The PT6A is a free turbine providing 500 to 1,940 shaft horsepower (433 to 1,447 kW).
- PT6A-6
- "Small" engine of 525 equivalent shaft horsepower (eshp) and 500 shaft horsepower (shp)
- PT6A-11
- "Small" engine of 528 eshp and 500 shp
- PT6A-15AG
- "Small" engine optimised for agricultural aircraft of 715 eshp and 680 shp
- PT6A-20
- "Small" engine of 579 eshp and 550 shp
- PT6A-21
- "Small" engine of 580 eshp and 550 shp
- PT6A-25
- "Small" engine of 580 eshp and 550 shp (-25, -25A) or 783 eshp and 750 shp (-25C)
- PT6A-27
- "Small" engine of 715 eshp and 680 shp
- PT6A-28
- "Small" engine of 715 eshp and 680 shp
- PT6A-29
- "Small" engine of 778 eshp and 750 shp
- PT6A-34
- "Small" engine of 783 eshp and 750 shp
- PT6A-35
- "Small" engine of 787 eshp and 750 shp
- PT6A-36
- "Small" engine of 783 eshp and 750 shp
- PT6A-38
- "Medium" engine of 801 eshp and 750 shp
- PT6A-40
- "Medium" engine of 749 eshp and 700 shp
- PT6A-41
- "Medium" engine of 903 eshp and 850 shp
- PT6A-42
- "Medium" engine of 903 eshp and 850 shp
- PT6A-45
- "Medium" engine of 1,070 eshp and 1,020 shp
- PT6A-50
- "Large" engine of 1,022 eshp and 973 shp
- PT6A-52
- "Large" engine of 898 eshp and 850 shp
- PT6A-60
- "Large" engine of 1,113 eshp and 1,050 shp (-60, -60A) or 1,081 ehsp and 1,020 shp (-60AG)
- PT6A-61
- "Large" engine of 902 eshp and 850 shp
- PT6A-62
- "Large" engine of 1,218 eshp and 950 shp
- PT6A-64
- "Large" engine of 747 eshp and 700 shp
- PT6A-65
- "Large" engine of 1,249 eshp and 1,173 shp (-65B, -65R) or 1,298 eshp and 1,220 shp (-65AG, -65AR)
- PT6A-66
- "Large" engine of 905 eshp and 850 shp (-66, -66A, -66D) or 1,010 eshp and 950 shp (-66B)
- PT6A-67
- "Large" engine of 1,272 eshp and 1,200 shp (-67, -67A, -67B, -67P), 1,285 eshp and 1,214 shp (-67D), 1,294 eshp and 1,220 shp (-67AF, -67AG, -67R, -67T), or 1,796 eshp and 1,700 shp (-67F)
- PT6A-68
- "Large" engine of 1,324 eshp and 1,250 shp
- PT6A-110
- "Small" engine of 502 eshp and 475 shp
- PT6A-112
- "Small" engine of 528 eshp and 500 shp
- PT6A-114
- "Small" engine of 632 eshp and 600 shp (-114) or 725 eshp and 675 shp (-114A)
- PT6A-116
- "Small" engine of 736 eshp and 700 shp
- PT6A-121
- "Small" engine of 647 eshp and 615 shp
- PT6A-135
- "Small" engine of 787 eshp and 750 shp
- PT6B
- The PT6B is a 981 horsepower (732 kW) engine designed for helicopters.
- PT6C
- The PT6C is a 1600 to 2300 horsepower (1190 to 1720 kW) engine for helicopters and tiltrotors.
- PT6D
- The PT6D-114A is based on the PT6A-114A. The main difference is the deletion of the second stage
reduction gearing and output shaft, as the engine is intended for integration with a combining gearbox incorporating power turbine governors and a propeller output shaft.
- ST6
- The ST6 is a variant of the PT6 that was originally developed as a powerplant for the UAC TurboTrain power cars, but later developed as a stationary power generator and auxiliary power unit.
- ST6B
- The ST6B-62 was a 550 bhp (410 kW) version of the PT6 developed for use in the STP-Paxton Turbocar, raced in the 1967 Indianapolis 500.
- STN 6/76
- The STN 6/76 was a 500 bhp (370 kW) version of the PT6 developed for use in the Lotus 56, raced in the 1968 Indianapolis 500 and later in Formula One races, in 1971.
- T74
- United States military designation for the PT6A-20/27, used in the Beechcraft U-21.
- T101
- United States military designation for the T101-CP-100 / PT6A-45R, used in the Shorts 330 and Shorts C-23 Sherpa.
Read more about this topic: Pratt & Whitney Canada PT6, Variants