PA-31T-620 Cheyenne - Two 460kW (620shp) Pratt & Whitney Canada PT6A-28 turboprops driving three blade constant speed Hartzell propellers.
PA-31T2-620 Cheyenne IIXL - Two 560kW (750shp) PT6A-135s.
PA-31T-620 - Max speed and max cruising speed 516km/h (280kt), economical cruising speed 452km/h (244kt). Initial rate of climb 2800ft/min. Service ceiling 29,000ft. Range at max cruising speed 1555km (840nm).
PA-31T2-620 - Max speed 510km/h (275kt), max cruising speed 500km/h (270kt), economical cruising speed 385km/h (208kt). Service ceiling 32,400ft. Range at max cruising speed 2608km (1408nm), at economical cruising speed with max fuel 2740km (1478nm).
PA-31T-620 - Empty equipped 2260kg (4983lb), max takeoff 4082kg (9000lb).
PA-31T2-620 - Empty equipped 2580kg (5680lb), max takeoff 4335kg (9540lb).
PA-31T-620 - Wing span 13.01m (42ft 8in), length 10.57m (34ft 8in), height 3.89m (12ft 9in). Wing area 21.3m2 (229sq ft).
PA-31T2-620 - Same except for length 11.18m (36ft 8in).
Cheyenne II, I, IA, and IIXL typically seat six, including pilot, or optionally eight.
Total PA-31T Cheyenne production of 823, comprising 526 Cheyenne and Cheyenne IIs, 215 Cheyenne I & IAs and 82 Cheyenne IIXLs.
Twin turboprop corporate transports
The Piper Cheyenne family of turboprop corporate aircraft is based on the popular Navajo and Chieftain piston twins.
Although the first Cheyenne was not delivered until mid 1974, work on a turboprop version of the Pressurized Navajo dates back almost a decade earlier to the mid 1960s. The prototype of the Cheyenne flew for the first time on August 29 1969, but Piper had to redesign the flight controls to handle the increased loads on the airframe due to the higher speeds. Production deliveries were further delayed due to flooding at Piper's Lock Haven plant in June 1972.
Certification had been granted on May 3 1972, while the first production aircraft (powered by 462kW/620shp PT6A-28s) first flew on October 22 1973.
Piper introduced the lower powered (373kW/500shp PT6A-11s) and less expensive Cheyenne I in 1978, and renamed the original Cheyenne the Cheyenne II. Refinements to the Cheyenne I made in 1983, including more power at altitude, revised cowlings and interior, resulted in the Cheyenne IA.
Meanwhile the stretched Cheyenne IIXL had been introduced in 1979. Compared with the standard length Cheyennes, the IIXL was 61cm (2ft) longer, featured an extra cabin window on the left side, 180kg (400lb) increased max takeoff weight and 560kW (750shp) PT6A-135s. An improved IIXLa was planned, but did not enter production.
The further stretched and T-tail PA-42 Cheyenne III was also introduced in 1978, and is described separately.