The Wright R-975 Whirlwind was a series of nine-cylinder air-cooled radial aircraft engines built by the Wright Aeronautical division of Curtiss-Wright. These engines had a displacement of about 975 cu in (15.98 L) and power ratings of 300–450 hp (220–340 kW). They were the largest members of the Wright Whirlwind engine family to be produced commercially, and they were also the most numerous.
A Grant tank R-975 engine being removed by Royal Army Ordnance Corps mechanics
The Lockheed Model 10 Electra is an American twin-engined, all-metal monoplane airliner developed by the Lockheed Aircraft Corporation, which was produced primarily in the 1930s to compete with the Boeing 247 and Douglas DC-2. The type gained considerable fame as one was flown by Amelia Earhart and Fred Noonan on their ill-fated around-the-world expedition in 1937.
Clarence "Kelly" Johnson is testing an Electra model with single vertical tail and forward-sloping windshield in the University of Michigan's wind tunnel.
Lockheed 10B of Marshall Airways (Australia) in 1970, had been initially delivered to Ansett Airways in 1937
Flight deck of a Model 10A, which has been updated with a more modern instrument panel