The Technology Powering the PT6 Engine

Ranging in power from 500 shp to over 2,000 shp, PT6 engines offer unsurpassed flexibility for a variety of applications. The numbers speak for themselves:

  • PT6 engines currently power aircraft in service with more than 7,200 operators in more than 180 countries
  • More than 51,000 PT6 engines have been produced since the first PT6 engine was delivered in 1963.
  • PT6 engines have logged 380 million flying hours

The PT6 engine is a scalable technology that can be redeveloped and redesigned based on customer specifications. PT6 engines have demonstrated their versatility in powering aircraft applications spanning the airline, general aviation, business, helicopter, agricultural and utility markets.

The PT6A engine family includes three engine series with increasing power levels, referred to as PT6A “Small,” “Medium” and “Large”. The increased power levels are achieved by increasing compressor air flow and the number of power turbine stages. Most recent models have the advantage of advanced technologies in materials, turbine cooling and aerodynamic design.

P&WC has consistently taken advantage of major advancements in aerodynamics, materials and other design methodologies to enhance the performance of the engine. 

  • Compared to the first PT6 engine, today’s PT6 is up to four times more powerful with a 40% better power-to-weight ratio and up to 20% lower specific fuel consumption.
  • The engine has a modular design, so that various gas generators and reduction gearboxes can be matched to create new applications.
  • Every new PT6 engine developed has focused on higherspeed, greater payload, longer range and better fuel efficiency at the aircraftlevel.

More on the PT6A family
More on the PT6B family
More on the PT6C family
More on the PT6T family

PT6 engine technology:

Multi-stage axial and single-stage centrifugal compressor

  • Reverse flow, radial inlet with screen for foreign object damage protection
  • Large high-power PT6A engine models incorporate 4-stage axial and 1-stage centrifugal
  • Small and Medium PT6A engine models incorporate 3-stage axial and 1-stage centrifugal

Reverse flow combustor

  • Low emissions, high stability, easy starting, durable

Single-stage compressor turbine

  • Cooled vanes in some models to maintain high durability

Independent “free” power turbine with shrouded blades

  • Large and Medium PT6A engine models incorporate 2-stage axial power turbine
  • Small PT6A engine models incorporate 1-stage axial power turbine
  • Forward facing output for fast hot section refurbishment

Epicyclic speed reduction gearbox

  • Enables compact installation
  • Output speed optimized for highest power and low propeller noise
  • 1,700- to 2,200-rpm output speed

Electronic engine controls on multiple PT6A engine models

Other models incorporate control modules and override features to promote ease of operation and safe flight

COVER PHOTO: The mesmerizing makeup of a PT6 compressor.