The Boeing XF5B-1 (Model 205) was the US Navy's version of the experimental parasol wing XP-15 (Model 202), and like the Army version didn't enter production although the Navy did use it for experimental flights for three years.
The Model 202 and Model 205 were produced by Boeing as private ventures, in case their more advanced monoplane designs failed (the contemporary Boeing XP-9 was indeed rejected by the US Army). They used a fuselage similar to that developed for the XP-9, with a metal semi-monocoque rear fuselage, a welded frame covered with access panels at the front and an all metal wing. The upper wing resembled that of the P-12 (other than the metal construction and a 6in increase in span), and was connected to the fuselage by struts.
The XP-15 (Model 202) was designed as a pure fighter, but the Model 205 was designed as a fighter-bomber. It used a Pratt & Whitney SR-1340C engine that produced 480hp at sea level (the Model 202 used an engine that produced less maximum power but at highest altitudes). The Model 205 carried naval equipment including arrestor gear. It could carry one 500lb bomb or five 30lb bombs. The extra equipment increased the weight of the Model 205, and reduced its top speed by 14mph.
The Model 205 first flew in February 1930, one month after the Model 202 (it was actually delivered to the Navy on 9 February, before its first flight). It was tested by the Navy while still Boeing property, and at first the XF5B-1 designation was thus unofficial. The Navy later purchased the aircraft for $50,000 and the designation became official. As with the XP-15, the XF5B-1 wasn't accepted for production, but the Naval aircraft survived rather longer than the Army one, which crashed early in 1931. The XF5B-1 was used for experimental flights for three years. In October 1933 the fuselage was static tested to determine the strength of the all-metal structure. The wings survived for longer, but were static tested to destruction in March 1936.
Engine: Pratt & Whitney SR-1340C Wasp
Power: 480hp at sea level
Span: 30ft 6in
Height: 9ft 4in
Empty Weight: 2,062lb
Gross Weight: 3,419lb
Maximum Speed: 171mph at sea level
Cruising Speed: 145mph
Climb rate: 1,850ft/ min at sea level
Range: 690 miles
Guns: Two 0.3in or one 0.3in and one 0.5in machine guns
Bomb load: Five 30lb bombs or one 500lb bomb