Grumman JF Duck

JF Duck
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Grumman JF-2 Duck in United States Coast Guard service.
Role	Utility amphibian
Manufacturer	Grumman
First flight	24 April 1933
Introduction	1935
Primary users	United States Navy United States Coast Guard United States Marine Corps
Number built	48
Developed into	Grumman J2F Duck

The Grumman JF "Duck" was a single-engine amphibious biplane, built by Grumman for the United States Navy during the 1930s.

Design and development

The Grumman JF Duck was manufactured from 1934 until 1936, when production switched to the J2F Duck and later variants. The more obvious external appearance clue to distinguish a JF from an early J2F is the deletion of the inter-aileron strut between the wings on the J2F; less noticeable perhaps is the J2F's slightly longer rear fuselage/float joining fillet beneath the tail.

The Duck's main pontoon was part of the fuselage, almost making it a flying boat, though it appears more like a standard aircraft with an added float. This general configuration was shared with the earlier Loening OL. The XJF-1 prototype first flew on 24 April 1933 piloted by Grumman test pilot Paul Hovgard.

Operational history

The JF-1 that was first ordered, had the same Pratt & Whitney R-1830-62 engine as the XJF-1 prototype. The US Navy ordered 27 JF-1s with the first Ducks delivered beginning in May 1934 to Norfolk NAS. These early production series had provisions for mounting a machine gun at the rear seat facing aft, a single bomb rack mounted under each wing, capable of carrying a 100 lb (45.4 kg) bomb or depth charge on each. The main float was also a Grumman design (Grumman Model "A") and like the prototype, it included retractable main landing gear, making the Duck a true amphibian. Ducks served as general/utility amphibians for photographic, target-towing, scouting and rescue work.

Variants

XJF-1

Prototype with 700 hp Pratt & Whitney R-1535-62 engine, one built (BuNo 9218).

File:Grumman JF-1 Duck at NACA Langley Summer 1934.jpg

Grumman JF-1 Duck at Langley

JF-1

Production variant with 700 hp Pratt & Whitney R-1830-62 Twin Wasp engine, 27 built (BuNos 9434-9455, 9523-9527).

JF-2

Variant for the United States Coast Guard powered by a 750 hp Wright R-1820-102 Cyclone engine, 15 built (BuNo 0266, 00371-00372, 01647, USCG V141-V155).

JF-3

JF-2 for the U.S. Navy, five built (BuNos 9835-9839).

JF-4

JF-5

JF-6

Grumman G-20

Armed version of the Grumman JF-2 for export to Argentina. Eight built.

Operators

United States

• United States Navy
• United States Coast Guard
• United States Marine Corps - Operated one JF-2

Argentina

• Argentine Navy - Operated eight G-20s.

Specifications (JF)

Data from

General characteristics

• Crew: 3
• Capacity: 851 lb (386 kg) payload
• Length: 32 ft 7 in (9.93 m)
  

JF-1 & JF-3: 33 ft (10 m)

• Wingspan: 39 ft 0 in (11.89 m)
• Height: 15 ft 1 in (4.60 m)
• Powerplant: 1 × Pratt & Whitney R-1830 Twin Wasp 14-cyl two row air-cooled radial piston engine, 700 hp (520 kW)
  

JF-1: 1 x 700 hp (522 kW) Pratt & Whitney R-1830-62

JF-2: 1 x 720 hp (537 kW) Pratt & Whitney R-1830-102

JF-3: 1 x 750 hp (559 kW) Pratt & Whitney R-1830-80

Performance

See also

Related development

• Grumman J2F Duck

Aircraft of comparable role, configuration and era

• Loening OL
• Loening C-2

References

Notes

Bibliography

• Allen, Francis J. "A Duck Without Feathers". Air Enthusiast, Issue 23, December 1983—March 1984, pp. 46–55, 77—78. Bromley, Kent UK: Pilot Press, 1983.
• Thruelsen, Richard. The Grumman Story. New York: Praeger Publishers, Inc., 1976. ISBN 0-275-54260-2.
• Treadwell, Terry. Ironworks: Grumman's Fighting Aeroplanes. Shrewsbury, UK: Airlife Publishers, 1990. ISBN 1-85310-070-6.

External links

• The Grumman J2F Duck