Martin MB-2 (NBS-1)

The 'Glenn Martin Twin' is best identified as the Martin MB-2, redesignated NBS-1 (Night Bomber, Short Range) in Army service. Built by the Glenn L. Martin Company, it was an enlarged, improved development of the 1918 Martin MB-1 and became the first U.S.-designed bomber produced in quantity. The twin-engine biplane first flew on 3 September 1920, powered by two 420 hp Liberty 12A engines, and was crewed by four. It carried up to 2,000 lb of bombs and gained fame in 1921 when Billy Mitchell's bombers used MB-2s to sink the captured German battleship Ostfriesland in trials demonstrating air power against warships.

The supplied hint dimensions and a speed near 100 mph and range near 400-480 miles match the MB-1/MB-2 family; the figures here reflect the MB-2/NBS-1, the dominant production version.