North American T-6 Texan - Development

Development

The Texan originated from the North American NA-16 prototype (first flown on April 1, 1935) which, modified as the NA-26, was submitted as an entry for a USAAC "Basic Combat" aircraft competition in March, 1937. The first model went in to production and 180 were supplied to the USAAC as the BC-1 and 400 to the RAF as the Harvard I. The US Navy received 16 modified aircraft, designated the SNJ-1, and a further 61 as the SNJ-2 with a different engine.

The BC-1 was the production version of the NA-26 prototype, with retractable tailwheel landing gear and the provision for armament, a two-way radio, and the 550 hp (410 kW) R-1340-47 engine as standard equipment. Production versions included the BC-1 (Model NA-36) with only minor modifications (177 built), of which 30 were modified as BC-1I instrument trainers; the BC-1A (NA-55) with airframe revisions (92 built); and a single BC-1B with a modified wing center-section.

Three BC-2 aircraft were built before the shift to the "advanced trainer" designation, AT-6, which was equivalent to the BC-1A. The differences between the AT-6 and the BC-1 were new outer wing panels with a swept forward trailing edge, squared-off wingtips and a triangular rudder, producing the definitive Texan appearance. After a change to the rear of the canopy, the AT-6 was designated the Harvard II for RAF/RCAF orders and 1,173 were supplied by purchase or Lend Lease, mostly operating in Canada as part of the British Commonwealth Air Training Plan.

Next came the AT-6A which was based on the NA-77 design and was powered by the Pratt & Whitney R-1340-49 Wasp radial engine. The USAAF received 1,549 and the US Navy 270 (as the SNJ-3). The AT-6B was built for gunnery training and could mount a .30 in machine gun on the forward fuselage. It used the R-1340-AN-1 engine, which was to become the standard for the remaining T-6 production. Canada's Noorduyn Aviation built an R-1340-AN-1-powered version of the AT-6A, which was supplied to the USAAF as the AT-16 (1,500 aircraft) and the RAF/RCAF as the Harvard IIB (2,485 aircraft), some of which also served with the Fleet Air Arm and Royal Canadian Navy.

In late 1937 Mitsubushi purchased two NA-16s as technology demonstrators and possibly a licence to build more. However, the aircraft developed by Watanabe/Kyushu as the K10W1 (Allied code name Oak) bore no more than a superficial resemblance to the North American design. It featured a full monocoque fuselage as opposed to the steel tube fuselage of the T-6 and NA-16 family of aircraft, as well as being of smaller dimensions overall and had no design details in common with the T-6. It was used in very small numbers by the Imperial Japanese Navy from 1942 onwards. After the war the Japanese Air Self Defense Force operated Texans.

The NA-88 design resulted in 2,970 AT-6C Texans and 2,400 as the SNJ-4. The RAF received 726 of the AT-6C as the Harvard IIA. Modifications to the electrical system produced the AT-6D (3,713 produced) and SNJ-5 (1,357 produced). The AT-6D, redesignated the Harvard III, was supplied to the RAF (351 aircraft) and Fleet Air Arm (564 aircraft). The AT-6G (SNJ-5) involved major advancements including a full-time hydraulic system and a steerable tailwheel and persisted into the 1950s as the USAF advanced trainer.

Subsequently the NA-121 design with a completely clear rearmost section on the canopy, gave rise to 25 AT-6F Texans for the USAAF and 931, as the SNJ-6 for the US Navy. The ultimate version, the Harvard 4, was produced by Canada Car and Foundry during the 1950s, and supplied to the RCAF, USAF and Bundeswehr.

A total of 15,495 T-6s of all variants were built.