Pratt hoping to power the 737's replacement

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Pacific Historian
Jun 4, 2005
Orange County, CA
This looks interesting. I hope P&W pull it off.

The Seattle Times: Boeing/aerospace: Pratt hoping to power the 737's replacement

By Dominic Gates
Seattle Times aerospace reporter

Before Boeing commits to developing a replacement for its best-selling narrow-body jet, the 737, commercial airplanes chief Alan Mulally wants a breakthrough in engine efficiency.

He may have it sooner than expected. Pratt Whitney, hungry to reclaim its lost share of the huge market for narrow-body jet engines, is moving aggressively to ready "a game changer that takes us to the next level of propulsive efficiency," said Steve Heath, president of its commercial-airplane engine division.

Heath met with Boeing officials in Seattle last Friday to discuss progress on his company's so-called "geared turbofan" — an engine it claims will burn 12 percent less fuel than today's engines, cost up to 15 percent less to operate, and reduce noise and emissions as well.

Pratt has put development work on a fast track, with a ground test planned next fall and flight test in 2008. If the tests go well, Heath said Pratt could formally launch an engine for the narrow-body market by the end of that year. With a typical four-year engine-development program, that could allow Boeing to deliver a 737 replacement jet as early as 2012.

Mulally has said Boeing will have a new narrow-body ready to enter service sometime between 2012 and 2015, and Airbus insists it will be ready to respond. But both plane makers routinely downplay talk of an early launch, reluctant to curtail sales of recently updated existing models. The current Boeing 737s and Airbus A320s are selling well and have huge order backlogs.

Key technology: A gearbox reduces the speed of the fan to optimize efficiency.

Claimed benefits: Compared to today's 737 engines, up to 12 percent better fuel burn, 12 to 15 percent lower operating costs, plus noise and emissions reductions.

Next steps: Ground test, fall 2007. Flight test, fall 2008.

Development history: Gearboxes are typically used on relatively low-speed turboprop engines, powering propeller-driven aircraft. Pratt experimented with different fan types on jet engines beginning in 1987 and developed the gear system over the past 15 years.

The launch of the 787 depended crucially on next-generation engine technology to significantly reduce fuel burn. So it will be with the 737 replacement.

Pratt's geared turbofan, if it lives up to the promises, could let Boeing make an aggressive move early in Mulally's time frame, launching soon after the wide-body 787 enters service in 2008, while Airbus is still shouldering major development work on its wide-body alternative, the A350. "We're not waiting," Heath said in a recent interview in London. "We're developing the technology. ... We'll be ready for it in 2008."

Boeing remains tight-lipped about its study of a 737 replacement. At the rollout this week of the latest and biggest 737 derivative, the 737-900ER, Carolyn Corvi, Boeing's vice president of airplane production, said it's hard to beat the current plane's efficiency, and she repeated the need for a new engine.

Could that be Pratt's geared turbofan? "We keep talking to them about it," Corvi said.

A work in progress

Pratt has placed its faith, and about $1 billion in investment so far, in an advanced-technology gearbox behind the fan of an airplane engine.

A turbine engine's central shaft must turn at high speed for maximum efficiency in compressing the intake air. In Pratt's design, the gearbox between fan and shaft lets the fan turn at a relatively low speed, allowing a bigger fan and a higher flow of bypass air for greater thrust.

Pratt has been working on the technology for almost 20 years, fanning skepticism that it will ever work well. The cogged metal gears must move against one another at thousands of revolutions per minute to generate 30,000 horsepower. And it must be designed so that if the gearbox fails, the fan doesn't seize, but keeps turning.

"Not everybody shares their enthusiasm" for the geared turbofan, said Adam Pilarski, an analyst with Avitas. "It's not proven yet."

Heath hopes the tests planned for 2007 and 2008 will convince skeptics that Pratt has solved the technical problems. He said engineers had to design not only a lightweight gear system, but also a new lubricating oil, and a sophisticated cooling system for the oil that together ensure "a durable, reliable gear with high efficiencies."

Pratt's last chance

The project may be Pratt's last chance in the commercial-airplane engine business. Once a dominant player with 75 percent of the narrow-body jet engine business, Pratt made a major strategic misstep in the mid-1980s, when it chose not to replace its existing narrow-body model. That allowed CFMI, a joint venture between General Electric and the French company Snecma, to take the market.

Pratt learned, said Heath, that "if you don't obsolete your product, somebody else will." Today, CFMI provides all the engines on new 737s and more than half the engines on new A320s. The rest of the A320 engines are made by International Aero Engines (IAE), a joint venture that is one-third Pratt, one-third Rolls-Royce, one-tenth MTU and the balance a consortium of Japanese companies.

"I definitely don't want to miss the single-aisle market again," said Heath. "This is absolutely crucial to Pratt Whitney's future in the commercial engine business."

Both Heath and Mark Thompson, Rolls-Royce's director of customer business with Boeing, said Pratt and Rolls are working independently for now on new narrow-body engines but will eventually join forces again to launch a narrow-body engine through the IAE alliance.

To reduce fan speed, Rolls favors adapting a three-shaft design used on its wide-body engines. The two engine makers eventually will have to choose between these differing technical approaches.
In 2004, Pratt failed to get on the 787 wide-body engine program. So Pratt certainly has motivation.

"Pratt lost sufficient ground that if they don't come back with something strong, they are out of the commercial-airplane engine business," said Pilarski. "They do have to go for broke."


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Pratt better do something. Over the years they have gotten a great share of the market taken from them by GE and Rolls Royce. There have been several costly Airworthiness Directives against their engines that were under warrantee, that also hurt. Hopefully if they get this it will stabilize their business foundation, I'd hate to see another long-time aircraft company go bust or get swallowed up by the competition.

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