Some Mosquito Info

[Wuzak]

A while back we had the stats for Mosquito losses on night bombing operations, from May 1943 to May 1945. This amounted to 106 lost and 88 damaged beyond economical repair, in a total of 26,936 sorties.

This gives a loss rate of 0.39%, a rate of 0.33% damaged beyond economical repair, a total of 0.72%.

REading Ian Thirsk's de Havilland Mosquito, An Illustrated History, Volume 2 I cam across an interesting statistic:

Mosquito bombers flew a total of 39,795 sorties during the Second World War, delivering 26,867 tons of bombs. Losses amounted to 254 aircraft, representing a loss rate of 0.63 percent, the lowest of any aircraft in Bomber Command

This means that in 12859 (presumably) daytime sorties there were 148 Mosquitos lost, at a rate of 1.15%. Not unsurprisingly, significantly greater than for night time operations. But still way below the loss rate of Lancasters (which flew mostly at night).


Also, in 1942 de Havilland first fitted two stage Merlins to the Mosquito prototype. With two Merlin 61s the prototype W4050 managed a maximum leve speed of 437mph (703.6km/h) at arond 25,000ft (7620m). The protype differed from standard Mosquitos with smaller span wings and tail plane. The main wings were about 1'8" smaller (0.5m) whilst the tailplane was less than 1' smaller (0.3m). [I haven't got the reference with me, but I can get the actual numbers.] The prototype also started with the short nacelles, but I believe it flew with the extended nacells when fitted with the two stage engines. The MkIX Mosquito and subsequent variants had the strengthened basic wing introduced with the FBVI. The only other difference I can think of is the canopy blisters, particularly the one located over the navigator's seat in later production bombers and PR aircraft. So, definitely the speed capability was there. Oh, and the bulged bomb bay in the MkXVI and some MkIX.

The B MkXVI had a top speed of 419mph (674.6km/h).

A further prototype fitted with a Merlin 72 and a Merlin 77 reached 439mph (706.8km/h).


One Candian built Mosquito, at least, was field modified to fit two stage Merlins, after it was converted to use the 4000lb cookie.

[Ricky]

This means that in 12859 (presumably) daytime sorties there were 148 Mosquitos lost, at a rate of 1.15%. Not unsurprisingly, significantly greater than for night time operations. But still way below the loss rate of Lancasters (which flew mostly at night).

More appropriately, how does that loss rate stack up against other daylight bombers?

[Red Admiral]

If you have a look at this (http://www.wwiiaircraftperformance.org/mosquito/mosquito-performance-aussie.pdf) report you'll find considerably different speeds. I think they must be for aircraft with the normal wing and tail. Its interesting to note that the report has estimated speeds when a 3-speed 100 series engine is used with +30lb boost. Performance jumps up to around 450mph at 30,000ft.

[Wuzak]

That is interesting info Red.

450mph...the Luftwaffe would have needed all the Do335 and jets they could get their hands on!

Another interesting thing revealed in the book was that the first bombers were painted with yellow leading edges. The yellow leading edges appeared when the wings carried guns - at least in the early part of the war. So there was a genuine attempt to confuse the Germans as to the unarmed natire of the Mossie.

[Wuzak]

More appropriately, how does that loss rate stack up against other daylight bombers?

This site http://www.taphilo.com/history/8thaf/8aflosses.shtml gives a list of all 8th AF missions of WW2. The excel spreadsheet which contains the data is at: http://www.taphilo.com/history/8thaf/8thaf-missions.xls

Just a quick set of calcs show that the 8th AF B-17s had 50652 sorties, 3.5% were recalled, 2.38% aborted and a total loss rate of 3.04%.

[Wuzak]

I've trawled through the data on the XLS from the website and extracted day bomber losses.


A/C Type | B-17 | B-24 | B-26 |
---------------------┼--------┬---------┼--------┬---------┼-------┬---------┤
Dispatched | 50652 | | 13891 | | 3622 | |
Recalled | 1771 | 3.5% | 398 | 2.87% | 186 | 5.14% |
RTB | 2305 | 4.55% | 636 | 4.58% | 619 | 17.09% |
Aborted | 1208 | 2.38% | 253 | 1.82% | 100 | 2.76% |
Lost-en-route | 152 | 0.3% | 0 | 0% | 0 | 0% |
Bombed | 31550 | 62.29% | 7975 | 57.41% | 2062 | 56.93% |
Bombed Opportunity | 5929 | 11.71% | 2091 | 15.05% | 0 | 0% |
Lost-return | 63 | 0.12% | 0 | 0% | 1 | 0.03% |
Total-Lost | 1542 | 3.04% | 352 | 2.53% | 9 | 0.25% |
Crashed | 5 | 0.01% | 0 | 0% | 2 | 0.06% |
Cat-E | 219 | 0.43% | 95 | 0.68% | 9 | 0.25% |
Damaged | 12310 | 24.3% | 1685 | 12.13% | 520 | 14.36% |


There are some issues with these numbers.

