It might take a long time in some circumstances, but it does happen.

The type of material in question is also important. Spring steels are better than other steel grades at handling the cycling of loads.


quote:Originally posted by Lightning

It doesn't matter how fast you flex the wire, the same amount of heat will be generated. Temperature is a measure of the concentration, not the amount, of heat. Spread out the time over which the heat is generated, and the temperature will be lower. The only real difference here is that failure of the kinked wire will be hastened by the elevated temperature, but failure will occur regardless.


It does matter how fast you bend the wire. If nothing else because the heat disspates between cycles.

[Lightning]

Hi Wuzak,

Your quote: quote:It does matter how fast you bend the wire. If nothing else because the heat disspates between cycles.

I addressed this above with the following quote:: quote:Spread out the time over which the heat is generated, and the temperature will be lower. The only real difference here is that failure of the kinked wire will be hastened by the elevated temperature, but failure will occur regardless.


Regards,
Lightning

[Lightning]

Hi All,

In this discussion of wood vs metal [P-38J lightning (sic) vs Do335-A1?], let's not lose track of reality and history.

Years ago they built bridges, ships, automobile frames, and truck wheels out of wood. All of these are now made of metal; why?

Early man used wooden spear points; the Romans used metal; why?

Why don't they use wooden wing spars on the heavy-lifters like the C-17, the C-5A, and the AN 225?

Why don't they use wooden propellers on the C-130?

And while we're on the subject of propellers, have any of you ever witnessed a propeller-strike against the ground? I have--both of wooden props and of metal props. The wooden prop disintegrates into hundreds of splinters, often leaving only the hub recognizable. The metal prop, on the other hand, has its tips bent back but otherwise remains intact.

Also, there were many cases of aircraft in WWII returning to base with bullet holes completely through their metal propellers. Had these props been made of wood, there would have been a shower of splinters followed by a rapid descent.

The replacement of wood by metal in these instances was the normal evolution from the good to the better. At the present time, that process of evolution appears to be progressing, in the form of modern composites, toward the best.

Regards,
Lightning

[Corsarius]

Hi Lightning, hi everyone else. Sorry I've been away. A couple of reasons:
1) I felt that we were getting a little 'stale' here on the forums. I recall that when I left there was a bit of a push for us to even go up to Korean and Vietnam war-era aircraft (not that I have a problem with that, but still... )

2) I have had some fairly heavy study commitments. It's not easy going back to university when you were last at high school 13 years ago! It seems that atomic theory has changed since I last studied it!!! (what the heck is 'quantum' anyway? Why can't we just keep the 'shell' model and keep everyone happy? I understood that one).

3) I have dropped in periodically to check things out here (you guys know how much of a rabid fan I am of WWII aircraft and discussions thereof!) but I couldn't find anything that I wanted to say to contribute, so I left again.

sooooo.... anyway, I am back now and I intend to stick around this time. Lightning: I know it was last month and all now, but I hope that the trouble and strife (ie: the wife) is getting better. I'm also going to harass you as my first post 'back':

Wood is a GREAT material. It's light and strong and can twist and still retain its strength. It's the 'secret' behind the mosquito, and until the advent of carbon fibre, it was still the superior material. I'll answer your questions for you though:

1) The romans used metal spear points because they tasted better than the nasty wooden ones the barbarians used and looked they shiny along with their shiny metal armour. It's good for morale to be bright and shiny on the battlefield.

2) C-17, C5A, AN-225 all make use of large amounts of polymers and carbon fibre in their construction. This lightens the aircraft but maintains the level of strength provided. Also, for these heavy-lift aircraft, absolute strength, not flexibility, is paramount. Metal is easier to work at tolerances and has less imperfections for something so large as a spar for these brutes.

3) You've already explained why not, impacts upon a wooden propeller WILL shatter it. OF course, the C-130J has carbon fibre propellers, so I suppose we're back to 'wood substitue'. Carbon fibre is the 'new wood' of the aircraft world. Light, immensely strong, and flexible.

4) I saw Col Pay nose his spitfire and it's wooden prop into the ground at an airshow. Much splinterage. He shaved about 6 inches off each blade, but it didn't entirely self-destruct. Metal blades go clang-alang-alang-alang if they hit the ground and tend to bend in funny ways. They also have a nasty habit of coming off and hitting the pilot in the face, which he probably would not really like and would have been thankful for a wooden one.

5) Agreed. I know of plenty of WWI stories of 'emergency forced landings' with no prop because the SPAD or Albatros or whatever had just taken a hit on the propeller and hand to land. Mind you, Max Immelman had a fokker E1 made up with three machine guns (alas, not so well synchronised) and when he fired them, they nearly blew his prop off. He landed the aircraft with a seriously imbalanced propeller (it had a lot of bullets stuck in it). However, according to your laws, it also mysteriously failed to explode in a shower of splinters. (kind of like the lances in 'a knight's tale'. Do you know that the 'splinters' in that movie were actually PASTA in a hollow balsa wood lance?)

6) Agreed agreed and agreed again. I also place the evolution of technology (the mosquito notwithstanding) at wood -&gt; duralinum -&gt; carbon fibre/polymers.

Oh, and for the record of the topic subject? I'll give it to the Do-335, one of my all-time favourite fighters. With such a stubby profile, it might not have been longitudally manoeverable, but I'd say it could roll with a zero or Yak-3. Certainly it's wing loading was quite light for it's size. It's extremely high speed means that it could take on the P-38 at its own game, and 'zoom and boom' it using superior speed and climbing ability, as well as superior armament. All altitudes and numbers of aircraft being equal, it could choose when and where to do battle, something that the lightning cannot do due to the insufficiencies in rate of climb and speed. And in the end, if it doesn't want to play any more, then the Pfeil can just walk away from the Lightning. I quite like the p-38, it's one of my favourite american aircraft, but the Pfeil owns the lightning.

[Lightning]

Hi Corsarius,

I'm very pleased that you're back. You were (and are) always a worthy adversary in these dicussions. In this case, however, you missed the mark.

Your replies to my queries, though colorful and entertaining, simply do not refute the facts. Wood is a beautiful material with many uses. In the right hands, it can be turned into absolute works of art. In the production of strong, enduring, weather-resistant, fire/heat-resistant, stress-resistant, etc. structures--to definitely include aircraft--it is demonstrably inferior to the appropriate metal. The examples I gave are perfectly valid.

A wooden propeller taking a hit by a large-caliber round will disintegrate. It will also tear itself apart as the result of becoming unbalanced as it sheds chunks and splinters. A metal prop, on the other hand, can be bent and even lose part of itself and still be usable to the extent that it will allow the pilot to maneuver to a forced landing. A lot of vibration, depending on the amount of power applied during this maneuvering, will certainly result, but, unless the engine falls out, the pilot has options he would not have with a wooden prop.

Your quote: quote:Carbon fibre is the 'new wood' of the aircraft world. Light, immensely strong, and flexible.

Carbon fiber is just that: carbon. It is not wood; it is not related to wood; it is superior to wood. Fibers and composites are the materials of the future; wood, at least as far as modern aircraft structures are concerned, is the material of the past. Aircraft metals fall in between.

As to the Do-335 "owning" the P-38, my reasons for choosing the Lightning over the Pfeil were given earlier in this thread and were valid. One great advantage the P-38 had was its superior ceiling. It's hard to "boom 'n zoom" against a plane that is flying higher than you can fly.

I have never seen any evidence that a Do-335 could outmaneuver a P-38. In fact, all indications, based on the ability of the Lightning to engage and defeat single-engined fighters, are to the contrary.

