European safety authorities are ordering operators of Sukhoi Superjet 100 aircraft to replace certain gearshafts in the type's PowerJet SaM146 engines after an in-service failure.
The airworthiness directive, from the European Aviation Safety Agency, covers both the basic SaM146-1S17 and the -1S18 variant.
It has been prompted by the failure of a spur gearshaft in the integrated drive generator, resulting in an in-flight engine shutdown.
EASA says an investigation found that the gearshaft failed as the result of a defect introduced by a rework process during original manufacture.
"The rework process was applied to a limited number of parts," it says.
PowerJet has issued a service bulletin identifying the affected gearshafts. The directive orders Superjet operators to examine SaM146 accessory gearboxes to determine whether the specific gearshaft is installed and, if so, replace it before the next flight.