Boeing to Fix Pins Suspected in Pair of 747 Jetliner Crashes : Safety: Until repairs are complete, frequent inspections will watch for corrosion that may have caused the accidents.

Addressing a potential flaw that might have contributed to two fatal crashes of its 747 jumbo jets, Boeing Co. on Friday said it plans to make a “major structural modification” to the wings of the nearly 1,000 planes now in service.

The Seattle-based company said the cost of strengthening the struts connecting the engines to the wings will be shared with customer airlines, who will meet with Boeing and Federal Aviation Administration officials in July to discuss the plan. The FAA must approve the changes in the struts before they are made.

Although Boeing would not discuss the cost of the changes, the price could reportedly be from $100 million to $300 million for the 948 planes in service.

Domestic passenger airlines operate more than 100 of the jumbo jets, the world’s largest commercial airliners, which typically seat about 400 passengers. United Airlines, with 55 of the jets, and Northwest, with 38, are by far the largest U.S. operators of the planes, according to 1992 fleet figures compiled by Salomon Bros.

The aircraft manufacturer said its plan to strengthen the struts would require two weeks of work, which could be performed while the jets are sidelined during scheduled overhauls.

“It will take several years before it is all done,” Boeing spokeswoman Susan Davis said.

Until then, she said, 747 operators will continue a stepped-up inspection program to search for corroding and cracked struts. The program was launched following the two crashes.

Boeing had already announced it was redesigning portions of the struts, which have been implicated in last October’s crash of an El Al 747-200 freighter that smashed into an apartment block in Amsterdam, killing about 50 people, and in the fatal crash of a similar jet off Taiwan in December, 1991.

“The strut design has been in use for 23 years and more than 8 million flights,” Jim Johnson, Boeing vice president in charge of 747 production, said in a statement. “But based on recent flight tests, data from the fleet and extensive analysis, we now believe it is prudent to upgrade the structure in all 747 struts. When completed, these upgrades will significantly reduce the frequency of the inspections currently in place.”

Under Boeing’s plans, fuse pins--large bolts--that help connect the engine to the wing will be replaced with corrosion-resistant, stainless steel pins. The pins are designed to permit a failed engine to fall off, preventing serious structural damage to the fuel-laden wings.

In addition, Boeing will add a set of stainless steel brackets to hold the engines to the wings should the pins fail.

Separately, Boeing said it laid off 1,586 workers in the last month and has furloughed 4,623 employees worldwide this year. The company, which announced earlier this year that it would cut commercial jetliner production by 35% because of the airline industry’s prolonged slump, has reduced net worldwide employment this year from 132,344 to 124,910.

Of the cuts, 4,623 were from layoffs, 1,567 were from retirements and the remainder were for other reasons, a Boeing spokesman said.

Reuters contributed to this report.