The Wasp Jr. R-985 was the third engine type designed by Pratt & Whitney Aircraft, following the Wasp R-1340 and Hornet R-1690, all of which were nine-cylinder engines. Virtually a Wasp of reduced dimensions, the Wasp Jr. followed closely the details of construction throughout. The Wasp Jr., originally rated at 224 kW (300 hp), was first type certificated in January 1930. Designed for light transports, trainers, sport aircraft, and helicopters, number of R-985 models were made, most at 298 kW (400 hp) or more power. The R-985 powered a wide variety and large number of military and commercial aircraft, making it one of the most successful reciprocating engines ever built in its power class.
The Jacobs Aircraft Engine Company of Pottstown, Pennsylvania built this Pratt & Whitney-designed R-985-AN5. Jacobs converted it for vertical helicopter installation. It powered the Sikorsky XH-5, YH-5A/D/E, H-5A/D/F/G and Kellett YH-10 helicopters.
Display Status
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date
Circa 1940
Country of Origin
United States of America
Type
PROPULSION-Reciprocating & Rotary
Manufacturer
Jacobs Aircraft Engine Company (Pottstown, Pennsylvania)
Designer
Pratt & Whitney
Physical Description
Type: Reciprocating, 9 cylinders, radial, air cooled
Power rating: 336 kW (450 hp) at 2,300 rpm
Displacement: 16.1 L (985 cu in.)
Bore and Stroke: 132 mm (5.2 in.) x 132 mm (5.2 in.)
Weight: 310.3 kg (684 lb)
Dimensions
Other: 46 1/4 x 48 x 53 x 54 x 49 3/4in. (117.5 x 121.9 x 134.6 x 137.2 x 126.4cm)
Approximate (Weight on Stand): 430kg (948lb.)
Diameter 117.5 cm (46.25 in.), Length 121.9 cm (48 in.)
Materials
HAZMAT: Cadmium Plating
Steel, Aluminum, Paint, Preservative coating, Leather, Rubber, Copper
Inventory Number
A19600112000
Credit Line
Transferred from the U.S. Air Force Central Museum
Data Source
National Air and Space Museum
Restrictions & Rights
Open Access (CCO)
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