Failed to Note United’s Faulty 747 Door Inspections, FAA Admits

A federal official conceded Thursday that his inspectors failed to note that for several months United Airlines had not followed a Federal Aviation Administration rule concerning the closing of cargo doors on Boeing 747 jetliners.

The testimony by FAA supervisor Robert Sanchez came during the third day of National Transportation Safety Board hearings here on why a cargo door tore from one of the airline’s 747s near Hawaii on Feb. 24, hurling nine passengers to their deaths.

Sanchez, who heads up an FAA inspection team in San Francisco, said spot checks by his inspectors failed to turn up the discrepancies. Reviews by subordinate supervisors failed to note that the procedures outlined on a United operational bulletin differed from the FAA directive on which the bulletin was based, he said.

Robert B. Doll, a United vice president, had testified here Wednesday that because of a “clerical error” made while transcribing the directive into the “lingo” familiar to ground crews, a paragraph was inadvertently omitted that ordered latch locks to be inspected for damage after each time a 747 cargo door is closed manually rather than electrically.

The directive, which followed a similar FAA recommendation a few months earlier, went into effect in July, 1988, seven months before the door on the United jumbo jet ripped off.

It has not been determined whether the failure to make these inspections in any way contributed to the accident aboard Flight 811. The NTSB will not render its conclusions as to what caused the accident for several months.

Records show that a series of minor malfunctions--none of which was considered extraordinary--disabled the electrical closing system on the cargo door of the United plane and forced ground crews to use wrenches to close the door manually on several occasions in the weeks prior to the accident. The last time the door was closed before the accident, it was shut electrically.

Testimony of others has indicated that repeated and overzealous or incorrect use of wrenches, especially power wrenches--or attempts to test the “give” in the door by activating the electrical latch winches after the door is locked--could damage the locking mechanism, possibly causing the door to burst open during a flight.

Doll testified that United approved the use of power wrenches despite a Boeing recommendation such wrenches not be used. But Doll said the force and speed of the power wrenches were not excessive.

“We decided that the critical parameters were the torque and the RPM,” Doll said.

He said the decision to use power wrenches was made without consulting the FAA, but he added that the FAA was advised that the new procedure was in use, and the agency did not object.

Sanchez gave contradictory testimony about this Thursday, at first saying the FAA had approved the procedure and later saying the FAA apparently was unaware that the power tools were being used.

Doll said that after the accident, a thorough inspection was made of the cargo doors on all United 747s, and only “minor gouges” were found in the locking mechanisms, indicating they had suffered little or no damage. The door from Flight 811 is missing, but NTSB investigators hope that it may be recovered some time in the future by using a special retrieval ship or a miniature submarine.

When the outer door ripped from Flight 811, it carried with it a large slab of the outer passenger cabin wall. In addition to the nine who were flung from the plane by the explosive decompression at 22,000 feet, another 27 were injured, mostly by debris flung about the interior of the shattered business class passenger compartment.

As a result of the accident, the FAA directed all airlines to accelerate a previous order to add steel plates to the 747 cargo door locking mechanisms to strengthen them and lessen the likelihood that they would be damaged by wrenches or by the inappropriate activation of the electrical latching system after the locks are closed.

The directive was originally issued after a cargo door on a Pan American World Airways 747 opened partially on a flight from London to San Francisco in May, 1987, forcing the plane to return to England.