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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.