Begun in 1949, the J71 was the first turbojet wholly developed by Allison, drawing on the company's technology base from its uprating of the J33 and J35 turbojets, and development of the T38 and T40 turboprops.

The J71 was used during the 1950s in the initial version of Northrop's S-62 intercontinental missile, early versions of Martin's XP6M-1 flying boat, McDonnell F3H-2N fighter, and Douglas B-66 bomber. However, it could not penetrate the high-performance combat aircraft marketplace dominated by the more technically advanced GE J79 and P&W J57 turbojets, which were lighter and had better fuel economy. With phase out of the F3H program, failure to attract further aircraft, and no new orders in sight, Allison dropped the program in the late 1950s after producing 1,707 engines.

This flight-test engine was one of four that powered the prototype Martin XP6M-1 Seamaster, was similar to the J71-A-2, but had a single air intake and short afterburner for takeoff.

 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 1955 Country of Origin United States of America Type PROPULSION Manufacturer Allison Division, General Motors Corporation
 Physical Description Type: Turbojet Thrust: 57,824 N (13,000 lb) at 6,100 rpm Compressor: 16-stage axial Combustor: Single annular Turbine: 3-stage axial Weight: 2,030 kg (4,476 lb) Dimensions Length 512 cm (201.5 in.), Diameter 100 cm (39.5 in.)
 Inventory Number A19600222000 Credit Line Transferred from the U.S. Navy, Bureau of Ships, Property Disposal Division. Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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