Powerplant: 1 × Wright R-975 Whirlwind air cooled radial, 400 hp (300 kW)
Propellers: 2-bladed Hamilton Standard
Maximum speed: 170 mph (270 km/h, 150 kn)
Range: 700 mi (1,100 km, 610 nmi)
One for United States Army Air Corps (USAAC) (trials) developed into NA-18 and BT-9 series, powered by Wright R-975 Whirlwind
When the North American NA-16 was first conceived, five different roles were intended for the design, designated NA-16-1 thru NA-16-5:
General purpose two-seat aircraft – which became the Harvard I
Two-seat fighter – produced under license in Australia as the CAC Wirraway.
Two-seat light attack bomber.
The first aircraft in this category was the retractable gear NA-26 which evolved into the NA-36 (BC-1).
The fabric-covered fuselage was replaced by an all-metal monocoque to create the NA-44, which provided the basis for a line of light attack bombers whose improvements would result in the AT-6.
Advanced trainer – became the BT-9 for the USAAC and which provided the bulk of early production.
The improvement of the BT-9 with a longer metal skinned fuselage as on the NA-44 would create the NA-64 (Yale) and improved wings would result in the BT-14.
Single-seat fighter – although this designation was never used, it became the NA-50 for Peru, and later the NA-68, which saw limited USAAF service as the P-64.
42 built for USAAC – Minor changes from NA-18, new canopy, powered by Wright R-975 Whirlwind
40 built for USAAC – Armed BT-9 with one cowl gun, one rear flexible gun and modified canopy, powered by Wright R-975 Whirlwind
One built for trials, sold to Honduras (FAH) powered by Wright R-975 Whirlwind
One built for USAAC trials but rejected as severely underpowered.
Open cockpits as per early NA-16 and Townend ring on engine, powered by Wright R-760 Whirlwind
117 built for USAAC – Unarmed with fixed rear on canopy, powered by Wright R-975 Whirlwind
One modified BT-9B for USAAC – BT-14 prototype with new outer wings, Harvard type canopy, lengthened fabric covered fuselage, triangular rudder and detail alterations, powered by Pratt & Whitney R-985 Wasp Junior
NA-16-3 Basic Combat demonstrator (NA-26)
One armed demonstrator and the first variant with retractable undercarriage, eventually sold to RCAF who modified it with Yale and Harvard parts, powered by Pratt & Whitney R-1340 Wasp
One armed demonstrator sold to Royal Netherlands Air Force – not the same as the previous NA-16-2H, powered by Pratt & Whitney R-1340 Wasp
40 built to US Navy specifications, up engined BT-9B as advanced trainer with fixed gear, powered by Pratt & Whitney R-1340 Wasp
66 built for USAAC – BT-9A with minor changes, powered by Wright R-975 Whirlwind
One built for USAAC – BT-9 with larger engine, similar to USN NJ-1 but armed and detail differences in engine installation, powered by Pratt & Whitney R-1340 Wasp
Cancelled production version of Y1BT-10 for USAAC, powered by Pratt & Whitney R-1340 Wasp
138 built for Sweden’s Flygvapnet as Sk 14/Sk 14A. Sk 14N trialled nosewheel for SAAB 21, powered by Wright R-975 Whirlwind (Sk 14) or Piaggio P VII C (Sk 14A)
One built for Royal Australian Air Force but rejected in favour of NA-16-2K, fixed landing gear, similar to Y1BT-10, powered by Pratt & Whitney R-1340 Wasp
756 for Royal Australian Air Force in Australia with local improvements as CAC Wirraway, powered by Pratt & Whitney R-1340 Wasp
29 built for Argentina (Army Aviation) – 1st major export order (previous orders involved licensed production), powered by Wright R-975 Whirlwind
One built for Imperial Japanese Navy as a technology demonstrator KXA-1 with fixed u/c and three-blade prop., powered by Pratt & Whitney R-985 Wasp Junior
35 built for China (RoCAF) – Fixed gear, fabric covered fuselage, powered by Wright R-975 Whirlwind
Two built for Honduras (FAH), powered by Pratt & Whitney R-1340 Wasp
Intended for Brazil (Army) but order cancelled. Was to have been similar to BT-9C, powered by Wright R-975 Whirlwind
Armed company demonstrator sold to Canada. Designation reused for AT-6s sold to Brazil (NA-72) and Chile (NA-74), powered by Wright R-1820 Cyclone.
Three built for Venezuela (FAV) similar to USAAC NA-36 BC-1 but with round rudder and bomb racks under wing center section., powered by Pratt & Whitney R-1340 Wasp
12 built for Brazilian Navy, powered by Wright R-975 Whirlwind
One built for Imperial Japanese Navy as a technology demonstrator KXA-2 similar to NA-16-4R but smaller engine, powered by Wright R-975 Whirlwind
15 built for China (RoCAF) – Retractable undercarriage, fabric covered fuselage, powered by Pratt & Whitney R-1340 Wasp
430 for Royal Air Force and Royal Canadian Air Force as the Harvard I with new canopy and square rudder.
Also used by South Africa and Southern Rhodesia, powered by Pratt & Whitney R-1340 Wasp
50 built for China (RoCAF) – Entirely new design with longer metal fuselage, triangular rudder and later T-6 style wing.
Basically a BT-14 with the AT-6s R-1340 engine and canopy, powered by Pratt & Whitney R-1340 Wasp
230 improved NA-23s for France as NAA 57-P-2, most captured and used by Germany, some retained by Vichy France, powered by Wright R-975 Whirlwind
Three built for Venezuela (FAV), powered by Pratt & Whitney R-1340 Wasp
I.Ae. D.L. 21
An Argentinian version incorporating the NA-16-1 fuselage with locally designed wings.
Rejected in favour of the I.Ae. 22 DL, an original design from the Fabrica Militar de Aviones (FMA).