Grumman FF-1

The Grumman FF, nicknamed Fifi and carrying the company designation G-5, was an American two-seat biplane fighter flown by the United States Navy in the 1930s and the first carrier aircraft with retractable landing gear. It was Grumman's first complete aircraft design for the Navy, which had asked whether Grumman's retractable gear could be fitted to its Boeing fighters but received a new fighter design instead. The prototype XFF-1 first flew on 29 December 1931. Canadian Car and Foundry built the improved G-23 under license as the Goblin, and the type also served in Spain as the Delfin.