Consolidated Model 21 was an American two-seat training aircraft built by the Consolidated Aircraft Company. It was used by the United States Army Air Corps with the designation PT-11 and the United States Coast Guard under the designation N4Y
The Model 21 was an aerodynamic cleaned up version of the
Model 12/PT-3, one of the distinguishing features was curved instead of angular tail surfaces. The aircraft was a single-engined biplane with fixed tailwheel landing gear and accommodation for two in open cockpits. Designated the PT-11 by the United States Army Air Corps it progressed through a number of trial variants but was not built in large numbers. 11 Examples of the model 21-C were built in Canada as the 21-M for Mexico but none were built for local use.
(Model 21A). Prototype powered by 170 hp (130 kW) Kinner engine, first flew February 1931.
Evaluation aircraft for US Army based on the Model 21A with a 165 hp (123 kW) Continental R-545-1 engine, four built.
One YPT-11 was re-engined with a 175 hp (130 kW) Curtiss R-600-1 Challenger engine, originally as Y1PT-11A, later converted to PT-11C standard.
One YPT-11 was re-engined with a 210 hp (160 kW) Kinner YR-720-1 engine and designated YPT-11B. 5 production aircraft for US Army with another for the United States Coast Guard and designated N4Y-1.
PT-11A re-engined with a 180 hp (130 kW) Lycoming YR-680-1 engine. One or two converted for US Army, with 18 new build aircraft for Colombia.
Production version with 220 hp (160 kW) R-680-3 engine, originally designated Y1PT-11D. 21 new-built, plus five conversions from Y1PT11-Bs and two from Y1PT-11s.
A version of the PT-11 with a 300hp R-985-1 engine and detailed changes, ten built later re-designated BT-7.
One YPT-11 was re-engined with a 300hp R-985-1
Redesignation of Y1BT-6.
PT-12 aircraft re-designated.
Evaluation aircraft for the United States Coast Guard, three built.
One YPT-11B for the USCG, later modified to the same standard as the XN4Y-1
Specifications (PT-11D) Edit Data from "The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985)" Orbis Publishing
Length: 26 ft 11 in (8.20 m)
Wingspan: 31 ft 7 in (9.63 m)
Height: 9 ft 8 in (2.95 m)
Wing area: 280 ft² (26.01 m²)
Empty weight: 1,918 lb (870 kg)
Max. takeoff weight: 2,585 lb (1173 kg)
Powerplant: 1 × Lycoming R-680A radial piston, 200 hp (149 kW)
Maximum speed: 118 mph (190 km/h)
Service ceiling: 13,700 ft (4175 m)
The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.
Wegg, John (1990). General Dynamics Aircraft and their Predecessors. London: Putnam Aeronautical Books. ISBN 0-85177-833-X.