The development of emerging nanotechnology coatings, which provide an enhanced thermal barrier, is helping to extend on-wing component life, says Juneau. “We see significant progress made in the coatings world. This should lead to longer on-wing time, although it is still too early to know for sure.”
Airlines appear to be taking somewhat of a wait-and-see attitude with respect to the new engine technology, especially where performance and life-cycle support agreements are concerned.
“The maintenance contracts being negotiated with GE for the Leap-1B are similar to those for our CFM56,” says Southwest's Tiffany. “But we are including provisions in our agreements with both GE and Boeing that will guarantee the advertised fuel-burn and exhaust-gas-temperature (EGT) performance—after overhaul.”
Because of the engine's new trending technology, it will be possible to track the variables that influence fuel-burn and EGT performance more accurately than in the past, he notes. “This is the first time, at Southwest, that we have included this in a maintenance service contract.”
Interestingly, Tiffany says that there has been less discussion about engine on-wing time, than fuel burn. “We expect that the time on wing will be comparable to, if not better, than what we are experiencing with the CFM56-7.”
Oslo-based Norwegian Air Shuttle ASA, or Norwegian, has ordered 100 each of the 737 MAX and the A320NEO. The Pratt & Whitney PW1127G has been selected to power the A320NEOs, to be delivered starting in mid-decade. But Tore Jenssen, the airline's fleet manager, says that he is actually expecting less on-wing time than with the CFM56.
“When you compare the Leap-1B to the CFM56, you are looking at a larger engine which runs hotter, in order to achieve better fuel burn,” Jenssen notes. “You cannot have both fuel burn and maintenance efficiency, so the trade-off is better fuel burn for less time on wing.”
He adds that time on wing for the PW1127G should be at least as good as the Leap-1A, even though it's a bigger engine. “Because of its larger, slower-speed fan, it will run cooler and still be more fuel efficient.”
Pratt & Whitney Commercial Engines' marketing director, Paul Finklestein, points out that fuel savings will be achieved largely through the application of its geared technology, which was designed to permit a slower-speed fan to run, in combination with a higher-speed, low-pressure compressor and low-pressure turbine. “Using fewer stages to produce more power, the engine achieves the required thrust and better fuel efficiency, yet runs cooler than conventional engines,” he explains.