US airlines could be required to replace an engine component on hundreds of 70- to 88-seat regional jets if the Federal Aviation Administration (FAA) adopts a proposed new airworthiness rule.
The FAA has learned two General Electric CF34-8 turbofan engines caught fire after ring locks failed on the fuel lines inside a component called an operability bleed valve, according to a notice of proposed rulemaking announced today.
The CF34-8C and CF-348E power multiple aircraft types - Bombardier CRJ700/900 and Challenger 870/890, and the Embraer 170/175.
The FAA estimates that replacing the operability bleed valves across the US-registered fleet will cost a total of $7.55 million, or about $25,000 per engine.
The components failed because of fatigue caused by improper broaching of the housing around the valves during manufacture, according to the FAA. As a result, the problem is "likely to exist or develop in other products of the same type design", the FAA adds.
GE has already issued service bulletins regarding the problem on 14 September. Service bulletins recommend changes, but FAA rulemakings render them mandatory.
By publishing the rulemaking notice, the FAA opens a mandatory 60-day comment period.