The first prototype was subsequently used as an engine testbed, its Lycoming R-680-13 radial being replaced by a Lycoming GSO-580 horizontally-opposed eight-cylinder. It was lost in an accident in1950.
The second aircraft, fitted with a larger stabilizer, was evaluated by the USAF as a primary trainer in 1949, designated T-31, others evaluated were the Beech 45 T-34 and the Temco TE-1A. On March 24, 1949, after only three weeks of trials at Wright Field, Dayton, Ohio, the T-31 was selected. Fairchild would produce 100 aircraft as the Model 129, however, due to budget restrictions the order was cancelled later in 1949.
Subsequently BuNo. 75726 came on the civil register as N5756 and was operated for ten years by the Civil Air Patrol in Washington, D.C., where after it it was acquired by a private owner. In the mid-1970s the aircraft was offered to the Antique Airplane Association of Blakesburg, Iowa. On April 15, 1983, the aircraft was registered to Dominick D. 'Don' Pellegreno of Rhome, Texas, who restored the aircraft, and it was flown again on May 20, 1992. It is still on the register as of this day. The following data is referring to the XNQ-1.
TYPE. Two-seat Primary-Basic Trainer.
WINGS. Low-wing cantilever monoplane. All-metal structure with stressed metal skin. Trailing-edge flaps between ailerons and root joints. Flaps all-metal including covering, ailerons metal-framed and fabric-covered.
FUSELAGE. All-metal structure.
TAIL UNIT. Cantilever monoplane type. All-metal tailplane and fin, metal-framed fabric-covered elevators and rudder. Trim-tab in movable surfaces.
LANDING GEAR. Retractable type. Main wheels raised inwardly into pockets in leading-edge of wing roots. Electrical retraction. Non-retracting castoring and steerable tail-wheel.
POWERPLANT. One Lycoming R-680-13 nine-cylinder radial air-cooled engine with normal rating of 280 hp and with 295 hp available for takeoff. Hamilton Standard two-blade constant-speed air-screw. Fuel capacity 80 gal (302 l).
ACCOMODATION. Crew of two in tandem beneath a one-piece sliding "bubble" canopy. Dual controls. Air Force-Navy standardized functional safety cockpit layout.
Span: 41 ft 4 in (12.60 m)
Length: 27 ft 11 in (8.50 m)
Height: 9 ft 10 in (3.00 m)
Wheel track: 9 ft 2 in (2.80 m)
Empty weight: 2,718 lb (1,280 kg)
Loaded weight: 3,750 lb (1,705 kg)
Max speed: 166 mph (268 kmh) at sea level
Cruise speed: 142 mph (228 kmh)
Stall speed: 55.6 mph (89.5 kmh)
Climb: 1,070 ft (326 m)/min
Takeoff run: 610 ft (186 m)
Takeoff to 50 ft (15 m): 950 ft (163 m)
Service ceiling: 19,300 ft (5,890 m)
Range: 880 mls (1,450 km)
Endurance: 4 hr 42 min