OLD aircraft are not necessarily unsafe aircraft. If maintained properly and operated safely, they can fly for decades with high reliability. But the act of flying - creating lift - is by definition highly stressful. Add in the cabin pressures necessary to keep crew and passengers comfortable, the jolt of cumulative landings, metal fatigue and corrosion, and the necessity for regular inspection and preventive maintenance becomes clear.
Increased competitiveness in the airline industry, due to deregulation, also affects air safety. It's cheaper to maintain and fly older planes than it is to buy new ones. But time spent in the hangar is money lost - as much as $75,000 a day. And the longer that planes stay in service (most of the planes made since the jet age began in the 1950s are still flying), the more often they change ownership. This makes it harder to keep track of maintenance records.
Aircraft manufacturers, commercial airlines, and the Federal Aviation Administration have long recognized the problem of aging aircraft. Recent steps to prevent structural failure from age and stress have been taken.
When an airliner lost part of its upper fuselage over Hawaii last year, the FAA ordered airlines to replace rivets in the seams of older 737s, whether or not routine inspection showed them to be corroded. As a result of the Aloha Airlines incident, and several others involving questions of structural safety, a task force of government and industry experts has been working on new inspection and repair standards, which were made public this week.
Tougher standards are necessary, especially regarding the timeliness of repair. Problems with 747 cargo doors have been occurring for some time, yet the FAA last summer gave airlines two years to strengthen cargo door locks. Airlines are speeding up inspection and repair of 747 cargo doors as a result of last week's accident involving an 18-year-old plane. But the FAA should have taken a harder line in the first place.
The agency should act deliberately but quickly on the new repair standards presented this week. It needs to focus not only on the materials used in aircraft construction, but also on the inspectors themselves. Their work is crucial, but tedious. The FAA should also insist on more frequent replacement of critical parts before they show signs of wear.
Passengers and crew need not be alarmed about older aircraft. But they should expect that such craft will be truly airworthy.