Much is aways made about the '335's tremendous speed. The truth is that once it began to venture into that realm, the Pfeil was a very unruly aircraft. It doesn't matter how fast an airplane is if that speed results in serious controlability problems, as was the case with this aircraft. The pilot would be fighting his own aircraft more than he would the P-38!

And, alas, the Lightning was a proven success. Like it or not, it was one of the great fighters of WWII. It had problems early-on, but these were ironed out in the later models. The Do-335 was a tempermental, unproven design who's ownly real claim to fame was its questionable, never-realized potential. Had it ever reached full production and full-operational status, who knows what problems would have arisen? It is very possible that it would have been a failure. You can only compare what might (or might not) have been with what actually was.

Regards,
Lightning

[ickysdad]

roll with a Zero or yak III??? What about tolling with a P-47 or P-51? Well as far as the Do. 335 being faster for one thing we really don't know it's top speed do we? Erich Brown tested one and it only hit 453 MPH furthermore it had severe problems when it hit those high speeds .The P-38 hit 440 MPH and climbed at about 4500-4600 FPM(maybe more) on WEP on 100 octane fuel ,the 150 octane came in late '44 so presumedly it could go even faster & climb better.

[Wuzak]

quote:Originally posted by Lightning

Carbon fiber is just that: carbon. It is not wood; it is not related to wood; it is superior to wood. Fibers and composites are the materials of the future; wood, at least as far as modern aircraft structures are concerned, is the material of the past. Aircraft metals fall in between.


Wood is, in effect, a natural composite. It has fibres within a binding material. And is substantially made of carbon based material (as all [known] living things are).

Carbon fibre has the advantage of much more organised fibres. Even then it is quite useless in compression or shear! This is overcome with careful layering with different fibre orientations to take the load required.

Also remember that wooden structures in aeroplanes were not always simple blocks of wood. They were often laminated, which gave extra strength, or combined with disparate materials (like other types of wood) to give the desired strength.

I think one of the key advantages of metal (and carbon fibre) is the ability to create a load bearing skin.

[GregP]

The only real disadvantage I can see to wood is that it must be absolutely sealed in order to last in the elements.

If you seal it well and care for it, it lasts as long as any airplane.

Take a trip to Old Rhinebeck Aerodrome on New York and look at the old planes there that fly every day.

They are ALL wood, and some are older than any metal aircraft in existence. Some are relatively "new," Cole built one of the replicas in the 1960s, and it still flies regularly. His oldest plane, I believe ... but could be wrong, is a Bleriot with much of the original airframe still flying every once in awhile.

Any Beechcraft Staggerwing is older than any P-51, and there are a lot of Staggerwings still flying.

Be careful when you bash wooden aircraft ... they are defeinitely older than metal aircraft, so your durability criteria is backwards, when the wood is properly cared for, that is.

Just to drive the point home, the oldest commissioned ship in the U.S. Navy is the U.S.S. Constitution, "Old Ironsides." It was fighting before the year 1800, and it has been properly cared for in the harshest environment known to man, salt water ... and it still floats and sails occasionally.

Before anyone asks, yes ... I know the Constitution is not an airplane ... ;)

The point is durability, and wood can have it if properly cared for. I have an acquaintance with a Pitts S-1 that was built in the 1950s ... with wood spars, and it still flies regular aerobatics.

[Corsarius]

I didn't mean to say that wood equalled carbon fibre, or was any way related to it in what it is. We don't have carbon fibre trees... well, not ones that actually grow, anyway.

My point was that Carbon Fibre is now doing all the things that wood used to in construction, and doing it better, as it retains strength after flexion, which metal does not. Of course, as mentioned above, wood needs to be specially treated against the elements. While CF is mostly good, sunshine will eventually do it's duty against it. Still, I stand with my statement that Carbon Fibre is the 'new wood' of the aircraft building world.

[Tony Williams]

quote:Originally posted by Lightning

A wooden propeller taking a hit by a large-caliber round will disintegrate. It will also tear itself apart as the result of becoming unbalanced as it sheds chunks and splinters.

Depends what you mean by 'large calibre'. If you mean cannon shell, that would finish off any propeller. In WW1, before synchro gear was perfected, one approach was to bind cloth tightly around the prop at the level of the gun muzzles. That was reckoned to hold together the wooden propeller well enough to survive the few hits which would be experienced on a typical sortie.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Kutscha]

It is better to have a wood prop over a metal prop if the prop hits the ground. The shattering of the wood prop causes less damage to the engine as the prop no longer is hammering the ground, unlike a metal prop that hits a least 3-4 times ever rev. A metal prop strike usually requires a reduction box replacement at the least and a major rebuild, or scrapping, at the worst. Not that wood strikes were any good for an engine either but they were less stressful on the engine.

Wood props were not made out of a single piece of wood but many lamanated pieces. The Germans and the Brits both used wood props extensively with no complaints due to enemy action.

[andyo2000]

http://www.abc.net.au/science/k2/moments/s888510.htm

is a site by a wooden propellor manufacturere defending its product. Biased for one side, but if their claims are true then it's interesting reading.


http://www.pipercubforum.com/woodprop.htm

"...if you have a tip strike; it acts as a 'fuse' when you get a tip strike -- the strike makes a bunch of toothpicks; but your engine probably won't be wrecked -- it's cheaper to replace a prop than a crankshaft."
Thats for you, Kutscha;)


Also, in the early days of metal propellors, some were made as one piece of aluminum. That's great, but how do you change pitch? You were supposed to bend it to what you liked. Somehow, I don't think that does too much to improve the life and reliabilty of the propellor.

[Kutscha]

Yes Andy. Guess I could have worded it better.[:p]

Being bent backwards and forwards millions of times makes a metal propeller build up invisible internal flaws - but wood doesn't get affected by this vibration cycle.

Metal fatigue.:)

Should add that the Germans and Brits used wood props extensively on their fighter a/c.

[andyo2000]

I didn't mean to correct you, your wording was fine. I just included it because it backed up what you had said [^]

[Wuzak]

quote:Originally posted by andyo2000

Also, in the early days of metal propellors, some were made as one piece of aluminum. That's great, but how do you change pitch? You were supposed to bend it to what you liked. Somehow, I don't think that does too much to improve the life and reliabilty of the propellor.


That would be no different to early wooden props. The Spitfire MkI, for instance, came originally with a 2 blade fixed pitch wooden propellor.

The method for propellor pitch control would be the same for wooden or metal propellors.

[Lightning]

Hi Wuzak,

quote:Wood is, in effect, a natural composite. It has fibres within a binding material. And is substantially made of carbon based material (as all [known] living things are).

Carbon is an element. Carbon chemically bonded to one or more other elements (e.g. carbon dioxide, calcium carbonate) is a chemical compound. The smallest individual particle of a chemical compound is a molecule.

There is no such thing as a "wood molecule". Wood is a fiberous "substance" that has no chemical formula and no more resembles carbon than your hand does.

As to wood being a "composite", the only time that term is used to describe wood is in the botanical classification of a large family of herbs, shrubs, trees, etc. in which context it does not refer to the structural strenth or make-up of the plants in question

I reiterate: It (carbon) is not wood.

Regards,
Lightning

[Lightning]

Hi Greg P,

Just because wooden airplanes preceded metal ones does in no way imply that wood is superior to metal. Is wood superior to space-age composites and metals in the constructon of airplanes and spacecraft?

Think back on all the wrecked aircraft hulks from WWII that have been salvaged and restored to flying condition--using much of the original structures. These planes were found, after over 60 years, in steaming jungles; in water, both shallow and deep, both fresh and salt; under hundreds of feet of ice (e.g."Glacier Girl"); on mountain sides where they were under the full attack of the elements in all seasons. How many were wooden or had major components made of wood?

