FF-1 (G-5) "FiFi"Grumman G 5 airplane model. First flown in 1931, the Grumman FF 1 (affectionately known as "Fifi )" was noteworthy for its innovative design characteristics that marked a great step forward in aircraft design first fighter with retractable landing gear, an enclosed canopy for both cockpits, and, an all metal, stressed skin fuselage. The "Fifi" was of rugged design typical of all future Grumman aircraft. The single significant drawback to the FF 1 was