North American NA-16

NA-16/BT-9/NJ-1/ Harvard I/NA-57/Sk 14
NA-16-2A/NA-42 "FAH-21" displayed outside at the Honduras Air Museum at Toncontín
Role	Trainer
Manufacturer	North American Aviation
First flight	1 April 1935
Status	retired
Primary users	United States Army Air Corps Royal Australian Air Force Swedish Air Force French Air Force
Produced	1935 to 1939
Number built	1,935
Variants	North American BT-9 CAC Wirraway
Developed into	North American T-6 Texan North American P-64

The North American Aviation NA-16 was the first trainer aircraft built by North American Aviation, and was the beginning of a line of closely related North American trainer aircraft that would eventually number more than 17,000 examples.

The NA-16 is a family of related single-engine, low-wing monoplanes with tandem seating.

Variants could have an open cockpit (the prototype and the NA-22) or be under a glass greenhouse that covered both cockpits. On some variants, the rear of the canopy could be opened for a gunner to fire to the rear. A variety of air-cooled radial engines, including the Wright Whirlwind, Pratt & Whitney Wasp and Pratt & Whitney Wasp Junior of varying horsepowers, could be installed depending on customer preferences. The fuselage was built up from steel tubes and normally fabric covered; however, later versions were provided with aluminium monocoque structures.

During the development of the design, a six inch stretch was made by moving the rudder post aft. Many versions had a fixed landing gear, but later versions could have retractable gear, mounted in a widened wing center section (which could have either integral fuel tanks or not). Most had a straight trailing edge on the outer wing while again, some had the wing trailing edge swept forward slightly in an attempt to fix a problem with stalls and spins. Several different rudders were used, with early examples having a round outline, intermediate examples having a square bottom on the rudder (Harvard I) and late examples using the triangular rudder of the AT-6 series, due to a loss of control at high angles of attack with the early types. Horizontal and vertical tails were initially covered in corrugated aluminum, but later examples were smooth-skinned, and the horizontal stabilizer was increased in chord near its tips on later versions.

The NA-16 flew for the first time on 1 April 1935, and was submitted to the United States Army Air Corps for evaluation as a basic trainer. The Army accepted the trainer for production but with some detail changes. The modified NA-16 was redesignated by North American as the NA-18, with production examples entering Air Corps service as the North American BT-9 (NA-19). Similar aircraft continued to be sold outside the U.S. under the NA-16 designation.

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Wikipedia