Boeing 66 / XP-8
In April 1925 the USAAC issued a specification for a single-seat fighter to be powered by a new 447kW Packard engine of inverted layout. Boeing's airframe for this requirement was generally similar to that of the Model 15 family, but incorporated a coolant radiator in the centre-section of the lower wing.
Designated XP-8 (Boeing Model 66), this model preceded the XP-7, delivered in July 1927, having been launched as a private venture late in the previous year. Powered by a 600hp Packard 2A-1500 water-cooled engine, the XP-8 utilised an airframe essentially similar to that of the US Navy XF2B-1, but performance failed to meet the requirements of the 1925 USAAC specification which it had been designed to meet, and the aircraft was finally scrapped in June 1929. Armament comprised one 7.62mm and one 12.7mm machine gun.
Engine: 600hp Packard 2A-1500 water-cooled
Take-off weight: 1552 kg / 3422 lb
Empty weight: 1084 kg / 2390 lb
Wingspan: 9.16 m / 30 ft 1 in
Length: 6.95 m / 22 ft 10 in
Height: 3.27 m / 10 ft 9 in
Wing area: 22.57 sq.m / 242.94 sq ft
Max. speed: 278 km/h / 173 mph