Airplane Tales – Request for Data R-40C: The Vultee XP-54 Swoose Goose

"ttyymmnn" (ttyymmnn)
10/18/2017 at 12:35 • Filed to: wingspan, Planelopnik

Fearing that American aircraft development was stagnating in the face of technological advances made overseas, the US Army Air Corps issued Request for Data R-40C in 1940 which the Army hoped would encourage designers to create innovative new aircraft that went beyond the traditional monoplane with engine in front arrangement that had become standard during the 1930s. Three aircraft came out of this request: the Vultee XP-54, the Curtiss XP-55 Ascender, and the radical Northrop XP-56 Black Bullet.

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This is the first installment in a three-part series that takes a look at the Request for Data R-40C aircraft.

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(US Air Force)

Before merging with !!!error: Indecipherable SUB-paragraph formatting!!! in 1943, the !!!error: Indecipherable SUB-paragraph formatting!!! had found its greatest success with the !!!error: Indecipherable SUB-paragraph formatting!!! dive bomber and the !!!error: Indecipherable SUB-paragraph formatting!!! trainer. Hoping to remain relevant and acquire another military contract, Vultee responded to the R-40C request with the XP-54, unofficially as the Swoose Goose. Vultee planned to use the experimental !!!error: Indecipherable SUB-paragraph formatting!!! “ !!!error: Indecipherable SUB-paragraph formatting!!! ,” which they expected to provide up to 2,200 turbocharged horsepower and carry the Swoose Goose to a tope speed of 510 mph at 20,000 feet. But when the X-1800 engine was cancelled, Vultee was forced to substitute a less powerful !!!error: Indecipherable SUB-paragraph formatting!!! engine, which turned out to be inadequate for such a large aircraft. Without enough power for dogfighting at high altitude, the Swoose Goose was reclassified as a bomber-interceptor.

(San Diego Air and Space Museum)

Since the XP-54 was no longer a dedicated fighter, its armament was reconfigured to give a heavier punch, and the six .50 caliber machine guns in the nose were changed to two .50 caliber machine guns and two 37mm cannons. But the lower muzzle velocity of the cannons caused difficulty with aiming, so Vultee came up with a novel solution. They devised a system where the entire nose of the aircraft could be tilted upward three degrees in order to lob the cannon shells at the target. The nose could also be lowered six degrees for attacking ground targets. Another Vultee innovation was a pilot’s seat that lowered beneath the plane through a hatch so the pilot could be raised into the cockpit. This mechanism also served to drop the pilot through the bottom of the fuselage in case of emergency, making it essentially an early downward ejection seat.

The pilot’s seat lowered for access to the cockpit (San Diego Air and Space Museum)

Two prototypes were built, and the maiden flight took place on January 15, 1943, followed by 86 test flights. But as is so often the case in aircraft development of the period, the Lycoming engine just wasn’t up to the task and the XP-54 never achieved the hoped-for performance. It managed a top speed of only 381 mph and took 10 minutes to reach 23,000 feet. With the completion of a second prototype, the first was used for spare parts, but the second Swoose Goose few only once before the project was canceled in 1942. Vultee considered developing the XP-54 into the XP-68 Tornado by using a more powerful !!!error: Indecipherable SUB-paragraph formatting!!! 42-cylinder engine, but when development of the Tornado engine was also cancelled the Tornado airplane followed suit, and the XP-54 became the last airplane designed by Vultee before the merger with Consolidated to form Consolidated-Vultee, or Convair.

(US Air Force)

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Connecting Flights

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If you enjoyed this post, please join in the conversation and let me know. For more stories about aviation, aviators and aircraft oddities, head over to !!!error: Indecipherable SUB-paragraph formatting!!! .

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DISCUSSION (13)

Rusty Vandura - www.tinyurl.com/keepoppo > ttyymmnn
10/18/2017 at 12:51

10 minutes to 23,000 feet? 42 cylinders? Crazy numbers.

user314 > ttyymmnn
10/18/2017 at 12:56

The X-1800 was an H-block?

Kinja'd!!!

I can’t imagine why that didn’t turn out....

You can tell a Finn but you can't tell him much > ttyymmnn
10/18/2017 at 13:00

It’s crazy to me that they thought to make the entire nose pivot up and down, but it never occurred to anyone to just have the cannons pivot in the nose.

uofime-2 > user314
10/18/2017 at 13:02

all of the “hyper engines” were basically flops, plagued with delays and underwhelming performance. I cant remember if ttymmnn wrote it or it was just on wiki but I recall an interesting article about them

ttyymmnn > You can tell a Finn but you can't tell him much
10/18/2017 at 13:11

The pivoting would have affected both the cannons and the machine guns. It probably would have been harder to develop a separate system for both.

ttyymmnn > uofime-2
10/18/2017 at 13:12

I have not written an article on H blocks, but it’s not a bad idea. IIRC, the single block engine was fine, but the troubles arose when they stacked one atop the other. What I really need to write about is the Liberty Engine. It’s the engine that won WWI and some of WWII.

uofime-2 > ttyymmnn
10/18/2017 at 13:19

pretty sure it also won rum-running

note it was wikipedia that had the article:

https://en.wikipedia.org/wiki/Hyper_engine

user314 > Rusty Vandura - www.tinyurl.com/keepoppo
10/18/2017 at 13:54

Yeah, ~2300 fpm climb is about what the P-40 was pulling, or about half of what a P-38 or -51 could achieve.

RamblinRover Luxury-Yacht > user314
10/18/2017 at 14:04

H-blocks are incredibly rare - considering the only ones I can think of are an H4 that was in a motorcycle and the BRM H16 made for Formula 1 - but it’s by no means a bad idea. If you get oiling taken care of, the balance is superb (actually better than a V or even a boxer), and the packaging is pretty dense.

Shane MacGowan's Teeth > ttyymmnn
10/20/2017 at 12:00

“Hey John, what’s your new airplane like?”

“Aw dude, it’s great. The nose wobbles around, and the floor can open up to dump me out into the giant blender in the back.”

ttyymmnn > Shane MacGowan's Teeth
10/20/2017 at 12:36

Curtiss had a unique solution for that problem. You can read about that next week!

Shane MacGowan's Teeth > ttyymmnn
10/20/2017 at 16:25

Still slightly concerning that Curtiss had a system (didn’t they have an explosive disconnect for the prop?) but Vultee didn’t.

ttyymmnn > Shane MacGowan's Teeth
10/20/2017 at 16:33

I have not read anywhere if Vultee’s system included a charge or if it was just a gravity drop. I suppose there would be more danger with somebody climbing out of the cockpit and jumping rather than getting dropped out.