| BT-9/BT-14/NJ | |
|---|---|
 A U.S. Navy NJ-1 in flight, 1938 | |
| General information | |
| Type | Trainer |
| Manufacturer | North American Aviation |
| Primary users | United States Army Air Corps |
| Number built | +260 |
| History | |
| First flight | April 1936 |
| Developed from | North American NA-16 |
| Developed into | North American BC-1 North American NA-64 Yale |
TheNorth American BT-9 was theUnited States Army Air Corps (USAAC) designation for a low-wing single enginemonoplane primarytrainer aircraft that served before and duringWorld War II.
It was a contemporary of theBoeing-Stearman PT-13 Kaydetbiplane trainer which pilots learned to fly on before advancing to Basic Flying Training on the BT-9. If they passed, they would continue on to theNorth American BC-1 and later the AT-6 and other aircraft types specific for each role. During the war, it was discovered that increasing the number of hours of Primary Flying Training eliminated the need for intermediate trainers like the BT-9 and so production never reached the levels for the PT and AT types.TheNJ-1 was used by theUnited States Navy for a similar role, but was closer to the one off BT-10.
The BT-9, designatedNA-19 by the manufacturer, evolved from theNorth American NA-16, which first flew in April 1935. The BT-9 design first flew in April 1936.[1]
The wing and tail control surfaces were fabric-covered, as well as the sides of the fuselage from just behind the firewall to the tail. The remainder of the aircraft was metal-covered and featured fixed (non-retractable) landing gear. The Army Air Corps purchased a total of 199BT-9s,BT-9As andBT-9Bs. Many foreign countries also used variants of this aircraft under North American'sNA-16 designation.
The first BT-9C s/n 37-383 was built with a 600 hpPratt & Whitney R-1340-41, but was otherwise similar to the normal BT-9Cs. It was delivered as the Y1BT-10, and later redesignated BT-10.
The BT-9D was a one off prototype that tested out a number of ideas that went into production as theBT-14 (NA-58), which the similarNorth American NA-64 Yale represented a major aerodynamic improvement over the NA-16 series, with a longer all-metal fuselage replacing the fabric covered fuselage of the earlier NA-16s. The BT-14 featured aPratt & Whitney R-985 engine versus theWright R-975 used on the BT-9. As well as metal skin replacing the fabric on the fuselage, the fin was moved aft slightly, lengthening the rear fuselage while the engine was moved forward to maintain thecenter of gravity. The rudder was also changed from the rounded shape used previously to one with a roughly triangular shape, with the broadest part being at the bottom, and the canopy was redesigned. The new fuselage would provide the basis for the entireAT-6 family, when fitted with the largerPratt & Whitney R-1340 engine, a new wing with retractable undercarriage and minor changes for a gunners position.
The BT-9 suffered from stall/spin problems and a variety of fixes were tried. The USAAC temporarily settled on using slats on the later versions of the BT-9. However these did not work well, and the BT-14s longer fuselage and swept forward outer wing panels, unlike the straighttrailing edges of the BT-9 helped somewhat.
![[icon]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aWiki_letter_w_cropped.svg) | This sectionneeds expansion. You can help byadding to it.(March 2016) |
TheNA-26, an improved model with retractablelanding gear which became the prototype for AT-6 Texan advanced trainer, was developed from the NA-16 design.
No original aircraft, but several Yales have been painted or partially modified as BT-14s
General characteristics
Performance
Related development
Aircraft of comparable role, configuration, and era
Related lists
