PRECEDE Zurich Boeing Held Meeting on Possible Engine-Mount Problem Before Crash
SEATTLE (AP) _ Boeing officials met with operators of early model 747 jets to discuss possible problems with engine mounts two weeks before a cargo version of the plane smashed into a Dutch apartment building, the company said today.
The Sept. 16 meeting was held because of a longstanding concern about fatigue cracking in fuse pins, which hold the four engines onto the 747′s wings, said Boeing Commercial Airplane Group spokesman Jack Gamble.
Boeing is redesigning the pins, and on Monday issued a service bulletin asking operators of some 747 models to inspect the pins and repair or replace them if necessary.
Swissair spokesman Hannes Kummer said earlier today that the Swiss carrier received a telex from Boeing last week suggesting checks for cracks in the pins within 90 days. Gamble said the need for the inspections was discussed at the Seattle meeting, which was attended by Swissair and El Al representatives.
Dutch officials said the Israeli El Al 747-200F freighter that crashed Sunday evening lost the two engines from its right wing shortly after taking off at Amsterdam’s airport. They said the pilot was unable to maneuver the plane back for an emergency landing. More than 250 people were feared killed on the ground.
The crash was similar to a China Airlines accident last December in which a 747-200 freighter dropped two engines from its right wing shortly after taking off from Taipei. Five crew members were killed in that crash.
Investigators have not determined the cause of either accident.
Gamble said that while both accidents involved the same type of aircraft, the right-wing engines, and occurred while the jets were climbing after takeoff, there was no way to tell yet whether the fuse pins were a factor.
″There is no factual evidence that would link this pin to either China or El Al,″ he said.
Fuse pins are steel parts about 2 1/4 inches in diameter and 4 inches long. Four pins, two in the center and one each in front and back, are used to connect engine struts to plane wings. Engines are bolted to the struts.
Gamble said there have been no accidents involving Boeing planes in which fuse pins were determined to be the cause. However, he said Boeing had decided to redesign the pin because of reports of problems.
″We have received reports over the last seven years of 15 fuse pins that have shown signs of fatigue cracking, usually as a result of corrosion,″ Gamble said.
The service bulletin Monday went to operators of 747 models 100, 200 and 300 jets with Pratt & Whitney or Rolls Royce engines, asking them to inspect the fuse pins and repair or replace them if necessary, Gamble said. Most of the planes were built between 1980 and 1989.
Gamble said Boeing has asked the Federal Aviation Administration to issue an airworthiness directive concerning the pins, which would require U.S. carriers to make the inspections and any necessary repairs. Most foreign regulatory agencies normally adopt FAA airworthiness directives.
FAA spokesman Dave Duff in Seattle said the agency is expected to make Boeing’s recommendation an order within the next few weeks.
Gamble said the service bulletin does not affect new Boeing 747-400s or planes equipped with General Electric engines, which use a different type of connector.
He said Boeing hopes to have a redesigned pin available to operators by mid- to late 1993.
Investigators have found the engines but not the struts or surrounding structures from the China Air accident. The cause of the Taipei accident has not been determined.
The fuse pins are designed to break off if an engine seizes up during flight, Boeing spokesman Tom Cole said. A faulty engine that stays fixed to the wing could twist and rip open a fuel tank, he said. Fuse pins designed to break allow the engine to fall cleanly from the wing.
At higher altitudes 747s can fly even if two of the four engines are lost, but maneuverability may be limited, Cole said.
The Boeing service bulletin was issued to 69 operators worldwide, most of them passenger airlines.
Boeing officials have flown to Amsterdam to help investigate the El Al crash.