Debacle of the DC-10

Disturbing long-range questions about the worst air disaster in U.S. history

We are a little uneasy. We have no handle on this one yet. Was it aging metal in a high-time machine? Was it stress? And what kind of stress? Was it quality control of the metal? And if we find out, what kind of fix can we ask to have made? We don't know.

Those worried--and worrisome --comments came last week from a member of a band of experts who normally know all the answers: the National Transportation Safety Board's "go teams" of plane-crash investigators. Over the years they have been able to pinpoint a "probable cause" in 97% of all U.S. air accidents. Yet even these legendary investigators remained in doubt about the precise cause of the worst U.S. air tragedy in history--the crash of an American Airlines DC-10 jumbo jet near Chicago's O'Hare International Airport on Memorial Day weekend that killed 275. While the experts hunted for both a cause and a cure, 138 DC-10s in the U.S. and 132 more around the world were grounded. As the airlines using DC-10s lost an estimated $5 million a day, the public developed new doubts about the industry's vaunted competence and, equally important, the ability of its federal regulators to protect travelers against disaster.

After vacillating for twelve days, Federal Aviation Administrator Langhorne Bond last week issued an "emergency order of suspension" that indefinitely lifted the design certificate of the DC-10s in the U.S. The grounding was voluntarily followed by all but one airline outside the U.S. (Venezuela's Viasa, which uses five DC-10s). A total of 41 airlines that normally carry 60,000 passengers a day on the $40 million plane built by the McDonnell Douglas Corp. had suddenly lost key portions of their fleets. The initial result was confusion and tedious delays in airport terminals as travelers scrambled to get seats on other flights and airlines struggled to shift their available aircraft to plug the gaps left by the grounded planes. The crisis created turmoil in an industry that depends heavily upon the public's overcoming any fear of flying. What was more, the events clouded the financial future of McDonnell Douglas (see box).

There have been few heroes in the distressing developments since the accident. The primary issue throughout has been why the left engine on the three-engine jetliner literally took off on its own as the 120-ton airplane was rising from the runway at O'Hare. The four-ton engine, exerting a thrust of 40,000 Ibs., had ripped away with the pylon that attached it to the wing. Climbing, the engine apparently tore into the wing, severing at least two of the three hydraulic pressure lines embedded near the forward edge. The loss of the engine, its hydraulic pumps and the hydraulic lines that power vital controls rendered the craft uncontrollable.

The FAA grounded the DC-10s until their pylon assemblies could be inspected for cracks and faults. The jets were barely back in the air again when the confusion was compounded. The Safety Board had discovered the possibility that the inspection process itself might be creating a problem. During the searches, some airlines had adopted the time-saving practice of dropping the engine and the pylon from the wing as a unit and using a fork lift to move the assembly. McDonnell Douglas' maintenance manuals recommend removing the engine first, then the pylon, and remounting them one after the other. The Safety Board suspected that using a fork lift in this operation, which is restricted to a tolerance of one-sixteenth of an inch, could have caused banging that in turn damaged vital parts.

Once again, Bond acted tentatively. He grounded only the DC-10s that had been inspected by the short-cut method using the fork lift. The half steps by FAA gave Bond's critics an opening to demand more sweeping action. The Airline Passengers Association, a highly commercial Texas-based company that sells flight insurance, baggage tags and "prestigious membership" certificates to air travelers, sought an order in two separate actions in a Washington federal court requiring the FAA to ground all DC-10s until the plane's problems were solved. One judge deferred to the decision of the FAA. But Judge Aubrey Robinson, acting independently, disagreed. He granted a grounding decree, declaring that those who chose to fly should be protected. Otherwise, he said, they could suffer "irreparable damage," while "all the airlines lose is money."

In light of what was to happen, the FAA then proceeded to make itself look both defensive and overconfident. It urged Judge Robinson to delay the grounding until the agency could present a case showing that it had acted prudently. The judge agreed, postponing his order until a hearing set for the following day.

Bond had gone to London on his way to attend the biennial Paris Air Show. Even before his agency's lawyers reached him to inform him of the judge's action, he had learned more startling news from his Washington advisers: definite hairline cracks had been found by American Airlines mechanics in the aft bulkhead fitting on two DC-10s (see diagram). Not only had the two jets been previously cleared, but fork lifts had not been used in their inspections. The same bulkhead, which had held a bolt that broke, was cracked on the doomed jetliner.

Bond flew back to Washington on a supersonic Concorde and at a jammed press conference announced his grounding order. Those latest cracks, he said, "changed my certitude from the position of high likelihood of no risk to a sufficient likelihood of risk" in the entire DC-10 engine-and-pylon assembly and its attachment to the wing. Even the process by which that part of the plane's design had been certified as airworthy by the FAA would be reviewed. Bond said he was fully aware of the possible impact on the manufacturer, the airlines and the rerouted passengers. "I did not come by the decision lightly. My concern is for safety."

