The Glen L. martin Company designed its World War 2-era "Model 177" to compete against a standing USAAC / USAAF contract seeking a new, all-modern attack platform. This configuration generally involved a twin-engine arrangement, fixed forward-firing armament, flexible armament, and a useful bombload. The service went on to entertain all manner of designs attempting to fit the description and, in the end, settled on a few classic examples such as the Douglas A-26 "Invader" detailed elsewhere on this it.
The three-man Model 177 certainly looked the part, carrying a most conventional design arrangement centered on the expected twin-engine layout. The air-cooled radial engines were held in nacelles integrated into each wing mainplane member, the nacelles extended beyond the wing's leading edge and terminating at the trailing edge. Each engine was to turn a three-bladed propeller unit. The mainplanes themselves were low-mounted along the fuselage sides and tapered at both leading and trailing edges while being rounded out at the tips.
The fuselage was slab-sided with rounded edges and the forward section was heavily glazed in a "greenhouse" style framing, incorporating the flight deck into its shape (as opposed to stepped). The fuselage extended aft in the usual fashion and tapered quickly at the extreme end point. The tail was positioned just ahead of the fuselage's termination point and involved a twin rudder fin configuration, these fins being rounded in their general shape and held outboard along individual horizontal planes.
Dimensions included a running length of 46.6 feet and a wingspan measuring 61.3 feet.
For ground-running, the aircraft would travel through a tail-dragger undercarriage arrangement featuring a pair of single-wheeled main legs and a diminutive tail wheel under the rear. The main legs were positioned under each nacelle and recessed into their respective housings.
In terms of armament, the aircraft was to feature both fixed and flexible mountings: a total of four fixed, forward-firing machine guns would be installed at the trailing edge of each wing member (outboard of the engine nacelles and clear of each propeller arc), two guns to a wing (either 0.30 or 0.50 in caliber). Over the dorsal line of the fuselage would be a retractable turret emplacement featuring 1 x 0.30 caliber machine gun. At the tail position was planned 1 x 0.50 caliber heavy machine gun.
To cover the bombing requisite, the Model 177 was drawn up with a war load capability up to 1,200lb; this could be a single 1,100lb weapon, 2 x 600lb bombs, or 4 x 300lb types.
The Model 177 project aircraft was proposed in April of 1939, months before the official start of World War 2 (1939-1945) and years ahead of America's formal involvement in the long-running, and bloody, conflict.
The Martin Model 177 submission was not selected for further development, joining many other proposals to cover the USAAC requirement before the war. The Model 177A was an offshoot of this same design though penciled out with much smaller dimensions so as to become more compact and was to be powered by liquid-cooled inline piston engines. This design, too, went nowhere for the company.
Performance specifications on this page are estimates on the part of the author.