January 15, 1943: First Flight of the XP-54 Flown by Vultee Aircraft Corporation

The first flight of the XP-54 took place flown by Vultee Aircraft Corporation test pilot Frank Davis. Informally nicknamed the Swoose Goose, the aircraft was the second of three pusher fighter aircraft designs to come out of the Army Air Corps’ Circular Proposal R‑40C for a highly advanced fighter plane. The others were the XP-55 and XP-56, none of which went into production. The XP-54 was a sleek twin-boom, inverted gull-wing aircraft with tricycle landing gear whose performance never lived up to its appearance.

Vultee submitted a proposal in response to a U.S. Army Air Corps request for an unusual configuration. The Vultee design won the competition, beating the Curtiss XP-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 January 8, 1941. A second prototype was ordered on March 17,1942. Although it appeared to be a radical design, performance was lackluster, and the project was canceled.  The XP-54 was designed with a pusher engine in the aft part of the fuselage. The tail was mounted rearward between two mid-wing booms, with the twelve-foot propeller between them. The design included a "ducted wing section" developed by the National Advisory Committee for Aeronautics to potentially enable installation of cooling radiators and intercoolers in the inverted gull wing. The Pratt & Whitney X-1800 engine was proposed as the powerplant, but after its development, was discontinued. The liquid-cooled Lycoming XH-2470 was substituted.  In September 1941, the XP-54 mission was changed from low-altitude to high-altitude interception. Consequently, a turbo-supercharger and heavier armor was added, and empty weight increased to 18,000 pound pound.

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, necessitating a downward ejection of the pilot and seat to clear the propeller arc.  Also, the nose section could pivot through the vertical, three degrees up and six degrees down. In the nose, two 37 mm T-9 cannon were in rigid mounts while two .50 caliber 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.