Keystone NK
The Keystone NK or Keystone Pup was a two-seat biplane trainer built by Keystone Aircraft for the United States Navy.The NK was an open-cockpit two-seat biplane with a convertible wheel or float landing gear. It was powered by a 220 hp Wright R-790 Whirlwind. The company prototype designated the Pup was entered into a United States Navy design competition for a trainer and was awarded a contract for three prototypes designated XNK-1. Following evaluation a production batch of 16 was ordered designated NK-1 which were delivered during 1930.Variants
;Pup
;XNK-1
;NK-1Operators
