Ranger Engineering of Farmingdale, New York was a unit of the Fairchild Engine and Airplane Corporation which entered the aircraft engine business in 1925 with formation of the Fairchild-Caminez engine corporation. Initially a manufacturer of radial engines designed by Harold Caminez, whose earlier career was at the U.S. Army’s McCook Field, Fairchild later became a successful manufacturer of air-cooled in-line aircraft engines.

In 1936, the U.S. Navy contracted for XV-770-4 engines having a take-off rating of 373 kW (500 hp). Low projected frontal area and inverted installation permitted excellent pilot visibility, attractive for scout observation aircraft. Later changes in the -6 model, incorporated to improve structural and vibration deficiencies, allowed installation in the Curtiss SO3C-1 aircraft.

Improvements in the supercharger and structural refinement begun 1n 1942 resulted in the V-770-8, approved for installation in other SO3C and XOSE-1 aircraft.

The V-770-15 was an Air Force engine, and powered the Fairchild AT-14A and AT-21 aircraft.