Boeing Tweaks Engine for New 737 Max

By JON OSTROWER 

 The Wall Street Journal

Boeing Co. said Thursday it planned to increase the size of the engine on its new 737 Max jetliner as it continues a fierce battle for sales with the rival Airbus A320neo.

The company revealed to The Wall Street Journal that the revamped 737's engine would have a 69.4-inch diameter fan, one inch more than the size outlined in March.

The new more fuel-efficient engines are central to the improved efficiency of the new Boeing and Airbus planes, though the Max—which is offered with a single engine choice made by CFM International—will still have a smaller fan than the two rival offerings on the A320neo.

CFM is a joint venture between General Electric Co. and France's Safran SA, the exclusive engine supplier for the existing 737 range, which is also squaring up with the Pratt & Whitney unit of United Technologies Corp. to power the Airbus A320neo.

A larger fan makes an engine more efficient, but is also heavier and creates more drag, requiring aircraft engineers to find the best balance. The CFM engine on the A320neo has a 78-inch fan while the Pratt & Whitney offering measures 81 inches.

Boeing's engine remains smaller than the Airbus offerings because the 737 sits lower to the ground than the A320. The U.S. company has made several modifications to the Max including lengthening the nose landing gear so the new engines are far enough above the ground.

The larger fan will be paired with a smaller engine core than previously identified, said Boeing spokeswoman Lauren Penning, part of a series of design refinements before the company settles on the final configuration in mid-2013.

The 737 Max is due to fly for the first time in 2016 and enter service with launch customer Southwest Airlines Co. the following year. The A320neo is due to enter service before the end of 2015.

GE and United Technologies have invested heavily in the new engines, which executives said will be central to their efforts to boost earnings at their core industrial units.

The battle between the engine makers has been every bit as fierce as that between Airbus and Boeing, with claims and counter-claims about their expected performance.

CFM is also offering its Leap-X engine on China's Comac C919 jetliner, which is being marketed as a potential rival to the new Airbus and Boeing single-aisle planes. Pratt & Whitney's geared turbofan, or GTF, is also being marketed on a yet-to-fly new plane from Bombardier Inc. and regional jets from Mitsubishi Aircraft Corp. and Irkut, a unit of Russia's United Aircraft Corp.

Pratt & Whitney has firm orders and options for more than 2,500 GTF engines while CFM said it holds orders for 3,600 Leap-X engines, including commitments for the 737 Max that have yet to be added to the Boeing backlog.

Boeing has secured more than 1,000 commitments for the 737 Max, including 415 firm orders against the more than 1,300 for the A320neo. Boeing executives said this week they expected to achieve parity with Airbus in sales for their marquee new single-aisle planes by the middle of next year at the latest.

Source:  http://online.wsj.com