The PT6T Twin-Pac® alone created the foundation for P&WC’s success in the global helicopter market, with a heritage that is second to none. Our customers associate the “Twin-Pac®” with lasting dependability since its service entry in the 1970s. PT6T engines continue to enjoy strong sales today based on the excellent reputation and performance of the Agusta and Bell 212 and 412 helicopters and the PT6T’s excellent record of dependability together with a steady influx of advanced, value-based technologies.

The 1,800 to 2,000 shaft horsepower class, twin-power section PT6T has been produced in 12 models and its versatility has been demonstrated in a wide variety of applications. PT6T engines power aircraft in service with 350 operators in 96 countries. More than 6,000 PT6T engine power sections have been produced since the family entered service in the 1990s, accumulating more than 33 million flying hours in such applications as oil exploration, Emergency Medical Service, maritime patrol and utility operations.

Operators of PT6T series engines are supported by P&WC’s industry-leading global customer support. This includes over 30 P&WC-owned and designated service facilities around the world, more than 100 field support representatives on all major continents, a 24/7 Customer First Centre for rapid expert support, the most advanced diagnostic capabilities for this market and the largest pool of P&WC rental and exchange engines in the industry. P&WC’s helicopter engine support has also been consistently ranked No. 1 by operators in Pro Pilot magazine’s annual powerplant support survey.

Features of the PT6T engine family have continued to expand, incorporating the latest technologies in the drive to exceed our customers’ expectations in performance, reliability, durability, fuel consumption and environmental friendliness. PT6T models are available ranging in shaft horsepower power from 1,800 to over 2,200 shaft horsepower. The latest aerodynamic and material technologies have enabled the PT6T engine to gain more power without significantly increasing in size. Other innovations have further enhanced ease of operation with the introduction of Electronic Engine Control (EEC) on some models.

The PT6T basic configuration consists of two PT6A power sections coupled to a combining gearbox with a novel clutch system enabling both twin and single engine operation. The power section configurations are exactly the same as that of the PT6A turboprop, i.e. a two-shaft configuration consisting of a multi-stage compressor driven by a single-stage compressor turbine and an independent shaft coupling the power turbine to the output shaft through the combining reduction gearbox. In fact, the first PT6T-3 power section was the same as that of the PT6A-34 airline turboprop, laying the foundation for airline-type reliability in P&WC’s first helicopter engine.

Twin-PT6 power sections with combining gearbox

• Clutch system enabling twin and single engine operation

Multi- stage axial and single-stage centrifugal compressor

• Reverse flow, radial inlet with screen for FOD (Foreign Object Damage) protection
• 3-stage axial and 1-stage centrifugal

Reverse flow combustor

• Low emissions, high stability, easy starting, durable

Single-stage compressor turbine

• Cooled vanes to maintain high durability

Independent ‘free’ power turbine with shrouded blades

• Forward facing output for fast hot section refurbishment

Electronic Engine Control (EEC) on some engine models

• Other models with Automatic Fuel Control and manual override

	Thermodynamic PowerClass* (Shaft Horsepower)	Mechanical PowerClass* (Shaft Horsepower)	Output Shaft Speed (RPM)	Height** (Inches)	Width** (Inches)	Length** (Inches)
PT6T-9 Series	2,243	1,855	6,600	32.5	43.5	66
PT6T-6 Series	1,970	1,875
PT6T-3 Series	1,800 to 1,920	1,800 to 1,875

* Powers are approximate values at take-off. Available at sea level, standard day, static conditions, uninstalled.

** Dimensions are approximate values.

• Agusta Bell Model 212 : PT6T-3B, PT6T-3
• Agusta Bell Model 412SP/HP/EP : PT6T-3B, PT6T-3D, PT6T-3DF, PT6T-3BE, PT6T-3BF, PT6T-3BG, PT6T-9
• Bell CFUTTH CH-146 Griffon : PT6T-3D
• Sikorsky S-58T : PT6T-3, PT6T-6