Firstly, the data is by no means complete. Mission data is only available for dates up to May 6 1944.

Secondly, the numbers don't seem to add up. It could be that some categories overlap.

After May 1944 bomber losses would have declined because:
The Luftwaffe were becoming much less effective
Escorts were becoming more effective and tactics were improving
Bomber fleets were larger. Doolittle and Spaatz recognised early in 1944 that with larger bomber fleets the losses would not be improved (or worsened), but the loss rates would be significantly improved.

Many of the early missions (1942-3) were shallow penetration missions into France, which allowed RAF Spitfire escorts. From August 1943 the 8th AF began deep penetration raids into Germany, initially without fighter cover over the target area.

[Wuzak]

If you have a look at this (http://www.wwiiaircraftperformance.org/mosquito/mosquito-performance-aussie.pdf) report you'll find considerably different speeds. I think they must be for aircraft with the normal wing and tail. Its interesting to note that the report has estimated speeds when a 3-speed 100 series engine is used with +30lb boost. Performance jumps up to around 450mph at 30,000ft.

The chart shows a maximum speed of 419mph @ 22,200ft for the PR XVI - which is directly analogous to the B XVI.

And jsut by changing the altitude settings of the engines they got an extra 9mph out of the PR 34 at 2,500ft higher.

[Kutscha]

This is from 'Mosquito: Squadrons of the RAF'
Chaz Bowyer

http://img.villagephotos.com/p/2005-12/1114844/Mossie1-2.jpg

[Groggy]

A while back we had the stats for Mosquito losses on night bombing operations, from May 1943 to May 1945. This amounted to 106 lost and 88 damaged beyond economical repair, in a total of 26,936 sorties.

This gives a loss rate of 0.39%, a rate of 0.33% damaged beyond economical repair, a total of 0.72%.

REading Ian Thirsk's de Havilland Mosquito, An Illustrated History, Volume 2 I cam across an interesting statistic:



This means that in 12859 (presumably) daytime sorties there were 148 Mosquitos lost, at a rate of 1.15%. Not unsurprisingly, significantly greater than for night time operations. But still way below the loss rate of Lancasters (which flew mostly at night).


Also, in 1942 de Havilland first fitted two stage Merlins to the Mosquito prototype. With two Merlin 61s the prototype W4050 managed a maximum leve speed of 437mph (703.6km/h) at arond 25,000ft (7620m). The protype differed from standard Mosquitos with smaller span wings and tail plane. The main wings were about 1'8" smaller (0.5m) whilst the tailplane was less than 1' smaller (0.3m). [I haven't got the reference with me, but I can get the actual numbers.] The prototype also started with the short nacelles, but I believe it flew with the extended nacells when fitted with the two stage engines. The MkIX Mosquito and subsequent variants had the strengthened basic wing introduced with the FBVI. The only other difference I can think of is the canopy blisters, particularly the one located over the navigator's seat in later production bombers and PR aircraft. So, definitely the speed capability was there. Oh, and the bulged bomb bay in the MkXVI and some MkIX.

The B MkXVI had a top speed of 419mph (674.6km/h).

A further prototype fitted with a Merlin 72 and a Merlin 77 reached 439mph (706.8km/h).


One Candian built Mosquito, at least, was field modified to fit two stage Merlins, after it was converted to use the 4000lb cookie.

Hi,
Has any one details of the Mosquito performance when given “super fuel” for the Berlin run.

One of Rod Banks’s super brews used towards the end of WW2?

“One Canadian built Mosquito, at least, was field modified to fit two stage Merlins, after it was converted to use the 4000lb cookie.” …Performance?

Merry Xmas

[ChrisMcD]

A while back we had the stats for Mosquito losses on night bombing operations, from May 1943 to May 1945. This amounted to 106 lost and 88 damaged beyond economical repair, in a total of 26,936 sorties.

