The Abrams Explorer is a unique aircraft specifically designed for aerial survey and mapping functions. Built in 1937, the aircraft was designed by Kenneth Ronan, former chief designer for Stinson, and Edward Kunzl, also of Stinson. Dr. Talbert Abrams, founder and CEO of the then newly-formed Abrams Air Craft Corporation and the established Abrams Aerial Survey Corporation of Lansing, Michigan, envisioned the aircraft as an obstruction-free camera platform for survey and mapping businesses, a design in which the U.S. Army showed interest. The initial requirement was to provide the capability for aerial photography, aerial survey, and mapping from near sea level up to an operating altitude of 20,000 feet. It was to provide an unobstructed field of view for the several cameras which meant displacing the usual struts, wing panels, engine cowls, and propeller arc away from the cameraman's normal line of sight. The aircraft was to have an endurance of at least eight hours, climb quickly to altitude, and cruise at a speed of 180 to 200 knots.
The resulting configuration was a specially designed two-place non-conventional mid-wing pusher monoplane which had twin booms extending back from the wing trailing edge to support the tail assembly. The-two place crew nacelle was located entirely forward of the wing leading edge and included clear safety glass windows over most of area above the cockpit floor. This is similar to the bombardier's nose section of a World War II medium bomber. The placement of the crew nacelle permitted an almost unobstructed view for photography except for a direct rear view past the engine, propeller and tail structure. The nacelle was pressurized and carried oxygen for crew comfort and operating efficiency at the 20,000 foot operating altitude. The nacelle was faired back over the wing center section to the engine compartment where the Wright R975-E.1 330 hp radial engine, equipped with a NACA cowl and Hamilton Standard controllable pitch propeller, were mounted just aft of the wing's trailing edge. The engine assembly was located between the two fuselage booms that extended back to support the horizontal tail with two vertical tail assemblies.
Hermetically-sealed camera ports were provided to permit unobstructed camera operation at those higher operating altitudes while still maintaining proper cabin pressure. The airplane has a fixed tricycle landing gear with low drag streamlined wheel fairings. The structure is of welded steel tubing and the combined crew nacelle and wing center section are covered with sheet aluminum panels. The twin tail booms are of semi-monocoque sheet aluminum construction and the tail assembly and outer wing panels are covered with fabric. The structure is stressed to handle engines of up to 1,000 hp for possible future production models.
The first flight was made in November 1937 and the Abrams company flew the airplane, with a full array of cameras, for government contract survey work until the beginning of World War II. The first Wright engine was replaced by a Wright Whirlwind 450 hp engine that raised the maximum speed to more than 200 mph and the performance ceiling to 25,000 feet. It had a rate of climb of 1,500 feet per minute. Unfortunately, Dr. Abrams' plans to produce and sell the airplane to the armed forces and to civilian aerial mapping companies were not successful. His timing was bad for the civilian applications because of the war and the military opted for the more survivable, converted high-speed fighter aircraft for photo reconnaissance. The good performance figures of 1938 were not enough for wartime reconnaissance and a single-purpose aircraft was no longer desirable. As a result, the airplane currently in the possession of the Smithsonian was the only example built.
Dr. Abrams lent the Explorer to the National Air Museum in 1948 and, although it was accessioned at that time, the "official" donation was not until 1973. It was acquired as one of the few aircraft designed and used specifically for aerial photography, and it was one of the first U.S. aircraft to employ a tricycle landing gear and the twin boom pusher concept. The aircraft was received with the Wright R-975-E3 450 hp engine and a plastic-covered cabin nacelle. It was transported by military air to Washington and was stored for several years at the Paul E. Garber Restoration and Preservation Facility in Suitland, Maryland. In 1975, the Museum lent the Explorer to the Michigan Aerospace Education Association in Lansing, Michigan, for restoration by students at the Lansing Community College, but, unfortunately, the restoration was not fully completed. In 1981 the airplane was returned to the Garber Facility where it awaits further restoration.
<< Back to article
