Boeing 69 F2B / 74 F3B
US Navy evaluation of the FB-4 with a Wright P-1 radial engine led to this aircraft being re-engined with a Pratt & Whitney Wasp and redesignated FB-6. It was flight-tested and demonstrated the clear superiority of the Wasp, leading to a decision to combine this engine with an airframe based on the Model 66. From this marriage of airframe and powerplant came the Boeing Model 69, designated XF2B-1 by the US Navy, and first flown in prototype form on 3 November 1926. It differed mainly in having the span of upper and lower wings more nearly equal, and by the propeller having a large spinner.
74 / XF3B-1
Satisfactory testing of the prototype resulted in an order for 32 production aircraft under the designation F2B-1, with deliveries beginning on 30 January 1928, and these served with US Navy Squadrons VF-1B (fighter) and VB-2B (bomber) on board USS Saratoga. The F2B-1s differed from the prototype by deletion of the spinner, and introduction of a balanced rudder.
Three F2B-1s were flown by the “Three Sea Hawks” Navy precision stunt flying team of the late 1920s.
Model 69 / F2B-1
Engine: 1 x 317kW Pratt & Whitney R-1340-B Wasp radial
Take-Off Weight: 1272 kg / 2804 lb
Empty Weight: 902 kg / 1989 lb
Wingspan: 9.17 m / 30 ft 1 in
Length: 6.98 m / 22 ft 11 in
Height: 2.81 m / 9 ft 3 in
Wing Area: 22.57 sq.m / 242.94 sq ft
Max. Speed: 254 km/h / 158 mph
Cruise Speed: 212 km/h / 132 mph
Ceiling: 6555 m / 21500 ft
Range: 507 km / 315 miles
Armament: 1 x 12.7mm + 1 x 7.62mm machine-guns, 5 x 11kg bombs