posted on Jun, 4 2006 @ 08:29 AM
The US Army sponsored Competition R-40C specifically for unconvensional designs, perhaps hoping that one of the designs would produce a worthwhile
advance in performance, albeit at some development risk over conventional designs. There were three aircraft types built as a result of the
Vultee XP-54 'Swoose Goose' (an unofficial name, and also the winner of the competition)
Curtiss XP-55 'Ascender' (unofficial name)
Northrop XP-56 'Black Bullet' (again an unofficial name)
The performance of these aircraft was no better than conventional designs, so the risk involved in the development of them was not justified. The
following extract from Lloyd S Jones' 1975 book 'US Fighters' might also explain why the XP-55 didn't get developed further.
'On November 15, 1943, The XP-55 flipped onto its back during stall tests and attempts to recover failed. The plane stabilized in the inverted state
but the engine quit and the XP-55 fell vertically 16,000 ft before the pilot decided an inverted landing would ruin his whole day and safely abandoned
the stricken machine. The possibility of this condition had been predicted by early wind-tunnel tests.......'
Without even looking at performance data, I would reckon that both the XP-55 and the XP-56 would have rather long take-offs due to the inability to
rotate the aircraft because of the danger of the prop / ventral fin striking the ground. The ventral part of the XP-54 fins also looks to serve as
'tail-bumpers' to prevent the prop hitting the ground.
[edit on 4/6/06 by The Winged Wombat]