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Grumman J2F Duck / OA-12 / JF / G-15



J2F Duck
The J2F was an equal-span single-bay biplane with a large monocoque central float which also housed the retractable main landing gear, a similar design to the Leroy Grumman-designed landing gear first used for Grover Loening's early amphibious biplane designs, and later adopted for the Grumman FF fighter biplane. The aircraft had strut-mounted stabilizer floats beneath each lower wing. A crew of two or three were carried in tandem cockpits, forward for the pilot and rear for an observer with room for a radio operator if required. It had a cabin in the fuselage for two passengers or a stretcher.
The Duck's main pontoon was blended into the fuselage, making it almost a flying boat despite its similarity to a conventional landplane which has been float-equipped. This configuration was shared with the earlier Loening OL, Grumman having acquired the rights to Loening's hull, float, and undercarriage designs. Like the F4F Wildcat, its narrow-tracked landing gear was hand-cranked.
Production of this general utility amphibian began in 1933 when the first prototype flew, and production continued until 1945. In all, nine series of the Duck were built.
The J2F-1 Duck first flew on 2 April 1936, powered by a 750 hp (559 kW) Wright R-1820 Cyclone, and was delivered to the U.S. Navy on the same day. The J2F-2 had an uprated Wright Cyclone engine of 790 hp (589 kW). Twenty J2F-3 variants were built in 1939 for use by the Navy as executive transports with plush interiors. Due to pressure of work following the United States entry into the war in 1941, production of the J2F Duck was transferred to the Columbia Aircraft Corp of New York. They produced 330 aircraft for the Navy and U.S. Coast Guard. If standard Navy nomenclature practice had been followed, these would have been designated JL-1s, but it was not, and all Columbia-produced airframes were delivered as J2F-6s.
The first appeared for the Navy in 1933 as the JF-1, powered by a 521.6kW Pratt & Whitney R-1830 Twin Wasp engine. This was followed by the JF-2 Coast Guard version, powered by a 559kW Wright Cyclone radial, and the JF-3.
The amphibian was originally used for photography, target-towing, scouting, and rescue work. Although the Duck is normally flown as a two-seater in tandem fashion, a folding floor in the rear cockpit gives access to a lower compartment for use in rescue work and the like; the lower compartment could house either two extra crew members or a stretcher.
A number of JF-2s were also delivered to Argentina.
By the beginning of 1941 about 115 JF and J2F-1 (company designation G-15) to J2F-4 Ducks were in service as general/utility amphibians for photographic, target-towing, scouting and rescue work. The J2F was an improved version of the earlier JF Duck, with its main difference being a longer float.
These were followed by J2F-5s and J2F-6s. The J2F6 was by far the most common. It featured aerodynamic improvements over the previous models, including a long-cord engine cowling.
The J2F-6 was produced in 1944 by the Columbia Aircraft Corporation of Valley Stream, Long Island, under licence from Grumman, bringing the total number of JF/J2Fs built to over 600.
J2Fs of the utility squadron of US Patrol Wing 10 were destroyed at Mariveles Bay, Philippines, by a Japanese air raid on 5 January 1942. The only Duck to survive the attack had a dead engine but had been concealed at Cabcaben airfield during the Battle of Bataan, to be repaired afterwards with a cylinder removed from a destroyed J2F-4 submerged in Manila Bay. Following repairs the J2F-4 departed after midnight on 9 April 1942, overloaded with five passengers and the pilot, becoming the last aircraft to depart Bataan before the surrender of the Bataan to the Japanese only hours later. Among its passengers was Carlos P. Romulo (diplomat, politician, soldier, journalist, and author), who recounted the flight in his 1942 best-selling book I Saw the Fall of the Philippines (Doubleday, Doran & Company, Inc., Garden City, New York 1943, pp. 288–303), for which he received the Pulitzer Prize for Correspondence.
Several surplus Navy Ducks were converted for use by the United States Air Force in the air-sea rescue role as the OA-12 in 1948.
The Argentine Naval Aviation received four new-build Grumman G-15s (equivalent to J2F-4s) in 1939, to supplement the eight Grumman G-20s (export version of the Grumman JF-2) received in 1937. In 1946–1947, 32 ex-US Navy Ducks (consisting of one J2F-4, 24 J2F-5s, and 7 J2F-6s) were acquired, with the last examples remaining in use until 1958.
The Colombian Navy operated three examples from 1948.
The Mexican Navy operated three ex-U.S. Navy J2F-6s from 1950–1951.
The Peruvian Navy operated one ex-USN example from 1961–1964.
In the United States the United States Army Air Forces, United States Coast Guard, United States Marine Corps, and United States Navy all operated the J2F.
A Grumman J2F-6 Duck was owned and operated by Kermit Weeks at Fantasy of Flight in Polk City, Florida.
The United States Coast Guard worked with North South Polar, Inc. to recover a J2F-4 Duck, serial number V-1640, downed in a storm on a Greenland glacier on 29 November 1942. Two Coast Guard airmen were lost along with a rescued U.S. Army Air Forces passenger from a downed B-17 searching for a downed C-53 with five on board. The three men of the Duck are presumed to still be entombed at the site. North South Polar, under the auspices of the Coast Guard team, located the aircraft in August 2012 resting 38 feet beneath the surface of the ice sheet.
Initial production version with 750 hp R-1820-20 engines, 29 built.
United States Marine Corps version with nose and dorsal guns and underwing bomb racks, 21 built.
As J2F-2 with minor changes for use in the United States Virgin Islands, nine built.
J2F-2 but powered by an 850 hp R-1820-26 engine, 20 built.
J2F-2 but powered by an 850 hp R-1820-30 engine and fitted with target towing equipment, 32 built.
J2F-2 but powered by a 1,050 hp R-1820-54 engine, 144 built.
Engine: 1 × Wright R-1820-54 nine-cylinder radial engine, 900 hp (670 kW)
Wingspan: 39 ft 0 in (11.9 m)
Wing area: 409 ft² (38 m²)
Length: 34 ft 0 in (10.37 m)
Height: 13 ft 11 in (4.25 m)
Empty weight: 5,480 lb (2,485 kg)
Loaded weight: 7,700 lb (3,496 kg)
Maximum speed: 190 mph (304 km/h)
Cruise speed: 155 mph (248 km/h)
Stall speed: 70 mph (112 km/h)
Range: 780 mi (1,255 km)
Service ceiling: 20,000 ft (6,100 m)
Rate of climb: ft/min (m/s)
Crew: two (pilot and observer)
Capacity: two rescued airmen
Armament: 1 × Browning .30 cal machine gun (7.62 mm) on flexible mount in rear cockpit
Bombload: 650 lb (295 kg)
Columbia Aircraft built version of the J2F-5 with a 1,050 hp R-1820-64 engine in a long-chord cowling, fitted with underwing bomb racks and provision for target towing gear; 330 built.
Air-sea rescue conversion for the United States Army Air Forces (and later United States Air Force, OA-12A).





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