European safety regulators have ordered replacement of several components, across a number of CFM International CFM56 engines, after they were potentially damaged during maintenance.

The measure follows discovery of evidence that critical engine parts were affected by electrical arcing after an induction heater tool was used.

Several parts which were subject to maintenance performed using the same tool could also be damaged, says the European Union Aviation Safety Agency.

FlightGlobal understands that a third-party shop informed CFM of the situation which involved life-limited parts on 57 CFM56 engines, and that the engine manufacturer pro-actively alerted customers ahead of the EASA directive.

The shop is working with customers on removing and replacing the affected parts.

EASA has formally instructed replacement of the components involved, which include third-stage high-pressure compressor disks, high-pressure turbine rear shafts, and compressor discharge pressure seals.

CFM56-c-CFM International

Source: CFM International

EASA’s directive covers components fitted on the CFM56-5B and -7B

EASA has listed the serial numbers of the 57 engines on which the specific components are known to have been fitted. Of these 47 are the CFM56-5B, used to power older Airbus A320s, while the other 10 are -7B engines for the Boeing 737.

It has also listed the individual part and serial numbers of the affected components. FlightGlobal understands that the parts come from an independent maintenance provider.

EASA says the components should be replaced before next flight, stating that any damage to the parts could lead to their uncontained release.