Airbus is relying on CFM International and Pratt & Whitney to provide the 15% improvement in fuel efficiency it has promised to deliver with the A320neo, but the rival engine manufacturers have opted to take fundamentally different engineering approaches to achieving that goal.
CFM is embedding new and exotic materials into its Leap-1A, while P&W has taken the plunge with the adoption of a reduction gear to decouple the fan and turbine in its PurePower PW1000G family. With both offerings promising broadly similar performance on paper, how will airlines and leasing companies determine which product offers the best value proposition during a lifetime of ownership?
"Pratt has taken the aerodynamic approach, while CFM has taken the thermodynamic approach," says Rob Morris, a senior aviation analyst at Flightglobal's advisory arm Ascend. Speaking in Powering The Bottom Line, an interactive special edition of Airline Business which examines the impact of the latest engine technology on airline operating economics, Morris says: "For Pratt, you've got fewer moving parts and we think there may be potential for longer time on-wing there. The downside may be uncertain maintenance costs."
He adds that for CFM, with its "approach of new materials and hotter temperatures", the engine "will be heavier with more moving parts".
In a video interview for Powering The Bottom Line, Leap programme manager Gareth Richards says: "The CFM56 today has an on-wing time of up to 20,000 cycles, and our customers expect that. So we've designed [the Leap] from the beginning for the expectation of 20,000 cycles on-wing."
Bob Saia, P&W vice-president for the next-generation product family, says: "About 25% of our engine operating cost reduction is tied to lower engine maintenance costs... We have fewer parts, six fewer stages and approximately 1,800 fewer airfoils than our competitor."
To watch, listen to and read the full debates surrounding engine architecture, MRO, environment, finance and operating costs, be sure to download Powering The Bottom Line from the Airline Business app, or visit flightglobal.com/bottomline to view the publication online.
Other engine programmes which are scheduled to enter service in the next five years, such as the Rolls-Royce Trent XWB, are also examined.