Special Report: Aircraft Safety: How Safe Is The U.S. Fleet?

Until now, the stubby and squat Boeing 737 has been an anonymous little workhorse, scarcely recognized by airline passengers even though most of them have flown on one. Trusted by the airlines for its seemingly tireless reliability and efficiency on short hops, the "guppie" has become the best- selling jetliner in history. The 737 fleet, which now exceeds 1,500 jets worldwide, has carried more than 1.7 billion passengers and flown more than 10 billion miles. But last week the venerable plane was suddenly the most infamous and scrutinized of jetliners, as the Federal Aviation Administration ordered U.S. airlines to conduct special inspections for cracks and other signs of metal fatigue on older 737s.

The agency was responding to the April 28 accident in which an Aloha Airlines 737 landed miraculously in Maui, Hawaii, after an 18-ft. section of the fuselage tore away, like the canvas roof on a convertible, while the plane was going 330 m.p.h. at 24,000 ft. Though Pilot Robert Schornstheimer made the best of a terrible situation, the incident killed one flight attendant and injured 61 passengers. Many of them were struck by chunks of metal and insulation that kept peeling off the plane during its frightening descent.

Fearful that similar planes could be equally vulnerable to disaster, the FAA called for inspections of all 737s that have made more than 30,000 takeoffs and landings, which included as many as 291 jets operated by U.S. carriers. Of those planes, 36 that have racked up more than 55,000 landings were prohibited from flying above 23,000 ft. until they could be thoroughly checked out. At higher altitudes, the cabin must be pressurized to a greater extent and more strain is put on the fuselage. Among those airlines most severely affected by last week's ruling were American and Piedmont. After inspecting the damaged jet, Joseph Nall, a member of the National Transportation Safety Board, declared, "My hope is that it will raise the consciousness" of air carriers and regulators about the hazards of overworked planes.

Passengers were concerned as well. Not long ago, they were focusing their airborne anxiety on such problems as crowded skies, rookie pilots and overstressed controllers. Now they have a new concern: the soundness of the jets. Are some planes too old? Are others sent aloft with known malfunctions? The financial competitiveness wrought by deregulation has raised suspicions, deserved or not, that some carriers may be courting disaster by skimping on maintenance and diligence.

The Aloha episode is only the most dramatic of mechanical snafus that have ranged from clogged fuel filters to rusted-through floors to cracked turbine blades. Last month the FAA launched a special inspection of all jets operated by Continental and Eastern airlines in response to recurring accusations that their parent, Texas Air, the largest U.S. airline company, was cutting corners on maintenance because of its financial troubles. Even the reliability of new jets came under assault last month, when two foreign carriers, Japan Air Lines and British Airways, complained strongly about malfunctions on freshly assembled Boeing 747s and 767s.