Grumman FF - Design and Development

Design and Development

The FF-1 was Grumman’s first aircraft design for the US Navy. The Navy had asked Grumman if their retractable landing gear made for the O2U-1 Scout planes could be retrofitted to the Navy's Boeing F4B-1 fighters; instead Grumman proposed a new fighter design. The prototype XFF-1 (serial number A8878) was built to a contract placed on 22 April 1931, first flying on 29 December of that year. A two-seat design, with an enclosed cockpit, fuselage of all-metal construction, and wings covered largely with fabric. The XFF-1 was powered initially by a 616 hp (459 kW) Wright R-1820-E Cyclone radial engine, it achieved 195 mph (314 km/h) during service trials, and when the original engine was exchanged for a 750 hp (560 kW) Wright R-1820-F Cyclone the XFF-1 reached a top speed of 201 mph (323 km/h), faster than any US Navy fighter in service at the time.

A production order was placed for 27 two-seat FF-1 (G-5) on 19 December 1932. Meanwhile Grumman had completed a second prototype (serial number A8940) to a two-seat scout configuration as the XSF-1 (G-6). Subsequently 33 production SF-1s were ordered based on the two-seat configuration. They differed from the FF-1 principally in having revised internal equipment and in being powered by R-1820-84 Cyclones instead of the R-1820-78 model installed in the fighter version. One XSF-2 was also completed, this having a Pratt & Whitney R-1830 Wasp engine in place of the Cyclone.