Some U.S. airlines had to take some Boeing Co. 757 jetliners out of service to correct cracks in a blade that helps direct air flow through the Pratt & Whitney-made engines, a Pratt & Whitney spokesman said.
The cracks were found in November and parts to correct the problem have been in short supply, said Mark Sullivan, a spokesman for Pratt & Whitney, a unit of United Technologies Corp.
The Federal Aviation Administration was aware of the Pratt & Whitney service bulletin recommending that airlines inspect the engines six to eight months ago, said spokeswoman Kathleen Bergen. It chose not to mandate inspections.
"We do not see this as a safety-of-flight issue," Bergen said.
Two engine failures have been reported as a result of the cracked blades, but the 757s continued the flights because the planes are capable of flying on one engine, Sullivan said.
Delta Air Lines Inc. said it has delayed putting some 757s back into service because of the problem with the cracked blade.
AMR Corp.'s Trans World Airlines unit took 757s out of service to fix the problem, which was compounded by the lack of parts. A spokesman couldn't say how many of TWA's 27 757s were still out of service.
UAL Corp.'s United Airlines said it took four of its 98 757s out of service late last year to fix the cracks, but all four planes are now flying.