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Grumman FF

The Grumman FF “Fifi” (company designation G-5) was an American biplane fighter aircraft operated by the United States Navy during the 1930s.

It was the first carrier aircraft with retractable landing gear.

It was produced under licence in Canada and known as the Goblin in Canadian service and Delfín in Spanish service.

The FF-1 was Grumman’s first complete 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.

Later the original engine was exchanged for a 750 hp (560 kW) Wright R-1820-F Cyclone and 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 Twin Wasp engine in place of the Cyclone.

The distinctive retractable main landing gear design for the FF-1 had originated with Grover Loening’s employment of Grumman’s future founder, Leroy Grumman, who had hired both Grumman and Jake Swirbul to work in his own aircraft firm in 1928 after the Loening Aeronautical Engineering Company folded in the 1932–33 timeframe, Loening in turn contributed to the Grumman firm’s later successes, with the Grumman-designed, manual crank-operated retractable main gear design used for a number of Loening’s military aircraft designs being used on the FF-1, and later Grumman F2F and F3F follow-on biplane fighter designs; culminating in the Grumman F4F Wildcat also using it, as well as the amphibious single-engined Grumman JF and J2F Duck multi-use biplane military aircraft.



Single prototype, serial number A8878 


27 built, two-seat U.S. Navy carrier-borne fighter


25 of the original FF-1 fighters converted by the Naval Aircraft Factory with dual controls to serve as fighter trainers


One built, second prototype, serial number A8940 


33 built, two-seat U.S. Navy carrier-borne scout 


One aircraft, an SF-1 airframe with the 650 hp (485 kW) Pratt & Whitney R-1535-72 Twin Wasp Junior engine driving a Hamilton Standard propeller 


G-23s built under licence by the Canadian Car & Foundry Company


A single Grumman G-23 supplied to the Imperial Japanese Navy Air Service for evaluation in 1935.

GE.23 Delfin 

Export variant for Spain.





24 ft 6 in (7.47 m)


34 ft 6 in (10.52 m)


11 ft 1 in (3.38 m)

Wing area

310 sq ft (28.8 m2)

Empty weight

3,098 lb (1,405 kg)

Max take-off weight

4,677 lb (2,121 kg)


1 × Wright R-1820-78 Cyclone radial engine,

700 hp (520 kW)


Maximum speed

207 mph (333 km/h, 180 kn) at 4,000 ft (1200 m)


685 mi (1,100 km, 595 nmi)

Service ceiling

22,100 ft (6,735 m)

Rate of climb

1,667 ft/min (8.47 m/s)


2× 0.30 in (7.62 mm) M1919 Browning machine guns


1x 0.30 in and 1x 0.5 in (12.7mm) Browning M2 fixed in fuselage

1x 0.30 in flex in rear cockpit

2× 100 lb (45 kg) M30


116 lb (53 kg) Mk4 bombs under wings.




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