Ryan
re-entered aircraft manufacturing in 1933 with braced low-wing
monoplane tandem open-cockpit trainer powered by a Menasco inline
engine...the S-T (Sport-Trainer). The U.S. Army
purchased this aircraft for the primary training role as the PT-16
in 1939. A few structural changes resulted in the PT-20.
In 1941, Ryan developed the ST-3KR by
changing the engine to a Kinner radial. The U.S. Army
purchased this trainer as the PT-21.
A more powerful Kinner radial and the deletion of
the landing gear fairings resulted in the most common version (over
1,000 built), the PT-22 Recruit. The Navy purchased
this aircraft as the NR-1.
