11/15/2014. Remarks by Johan Visschedijk: "Produced in parallel to the monoplane SB2U, the biplane SB3U was perhaps the most extreme example of the US Navy Bureau of Aeronautics' official ambivalence toward the suitability of monoplanes for carrier operations. In February 1935, four months after authorizing three scout-bomber monoplane prototypes, the USN ordered a retractable-gear biplane from Vought under the designation XSB3U-1. Utilizing the same basic airframe and engine as the SBU-2, the XSB3U-1 incorporated a rearward-folding landing gear and a somewhat longer chord cowling. Its armament consisted of a fixed forward-firing 0.50 in (12.7 mm) machine gun and a flexible 0.30 in (7.62 mm) machine gun in rear cockpit, while up 500 lb of bombs could be carried externally.

It is noteworthy that the XSB2U-1 and XSB3U-1 two-seat dive-bomber prototypes were completed and delivered to NAS Anacostia, Washington, D.C., in April 1936. Trials held between the two types, both equipped with a 750 hp Pratt & Whitney R-1535-82 fourteen-cylinder radial driving a two-bladed Hamilton Standard variable-pitch propeller, unquestionably confirmed the superiority of the monoplane's aerodynamics: though 500 lb (227 kg) heavier and dimensionally larger than the XSB3U-1, the monoplane XSB2U-1, equipped with an identical power plant, was nonetheless faster by 15 mph (24 kmh), had similar range, and could carry twice the bomb load, while exhibiting the same 66 mph (106 kmh) stall speed. The sole XSB3U-1 prototype was thereafter used at NAS Anacostia for test purposes and at Langley for NACA's investigation of tail loads until 1938."

Span: 33 ft 3 in (10.13 m)
Length: 28 ft 2 in (8.59 m)
Wing area: 327 sq.ft (30.38 sq.m)
Empty weight: 3,876 lb (1,758 kg)
Loaded weight: 5,837 lb (2,648 kg)
Max speed: 215 mph (346 kmh) at 8,900 ft (2,713 m)
Service ceiling: 26,500 ft (8,077 m)
Range: 590 mls (950 km)