View Full Version : Curtiss XP-55 Ascender - Flight Test Accident

Genghis the Engineer
14th Jul 2004, 13:00
As some will know, I've a long-term research interest in the flying characteristics of tailless aircraft.

I've come across a few references to loss of an XP-55 prototype following a stall test in 1943. What I can't find, is any more information than that.

Does anybody have any useful information about what happened, pilot's observations, BurAir wind tunnel results, etc. that might help shed a light on it.

For that matter does anybody have any other information on LOC in tailless aircraft that they're able to share? (Yes, I do know about the YB-49 and the flexwing tumble.)


14th Jul 2004, 16:53
The tragic loss of Robert Kronfeld at Lasham in 1948 is well documented but here are some interesting links G.
the nurflugel one is a gold mine.





14th Jul 2004, 22:07
'xp-55' in Google produces a number of sites worth a look...

18th Jul 2004, 12:38
Have you come across A V Roe's Type 698 in your research? It was the original proposal for what became the Vulcan.

The drawing I've seen somewhere showed a flying delta wing with small vertical surfaces at the wing tips.


Genghis the Engineer
19th Jul 2004, 13:45
I think that you are thinking of the Avro 707, which was an aerodynamic prototype, the 698 was the designation given to the Vulcan.

Unfortunately for my purposes (although fortunately for those involved) the 707 didn't suffer departures from controlled flight of quite the nature I'm trying to research.

I do wonder if the Dh108 might have done, but information on the detail of that accident is incredibly sketchy - and probably was at the time.


PPRuNe Pop
19th Jul 2004, 15:44
I imagine you have delved in to the three D H 108's that were built, a fair bit has been written about them, and a lot learned after Geoffrey de Havilland was killed when it broke into pieces in the Thames Estuary.

The 108 does seem to have been a remarkable aeroplane, and perhaps a little outside the complete understanding of its ability or otherwise. Although, John Derry seems to have made some remarkable discoveries about the 108 and, indeed, with very careful checks, also discovered that he had achieved Mach 1.0.

But the aeroplane did not always maintain controlled flight and must have been a nightmare throughout the envelope. All three crashed but John Derry received a Gold Medal connected with the 108 for achievements in the air.

Where to next.................................?

19th Jul 2004, 17:03

Found a copy of what I was thinking of...


Genghis, you are of course correct, I'd mixed my types up there somewhat :O

20th Jul 2004, 08:00
IIRC there was an article on the XP55 in Air International? maybe in the '70's which had something on the stall behaviour.

Genghis the Engineer
20th Jul 2004, 10:24
There's quite a lot published on the XP55 that I've found quite recently, although as it happens I've found myself much more interested in the (not very well documented) XP-79B nasty, which occurred on it's first (and only) flight.

I'm not convinced that very much is published about the actual technical detail of the dH108 accidents - I've come across a lot about the events around it but suspect that at the end of the day not much was really known about how and why the aircraft lost control. If, however, somebody can prove me wrong then I shall be in their debt.


20th Jul 2004, 13:23
There was a not-very-good prog on Discovery about the X-55 along the lines of "if research hadn't been stifled on this unconventional aircraft the war would have been over a year earlier" kind of rubbish. Lot's of sim pics but some good footage of the thing in flight.

12th Aug 2004, 12:23
Hi Gengis,

You might find it worth talking to the Planes of Fame who are operating the Northrop N9M; as Northrop refused to help with tech info, due to risks of product liability, the PoF team had to do quite a lot of Northrop flying wing research themselves...



James K