Curtiss XB-2 Condor

The Curtiss XB-2 Condor was a large twin-engine biplane bomber prototype developed for the U.S. Army Air Corps in the late 1920s. A single XB-2 was ordered in 1926 and first flew in 1927, evolving from Curtiss's earlier B-1 design but using a welded steel-tube fuselage, the thicker Curtiss C-72 airfoil, and a pair of 600-plus-horsepower Curtiss Conqueror liquid-cooled V-12 engines. A distinctive feature was the placement of a gunner's station in the rear of each engine nacelle.

In competitive trials the XB-2 outperformed the rival Keystone XB-1, but its higher cost limited procurement: the Army ordered only twelve production B-2 Condors. Capable of carrying a bomb load of around 2,500 pounds, the Condor represented the peak of American biplane bomber design before all-metal monoplanes such as the Martin B-10 rendered the configuration obsolete in the early 1930s.