The in-development geared turbofan (GTF) has been attracting most of the headlines at engine manufacturer Pratt & Whitney lately, and it does indeed promise to make a large leap in powerplant efficiency and environmental friendliness when it enters airline service in 2013. The GTF achieves its gains in large part from the integral gearbox that allows both the fan up front and the core farther downstream to turn at their optimum speeds– slower in the case of the larger-than-usual fan and faster for the compressor and power turbine.
The configuration is not especially well suited to propelling a business jet (it falls short on high-altitude thrust), but business aviation will reap some of the benefits of the program: the PW810 that was destined to power the now languishing Cessna Citation Columbus has the same core (including Pratt & Whitney’s Talon combustor technology for low oxides of nitrogen) as the PW1000G GTF chosen by Bombardier and Mitsubishi to power, respectively, their C Series and MRJ airliners. P&W uses the same program name, PurePower, for both engines.
Compared with existing engines of similar thrust, the PurePower engine in its airliner GTF guise will reduce fuel burn by between 12 and 15 percent and noise and nitrous oxide (NOx) emissions by more than 50 percent, according to P&W. The PurePower PW810, which is the group’s first foray into the large business jet segment, will be “seven to ten percent better than the state of the art,” Pratt & Whitney Canada president John Saabas told EBACE Convention News. “Big jumps in business jet efficiency will not be had by another squeeze of the existing lemon.”
The PW810 will, however, make decent gains in noise control, coming in 15 to 20 dB below Stage 4 limits. These improvements are attained by advanced fan shock-wave management and by sound attenuation panels that reduce more than one frequency, according to Saabas. The PW810 will also maximize a business airplane’s climb performance, which is important both for reducing external noise in the airport environment and for cutting fuel burn by propelling the airplane to fuel-efficient altitudes more quickly.
With its PW600 series, P&WC is the default engine for very light jets now in service, powering the Eclipse 500, Cessna Citation Mustang and Embraer Phenom 100. “We used the PW600 as a catalyst to change the ‘three Ps’ here–production, preparedness and process. The PW610 has pioneered processes for both the PW210 [the turboshaft chosen for the Sikorsky S-76D] and the PW810.”
Some 9,000 operators fly 45,000 P&WC engines in 193 countries, and “we track every AOG globally, with parts depots in Amsterdam and Singapore, Muskegon and Montreal, and we’re fixing field problems,” said Saabas. “Support accounts for half of Pratt & Whitney Canada’s business.”