7E7 Composite
Aerospace Notebook: Airlines cautious on 7E7 composite
Seattle Times 01/28/04
author: James Wallace
(Copyright 2004)
Emirates Airlines, fresh off the largest single jetliner order in history for Boeing and Airbus jets, has acknowledged that it is a possible customer for Boeing's 7E7.
But The Boeing Co. is going to have to prove to the Dubai-based carrier that the composite fuselage of its new superefficient plane will be able to stand up to the usual fender-bender mishaps that often occur with planes parked at airports, an Emirates executive said.
Aluminum-skinned jets can be dented by baggage trucks, boarding steps or those high loaders that are used to service planes -- everything from taking garbage off to putting food on.
"Our maintenance boys have been particularly hard on Boeing, given the extensive use of composites that will be used to lighten up the Dreamliner," Tim Clark, president of Emirates Airlines, said in a telephone interview from Dubai last week.
The Dreamliner is the name Boeing has given its 7E7.
Boeing is now out hunting for orders for the plane so development can officially begin this year, with entry into service in 2008.
The 7E7 will make extensive use of lightweight composites -- more than any previous commercial jetliner. The fuselage and wings of the plane will be composite.
This will make the 7E7 as much as 30 percent lighter per seat than current jets, Clark said.
But there may also be a drawback to having an all-composite fuselage, Clark said: ground damage. The hard, plasticlike material doesn't dent like aluminum, so some airlines, such as Emirates, are concerned that damage would be hard to spot.
Emirates, the fastest-growing airline in the Middle East, sees ground damage to its planes as much as a dozen times a day across its network, Clark said.
Usually, those planes don't need to be taken out of service for repairs because the damage is not serious, he said.
"But with composites, my understanding is you need to treat it immediately," Clark said.
"Boeing told us they have dealt with this issue. I said that's fine. But I can't afford to have aircraft stuck on the ground because of a small dent, which on other aircraft I would let go, but on the 7E7 I can't because of the composite material."
Boeing said this should not be an issue with the 7E7.
"The 'bangs' that cause minor damage to aluminum structure will not impact composite materials," Boeing said.
The composite material for the fuselage of the 7E7 will be the same as that used on the tail of the 777. Boeing said it has never had a maintenance issue with the composite tail of the 777, of which more than 400 are in service.
"If the damage is not visible (with the composite material to be used on the 7E7), the structure is sound and can be used," Boeing said. "Our service manuals will explain this in detail and also provide operators with directions for what to do in case of visible damage. We are meeting with the airlines around the world to explain both the structural- monitoring and composite-repair technologies."
Boeing plans a nervelike system of sensors that will be embedded in the composite structure of the 7E7 to provide constant data about the health of the plane. Damage-prone areas around cargo doors and catering doors will have these sensors.
Boeing is evaluating a couple kinds of sensors, including an optical one.
"Our approach to using structural health monitoring will provide excellent awareness of the health of the composite fuselage," Boeing said.
"This combination of structural- integrity monitoring and a more robust material system offers a dual advantage -- higher resistance to damage and better awareness of any damage that does occur."
Boeing added that as airlines learn more about the new 7E7 technology, concerns such as those expressed by Clark will disappear.
Clark said Boeing provided Emirates a two-hour briefing on the 7E7 just before the recent Dubai Air Show.
"We have already expressed a fairly strong interest in the plane," Clark said. "I say fairly strong because I've only seen a paper plane. ... But it looks to be an absolute beauty.
"I'm sure that it will be a wonderful machine," he added. "But the proof in the pudding is in the eating."
Dubai is the second-largest of the seven states that make up the United Arab Emirates. The government there is transforming Dubai into a world- class destination resort, and the ruling Maktoum family, which owns Emirates, has not been shy about spending money to make Emirates one of the world's top carriers.
At the Paris Air Show last year, Emirates placed a record order for new planes, worth $19 billion at list prices. It ordered an additional 21 Airbus A380 superjumbos and will lease two more. That brought to 45 the number of the double-decker 555-seat planes that Emirates has ordered.
Emirates also ordered long-range A340-600s and A340-500s from Airbus, and said it will lease 26 Boeing 777-300ER jets -- Boeing's next long-range jet, which is about to enter service.
The 7E7 will be a widebody jet smaller than the 777. It will carry 200 to 250 passengers.
Clark said Emirates would prefer the 7E7 have more capacity.
Still, the Maktoum family has made clear its interest in the new Boeing plane.
"If the price is right, and the economics are right, I could see that plane operating to city pairs that perhaps we had not planned to do before, perhaps second- or third-level city pairs in the United States," Clark said.
But Boeing is going to have to convince Emirates, and probably other airlines, that the composite skin of the 7E7 will hold up to the bumps and dents that jetliners experience when they are not flying through the sky.