The XP-15 was built by Boeing as a single-wing version of the P-12 and given the company designation Model 202. The aircraft was tested by the Army Air Corps but never actually purchased and carried only the civil registration X-270V. Although the XP-15 never entered production, Boeing used the all-metal fuselage design and improved tail assembly on the P-12E production aircraft. The only XP-15 built was destroyed in a crash on 7 February 1931.

SPECIFICATIONS
Length: 21 ft. 0 in.
Span: 30 ft. 6 in.
Height: 9 ft. 0 in.
Engine: Pratt & Whitney R-1340-D radial of 450 hp.
Maximum speed: 185 mph (with Townend ring cowl installed)
Service ceiling: 26,550 ft.
Maximum weight: 2,790 lbs