50 years of success for P&WC's PT6 plus a peek into the future

An overwhelming number of turboprop and helicopter OEMs have built winning aircraft using this outstanding powerplant design.


It turned out that a messenger had been walking in front of the test cell at the same moment the engine went to full power, and the envelope he'd been carrying was sucked out of his hands. The envelope, and the paychecks inside, was shredded instantly!

As a practical example of this reliability, only 2 single-engine aircraft types are approved for commercial night IFR operations in Canada—the Cessna 208 Caravan and the Pilatus PC12, both powered by PT6s.

The next 50 years

I asked Parisien about the next 50 years. Without actually giving away the Crown jewels, he gave me some insight. As he explained it, Pratt & Whitney Canada has always looked at new opportunities to evolve the product line.

Aircraft manufacturers continue to ask the company to develop PT6 engines below 600 shp and above 2000 shp. Pratt & Whitney Canada is open to considering both. Traditional design approaches would create challenges—not the least of which is blade size and clearances—as you reduce engine size and try to maintain efficiency.

The R&D group has tackled these challenges for nearly 50 years—this is how the engine has grown from 600 shp to nearly 2000 shp. They are constantly looking at ways to improve the SFC. (Better SFC translates into better range and endurance for the aircraft.)

The latest PT6—the PT6A-140 for the new Cessna Grand Caravan EX—has 5% better SFC than the previous model. Interestingly, although Pratt & Whitney Canada has developed some PT6 engines in the military trainer market with electronic controls, most PT6 customers have found the PT6 easy to start, operate and adjust the rugged hydromechanical controls and so have not been so eager to move to electronics. Reducing pilot workload is another priority.

To that end, P&WC is considering introducing a FADEC on selected PT6 engines going forward.

Pratt & Whitney Canada spends some $400 million a year on R&D and a significant portion is spent on reducing the CO2 footprint. Combined with its efforts to improve efficiency, Pratt & Whitney is dedicated to reducing the impact of aviation on the environment. With PT6 fleet total flying hours approaching 400 million—nearly 10 times the nearest competitor—that positive impact is significant.

Mike Venables is an aviation consultant and freelance writer. The principal at TriLink Technologies Group, Venables has been involved in the aerospace industry for more than 40 years, including aero engine, airframe, avionics and simulator manufacturers.


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