Created Saturday, Jul 8th 2023 07:43Z, last updated Thursday, Jan 30th 2025 15:08Z
A United Boeing 737-9 MAX, registration N37516 performing flight
UA-2376 from Fort Lauderdale,FL to Newark,NJ (USA) with 179 passengers and 5 crew, had landed on Newark's runway 22L and was taxiing to the apron, when a left hand engine (LEAP) fire indication came on. The crew shut the engine down and discharged one fire bottle into the engine, the fire indication ceased. No smoke or fire was visible, the aircraft was thus towed to the gate where passengers disembarked normally.
On Jul 7th 2023 the NTSB reported maintenance personnel saw evidence of a fuel leak from the engine. The thrust reverser doors were opened and heat damage and soot were observed on the engine case and external surfaces.
On Jan 30th 2025 the NTSB released their final report and investigation docket concluding the probable cause of the incident was:
A No. 1 (left) engine fire due a fuel leak that originated from the fuel nozzle 17 b-nut connection that was not properly torqued in accordance with the aircraft maintenance manual procedure.
The NTSB analysed:
The No. 1 (left) engine fire was caused by a fuel leak that originated from an improperly torqued fuel nozzle 17 pilot secondary inlet b-nut. The leaked fuel ignited when it contacted hot engine case surfaces and resulted in an undercowl fire. Fuel nozzle b-nut torque measurements recorded during the engine teardown revealed that the pilot secondary inlet bnuts of fuel nozzles 17 and 18 both had zero torque and backed off with no resistance. Four fuel nozzles (positions 4, 16, 17 and 18) were examined at the GE Aerospace Failure Analysis Laboratory in Evendale, Ohio and no anomalies were identified that would have precluded normal function if the b-nuts had been torqued in accordance with the aircraft maintenance manual.
Although, not directly causal to the incident engine fuel leak, CFM LEAP series engine fuel nozzle coking has driven early and repetitive fuel nozzle replacements throughout the fleet.
According to United Airlines (UAL), they have completed 443 fuel nozzle set replacements on their CFM LEAP fleet as of October 2024.
Related Flight:
UA2376,
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