The Consolidated Model 21 was an American two-seat training aircraft built by the

Consolidated Aircraft Company The Consolidated Aircraft Corporation was founded in 1923 in aviation, 1923 by Reuben H. Fleet in Buffalo, New York, the result of the Gallaudet Aircraft Company's liquidation and Fleet's purchase of designs from the Dayton-Wright Company as the ...

. It was used by the

United States Army Air Corps The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical ri ...

with the designation PT-11 and the

United States Coast Guard The United States Coast Guard (USCG) is the maritime security, search and rescue, and Admiralty law, law enforcement military branch, service branch of the armed forces of the United States. It is one of the country's eight Uniformed services ...

under the designation N4Y.

Design and development

The Model 21 was an aerodynamic cleaned up version of the Model 12/PT-3, one of the distinguishing features being 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.

Operational history

Designated the PT-11 by the

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.

Variants

;XPT-933 : (Model 21A). Prototype powered by Kinner engine, first flew February 1931.Wegg 1990, p. 64. ;YPT-11 :Evaluation aircraft for US Army based on the Model 21A with a Continental R-545-1 engine, four built. ;PT-11A :One YPT-11 was re-engined with a Curtiss R-600-1 Challenger engine, originally as Y1PT-11A, later converted to PT-11C standard. ;Y1PT-11B :One YPT-11 was re-engined with a Kinner YR-720-1 engine and designated Y1PT-11B. 5 production aircraft for US Army with another for the

and designated N4Y-1.Wegg 1990, p. 65. ;PT-11C :PT-11A re-engined with a Lycoming YR-680-1 engine. One or two converted for US Army, with 18 new-build aircraft for

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

.Wegg 1990, pp. 64–65. ;PT-11D :Production version with R-680-3 engine, originally designated Y1PT-11D. 21 new-built, plus five conversions from Y1PT11-Bs and two from Y1PT-11s. ;PT-12 :A version of the PT-11 with a 300hp R-985-1 engine and detailed changes, ten built later redesignated BT-7. Consolidated Y1BT-6

;Y1BT-6 :One YPT-11 was re-engined with a 300hp R-985-1 ;BT-6 :Redesignation of Y1BT-6. Consolidated BT-7

;BT-7 :PT-12 aircraft redesignated. ;XN4Y-1 :Evaluation aircraft for the United States Coast Guard, three built. ;N4Y-1 :One YPT-11B for the USCG, later modified to the same standard as the XN4Y-1

Operators

; *

Colombian Air Force The Colombian Aerospace Force (FAC, ) is the air force of the Republic of Colombia. The Colombian Aerospace Force is one of the three institutions of the Military Forces of Colombia charged, according to the 1991 Constitution, with working to exe ...

(PT-11C). ; *

Paraguayan Air Arm The Armed Forces of Paraguay () officially the Armed Forces of the Nation () consist of the Paraguayan Army, Paraguayan army, Paraguayan Navy, Paraguayan navy (including naval aviation and marine corps) and Paraguayan Air Force, air force. The c ...

(Model 21-C). ; *

Mexican Air Force The Mexican Air Force (FAM; ) is the air service branch of the Mexican Armed Forces. It is a component of the Mexican Army and as such overseen by the National Defense Secretariat (SEDENA). The objective of the FAM is to defend the integrity, in ...

(Model 21-M).

Specifications (PT-11D)

References