When old shipwrecks are found on the ocean floor (e.g. Titanic), the highly durable and rot-resistant teak wood decking and paneling has long-since rotted away, but the metal--although rusting--endures. There are exceptions to this in the form of ancient wooden ships that were burried beneath a protective layer of sea bottom that prevented, or at least slowed, the natural destructive processes, but that says more about the protective qualities of the mud than about the durability of the wood.

You stress that, in order to last a long time, wood must be properly prepared and cared for. This is certainly true, but then you must compare it to metal that has also been properly prepared and cared for.

Let's face it. If the "Spruce Goose" were built of superior material, the C-5A would be made of wood.

Regards,
Lightning

[Lightning]

Hi Tony Williams,

Of course an exploding cannon shell will destroy any propeller, but I refer you back to one of my prevous postings in which I cited numerous instances of aircraft returning to base with holes competely through their metal prop blades. These were obviously caused by non-exploding projectiles. I think you'll agree that had these propellers been wooden, they would have been destroyed. A multi-engined plane might have made it home, but a single-engined plane would have been lost.

As to the abilities of wooden propellers of WWI to survive bullet strikes by unsynchronized guns, Roland Garros (I hope I spelled that correctly) shot off his own propeller--even though it was protected by metal "cuffs". The metal didn't fail; the wood did. When his plane came down, the Germans learned his secret method of firing through the propeller.

Regards,
Lightning

[Kutscha]

Garros did not shoot his prop off. On 18th April 1915, a rifleman defending Courtrai railway station, managed to fracture the petrol pipe of the aircraft that Garros was flying. Garros was forced to land behind the German front-line.

[Lightning]

Hi andyo2000 and Kutscha,

I totally agree with your statements to the effect that a ground strike with a wooden propeller causes less damage to the engine than with a metal one. That, however, has nothing to do with our discussion on the relative durability of the two propeller types. In fact, it proves my point. It demonstrates that the wooden prop will fail completely before the force of the strike can be fully transmitted to the crankshaft.

quote:"...if you have a tip strike; it acts as a 'fuse' when you get a tip strike -- the strike makes a bunch of toothpicks; but your engine probably won't be wrecked -- it's cheaper to replace a prop than a crankshaft."

A perfectly well-made point! The analogy to a fuse is very meaningful. We all know that the only reason a fuse provides protection is that it is weaker than the device it protects. If a circuit can operate at an absolute maximum current drain of 20 amperes, the protective fuse will be rated lower e.g. 15 amperes. A chain is only as strong as its weakest link. In the case of a ground strike, more destructive force will be transmitted back to the engine by the stronger metal propeller than by the weaker, more breakable wooden one.

Regards,
Lightning

[Kutscha]

So the loss of so many German a/c was because the wooden props they used were shattered by a .50" bullet?

[Lightning]

Hi Kutscha,

I have to say that I believe you're right about Garros's forced landing. What you say rings a bell in my memory. I'll look further into this when I get home to my books. I distinctly remember that either Garros or another pilot using a similar "system" shot off his own propeller and was forced to land.

When Anthony Fokker did some preliminary experiments with the Garros systam, he rejected it out-of-hand as being unsatisfactory. He concluded that it would only be a matter of a short time before the bullet strikes destroyed the propeller. He then proceeded to develop his "interupter gear".

Thanks for putting me straight. I'll try to find a referrence to the incident I described.

Regards,
Lightning

[Lightning]

Hi Kutscha,

quote:So the loss of so many German a/c was because the wooden props they used were shattered by a .50" bullet?

So none of the many German a/c lost were because the wooden props they used were shattered by a 50 cal. bullet?

Really, Kutscha, you're a pretty sharp fellow. I can't believe you honestly thought that I was implying that which is reflected by your above quote.

Regards,
Lightning

[Wuzak]

quote:Originally posted by Lightning

Hi Wuzak,

quote:Wood is, in effect, a natural composite. It has fibres within a binding material. And is substantially made of carbon based material (as all [known] living things are).

Carbon is an element. Carbon chemically bonded to one or more other elements (e.g. carbon dioxide, calcium carbonate) is a chemical compound. The smallest individual particle of a chemical compound is a molecule.

There is no such thing as a "wood molecule". Wood is a fiberous "substance" that has no chemical formula and no more resembles carbon than your hand does.


Whoever suggested that there was a "wood element". What I did say was that wood "is substantially made of carbon based material". Ie wood is made up of carbon compounds.......

quote:Originally posted by Lightning

Wood is a fiberous "substance" that has no chemical formula and no more resembles carbon than your hand does.

As to wood being a "composite", the only time that term is used to describe wood is in the botanical classification of a large family of herbs, shrubs, trees, etc. in which context it does not refer to the structural strenth or make-up of the plants in question


We are talking in engineering terms here, not in botanical terms. When you have cut the tree down and formed it into a block of wood you now have an engineering material.

You state yourself that wood is "fiberous". That is correct. Wood is made up of fibres, which are carbon based compounds, which are bound together by a binding material.

Guess what, modern composites are also described as thus: fibres held in a binding or parent substance. Composites are not restricted to CF. FRP is also a composite (also known as glass fibre).

The difference between modern composites and wood is that the individuall fibres are stronger than that of wood (usually), and the fibres are placed more directionally within the structure.

quote:Originally posted by Lightning

I reiterate: It (carbon) is not wood.


I reiterate: nobody ever said it was.

[Wuzak]

quote:Originally posted by Lightning

When old shipwrecks are found on the ocean floor (e.g. Titanic), the highly durable and rot-resistant teak wood decking and paneling has long-since rotted away, but the metal--although rusting--endures. There are exceptions to this in the form of ancient wooden ships that were burried beneath a protective layer of sea bottom that prevented, or at least slowed, the natural destructive processes, but that says more about the protective qualities of the mud than about the durability of the wood.


Lightning, the same could be said for steel/iron structures on the bottom of the sea.

And it is not a protective layer of mud that preserves either.

Oxidisation requires, oddly enough, oxygen. Water does contain free oxygen (not part of its own structure), but at depth the levels are lower. Thus oxidisation is less likely to occur, and if it does it is slower.

Wood can and is used in environments which steel cannot survive. There is a zinc smelter in my stae which has been around for over 100 years. The "cell room" is built on a wooden structure, the largest wooden structure in the Southern Hemisphere IIRC. To look at the wood in the structure is to be scared! It looks rotten to the core, and not very strong. But in fact appearances are deceiving - the wood is strong and structurally sound.

The "cell room" has a particularly corrosive atmoshpere. If steel had been used in the structure it would have most probably been replaced (for the first time) 95 years ago!

There are many structures of steel on site, and many of them have severe cases of corrosion.

[Tony Williams]

quote:Originally posted by Lightning

When Anthony Fokker did some preliminary experiments with the Garros systam, he rejected it out-of-hand as being unsatisfactory. He concluded that it would only be a matter of a short time before the bullet strikes destroyed the propeller. He then proceeded to develop his "interupter gear".

From Flying Guns – World War 1: Development of Aircraft Guns, Ammunition and Installations 1914-32:

"The first crude solution to the propeller problem – angled steel deflectors fitted to the propeller blades – worked, but did nothing for the aerodynamic performance of the propeller. This method reduced the effective rate of fire due to the loss of about 25% of bullets deflected, and also incurred the risk of bullets being deflected back towards the engine, as well putting more strain on the propeller shaft from the impact of the bullets on the blades. Some propellers were specially designed for this purpose (they minimised the propeller area in the line of fire, which reduced the loss to 10% of bullets fired), but they were less efficient in doing their job. A more sophisticated alternative was to fit a supplementary rotating arm coaxial with the propeller, with wedges to deflect the bullets away from the propeller.

