The big XB-15 was designed as a long-range bomber, originally named XBLR-1. This was a bold attempt, both in its size and in its design. But the XB-15 was underpowered, too slow and too vulnerable, partly because the desired engines were unavailable. One built. It was later converted to the XC-105 transport.

Type: XB-15
Year: 1937
Crew: 10
Engines: 4 *746kW P&W R-1830-11
Wing Span: 45.42m
Length: 26.7m
Height: 5.51m
Wing Area: 258.26m2
Empty Weight: 17105kg
Max.Weight: 41713kg
Speed: 314km/h Ceiling: 5760m