In 1931, the third production P-6 (which had been converted to P-6A standard) was withdrawn from service and returned to Curtiss for extensive modification as the XP-22. Retaining the V-1570-23 engine, the XP-22 was cleaned up aero-dynamically and featured cantilever main undercarriage legs and wheel spats, plus a redesigned engine cowling with, initially, an annular radiator. The radiator was subsequently returned to a position beneath the rear of the engine. On 30 June 1931, the XP-22 demonstrated a level speed of 202.4 mph (326 km/h) and on 10 July a USAAC contract was placed for 45 Y1 P-22s. These were subsequently redesignated as P-6Cs, but prior to the start of production deliveries the designation was to be changed once more to P-6E. By this time the engine of the XP-22, complete with cowling and three-blade propeller, plus the main undercarriage members, had been grafted on to the YP-20 which had thus become the XP-6E while the XP-22 was returned to P-6A configuration.
Engine: Curtiss V-1570-23 Conqueror
Span, 31 ft 6 in (9,60 m)
Length, 23 ft 7 in (7,19 m)
Height, 8 ft 10 in (2,69 m).
Wing area, 252 sq ft (23,41 sq.m)
Empty weight, 2,597 lb (1178 kg)
Loaded weight, 3,354 lb (1 521 kg)
Max speed, 202 mph (325 km/h) at sea level
Max speed: 195 mph (314 km/h) at 10,000 ft (3050 m)
Initial climb, 2,400 ft/min (12,19 m/sec)