The alternative and even simpler solution was to do nothing to protect the propeller except bind it with varnished tape, calculating that in a typical action very few bullets would strike the propeller blades and two or three holes would not fatally weaken them anyway. Most pilots were not enthusiastic about this – worry about when the propeller was going to disintegrate cannot have been conducive to effective shooting – so it provided a further incentive towards the development of synchronised mountings."

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Lightning]

Hi Tony Williams,

Your quote: quote:The alternative and even simpler solution was to do nothing to protect the propeller except bind it with varnished tape, calculating that in a typical action very few bullets would strike the propeller blades and two or three holes would not fatally weaken them anyway. Most pilots were not enthusiastic about this – worry about when the propeller was going to disintegrate cannot have been conducive to effective shooting...

Three things here:

1) The propeller was supposed to be "bound' with varnished tape. This is therefore a little different than a strictly wooden propeller. This is something like "binding" a cannon barrel with turns of piano wire in order to provide exta srength for increased range...a method that I have read was used in the American Civil War.

2) The assumption that "two or three holes woud not fatally weaken" the propeller was based on, as you have said, a "calculation". Was this calculation ever verified by actual test? I would be very surprised if it was.

3) "Most pilots were not enthusiastic about this – worry about when the propeller was going to disintegrate cannot have been conducive to effective shooting..." This statement speaks for itself.

Regards,
Lightning

[Kutscha]

The wooden paddle blade props as fitted to the Fw190 were constructed of laminated 1/32" thick wood. The blade was then covered with cloth which was then glued/doped to the wood. The leading edge was made of brass.

[Lightning]

Hi Wuzak,

The fact that carbon compounds are found in wood has absolutely nothing to do with the comparison of wood to carbon. One is an element; the other is a substance..not even a compound. They don't look alike. They don't behave alike. One is an organic entity that is alive or has once lived; the other is a mineral element that has never lived and is incapable of living. There is absolutely no resemblance between the two.

The comment was made that carbon fiber was the "new wood" or words to that effect. That is what prompted my remark that carbon is not wood. It is not the "new", or any other form, of wood, figuratively or otherwise.

The preserved wooden wrecks were covered by mud. Other, much newer, wooden wrecks at the same depth are completely disintegrated, not only by oxidation, but by any number of other chemical reactions.

You keep mentioning "steel". There are many other metals, which are obviously preferable to steel, used to fabricate aircraft.

Regards,
Lightning

[Wuzak]

quote:Originally posted by Lightning

You keep mentioning "steel". There are many other metals, which are obviously preferable to steel, used to fabricate aircraft.


In fact it was you who mentioned steel this time - in your reference to shipwrecks, esp the Titanic. You made this reference to show that the metal lasted longer than the wood. The metal in that instance (as with most ships) is steel.


quote:Originally posted by Lightning

The fact that carbon compounds are found in wood has absolutely nothing to do with the comparison of wood to carbon. One is an element; the other is a substance..not even a compound. They don't look alike. They don't behave alike. One is an organic entity that is alive or has once lived; the other is a mineral element that has never lived and is incapable of living. There is absolutely no resemblance between the two.

The comment was made that carbon fiber was the "new wood" or words to that effect. That is what prompted my remark that carbon is not wood. It is not the "new", or any other form, of wood, figuratively or otherwise.


It is self evident that carbon fibre is not wood. If it were it would be called....wood!

I believe cf is termed "the new wood" for a couple of reasons. One of which is that both cf and wood are composite materials. That is to say that they both have fibres within a parent material.

Possibly the other reason cf is termed "the new wood" is that it is a non-metallic structural material, the last useful one of which was wood.


quote:Originally posted by Lightning

The preserved wooden wrecks were covered by mud. Other, much newer, wooden wrecks at the same depth are completely disintegrated, not only by oxidation, but by any number of other chemical reactions.


Perhaps they were preserved by mud. I don't know. But the absence of oxygen at depth plays a very big role in the preservation of things at the bottom of the sea.

[andyo2000]

Without putting myself in the heat of this battle,

I give you http://ehp.niehs.nih.gov/members/2004/112-15/innovations.html

Triton Logging is a company in Canada that is, well, a logging company. One twist though - their wood comes from the bottom of lakes and rivers. Yup, they provide sunken logs for commercial use. Some of the logs are up to 100 years old. The reason they give for the wood's survivability is the lack of oxygen in many water sources. And since they can compete with regular logging companies, I'm going to venture a guess that they don't have to throw away too much of the wood they drag up.

Here's another link http://marinesurvey.com/surveyguide/wood1.htm

Basically, if you scroll down, you can see the effect of climate on wood preservation. In colder climates, wood may be preserved for hundred or thousands of years. In warmer, tropical climates like Florida, ships as young as 60 years old may have disintegrated completely.

To bring this back to WWII, this would have a big impact on wooden seaplanes. And I'm sure the climate argument could apply to all wooden planes. Maybe someone else could tie this all together?

[Trexx]

quote:

* Lack of armament? The Lightning had four 50-cal machine guns with 500 rpg, and one 20mm with 150 rds. That's five guns, all concentrated in the nose, with 2150 available rounds. How does that compare with the Typhoon's wing guns? And while we're on the subject of the Typhoon, it was mainly designed as a fighter bomber. It never really distinguished itself in this role nor as a fighter.


uHHH... HELLO! THANK YOU.

The armnament of the Lightning has been characterized as 'spraying a garden hose spewing lead'.

[Tony Williams]

quote: Lack of armament? The Lightning had four 50-cal machine guns with 500 rpg, and one 20mm with 150 rds. That's five guns, all concentrated in the nose, with 2150 available rounds. How does that compare with the Typhoon's wing guns? And while we're on the subject of the Typhoon, it was mainly designed as a fighter bomber. It never really distinguished itself in this role nor as a fighter.

Correction: the Typhoon was specifically designed as a fighter, to replace the Hurricane. However, the aerodynamicists got their sums wrong and it performed poorly as a fighter, but fortunately turned out to be a very tough and effective fighter-bomber, much appreciated by its pilots.

The total destructive power of the Typhoon's four 20mm cannon was significantly greater than the Lightning's armament. On the other hand, the fact that the Lightning's guns were grouped in the nose provided a better concentration of fire at all ranges, rather than just at the harmonisation range, which compensated for that.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Lightning]

Hi Tony Williams,

You're right about the Typhoon's being originally designed as a fighter, but you apparently didn't read my posting of Oct. 31 in which I corrected this error:

quote:
First of all, let me take a hit: My quote:
quote:
--------------------------------------------------------------------------------
And while we're on the subject of the Typhoon, it was mainly designed as a fighter bomber. It never really distinguished itself in this role nor as a fighter.
--------------------------------------------------------------------------------



In reality, the Typhoon WAS a great fighter bomber. It carried a great offensive ordnance load for a single-engine fighter--to include two 1000-lb bombs at the end. It DID distinguish itself as a fighter bomber.

I also was wrong when I said that the Typhoon was originally designed as a fighter bomber. That's not true--it was designed as an interceptor.

Your correction was valid but a little belated.

