Our Beechcraft King Air C90GTx engine page covers the engine for the turboprop, the Pratt & Whitney Canada PT6A-135A. Engine specifications and dimensions are also listed here.

The Beechcraft King Air C90GTx uses the “popular” PT6 turboprop engine built Pratt & Whitney Canada. Specifically, the King Air C90GTx uses the PT6-135A version of the PT6 engine. Two Pratt & Whitney Canada PT6-135A engines are mounted on the wings of the King Air C90GTx. The PT6-135A version of the PT6 series engines was introduced on the King Air C90GT version of the C90 series (launched in 2005/2006). Beechcraft has built upon the C90GT with the C90GTi and then the C90GTx. Also note that the King Air C90GTx engine has a lower power rating (550 shaft horsepower) when compared to the base PT6-135A engine (750 shaft horsepower). The engine equipped on the C90GTx is capable of producing 750 SHP, however it is limited to 550 SHP.

The Beechcraft King Air C90GTx Engine The Pratt & Whitney Canada PT6-135A

Above Beechcraft King Air C90GTx engine photo by Alan Wilson on Flickr and Wikimedia Commons. Photo enhanced by FlyRadius and released under a Creative Commons License.

Below is more information on the King Air C90GTx engine, which includes full specifications and dimensions.

Overview of the engine construction:

The PT6-135A engine is a free turbine turboprop with a 3 axial plus one centrifugal stage compressor, single annular combustion chamber, single stage gas generator turbine and a single stage power turbine.

Beechcraft King Air C90GTx Engine Specifications

Reduction Gear Ratio: .0576:1

PT6-135A Engine Ratings:

Maximum Continuous:

  • Shaft Horsepower (SHP): 550 SHP
  • Output RPM: 1,900 RPM
  • N1 Gas Generator Speed: 101.5
  • Maximum Permissible Turbine Interstate Temperature: 805 C

Takeoff (for 5 Minutes) At Sea Level (The Same as Above):

  • Shaft Horsepower (SHP): 550 SHP
  • Output RPM: 1,900 RPM
  • N1 Gas Generator Speed: 101.5
  • Maximum Permissible Turbine Interstate Temperature: 805 C

Starting Transient (2 seconds):
Same as above, except:
Maximum Permissible Turbine Interstate Temperature: 1090 C

Maximum Reverse:

  • Shaft Horsepower (SHP): 300 SHP
  • Output RPM: 1,825 RPM
  • N1 Gas Generator Speed: 88.0
  • Maximum Permissible Turbine Interstate Temperature: 805 C

Oil Tank Capacity: 2.3 gallons (gal)
Useable Oil Tank Capacity: 1.5 gallons (gal)

Beechcraft King Air C90GTx Engine Dimensions - PT6-135A

Length: 61.89 inches (in)
Nominal Diameter: 18.29 inches (in)
Maximum Radius: 11.50 inches (in) (excludes exhaust ports)

C90GTx Engine Weight PT6-135A: 347 pounds (lbs) (Dry Weight)

Center Of Gravity (Dry Weight):
Forward Of Mount Plane: 3.87 inches (in)
Below Engine Centerline: 0.25 inches (in)
Right Of Engine Centerline: 0.35 inches (in)