Saving Sense of Paranoia

Nation

Saving Sence of Paranioa

The DC-10 crash proves the need for constant vigilance

Even before the last bodies had been found, the detective story began. Federal investigators started poking through the smoldering wreckage of the DC-10 in the flame-seared field near Chicago's O'Hare Airport, collecting pieces of metal that colleagues later examined under electron microscopes. Their findings last week were enough to chill the most seasoned air traveler: the key elements that destroyed American Airlines Flight 191 and killed 274 people appeared to be a bolt 3 in. long and 3/8 in. in diameter, and a cracked metal plate. Both were parts of the pylon assembly under the left wing that held one of the plane's three engines.

The very contrast between the small parts and the ghastly consequences of their failure in the worst U.S. air disaster would have been troubling enough. But other events stemming from their discovery were also unsettling. The Federal Aviation Administration, the governing body of U.S. flight, quickly ordered inspections of all 138 DC-10s still flying for U.S. airlines. Ernest Gigliotti, 31, and Lorin Schluter, 39, two conscientious United Airlines mechanics, found metal filings as fine as dust on one DC-10 in Chicago. Suspicious, they did the natural thing: they shook the pylon. It was loose. The two men discovered 27 fasteners that held together part of the pylon were missing or sheared. They also found that the spar web, a key pylon support, was cracked. Gigliotti told the press, "Eventually, that pylon would have separated from the plane."

Two hours after learning of that discovery, the FAA grounded all DC-10s, the first time it had ever done so to a fleet of jetliners. The move immobilized 12% of the capacity of U.S. passenger planes and substantially disrupted air travel. By week's end ominous faults of various kinds --cracked plates, loose bolts--had turned up in the pylons of 36 of the inspected aircraft. After repair, one got back into the air, with FAA permission, joining 102 found to have no defects. But Philip Hogue, a member of the National Transportation Safety Board investigating the American crash, said that he thought the planes should have been kept in hangars until the cause of the disaster had been more fully determined. Would he fly on a DC-10 as a passenger? Answered Hogue: "No, I would not."

The probe into the American crash seems certain to lead to a broader and deeper investigation, going all the way back to the initial design of the DC-10 by McDonnell Douglas Corp. and its certification by the FAA. The Government's recommendations about the DC-10 will largely depend on what the NTSB's crash detectives eventually find to be the "probable cause" of Flight 191's crash. The accident left no survivors to interview, and the cockpit voice recorder disclosed only two sounds after the routine checklist readings: an unexplained thud and the single word "Damn!" shouted by the pilot or copilot, apparently just as the engine tore away from the wing.

For a few days, the NTSB put all of the blame on a broken bolt that searchers found beside the runway. It was one of five that held the pylon to the wing, and officials thought it had snapped because of "metal fatigue"--the progressive weakening that results from repeated stress. One investigator even christened it "the murdering bolt." But electron microscope studies showed the bolt had been broken by a sudden, violent strain. Meanwhile, a crack had been found in the plate that formed the aft bulkhead.

Investigators theorize that as the plane rolled down the runway, the pylon wiggled and vibrated far more than normal. Why is not yet known; the cracks in the plate may have caused--or been caused by--the vibration. In any case, the stress snapped the rear "attach" bolt and it fell out. The remaining bolts could not hold the 20 tons of thrust being generated by the General Electric CF6 engine. It yanked itself and the pylon loose from the wing and took off on its own.

The rising engine and pylon, possibly trailing yards of metal "spaghetti," apparently tore through the skin of the whig. When the engine flew off, it carried away the pumps for one of the plane's three hydraulic systems. The engine may also have cut through hydraulic lines in the front of the wing. In either case, fluid necessary to maintain pressure on controls spilled out. The leading-edge flaps that were extended from the front of the whig to supply extra lift on takeoff may have been struck and damaged by the engine. Or the lack of hydraulic pressure to keep the flaps out may have permitted air pressure to push them back in. Now, the undamaged right wing, flaps still extended and engine still thrusting, had more lift than the left. It rose rapidly until it was perpendicular to the ground. At that terrifying angle, the DC-10 lost airspeed and plunged into a field half a mile from the runway.

The crash has raised troubling questions about the DC-10 design. Is the pylon basically strong enough to hold the engine on under the stresses of takeoff? If not, how should it be modified? And how much might McDonnell Douglas have to pay for it? (A new pylon costs approximately $500,000.)

As the probe went on, the NTSB asked the National Aeronautics and Space Administration to study the long-term effects of vibration and acoustics on engine pod and pylon attachments in all superjets, including those flown by the Air Force. If the NTSB eventually finds the DC-10 pylons are too weak, it could recommend that the plane be grounded again until they are strengthened or replaced, and the FAA most likely would issue such an order.

Also being critically examined last week were the procedures of the FAA, which writes the rules for inspecting jetliners and then supervises the work. There was a growing suspicion that the FAA may have relaxed too much, lulled by the fine safety record of jetliners. Shortly after the broken bolt was discovered, the FAA stipulated that pylon inspections had to be repeated every ten days or 100 flying hours, whichever came first. Formerly, it had been done only once a month or every 400 hours.

The FAA is now likely to come under pressure from Congress to tighten up all of its inspection procedures. Ironically, the FAA no longer requires the entire jetliner to be torn down at one time and inspected, although such a procedure was once standard for piston-engined passenger planes. Jerome Lederer, director of the Flight Safety Foundation, told TIME Correspondent Jerry Hannifin: "The FAA might consider some of the advantages of the old philosophy. It's expensive, with the aircraft out of service for a while, but the results are improved safety." Concludes Hannifin, himself a pilot who has reported many air crashes: "In the airline business, safety comes only from a kind of total paranoia--that is, always believing that you are not safe."

The crash came at a critical time for McDonnell Douglas. The company needs to sell 400 DC-10s, at $40 million each, to recoup the $1 billion development cost and begin turning a profit, perhaps in 1981. By last week it had delivered 281 DC-10s around the world; airlines have placed firm orders for another 58 and taken options on 70 more. That would bring the total to just over 400, if none of the options were canceled. None were last week; indeed, Varig airlines of Brazil ordered five more DC-10s.

The events set in motion by the crash of Flight 191 will not be settled for months or even years: the effect on the company and on the FAA; the insurance claims, which at a conservative estimate are likely to exceed $100 million; possible changes in the DC-10 itself. But one part of the story is over. Last week the NTSB finished raking through the debris at the crash site. One final pass was made with metal detectors. It turned up a set of keys and a wedding ring. American Airlines then seeded the field with grass.

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