On these figures almost a quarter of the night bombing mosquitos were apparently shot down by one man - Kurt Welter!

http://en.wikipedia.org/wiki/Kurt_Welter

As part of his score as the highest scoring jet ace ever he claimed 20+ mosquito night kills.

Pity a lot of them did not coincide with RAF losses!

[Trexx]

On these figures almost a quarter of the night bombing mosquitos were apparently shot down by one man - Kurt Welter!

http://en.wikipedia.org/wiki/Kurt_Welter

As part of his score as the highest scoring jet ace ever he claimed 20+ mosquito ...

Crimany Sakes Alive! Geeze...

[Wuzak]

Kurt Welter survived the war, but he wasn't so lucky after:

Welter survived the war and was killed on 7 March 1949 in Leck in Schleswig-Holstein waiting at a level crossing, when logs falling from an improperly loaded passing train crushed his car.

[Wuzak]

On these figures almost a quarter of the night bombing mosquitos were apparently shot down by one man - Kurt Welter!

http://en.wikipedia.org/wiki/Kurt_Welter

As part of his score as the highest scoring jet ace ever he claimed 20+ mosquito night kills.

Pity a lot of them did not coincide with RAF losses!

33 Mosquitos, according to Wiki, 3 of which matched RAF records.

Welter may have been guilty of overclaiming.

Nice piece of understatement on the Wiki page!

[Wuzak]

Hi,
Has any one details of the Mosquito performance when given “super fuel” for the Berlin run.

One of Rod Banks’s super brews used towards the end of WW2?

“One Canadian built Mosquito, at least, was field modified to fit two stage Merlins, after it was converted to use the 4000lb cookie.” …Performance?

Merry Xmas

No knowledge of Mosquito performance on "super fuel", nor for the Canadian Mosquito converted to two stage engines, though I would suggest it matched th Mk IX.

[PMN1]

Welter survived the war and was killed on 7 March 1949 in Leck in Schleswig-Holstein waiting at a level crossing, when logs falling from an improperly loaded passing train crushed his car.


Wood's revenge???

[Kutscha]

No knowledge of Mosquito performance on "super fuel", nor for the Canadian Mosquito converted to two stage engines, though I would suggest it matched th Mk IX.

Some Mosquitos used nitrous oxide. Any performance info?

[Wuzak]

Some Mosquitos used nitrous oxide. Any performance info?

No idea on that. I guess it depends on how it was used, how much was injected.

On the super fuels, the 70 series engines used in the Mk IX & XVI were rated at about 1700hp at altitude. 66 series Merlins were run at 2000hp at sea level with 150 grade fuel. The RM.17SM Merlin was cleared for 2200hp MS and 2100hp FS (forget the altitudes) just before the war ended.

[Wuzak]

Ok, time for an estimation....

Let's take the B XVI with a top speed of 419mph (675km/h) at 22,500ft (IIRC). It was fitted with two engines of 1710hp, or 3420hp total.

Let's us also assume that we can get the Merlins to give 2000hp at the required altitude (66s were low altitude engines, and were rated at 2000hp at seas level from late '43 IIRC), then we get a max speed of 441mph (711km/h). This is, of ocurse, assuming max speed at aximum power at rated altitude.

For the nitrous oxide, let's assume a 500hp shot (that's the way drag racers describe their nitrous installations). That would give 2210hp per engine, for a total of 4420hp.

That would give a max speed of 456mph (734.8km/h).

[Wuzak]

At sea level the max speed for a Mk XVI was 347mph (559km/h), presumably with the standard 1710hp for each engine.

With the 2000hp Merlin 66s installed estimated sea level performance is 366mph (589km/h).

With the 500hp nitrous boost per engine the sea level max speed becomes 378mph (609km/h).

[Wuzak]

This document shows a maximum speed for a Mosquit B XVI to be 401mph with +18psi boost.

http://www.wwiiaircraftperformance.org/mosquito/dz540.pdf

Improved fuels allowed the Merlin to operate at +25psi boost (which I presume corresponds to the 419mph maximum speed) whilst even better fuels allowed +30psi boost in some cases late in the war.

[curmudgeon]

This document shows a maximum speed for a Mosquit B XVI to be 401mph with +18psi boost.

http://www.wwiiaircraftperformance.org/mosquito/dz540.pdf

Improved fuels allowed the Merlin to operate at +25psi boost (which I presume corresponds to the 419mph maximum speed) whilst even better fuels allowed +30psi boost in some cases late in the war.