Regards,
Lightning

[Lightning]

Hi Kutscha,

Regarding the Roland Garros incident referred to earlier, I went back and did some reading. As you said, his forced landing was the result of engine failure--not because he shot off his propeller. The following passage is from:

"Ceiling Unlimited"
by Lloyd Morris and Kendall Smith
Macmillan Company, 1953
Page 152

"His [Garros's] invention, which the French quickly duplicated on all fighting machines, gave them a point of decided superiority over the Germans. Some months later, engine failure forced Garros down behind the German lines."

There were, obviously, numerous other French pilots using Garros's system.It was probably one of them of whom I read as having shot of his prop.

Regards,
Lightning

[ChrisMcD]

I cannot give the reference, but there is a story to the effect the Germans reloaded Garros's gun to test the system and proceeded to shoot the propellor through.

Garros was using soft lead bullets, while the Germans had used steel jacketed ones!

What Garros's exploits did do was to give legitimacy to various superior interrupter gears that were being proposed.

Fokker, with his usual skill was first onto the bandwagon with the Eindecker.

He claimed that it was all his own work and that he was given the problem on a Tuesday evening and presented a working system on Friday.

However, Fokker's team, including engineer Heinrich Lübbe, had been working on an interrupter mechanism since late 1914, probably based on Schneider's patent. Indeed in 1916 LVG and Schneider sued Fokker for patent infringement

[Lightning]

Hi All,

As regards which is superior for aircraft construction, wood or metal: Enough already! I'll base my case for metal on the following statements of of how things are in the real world:

Virtually all modern aircraft are made of metal.These include:
*Later-model sailplanes (even ultralights and hang gliders, as far as their structural, load-bearing members are concerned)
*Light, single-engine airplanes (i.e. Cessna, Piper, Mooney, Beechcraft, etc.) having two-to-six seats, with and without external bracing
*Light twins
*Business jets/turboprop/reciprocating
*Commuter planes
*Agricultural planes
*Cargo/passenger liners of all sizes
*Trainers--both military and civil
*Fighters
*Bombers
*Military heavy lifters
*High-altitude recon planes (e.g. the U-2)
*High-speed recon planes (e.g. the SR-71)
*All of the "X-Planes"
*Modern sport airplanes, to include many aerobatic competition and demonstration aircraft
*Purpose-built unlimited racers (Perhaps Greg P and Trexx can elaborate)
*Floatplanes and amphibians
*Helicopters

In addition, almost all of the propellers for the above-mentioned aircraft are metal.

Are their exceptions? Probably so, but they are so few in number as to be insignificant.

If, in the construction of all of these types and classes of aircraft, wood were better than metal--or even nearly as good--why is its use nearly nonexistent?

About the only place where wood still plays a prominent role in aircraft and propeller construction is in the area of homebuilt and kitbuilt sport planes, and this is beginning to change with the advent and development of modern materials.

The new composites and alloys are the wave of the future. They really have no bearing on the present comparison of wood to metal that is the subject of this discussion.

Come on, guys, wake up and smell the coffee!

Regards,
Lightning

[Trexx]

I've been reading this dang post for two days. Whoa...

Not one mention of the SUPERIOUR dampening quailities of wood versus metal?
Did you know that wood is the preferred material for UAV's (unmanned aerial vehicles) in the United States?
Why? You ask...
Wood propellers vibrate less than ALL other materials that have been tried. Electronics perform more predictably when they're shaken LESS.
There is something in the organic make-up that has defied all attempts to match it or exceed it.

There are many explainations here acurately descrbing why wood is not used in high performance airplanes any longer. But let there be no mistake, if wood were as moldable, strong, weather resistant and universal as it's replacement materials, it would most undoubtedly be the primary choice for propeller construction. (I think there's about ten people in the world that know how to make 'em outta wood...still hanging around working as sub-contractors for Lockheed...)

[Trexx]

Uhhh...

Kutscha,

Your revealation about the Germans using wood for their propellors was a long time coming in that pile of posts. Thank you, thank you for finally putting a light on the fact.

[Tony Williams]

quote:Originally posted by Lightning

As regards which is superior for aircraft construction, wood or metal: Enough already! I'll base my case for metal on the following statements of of how things are in the real world:

I can provide one answer for that: metal is more suited to mass production. Its qualities can be specified to the nth degree by varying the proportions of alloys, it is more suitable for machining and automated manufacturing and - crucially - requires standard skills on the part of the production line workers. It is therefore much cheaper to use.

Wood, being an organic material, is more variable and requires an entirely different range of skills in the workforce to those found in a conventional factory. This is highly inconvenient, as it means that skilled workers can be hard to find - you can't just switch them over from making some other widgets.

In WW2 these factors were not as marked as they are today. There were a lot more skilled wood-workers around and the use of metal was not as sophisticated or automated. So it was possible to enjoy the benefits of the superior strength-weight ratio which permitted the remarkable performance of the Mosquito :D

During the 1970s a British car designer called Costin (part of the Marcos sports car team) designed a sports car intended to be as light and strong as possible. He made it from moulded plywood monocoque (just like the Mossie). I no longer have the details, but I recall that the prototype was indeed remarkably light and went like the clappers (to use a technical British phrase...). However, lack of funding killed the project.

The British firm of Fairey also produced a range of high-performance sea-going motor cruisers after WW2, also made in hot-moulded ply. Their performance was legendary. But once fibreglass came along, wood was abandoned as too expensive to use in manufacture and too much trouble to maintain - the fact that fibreglass didn't have the strength-weight ratio of wood was less important to most owners.

Of course, modern aircraft (particularly high-performance combat planes) are subjected to very different stresses than WW2 ones. OTOH, they are increasingly using exotic alloys and non-metal composites to achieve their performance (a high proportion of the structural weight of the latest military and commercial aircraft is in composites).

I think that the analogy of carbon fibre and similar modern materials as 'the new wood' is valid, in that it has more structural similarities to wood than it does to metal. It is also probably the first mass-produced structural material to be clearly more efficient in strength-weight ratio than high-quality moulded plywood.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Tony Williams]

quote:Originally posted by Lightning

Hi Tony Williams,

You're right about the Typhoon's being originally designed as a fighter, but you apparently didn't read my posting of Oct. 31 in which I corrected this error:

Sorry, missed that one!

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Kutscha]

quote:Originally posted by Trexx

Uhhh...

Kutscha,

Your revealation about the Germans using wood for their propellors was a long time coming in that pile of posts. Thank you, thank you for finally putting a light on the fact.
Your're welcome Trexx.

I should also mention that the British Jablo blades were made of wood but have no details on their construction.

One other thing I should mention is that the Morgan sports cars had a wooden frame. These were raced quite successfully.

MTBs in WW2 were made of wood, not metal.

Tony makes a good point about wood being much more familular to people than metal in the '40s.

Yes Lightning, in the real world now, but not back in the '40s.

[Ricky]

quote:Originally posted by Kutscha

MTBs in WW2 were made of wood, not metal.

British ones, yes.

German Schnell-boots (E-boats, as we Brits called them) were made of metal.

Is it me or is this whole 'debate' a little silly?

Wood, metal and Carbon fibre all have their advantages and disadvantages*, and are used accordingly.

(*and this can include cost, labour etc)

[Trexx]

I think it's rather interesting.

It's not that obvious from today's vantage point in time.
Airplanes were built originally with seafaring technology: String, rope, cloth and wood. It was the beginning. Nessity has brought about growth in construction techniques and materials which in turn have consistantly improved performance and safety.

[Trexx]

Uhhh... The fact pointed out earlier about Clarence Johnson's original twin engined fighter proposals including the tandem, push/pull engined design is especially fascinating.
The Pfiel was really close to being a manifestation of that earlier sketch.
The twin boom Lightning with 'handed' engines was a more stable design. The Pfiel suffered from what 'Kelly' had possibly predicted and avoided... all that high speed porposing and snaking...that is...

