WASHINGTON U.S. safety investigators on Thursday urgently recommended stepped-up inspections of certain Pratt & Whitney engines on dozens of passenger jets to detect possible flaws linked to the most catastrophic type of failure.
The National Transportation Safety Board asked the Federal Aviation Administration to require that PW2037 engines undergo recurring inspections for the time being once they reach a certain point in their operation.
"Preventive safety measures must be taken," said Mark Rosenker, the safety board's acting chairman.
The action affects more than 700 engines on some 300 Boeing Co 757 aircraft worldwide, including at least several dozen operated by U.S. airlines.
These include Delta Air Lines Inc, United Airlines, a unit of UAL Corp, Northwest Airlines Co, and American Airlines, a unit of AMR Corp.
The safety board's action was prompted by uncontained failure of the right engine of Delta Flight 624 during takeoff on August 6 in Las Vegas.
The takeoff was aborted safely and there was no fire or injuries among the 166 passengers and crew.
An uncontained failure occurs when the engine gives out and parts are ejected through protective covering. Investigators fear that parts blown through the engine will penetrate the fuselage.
In the Delta case, investigators found holes in the engine cover as well as damage to the engine turbine. The investigation also revealed missing parts and cracked turbine blades.
Additionally, the safety board said it has since learned of cracked parts in other PW2037 engines.
A spokeswoman for Pratt, a unit of United Technologies Corp, said Pratt was cooperating fully with the Delta investigation and was committed to finding the cause of that incident.
(Reporting by John Crawley; Editing by Xavier Briand)