Nice data. 1943, and loaded and with faired wing tanks ...

What about the Oboe mosquitos and the late war night fighters?

Got to hand it to those engineers ... I guess they were aiming at the limits w'out worrying about workplace health and safety (being shot down being most distinctly unhealthy)

[Wuzak]

http://www.wwiiaircraftperformance.org/mosquito/mosquito.html


Aircraft and Armament Experimental Establishment
Boscombe Down
12 April 1945
Mosquito NF. Mk. 30 MM.748
(2 Merlin 72)

Position error and level speed performance trials

SUMMARY


Position error trials, and measurement of the level speed performance under combat and cruising power have been made on Mosquito NF Mk.30 MM.748 at a take-off weight of 21,600 lb., with 2 x 50 gallon under-wing tanks fitted.
The position error correction at 20,540 lb. varies non-linearly from +3.5 mph at 150 mph ASI to +8 mph at 180 mph ASI, then linearly to +19.0 mph at 340 mph ASI.

The maximum true level speeds are:-

M.S. Supercharger gear.



Max. cruising power. Combat power

340 mph at 17,000 ft. 371 mph at 12,200 ft.


F.S. Supercharger gear.


Max. cruising power. Combat power

364 mph at 27,500 ft. 397 mph at 24,800 ft.


The performance generally is up to the expected standard for this varient of the Mosquito.



Performance appears to be at +18psi boost.

http://www.wwiiaircraftperformance.org/mosquito/mm748-level.jpg

[Wuzak]

Merlin 66 power chart.

http://www.spitfireperformance.com/merlin66hpchart.jpg

This chart only goes up to 22,000ft, but has boost pressures of +18, +25 and +28psi. Probably some time in 1944, and definitely useing PN150 fuel for the higher boost pressures.

[Kutscha]

The highest boost used operationally by Merlins during the war was 25lb.

[Wuzak]

The highest boost used operationally by Merlins during the war was 25lb.

Yes, but Merlins were run at higher boost pressures during the war, and were certified to run at 30psi late in the war.

Even at +25psi boost the Merlin 66 topped 2000hp at low altitude (about 4,000ft) and about 1850hp at higher altitude (14,000ft).

The Merlin 66 was tuned more for low altitude operations.

[Groggy]

Yes, but Merlins were run at higher boost pressures during the war, and were certified to run at 30psi late in the war.

Even at +25psi boost the Merlin 66 topped 2000hp at low altitude (about 4,000ft) and about 1850hp at higher altitude (14,000ft).

The Merlin 66 was tuned more for low altitude operations.

Hi

I borrowed a copy of “I Kept No Diary” by Air Commodore F. R. "Rod" Banks some time ago and can not remember if it was from this book or a copy of one of his lectures that was published some time after the war had ended, but it left me with the impression that a significant performance was gained by the Mosquito towards the wars end with the use of special fuel and that was not recorded else where .
Merry Xmas

[Wuzak]

In July 1943 a Merlin 66 was run on the bench with +30psi boost and 3300rpm for 15 minutes whilst doing a type test.

This gave 2380hp. Presumably on PN150 fuel.

This equates to a maximum speed of 387.4mph (623.4km/h) for a B XVI at sea level, and 467.8mph (752.7km/h) at altitude. The power would probably be slightly less at altitude, however, possibly about 2200hp which would give a speed of 456mph (734km/h).

It was about that time that PR IX and B IX were being made, which were very similar to the Mk XVI. A Mk 66 would plug into the same space as a 70 series engine.

[Groggy]

In July 1943 a Merlin 66 was run on the bench with +30psi boost and 3300rpm for 15 minutes whilst doing a type test.

This gave 2380hp. Presumably on PN150 fuel.

This equates to a maximum speed of 387.4mph (623.4km/h) for a B XVI at sea level, and 467.8mph (752.7km/h) at altitude. The power would probably be slightly less at altitude, however, possibly about 2200hp which would give a speed of 456mph (734km/h).

It was about that time that PR IX and B IX were being made, which were very similar to the Mk XVI. A Mk 66 would plug into the same space as a 70 series engine.

Hi Folks, Happy New Year.

Thanks for the info. this must be about the potential limit for the Mosquito.