Junkers JU-52 with Three nine-cylinder Pratt & Whitney radial engines, PW 1340 S1 H1G Wasp, 550 hp (410 kW), 600 (447 kW).
The Pratt & Whitney R-1340 Wasp was a reciprocating engine widely used in American aircraft from the 1920s onward. It was the company's first engine, and the first of the famed Wasp family. It was a single-row, nine-cylinder air-cooled radial design, and displaced 1,344 in³ (22 L); bore and stroke were both 5.75 in (146.05 mm). A total of 34,966 engines were produced.