WASHINGTON - US Airways has found and fixed faulty wing fasteners on additional B-757 jetliners since part of the wing on one of its 757s broke off and struck a passenger window somewhere over Maryland last month, federal investigators said Tuesday.
In a written interim report on its investigation, the National Transportation Safety Board said that a 4-foot-by-5-foot panel of the wing flew off Flight 1250 on March 22 because the three clips that secured the leading edge of the panel to the wing had failed - two before the flight because of metal fatigue and the third during the flight.
The NTSB said it was investigating to determine whether the wing clip failure was caused by poor design, improper installation, or lax inspection and maintenance. The safety board did say that the clips that failed were redesigned fasteners installed in 1991 after problems with the 757 wings were identified in the late 1980s.
US Airways reported to the safety board that it had inspected all its 757s since then and found "problems with wing fasteners on several other aircraft, which were since repaired and returned to service," the report said. US Airways inspected all 18 of the 757s it owns that use these fasteners and found cracked wing fasteners on six of them, in addition to the plane that lost the wing panel, said NTSB spokesman Peter Knudson.