Boeing: Hundreds of Older 737s at Risk

MarketWatch: Boeing Co. said Tuesday that 570 older 737 jetliners were at risk for the same kind of fuselage cracks seen at Southwest Airlines Co., and recommended operators inspect their aircraft earlier and more often.

The cracks that led to a Southwest 737-300 jet losing a part of its fuselage while in mid flight last week radiated from lap-joint fasteners that hold pieces of the outer skin together, said Paul Richter, chief project engineer for the 737 jets built before 2000.

Such stress cracks were anticipated, but not before the jets had performed at least 50,000 flights. Now Boeing says safety checks for 737-300, 737-400 and 737-500 series jets delivered between 1993 and 2000 should be carried out after 30,000 flights, and then again every 500 flights.

“That’s a higher rate interval to impose, it is quite frequent, but it has been used before in similar situations…until the root causes are understood,” Richter said on a conference call.

The Federal Aviation Administration is expected to mandate the same guidelines in an air worthiness directive later this afternoon.

Boeing called for operators to inspect about 50 feet of fasteners at the crown of the 737 fuselage with the use of electromagnetic equipment that can detect cracking beneath the surface of the fuselage skin. The early cracking of the 737 fuselage should not occur in later 737 models, Richter said.

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