Vultee submitted a proposal in response to U.S. Army Air Corps request R40C.[1] The Vultee design won the competition, beating the CurtissXP-55 Ascender and the Northrop XP-56 Black Bullet. Vultee designated it Model 84, a descendant of their earlier Model 78. After completing preliminary engineering and wind tunnel tests, a contract for a prototype was awarded on 8 January 1941. A second prototype was ordered on 17 March 1942. Although it appeared to be a radical design, performance was lackluster, and the project was canceled due to budget overruns and extreme delays.
In September 1941, the XP-54s mission was changed from low-altitude to high-altitude interception. Consequently, twin Wright B turbo-superchargers[2] and heavier armor was added, and empty weight increased to 18,000lb (5,200 to 8,200kg).
The Swoose Goose
The XP-54 was unique in numerous ways. The pressurized cockpit required a complex entry system: the pilot's seat acted as an elevator for cockpit access from the ground. The pilot lowered the seat electrically, sat in it, and raised it into the cockpit. Bail-out procedure was complicated by the pressurization system and pusher configuration, necessitating a downward ejection of the pilot and seat to clear the propeller arc.[3] Also, the nose section could pivot through the vertical, three degrees up and six degrees down. In the nose, two 37mm M4 T-12/T-13 cannons were in rigid mounts while two .50 cal machine guns were in movable mounts. Movement of the nose and machine guns was controlled by a special compensating gun sight. Thus, the cannon trajectory could be elevated without altering the flight attitude of the airplane. The large nose section gave rise to its whimsical nickname, the Swoose Goose, inspired by a song about Alexander who was half-swan and half-goose: "Alexander was a swoose." – a name shared with the oldest surviving B-17.
Operational history
Flight tests of the first prototype, 41-1210, began on 15 January 1943. Trials showed the XP-54 had great handling although, the performance was found to be substantially below guarantees. Simultaneously, development of the XH-2470 engine was discontinued. Although the Allison V-3420 engine could be substituted, that required substantial airframe changes. Projected delays and mounting costs resulted in the decision to not consider purchasing of production aircraft.
The prototypes continued to be used in an experimental program until problems with the Lycoming engines and lack of spare parts caused termination. The second prototype, 42-108994 (but mistakenly painted as 42-1211) had the twin Wright turbo-supercharger setup replaced with a single experimental GE XCM turbo-supercharger,[2] this airframe made ten flights before it was relegated to a "parts plane" to keep the first prototype in the air.[4]
Balzer, Gerald H. American Secret Pusher Fighters of World War II: XP-54, XP-55, and XP-56. North Branch, Minnesota: Specialty Press, 2008. ISBN1-58007-125-2.
Buttler, Tony (2024). American Experimental Fighters of WWII: The Pursuit of Excellence. Crécy Publishing. ISBN978-1-80035-310-7.
Green, William and Gordon Swanborough. WW2 Aircraft Fact Files: US Army Air Force Fighters, Part 2. London: Macdonald and Jane's Publishers Ltd., 1978. ISBN0-354-01072-7.
Jenkins, Dennis R. and Tony R. Landis. Experimental & Prototype U.S. Air Force Jet Fighters. North Branch, Minnesota: Specialty Press, 2008. ISBN978-1-58007-111-6.