[DoBravery]

In regards to the Do335,
Facing the aircraft, did both props turn in the same direction or opposite? Were there any twisting or rolling effects from the engines other than the porpoising?

Could it fly on one engine better than most other twins?

I'm just curious about such an arrangement.

[Wuzak]

quote:Originally posted by DoBravery

In regards to the Do335,
Facing the aircraft, did both props turn in the same direction or opposite? Were there any twisting or rolling effects from the engines other than the porpoising?

Could it fly on one engine better than most other twins?

I'm just curious about such an arrangement.


Good question!

I imagine that if both were turning in teh same direction there would be a very strong torque reaction.

So I would think that they would turn opposite. But that may be the reason behind the porpoising.

I was wondering about pusher/puller arrangements in applications other than "centreline thrust". For example, some Dornier flying boats had twinned engine pods, with one pushing one pulling.

What if such an arrangement was used to build 4 engine heavies instead of having 4 individual engine nacelles. For example, when Avro came to convert the Manchester from a twin Vulture aircraft into the 4 Merlin Lancaster, would having the Merlins mounted in pairs in each wing, with one pushing, one pulling, been feasible?

[Tony Williams]

quote:Originally posted by DoBravery

In regards to the Do335,
Could it fly on one engine better than most other twins?

I would think that there is not much doubt about that. The asymmetric thurst from flying on one engine in a conventional twin must have added greatly to the aerodynamic drag.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Tony Williams]

quote:Originally posted by Wuzak
I was wondering about pusher/puller arrangements in applications other than "centreline thrust". For example, some Dornier flying boats had twinned engine pods, with one pushing one pulling.

What if such an arrangement was used to build 4 engine heavies instead of having 4 individual engine nacelles. For example, when Avro came to convert the Manchester from a twin Vulture aircraft into the 4 Merlin Lancaster, would having the Merlins mounted in pairs in each wing, with one pushing, one pulling, been feasible?


Well, first there's the small problem that the Lanc had a tailwheel undercart, so pusher props would have been very close to the ground. Also, the wing would have been designed to take the weight and stress of an engine on its forward spar, not at the back.

A push-pull layout has some advantages, but the efficiency of the rear prop may be reduced by having to work in the propwash of the front one. Also, props spread across a wing provide a bigger area of propwash over the wing and flaps, helping low-speed lift and therefore (other things being equal) reducing the landing and take-off speeds.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Ricky]

quote:Originally posted by DoBravery

In regards to the Do335,
Facing the aircraft, did both props turn in the same direction or opposite? Were there any twisting or rolling effects from the engines other than the porpoising?

Dunno...

If they both turned the same way, wouldn't that have the effect of increasing the roll rate? Or turning ability? (I can never remember which).

[Lightning]

Hi Trexx,

quote:...if wood were as moldable, strong, weather resistant and universal as it's replacement materials, it would most undoubtedly be the primary choice for propeller construction

And if my aunt were a man, she'd be my uncle. :)

Regards,
Lightning

[Lightning]

Hi Tony Williams,

I read your comments with interest. You sound high praise for wood, and give fine examples of its excellent qualities (ones that I don't disagree with), but you have done more to bolster my argument than to refute it.

The thing that started all this was my statement in my posting of October 28 in which I gave ease of repair as being an advantage of metal over wood. Your comments about a skilled workforce being necessary bears that out. (In fact, I brought out that same issue in the "Topic From Hell" of a month or so ago. :))

As far as metal being stronger than wood is concerned, there are so many obvious examples of this all around us in every day life that to deny it is to deny reality.

As to the longetivy issue, it's not a coincidence that they gave up making wooden lawn furniture in favor of metal. :D I contend that if a wooden airplane and a metal airplane are placed side-by-side and exposed to the elements indefinitely, the wooden plane will be completely destroyed while the metal one will be quite restorable.

Lastly, the extensive list of metal aircraft types given in my Nov. 17 posting provide overwhelming evidence of metal being the material of choice for modern aircraft construction as opposed to wood, and not only because mass production is easier. The safety and utility of such expensive machines (not to mention the national-defense implications) demand that the better material be used--regardless of ease-of-consruction. If wood were better, wood would be used.

Regards,
Lightning

[Tony Williams]

quote:Originally posted by Lightning

As far as metal being stronger than wood is concerned, there are so many obvious examples of this all around us in every day life that to deny it is to deny reality.
What I said was that a good quality moulded wood laminate has a superior strength-weight ratio to metal. It can provide a very stiff but relatively light structure. To return to your favourite plane for a moment - the Mosquito (I know how much you like hearing that mentioned) :) - can you name an all-metal twin-engined bomber of that period with a similar performance and carrying capability on the same horsepower? That is down to its very efficient structure; light but strong.

quote:Lastly, the extensive list of metal aircraft types given in my Nov. 17 posting provide overwhelming evidence of metal being the material of choice for modern aircraft construction as opposed to wood, and not only because mass production is easier.
For modern construction certainly; as I said in my post, high-speed jets are subject to all sorts of pressures, temperatures, etc which did not apply in WW2. However, the "new wood" - synthetic composites - is proving to be better still.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Lightning]

Hi Kutscha,

quote:Yes Lightning, in the real world now, but not back in the '40s.

Yes in the '40s! Look at all of the first-line fighters, bombers, transports, etc. of WWII. With few exceptions (e.g. the "Mosquito"), they were all metal aircraft. If you want to dispute that, I have a little challenge for you:

You make a list of all the first-line aircraft of WWII that were made of wood; I'll do the same with those made of metal. We'll then compare our lists. Whose do you think will be significantly longer? By how much?

And metal used for its strength in favor of wood for warships is also something that did not just appear on the scene. How come they put iron plates over the wooden structure of the "Virginia" (AKA the "Merrimack") in the American Civil War instead of the other way around? Those "ironclads" played havoc with their wooden adversaries. In fact, it took another ironclad (the "Monitor") to fight the Merrimack" to a draw. "Old Ironsides" notwithstanding, metal sheds cannon balls a lot better than wood. [}:)]

Regards,
Lightning

[ChrisMcD]

Regarding the power of the two engines on the Do335.

'Winkle' Brown tried both engines seperately and found that the front one was more powerful. He also commented that the rear engine seemed a bit marginal on cooling.

I cannot find the book, but as I remember he made no comment about torque problems. As has been said earlier Dornier were experts at push/pull layouts.

[Double T]

As to the comments concerning whether or not the props turned in opposite directions ie. counter-rotating...
If you take two identical DM603G engines, install one with the prop-shaft pointing out-front, and the second installed facing in the opposite direction...
Doesn't this result in counter-rotating props?

Tim

[Trexx]

quote:Originally posted by Lightning

Hi Trexx,

quote:...if wood were as moldable, strong, weather resistant and universal as it's replacement materials, it would most undoubtedly be the primary choice for propeller construction

And if my aunt were a man, she'd be my uncle. :)

Regards,
Lightning


...with fiberous carbon bonding, no doubt! HA!

[Trexx]

quote:Originally posted by Tony Williams

quote:Originally posted by Wuzak
I was wondering about pusher/puller arrangements in applications other than "centreline thrust". For example, some Dornier flying boats had twinned engine pods, with one pushing one pulling.

What if such an arrangement was used to build 4 engine heavies instead of having 4 individual engine nacelles. For example, when Avro came to convert the Manchester from a twin Vulture aircraft into the 4 Merlin Lancaster, would having the Merlins mounted in pairs in each wing, with one pushing, one pulling, been feasible?


