Rare Bird: The Vultee XP-54 “Swoose Goose”

The "Swoose Goose" in flight

For almost twenty years after the close of World War I in 1918, the Congress of the United States starved its military services, refusing to appropriate enough money to sustain a tiny Army, a minuscule Air Corps and just barely providing enough for the always-favored Navy.

Personnel took the hardest hit, with demotions being more likely than promotions, and pay frozen at a minimum-wage level. The most qualified officer imaginable, First Lieutenant Jimmy Doolittle, remained in that rank for eleven years, despite his having obtained masters and doctor degrees from M.I.T. in aeronautical engineering, and despite his setting one record after another. With a large family to support, Doolittle had no choice except to leave the service, as did many other highly competent people.
The tough times were equally hard on procurement, and the Air Corps was confined to buying very small quantities of aircraft annually, and to spreading these orders out among as many contractors as possible, in an attempt to keep the industry alive.

The threat of World War II eventually changed things, and the American aviation industry got a tremendous lift from the Anglo-French purchasing commission that came to this country to buy warplanes for their own neglected armed forces. Then as war became inevitable, the Congress began supplying more funds, enabling plants to be built.

Much of the burden of this expansion was on the shoulders of a hard-core of professional Army officers who had sweated out the depression years and now could not believe that they were being challenged to go convert an easy-going aircraft industry, used to producing perhaps 3,000 aircraft of all types, into an industrial powerhouse. Fortunately there were men like Majors E. M. Powers, K. B. Wolfe, Frank O. Carroll and H. Z. Bogert to do the job, and they turned to with such a will that by 1944, the United States aviation industry was producing aircraft at the rate of 100,000 per year, and would produce well over 300,000 in the course of the war.

The United States Army Air Forces was well aware that despite all publicity claims, its Bell P-39 and Curtiss P-40 aircraft were not equal to enemy aircraft such as the Messerschmitt Bf 109 or the Mitsubishi Zero. And while the Lockheed P-38, Republic P-47 and North American P-51 were coming along, it had to be assumed that the enemy would also be introducing new fighters of even higher performance.

In an attempt to accelerate progress (never an easy thing to do) Major Powers created Request for Data R-40C, in which he solicited the industry to become genuinely innovative. If the phrase had been current at the time, he would have asked industry to “think outside the box.” Powers requested three classes of aircraft to be investigated. Class I consisted of modifications to current models; Class II designs were to be unconventional, but were to take advantage of existing power plants and be easily placed into quantity production. Class III designs were allowed to take advantage of planned new engines, and could be as radical as the manufacturer dared.

Three aircraft emerged as top contenders in the Class III designs; they included the Northrop XP-56 “Black Bullet”, Curtiss XP-55 “Ascender” and what became, after a torturous series of changes, the Vultee XP-54.

The Vultee submission had actually won first place, and two XP-54s were ordered, to be powered with the Pratt & Whitney X-1800 engine, a liquid cooled twenty-four cylinder engine that offered 1,850 paper horsepower. With it, the paper XP-54 was to have a top speed of 510 mph at 20,000 feet.

Unfortunately, Pratt & Whitney did not want to build liquid cooled engines; they already had magnificent radial engines of equal or greater horsepower coming on line, and it made no sense to them to experiment with a radical new kind of engine at a time when they could fill their production lines with R-1830s and R-2800s.

Vultee was instructed to substitute a 2,200 Lycoming XH-240 engine for the P&W, a change which required much redesign, but promised an increase in performance to 520 mph at 17,000 feet. This was catching up, with a vengeance! And to provide for possible delays in the Lycoming engine, the XP-54 was also supposed to accept the Wright R-2160 Tornado. As things turned out, neither engine would ever reach production.

The poor Vultee engineers were beset with a long series of changes. They would finish one redesign only to find that it was now obsolete, not because of the aircraft itself, but because the war situation had changed, and with it, the perceived mission for the XP-54. One of the first of these called for the XP-54 to become an interceptor, with turbo-superchargers and a pressurized cabin. The magnitude of this change can be inferred from the change in weight. The original XP-54 was to have had a gross weight of 8,500 pounds; the interceptor version was predicted to weight 19,937 pounds—more than double the original.

The next mission change called for the interceptor to become a bomber-destroyer, carrying two 37-mm cannons and two .50-caliber machine guns, to save the United States from marauding German and Japanese bombers. The armament combination seems formidable but presented severe matching problems. The muzzle velocity of the cannon was relatively low, and to obtain the necessary range, an intricate mechanism had to be created to raise them in the nose, so that they could lob shells into the target. The muzzle velocity of the machineguns was high, however, so to harmonize, they had to be rigged to lower as the cannons raised. Only Rube Goldberg could have approved of such an arrangement, and it is certain that Vultee engineers must have been embarrassed to be forced to include it in a fighter design.

Before the days of the ejection seat, pusher designs always make it difficult for a pilot to leave in an emergency. Other pusher types, such as the Bell Airacuda or the Dornier Do 335 Pfiel had a detonator system to blow the propeller off, allowing the pilot to bail out without worrying about being sliced to pieces. This was not feasible on the XP-54, as the propeller was situated between the twin tail booms, and a jettisoned prop could be expected to tear the tail away, with complete loss of control. To solve this problem, Vultee engineers came up with a “rejection seat.” This was a mechanically leveraged arm that pulled the pilot’s seat down and way from the aircraft, shooting it like a sling-shot.

Nor was this all. To avoid the sealing problems inherent in a pressurized cabin with a moveable canopy, the rather stylish cockpit enclosure was fixed in place. The pilot entered and left by means of an elegant elevator. This was impressive to the casual on-looker, but presented enormous problems in cable routing, weight, and most particularly, hot-weather operation.

The first flight of the XP-54 took place on January 15, 1943 at Muroc Dry Lake. The Army engineers were already aware that the forecast 520 mph top speed was about 130 miles too optimistic, and that there was absolutely no chance of the XP-40 ever becoming a viable fighter.

After only ten flights, some of them very short because of engine problems, the XP-54 was returned to the factory for an engine change. This was not easy, for only three of the Lycoming XH-2470 engines had been made. The first XP-54 flew for a total of 63 hours before it was replaced in the test program by the second aircraft. It made only one flight, on May 24, 1944, and when both the engine and the turbo-supercharger malfunctioned, the aircraft was grounded and the program cancelled. The nickname “Swoose Goose” derived from a popular song of the time.

The USAAF had spent $1.5 million on the XP-54, and got little more than a learning experience from it. Nor was much derived from the Curtiss XP-55 and Northrop XP-56 programs. The problem was primarily the engines—the anticipated engines had not materialized, and with standard engines, none of the three aircraft had a chance to outperform the North American P-51 Mustang. The XP-55 had stability problems, and would fall like a rock in a stall. One remains, the property of the National Air & Space Museum. The XP-56 was so difficult that it once turned over while taxiing, severely injuring its test pilot. Despite the relative lack of success, it is fortunate the U.S. was so wealthy that it could spend money on programs like this, and still be capable of building less radical combat aircraft of sufficient quality and numbers to win the war.


Wingspan 53 feet 10 inches
Length 54 feet 8-3/4 inches
Height 14 feet 6 inches
Empty Weight 15,262 pounds
Gross Weight 19,337 pounds
Maximum Speed 381 mph
Service Ceiling 37,000 feet
Range 385 miles
Engine: 2,300 hp Lycoming XH-2470-1

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