Boeing is contemplating a long and virtually maintenance-free life for its 7E7 because of its predominantly composite structure.
The aircraft will be at least 50% composite materials by weight, a massive increase in usage of the material compared to the largest civil user of composites so far at Boeing, the 777 at 20%. Most civil airliners use from 5-15% of composites.
Modern military aircraft tend to use more. For example, Eurofighter features some 50% composites by weight.
The manufacturer is "very comfortable" with such a high proporation of composite, says Mike Bair, 7E7 senior vice-president. "Is that a big leap?" questions Bair. "We don't think so."
Boeing has no technical issues with composites, with the main challenge being putting the production processes in place to meet its fast assembly targets.
A big advantage of composite is that the material effectively does not corrode or suffer fatigue failure, says Bair. This will drive maintenance costs down.
"There is a reasonable chance of dramatically reducing heavy checks," he says. During the initial service life of the aircraft, it will have to be inspected just as regularly as current types to ensure the material is behaving as expected. If so, it is possible inspections could be phased out and heavier maintenance eliminated.
Composites
"The aircraft will have a longer life," says Bair. "We don't know how long, but it will be a long time." Airlines have been worried over the ability of composites to withstand damage from vehicles and tugs - which Bair terms "ramp rash" - when the aircraft is on the ground. He insists this will in fact be less than with aluminium aircraft.
To alleviate All Nippon's concerns, Boeing gave the launch customer's engineers a composite panel to try and damage. They took to it with a vengeance and used every tool within arm's reach to attack the material. The only damage they could inflict was with a punch, says Bair.
MARK PILLING
Source: Flight Daily News
