Engine Fire and Shutdown Due to Turbine Stator Retaining Ring Failure (N802MX)

Incident Overview

While climbing through approximately 4,000 feet mean sea level (MSL) on a scheduled domestic flight, the captain reported a loud pop followed by a shutdown of the right engine. A smell of smoke was noticed, and a fire was visually confirmed in the right engine nacelle. The flight crew activated the onboard fire extinguisher during the return to the departure airport. The aircraft landed without further incident.

Investigation Findings

The subsequent investigation revealed that the incident was caused by a failure of the turbine stator retaining ring, identified as Pratt & Whitney part number 3034363. It was noted that Pratt & Whitney had issued an outstanding service bulletin (S.B.) at the time of the incident. This particular engine was determined to be the only one in operational service on which that service bulletin had not been completed. Furthermore, this engine was the lead engine for the operational flight.