Designed specifically for mapping and aerial survey, the Abrams Explorer featured a twin-boom tail and pusher engine configuration for excellent stability and visibility. Its supercharged engine allowed high altitude flight, while ports on the floor accomodated heavy vertical cameras. Also called the Stratoplane, the Explorer was used extensively for five years before being retired. Only one example was built.
Engine: Wright Whirlwind R-975, 450 hp (Smithsonian caption)