Airplanes - Types - Building aeroplanes for the government. Front view, Martin twin-motored 800 H.P. Bomber, showing power plant installation and interplane wing structure. Plant of The Glenn L. Martin Co., Cleveland, Ohio. Duplicate of the bomber which on Jan. 17th, 1919, flew from McCook Field, Dayton, Ohio - 215 - in 1 hour and 15 minutes averaging 172 miles an hour. From The Glenn L. Martin Co