Well, first there's the small problem that the Lanc had a tailwheel undercart, so pusher props would have been very close to the ground. Also, the wing would have been designed to take the weight and stress of an engine on its forward spar, not at the back.

A push-pull layout has some advantages, but the efficiency of the rear prop may be reduced by having to work in the propwash of the front one. Also, props spread across a wing provide a bigger area of propwash over the wing and flaps, helping low-speed lift and therefore (other things being equal) reducing the landing and take-off speeds.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk



Insightful comments indeed...

[Tony Williams]

quote:Originally posted by Lightning

You make a list of all the first-line aircraft of WWII that were made of wood; I'll do the same with those made of metal. We'll then compare our lists. Whose do you think will be significantly longer?
Quantity and quality are two different things :)

quote:And metal used for its strength in favor of wood for warships is also something that did not just appear on the scene. How come they put iron plates over the wooden structure of the "Virginia" (AKA the "Merrimack") in the American Civil War instead of the other way around? Those "ironclads" played havoc with their wooden adversaries. In fact, it took another ironclad (the "Monitor") to fight the Merrimack" to a draw. "Old Ironsides" notwithstanding, metal sheds cannon balls a lot better than wood. [}:)]

You've answered your own question: the metal cladding was not added for strength, but for its resistance to cannon balls. The structural strength of the ships remained wood, on which the metal was hung.

In any case, what we are comparing here is not plain wood, but WW2 moulded plywood with WW2 metal.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Trexx]

Some dang planes were skinned with aluminum -AND- balsa wood... glued and sandwiched to make light and strong sheeting.

[Wuzak]

quote:Originally posted by Trexx

Some dang planes were skinned with aluminum -AND- balsa wood... glued and sandwiched to make light and strong sheeting.


And some had a combination of both - wood wings and metal fuselage, or vice versa.

Quite a few aircraft, some of them very famous, had fabric covered control surfaces.....

[Ricky]

I went back to my parent's house and checked my Do335 model.
If you are happy to believe the guys at Revell (and my ability to glue the right propellor to the right end of the plane) then they rotate as follows (both from the perspective of a guy standing at the rear of the plane looking forwards):

Front: clockwise
Rear: anti-clockwise

I have to confess I got a little excited when I first looked, as it appeared that they both rotated the same way... but then I remembered that the rear prop was a 'pusher', not a 'puller'!:D

[Kutscha]

A Google search will find all kinds of Do335 pics.

http://www.luftwaffepics.com/ldo3354.htm

[Ricky]

They seem to show that the props rotated in different directions...
Unless I'm getting myself confused[:o)]

[Kutscha]

The engines still rotated in the same direction. The front engine turns cw (rear view point). The front engine turns cw but since it is reversed it will turn ccw.

You is correct Ricky in your first post.

Front: clockwise
Rear: anti-clockwise

[Lightning]

Hi All,
Re Do-335 prop rotation:

From looking at all the photographs, both in my books and on line, the following is true:

Looking from the front of the aircraft, the front propeller rotates CCW (as on most US airplanes) while the rear propeller rotates CW. This means that neither engine had to be geared to provide reverse propeller rotation (a la the port engine on the production P-38). The only thing that would be necessary would be to reverse the pitch of the rear propeller. An obvious advantage of this is that all available engines could be used in either location without modification of its direction of rotation.

Regards,
Lightning

[Lightning]

Per T. Williams:

quote:Quantity and quality are two different things

Not in the case of the top-quality front-line fighters of WWII. Or are you implying that the P-38, P-47, P-51, F4U, F6F, Me-109 (the most-produced plane in history), B-17,
B-24 (the most-produced American warplane of the war), and the Spitfire (I believe there were about 20,000 of them built) were not quality planes? (And how many of them were wooden?)

Regards,
Lightning

[Tony Williams]

quote:Originally posted by Lightning

Per T. Williams:

quote:Quantity and quality are two different things

Not in the case of the top-quality front-line fighters of WWII. Or are you implying that the P-38, P-47, P-51, F4U, F6F, Me-109 (the most-produced plane in history), B-17,
B-24 (the most-produced American warplane of the war), and the Spitfire (I believe there were about 20,000 of them built) were not quality planes? (And how many of them were wooden?)

You still haven't answered my question, Lightning: which WW2 metal twin-engined bomber matched the performance and load-carrying capacity of the Mosquito on similar horsepower?

We have already explored why wood wasn't much used, and it basically comes down to production economics; metal is essentially easier to work with for mass production, high-quality wood-working is more of a craft. However, when designers and manufacturers took the trouble to use good-quality moulded plywood, its advantage in strength-weight ratio showed up clearly.

After all, considering the large number of metal twin-engined bombers to see service in WW2, if metal was a better material than wood then at least some of them (actually, most of them) should have had a better performance than the Mosquito. Or were all their designers incompetent?

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Kutscha]

Tony, wood could not have been that hard to work with as women were the majority of the workers constructing the Mossie.

Not putting down women but they would not have been exposed to working wood as men would have during that time.


Lightning, the engines in the 335 could not be exactly the same as the thrust loading would be pulling on the front engine and pushing on the rear engine. This is why the rear engine had a 'Q' in its designation.

[Wuzak]

quote:Originally posted by Kutscha

Lightning, the engines in the 335 could not be exactly the same as the thrust loading would be pulling on the front engine and pushing on the rear engine. This is why the rear engine had a 'Q' in its designation.


I would think that the engine itself would be the same, but the bearing arrangement within the prop shaft assembly would have been altered to suit.

In fact it shoould have been possible to build a bearing assembly for which it did not matter in which direction the thrust loads were applied.

[Ricky]

quote:Originally posted by Kutscha

Tony, wood could not have been that hard to work with as women were the majority of the workers constructing the Mossie.

Not putting down women but they would not have been exposed to working wood as men would have during that time.
One of the awkward facts that arose out of WW2 as far as British Industry was concerned was that large numbers of untrained workers (including women) had entered industrial jobs without undertaking the traditional lengthy apprenticeship, and they had picked up the jobs very quicky, thus proving that the whole long apprentice thing was basically an unnecessary relic.

[Tony Williams]

quote:Originally posted by Kutscha

Tony, wood could not have been that hard to work with as women were the majority of the workers constructing the Mossie.

I didn't mean hard in the sense of requiring strength, but technically difficult.

A few further thoughts. I don't pretend to be an expert on plywood, but I do recall some info about it from years ago. It is really quite a technical subject.

Plywood gains its strength of course from the fact that the layers of wood are laid at different angles before being glued together, so the fibres are not all running the same way. The choice of woods used to make up the ply, plus the choice of glue (as the Germans found with the Ta 154) is critical to the performance of the ply. Today you can buy ordinary ply, or marine grade of much higher quality used to make boats, but there are clearly many other options. All woods perform in different ways, so you can imagine that sorting out which woods, in which sequence, make plys best suited to specific purposes, can be quite a complex business requiring a huge knowledge base (I wonder if that still exists?)

For structural use where curves are needed, ply can be hot-moulded or cold-moulded. I forget the pros and cons of that choice. However, the three-dimensional shapes produced by either process are very strong and rigid for their weight.

There are some obvious similarities with the process of producing carbon-fibre structures today.

TW

[Ricky]

Which means that Ply would make a good aircraft skin (though harder to patch when damaged, I'd think), but ply is probably not the best option for structural members, like the main wing spar, as ply is not at its strongest as a long, thin bar.