The FAA grounding order had been personally handed to McDonnell Douglas President John C. Brizendine at an unusual meeting in his Los Angeles office at 3:48 a.m. Both he and the bearer of the news, Regional FAA Director Leon C. Daugherty, had been called from their homes to keep their rendezvous. The key passage of the order declared that the engine-and-pylon assembly "may not be of proper design, material, specification, construction and performance for safe operation."

McDonnell Douglas angrily attacked the FAA for making what it called an "extreme and unwarranted" decision. The company protested that the order grounded all DC-10s when, in fact, the defects have only shown up on the earlier, shorter-range (2,700 miles) No. 10 series. The later series 30 and 40 aircraft (4,000-to 4,600-mile range) are used mainly on transoceanic flights. The engine-and-pylon assembly, however, is almost identical on all three models.

The company also lashed out at airlines whose procedures have been "contrary to McDonnell Douglas recommended procedures." Although not named, American Airlines knew that it was one target of the attack. American Vice President Donald J. Lloyd-Jones insisted that two McDonnell Douglas representatives had watched the airline change its very first DC-10 pylon on April 17, 1977. He also claimed that the manufacturer had observed numerous such changes since then and never objected to the one-step method. He termed the McDonnell Douglas charge "gratuitous and unnecessary." (The manufacturer withheld comment.)

The search for the cause of the DC-10 crash could be long and costly. Investigators, for example, are trying to determine just what effect the years of jolting landings and high-stress takeoffs have had on the key metal parts that hold the engine and pylon to the wing. They are even studying the possibility of "acoustical fatigue," the damage to metal that can be caused by oscillations of sound frequencies generated by the DC-10's engine and its associated metal structures. More than 100 FAA investigators are working with McDonnell Douglas to find the reasons for the problems. Other experts are subjecting pylons to stress, then tearing them down to see what damage might have been caused.

The whole engine-and-pylon assembly might have to be redesigned and manufactured with strengthened chrome steel, Duralumin and stainless steel fittings. These would be tested in wind tunnels, simulators and actual flights. The process could take weeks or months--or longer.

Longtime critics of the jet claim it has more basic problems. They charge that the plane does not have as many redundant or fail-safe systems to handle an emergency as other wide-bodied jets. In particular, they cite the hydraulic systems. The DC-10 has three, whereas the Lockheed TriStar has four and the Boeing 747 has five. The DC-10 places its hydraulic lines along the leading--and more exposed--wing edge, rather than in the trailing edge, where the 747's and Tri-Star's are located. Critics also claim the hydraulic lines under the DC-10's cabin are more vulnerable than the systems of the other two jets. The FAA could decide that more redundant systems should be built into the DC-10--a process that would be time consuming and expensive.

Bond's final order grounding the DC-10 was sweeping, but there were critics who wanted him to go further. Most notably, the Air Line Pilots Association demanded that the entire DC-10 aircraft be re-examined from nose to tail. Declared ALPA President John J. O'Donnell: "The fight against FAA lethargy is just beginning." Bond was scheduled to be grilled by a House subcommittee this week on all aspects of his agency's handling of the DC-10 crisis.

No charge of FAA "lethargy" can be laid solely against Bond, an expert on aviation law and a private pilot himself. The most dramatic--and eventually disastrous--evidence of the agency's seeming reluctance to crack a whip over McDonnell Douglas was its timid handling of the DC-10's notorious cargo-door problem. FAA inspectors were aware that a cargo hatch blew off during certification tests in 1970. The agency ordered the problem corrected. Yet another door burst open over Windsor, Ont., in 1972, luckily without causing any deaths. Even then, the FAA reached "a gentleman's agreement" to let the manufacturer make its own fix in its own time. McDonnell Douglas failed to do so until after a Turkish Airlines DC-10 crashed near Paris in 1974, killing 346.

The new controversy over the DC-10 again raises the question of whether federal regulators work too closely with the industry they regulate to remain as critical as they should be. Certainly the DC-10 was rushed into production in the early 1970s in a successful race to catch up with the TriStar, its main rival. Were corners cut by both the manufacturer and its watchdogs in the heat of competition?

The FAA'S Daugherty, who is deeply involved in the DC-10 investigation, insists that "we are not playing footsie with the industry. The manufacturers couldn't possibly be more concerned about safety." But even Daugherty concedes that two subtle kinds of pressure are at work as huge and enormously expensive aircraft development projects go forward. One is from the outside as politicians, mainly Congressmen anxious to bring jobs and business to their districts, gently prod top FAA officials to expedite the process of approving a new plane's design and flight results. Another is what Daugherty calls "peer pressure": company engineers seeking to impress FAA examiners with their expertise in order to nudge a project along a shade faster than might be wise.

Daugherty's worries, which are also held by some in the industry, are by no means proof that corners were cut, but they do raise troublesome questions about the complicated relationship between the aviation interests and their regulators. The manufacturers, the airlines and the FAA all are striving for safety, yet the evidence stemming from the DC-10 debacle is that procedures should be tightened even more, despite the excellent safety record of the industry. In the era of the wide-bodied jet, any failure can be a disaster.

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