Flight, January 1938

Abrams Explorer Survey Pusher

   Flown for the first time late in November, the Abrams Explorer survey machine was designed to give exceptional forward and downward vision, rapid climb to high altitudes, stability and endurance. It was decided, after due deliberation, to make the machine a pusher and to put the pilot in the nose, which is composed almost entirely of transparent panels. The sharp sweep-back of the leading edge increases the field of vision.
   Nacelle construction employs welded steel tubes and stressed aluminium alloy skin, the cantilever wing has a single spar of steel-tube construction, and the tail booms are of duralumin monocoque construction.

A Supercharged Cabin

   Provision is made for supercharging the cabin, though this must be a matter of some considerable difficulty in view of the large area of transparent covering. One door is fitted on each side of the nacelle, special arrangements being made for the photographer to take pictures at an oblique and forward angle without opening one of the outer doors. A hermetically sealed porthole for mapping is built into the floor.
   The prototype machine is fitted with a Wright Whirlwind J-6-9E radial of 330 h.p. driving an adjustable-pitch propeller (not variable in flight), but provision has been made for the installation of units of up to 450 h.p. Subsequent designs will be planned for higher powers.
   Data relating to the Explorer are: Wing area 191 sq. ft., weight empty 2,100 lb., gross weight 3,400 lb., top speed (sea level) 185 m.p.h., landing speed 60 m.p.h., service ceiling 19,000ft., cruising range 1,200 miles.

Flight, October 1938

SURVEY SPECIAL
The Abrams Explorer and its Equipment

   THOUGH aircraft built specially for survey work are no novelty - the Gloster survey machine, for instance, has performed faithful and efficient work since it was produced many years ago - there can never have been such a striking example of specialised design as the Abrams monoplane illustrated here.
   In an effort to keep abreast or ahead of their competitors in the aerial mapping field, the Abrams Aerial Survey Corporation, of Lansing, Mich., designed and built the Explorer, and the outcome was considered so successful that a company, the Abrams Aircraft Corporation, was formed to put the job into production.
   The prototype was described in Flight early this year, but it is now possible to give further details. The engine in the production type is a supercharged 450 h.p. Wright Whirlwind. The pusher arrangement, the sweep-back of the leading edge, and the almost completely transparent nose are all features intended to give maximum ''visibility" forward and downward. Construction is stressed aluminium alloy skin, with monocoque tail booms.
   Designed for high-altitude operation when required - the figure mentioned is 30,000ft., which, of course, would allow survey photography only in exceptional weather - the Explorer carries special oxygen equipment for its crew of two; a pressure cabin was hinted at in the original specifications, but presumably this has been abandoned.
   For use in the machine the company has evolved a camera which is claimed to be a long way ahead of existing types. It is said to carry sufficient film for 600 exposures - a 500ft. roll - and is made entirely of Dow metal, a magnesium alloy; its weight is 67 lb., loaded.
   The Explorer, it seems, has a higher performance than its appearance would suggest. Maximum speed at sea-level is 210 m.p.h., and at 20,000ft. 260 m.p.h. Rate of climb is 2,600ft./ min., service ceiling 36,000ft., range 2,000 miles, and landing speed 58 m.p.h.