[ickysdad]

I work in a wood working factory in southern Indiana we make things like curio cabinets, organ cabinets, whatnots and various other things . I don't know how our work would differ from aircraft manufacture but modern computer routers sure speed up our production and I have a feeling that in the 30's & 40's the man hours in producing an aircraft out of wood would be much more than producing one out of metal. Just MHO though......

[Kutscha]

Tony, I knew what you meant.:)

Ricky, wood has not that hard to patch. Fixed a few holes in the old wood race boat, I have :D(designed and built myself). The main spar was not one piece but lamanated from several pieces. Nice article on wood a/c structures, http://www.aeroplanemonthly.com/archive/redux/redux.htm

ickysdad, they had pentographs (I think that is the word) in the 'old days'. These would automatically following the 'master'.

[Lightning]

Per T. Williams:
quote:
You've answered your own question: the metal cladding was not added for strength, but for its resistance to cannon balls. The structural strength of the ships remained wood, on which the metal was hung.

On the contrary, I did not answer my own question (and neither did you). Notice that I was referring to the "Virginia" in this particular posting.

The Virginia was a former Union frigate (the "Merrimack") of wooden construction. It was salvaged by the South and converted to an ironclad by hanging metal plates on it's already-existing wooden structure. Because of the scarcity of iron at the South's disposal, this was to be common practice in their design of ironclads.

The Monitor, on the other hand, was a "purpose-built" ironclad. It was predominantly constructed of metal, both above and below the waterline. In fact, its hull was metal, to which a layer of wood was added. Over this wooden layer was hung the final metal layer of one-inch armor plate. So you see, the metal hull held layers of both wood and metal. Therefore, the structural strength of the new ironclads did not remain wood as you stated above.

Regards,
Lightning

[Tony Williams]

Ah sorry, my misunderstanding.

TW

[Lightning]

Per T. Williams,

quote:
You still haven't answered my question, Lightning: which WW2 metal twin-engined bomber matched the performance and load-carrying capacity of the Mosquito on similar horsepower?


If reduced weight due to wooden construction caused an increase in performance of the normally loaded Mosquito (and it did), then the added weight of a 4000lb bombload would have offset much of that gain.The Mosquito had better performance and bombload than any light bomber that I can think of. The fine performance of the Mk BXVI was due far more to its aerodynamic design and to the use of the superb Merlin engine than it was to the use of wood in its construction.

As to the Mosquito's abilities relative to other two-engined bombers of WWII, that has been covered ad nauseum in other threads. The subject of this discussion (although not this thread) is metal vs. wood.

Even in the "Golden Age" of wooden aircraft (the 1930s), aircraft metal was considered to be a "strategic material" whereas wood was not. The Mosquito, as a private venture, was therefore designed to be made of wood in order to conserve metal. High performance was,
in and of itself, not the reason wood was chosen.

There are still quite a few A-26, B-25, B-26 (relatively few), and PV2 two-engined bombers (not to mention the B-17 and B-24 four-engined types)--all metal-- still flying after over 60 years. How many Mosquitos are still flyable? Why? Don't bother to blame it all on bad glue. That's only one of the drawbacks of wood construction. Some others are rot, insect damage, warping, and susceptibility to heat and humidity.

Now you can answer my previously posed question that was asked in response to your implication that the pre-eminence of first-line metal aircraft in WWII was a matter of quantity over quality:


quote:Or are you implying that the P-38, P-47, P-51, F4U, F6F, Me-109 (the most-produced plane in history), B-17,
B-24 (the most-produced American warplane of the war), and the Spitfire (I believe there were about 20,000 of them built) were not quality planes? (And how many of them were wooden?)

Regards,
Lightning

[Ricky]

So who is going to mention all those wooden (or mostly wooden) Soviet fighters...:D

[simon]

Again though that was largely a matter of necessity rather than choice, the Soviets had huge forested areas of countryside with a nice readily available supply of wood, what they didn't have was huge quantities of Bauxite or the time to mess around refining it.

[ickysdad]

Alot of VVS fighters were indeed made of wood but after a certain point in trying to achieve higher performance the SU needed to import high tensile aluminum alloys to keep up in the fighter verse fighter race.

[Trexx]

Many of the wood versions of Soviet fighters were heavier than their metal predacessors. Making them out of wood was advantageous for increasing production numbers but not for better fighters.

[Tony Williams]

quote:Originally posted by Trexx

Many of the wood versions of Soviet fighters were heavier than their metal predacessors. Making them out of wood was advantageous for increasing production numbers but not for better fighters.

All types of wooden construction are most definitely not the same. As I posted previously, the moulded ply construction of the Mossie was sophisticated and produced a strength-weight ratio far more than could be achieved by using plain wood.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Tony Williams]

quote:Originally posted by Lightning

As to the Mosquito's abilities relative to other two-engined bombers of WWII, that has been covered ad nauseum in other threads. The subject of this discussion (although not this thread) is metal vs. wood.
We seem to be arguing (not for the first time) at cross-purposes here.

I have never denied that metal was a better material for mass-producing aircraft in WW2, given the practical realities of industrial production. I have never advocated that it would have been better if we had used wood for all of our planes.

All I have claimed - and you have so far not produced anything to contradict it - is that a well-designed moulded ply monocoque structure had a superior strength-weight ratio to WW2 alloy structures, and thus facilitated the achievement of remarkable performance in a plane designed to take advantage of it.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Lightning]

Hi All,

This metal vs wood thing has about run its course. It's time for closing statements.

As preface to my remarks, the following:

Advantages of Metal:
-Stronger. (Strength-weight ratio notwithstanding, metal planes are stronger than wooden ones--especially today.)
-More crash resistant.
-Easier to mass produce.
-Easier to repair.
-Requires less care and maintenance.
-Not susceptible to rot, insect damage, warping, heat and moisture, the elements in general.
-Replacement components (ribs, panels, spars, etc.) more easily stored without need for benign conditions.
-Has greater longevity.

Advantages of wood:
-Lighter.
-Cheaper.
-Natural "damping" results in smooth ride.
-Doesn't corrode.
-Less susceptible (but not impervious) to fatigue.
-Long members better in compression than metal, but weaker in shear and tension. This generates the "stressed-skin" vs. monocoque" controversy.

With these points in mind, my remarks:

In the mid 1920s, the National Advisory Committee for Aeronautics (NACA) declared that metal was superior to wood because "it does not splinter, is more homogenious, and the properties of the material are much better known and can be relied upon..." That was in the 1920s.

The evolution of aircraft construction since then proves the superiority of metal over wood. Since the late 1930s, wood construction has steadily declined while metal has relentlessly come to the fore. Today, virtually all commercial, military, and general aviation aircraft are made of metal.

The advantages and disadvantages of metal vs. wood are well known to manufacturers and end-users alike. Aircraft designers, military aviation experts, airline planners/decision-makers, and the entire general aviation industry have abandoned wood in favor of metal. They all have, and have had for a very long time, their choice between the two materials. They have chosen metal.

As to WWII, the predominance of metal over wood is undeniable.The Mosquito was an exception, but its considerable success was more a result of its aerodynamic qualities than of the material from which it was constrcted. The air war was won, almost exclusively, by metal aircraft.

The foregoing are facts. They can be argued against, interpreted, and rationalized ad infinitum, but they cannot be denied or changed. To do so would be to deny and change reality.

Regards,
Lightning

[Tony Williams]

What would be very interesting to know is whether anyone has done a design study to work out what the Mosquito would have weighed had it been made of metal, using contemporary materials and design capabilities. I'm not a betting man, but I'd lay a small sum that a metal Mossie would have been heavier and its performance reduced thereby.

And that's my last word on the subject, unless anyone can come up with such a study!

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk

[Trexx]

I like plastic. :D