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GOT: The Curtiss-Wright XP-55 Ascender


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#21 Romantic Technofreak

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Posted 27 December 2016 - 08:42 AM

Actually I meant to say I didn't want to argue about it and did not want to imply that a flying RC represented a good model of a full size aircraft. Let's say non-escalational wording got in the way.

The German word "Diskussion" never has a negative tune. So I did not expect one in the English word. Looks like my knowledge of English once more found a limit.

 

 

I think all modern military fighter type aircraft need computer control because of the relaxed stability, no matter what the configuration.

Looks like this was what Greg intended to say. Sorry for the misunderstandings. I use to have a certain mental dimness at Chistmas (the countering question "At Christmas?" is already anticipated :))

 

 

You almost make me wish I would start incorporating experimental aircraft in the AIRCRAFT PERFORMANCE section so that I could include your post. :)

Makes YOU wish? Makes US wish! :D

 

Regards, RT



#22 Ricky

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Posted 27 December 2016 - 10:28 AM

(the countering question "At Christmas?" is already anticipated :))


Spoiling all my fun :D

#23 Wuzak

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Posted 01 January 2017 - 11:46 PM


  • GregP likes this

#24 Armand

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Posted 02 January 2017 - 12:35 AM

Thought so. We all know that modern jet canards wouldn't fly very long without a computer to help out,

The SAAB J37 Viggen did quite well, though from a time with limited computerization (early 60's)!

The shear possibility of using canards for control due to the modern computer power is evident, but except from the earliest box-kite like aircraft, isn't the design originally a fixed winglet wich supported the pitch but would stall before the main wing - Thus catch the wing-stall by lovering the nose!?

Edited by Armand, 02 January 2017 - 12:37 AM.


#25 Armand

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Posted 02 January 2017 - 12:50 AM

The German word "Diskussion" never has a negative tune. So I did not expect one in the English word. Looks like my knowledge of English once more found a limit.
 


Schaue es sonst als "Debatte" an -> 'debate' !



#26 Romantic Technofreak

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Posted 02 January 2017 - 06:29 AM

Hi Armand,

 

you see I corrected once more your original sentence: "Anschau es sonst als debatte -> 'debate' !" to a valid German syntax. I hope we don't bore the native English speakers by discussing the details of German language. "Debatte" is in fact a bit more tempered than "Diskussion", but still far from ill. "Auseinandersetzung" truly can have both a positive and a negative meaning. It can mean "discussion", but there is also  "Kriegerische Auseinandersetzung"... = "armed conflict"...

 

 

Thus catch the wing-stall by lovering the nose!?

A very good question! Does anybody have an answer?

 

Regards, RT



#27 Wuzak

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Posted 08 January 2017 - 06:37 AM

Some great photos.
I am surprised not to see a mention of what was supposedly the the plane's very appropriate nick name, the Arse ender.
As seemed a habit for the company Curtiss managed to create a very 1930s looking plane that existed in the 40s and performed below their expectations.

 
From Gerald H. Balzer,  American Secret Pusher Fighters of World War II
 
Balzer quotes Walt Boyne's account of the naming of the airplane the "Ascender" :
 
 

'Bud' Flash related how he fathered a little joke that was played on the usually stuffy bureaucrats that name airplanes. A contest was underway at the Curtiss plant to provide a popular name for teh C-46 transport, which of course became known as teh 'Commando'. Flash and long-time Curtiss engineer George Page were eating lunch and discussing their tail-first project and teh seemingly endless problems involved. Finally, Flesh said, "George, I know one thing; if they ever have a contest for this bird, I'm going to call it the Ascender". And, subsequently, with the bureaucrats either missing or enjoying the double entendre nomenclature, the XP-55 was called just that.



#28 GregP

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Posted 20 January 2017 - 02:07 AM

Hey Armand,

A question ...

 

I was under the impression that the Viggen had fixed canards (did not use the canards for pitch control), and only used the movable canard surfaces during landing more or less as flaps, to hold the nose up for touchdown. As I recall, the canards were set at a sightly higher pitch angle than the wings, so they would stall first and result in a predictable nose-down pitch motion rather than flipping over backwards at stall.

 

Is that wrong? Could be, but if so, I've been under the wrong impression for a long time.



#29 Wuzak

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Posted 20 January 2017 - 02:53 AM

Looks like you have been mistaken Greg.

 

AJ37_Viggen_Aircraft.jpg

 

Saab_SF_37_Viggen_37951_F_13_Br%C3%A5val



#30 GregP

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Posted 20 January 2017 - 03:09 AM

Not too sure about that. Looks like it is doing exactly what I said.

 

The front part of the canrds (in front of the movable surface) are fixed and the rear drop like flaps to hold the nose up, but not for pitch control. Here is a video:

 

https://youtu.be/aUZ1YVSgo4k

 

The canard doesn't move like an elevator when it taxis, and once it is retracted, it never seems to move at all. The tailerons seem to control pitch in-flight, with the canard seeming to me to move only like flaps when in landing configuration.

 

You don't seriously think he taxis and flies around at lower speeds in landing configuation with the stick locked full aft, do you? If he did, how would he control pitch? Watch a video of a Typhoon or a Gripen, and the canard only moves for pitch, and can be seen moving around near touchdown when small pitch changes are required. Every time I have seen a Viggen fly, the trailing edges of the canard never move except either in trail or full down (nose up). The only time they seem to be between those points is when they are lowered or raised during the takeoff / landing sequence.

 

Here''s a quote from Air Vectors:

 

"The wing had a somewhat complicated form, designed as a double delta with something of a "hoop skirt" appearance in planform, and a dogtooth on each outer span. The dogtooth was added to improve longitudinal stability when carrying external stores. Each dogtooth was further marked by a bullet fairing for a radar warning receiver (RWR) antenna. There were two-section hydraulically actuated elevons on the trailing edge of each wing.

 

The canards directed turbulent airflow over the main wing at low speeds, lowering the stall speed on landings. They had no dihedral and were fixed at a few degrees of incidence, but had trailing-edge flaps to improve takeoff performance. The canards on the first prototype had a noticeable dihedral as the aircraft was initially rolled out, but the dihedral was eliminated before the machine took to the air. The tailfin was fixed, with a one-piece rudder. The tailfin folded to the left to allow the aircraft to be stowed in hardened shelters at field bases. There was a fixed ventral fin under the tail."

 

And here's the clicher concerning computers, another quote from Air Vectors:

 

"The control layout was analog, as would be expected of aircraft of its period, but featured a Svenska Radio / Ericsson (SRA) head-up display (HUD) for primary flight data, including displays generated by the instrument landing system to help guide the aircraft down. The most significant element in the AJ 37's avionics suite was its Ericsson PS-37A monopulse X-band radar, which was primarily focused on air-to-ground and navigation, though it had limited air-to-air capabilities. The rest of the avionics was impressive -- or at least it was for its era ..."

 

You can read the whole thing here: http://www.airvectors.net/avvig.html






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