EasyJet wants powerplant manufacturers to pursue open-rotor architecture as the prime engine technology for next-generation narrowbody airliners as it offers the most significant efficiency and environmental gains.
"It may well be that somebody, while flight testing prototypes, comes up with a reason why open rotor technology can't work, but starting here and working forwards, it really should be the plan A," says EasyJet strategic planning manager Hal Calamvokis.
Last year the airline revealed a concept aircraft design that featured two rear-mounted open rotor engines, and promised as much as 50% improvements in fuel efficiency and carbon dioxide emissions.
Geared turbofan technology, which Pratt & Whitney is currently pursuing with its GTF trials, "seems to be the most appropriate technology for the aircraft size below the one we're looking at", says Calamvokis. The GTF has been selected for the new 100-seaters being proposed by Bombardier and Mitsubishi.
Calamvokis says that "a large chunk" - as much as 30% - of the environmental improvement offered by the new narrowbodies will be driven by the engine.
American Airlines executive vice-president of operations Bob Reding says that open rotor technology "seems to be really a paradigm shift in fuel consumption", adding that an engine that can provide a 30% improvement "would really get our attention".
Reding notes, however, that questions still need to be answered concerning the maximum cruise speed that aircraft can fly with open rotors, the noise characteristics and certification requirements.
The International Air Transport Association aims to get some of these questions answered soon, as in June it will provide airlines with a compact overview of the status of research and development efforts and what will be available and when in terms of new engine technology. At that point it will "try to align the airlines" behind a consolidated viewpoint, says IATA technical and operations specialist Juergen Haacker.
Meanwhile, Calamvokis believes that one of the issues that may be driving the current discussion on the timing of new technology single-aisles is that airframers would prefer to have two engine suppliers from the beginning for risk-management purposes. "Do we have to wait for the laggard manufacturer whereas the first manufacturer might be ready by 2015 and the second by 2018?" he asks.
Barring this consideration, however, EasyJet believes it has not been told a compelling reason why the date has to slip to the latter part of the next decade.
Source: Flight International
