Flight Details
Aircraft Type: Boeing 767-3S2F(ER)
Operator: FedEx Express
Registration: N287FE
Flight Number: FX541
Route: Memphis International Airport (KMEM) to McCarran International Airport (KLAS)
Date of Incident: 18 October 2023
Total Occupants: Not officially disclosed
Weather Conditions: VMC, early morning departure
Introduction
On the morning of 18 October 2023, FedEx Express flight FX541, a scheduled cargo service from Memphis, Tennessee to Las Vegas, Nevada, experienced a severe in-flight engine fire shortly after departure. The aircraft involved, a Boeing 767-300 freighter registered N287FE, had just taken off from Memphis’ runway 18R when the flight crew heard a loud bang and received a fire warning indication for the left engine (General Electric CF6-80C2).
The crew promptly executed emergency procedures, including shutting down the affected engine and activating both fire extinguishing bottles. The aircraft stopped its climb at approximately 3,700 feet MSL and returned to Memphis for a precautionary landing on runway 18C. Emergency services reported visible damage to the engine but no active fire upon arrival. The incident prompted a full investigation by the National Transportation Safety Board (NTSB).
Sequence of Events
At approximately 05:38 local time, flight FX541 departed from Memphis International Airport under clear visual meteorological conditions. The aircraft was lightly loaded for a domestic cargo run to Las Vegas. Initial climbout from runway 18R was uneventful until the crew experienced a sudden loud bang, followed almost immediately by a cockpit indication of fire in the left-hand engine (No. 1).
Flight crew reported to air traffic control that they were declaring an emergency due to an engine fire. The aircraft leveled off at roughly 3,700 feet and began a left-hand circuit to return. During the return leg, the flight crew noted that the fire warning had ceased, indicating the extinguishing agents had suppressed the flames. The aircraft was vectored for a priority landing and touched down safely on runway 18C approximately 15 minutes after initial departure.
Once on the ground, emergency crews confirmed the absence of an active fire, though they observed visible thermal damage to the left engine nacelle. The aircraft taxied under tow to the ramp, and no injuries were reported.
Crew Actions and Communication
The flight crew’s immediate response adhered strictly to Boeing’s Quick Reference Handbook (QRH) procedures for in-flight engine fire:
Fire handle pulled for engine No. 1. Both fire suppression bottles discharged sequentially. Thrust lever confirmed idle and fuel cutoff verified. Return-to-airport protocol initiated.
The coordinated actions demonstrated effective crew resource management (CRM), and all communications with Memphis Departure and Approach Control were executed clearly and without delay. The pilots provided updates on engine status and fire warning cessation. The decision not to continue to destination was justified due to the unknown extent of engine damage and the nature of the fire event.
Technical Analysis: Engine Failure and Fire Suppression
The aircraft was powered by two General Electric CF6-80C2 engines, a long-standing workhorse across freighter and passenger aircraft. Post-landing inspection revealed that the fire had originated beneath the engine cowling, in an area adjacent to the main fuel pump.
The NTSB’s investigation determined that the fire was caused by a high-pressure fuel leak stemming from the flange interface between the fuel crossover supply tube and the hydromechanical unit (HMU) idler adapter pad. The escaping fuel, under high pressure, atomised into a spray that made contact with hot engine components including the heat shield, leading to ignition.
Critical findings included:
The crossover tube bolts partially pulled out, failing to maintain a proper seal. Significant thermal damage and melting were observed at the fracture surface. The main fuel pump housing had separated from the supply line.
This undercowl fire presented significant risk, not only due to fuel ignition but also potential uncontained engine failure had the fire persisted or spread.
Manufacturing Defect and Design Non-Conformance
The root cause of the leak was traced back to manufacturing deficiencies. Specifically, Avio Aero, a supplier of the HMU adapter pad, had produced the bolt holes with out-of-spec geometry that failed to conform to GE Aerospace’s design specifications.
Key technical findings include:
Improperly installed threaded inserts were found protruding from the idler adapter pad. Multiple bolt holes showed evidence of stripped threads, cross-threading, and linear scoring. Threaded inserts were not seated flush, preventing adequate clamping of the crossover flange. An unapproved “pre-tap” operation was carried out on the adapter pad to simplify insert installation.
Avio Aero failed to notify GE Aerospace of this deviation and proceeded to ship the component without required concessions or requalification. GE’s subsequent quality review failed to detect the deviation. This lapse in quality control enabled a structurally compromised component to be installed and enter commercial service.
Passenger and Cabin Impact
As this was a cargo-only flight, no passengers were onboard. However, crew welfare remained a priority. There were no reports of smoke ingress into the cockpit or flight deck pressurisation issues. The fire was confined to the left engine’s lower cowl region, and the cockpit warning systems operated as intended.
The crew was able to complete a normal post-landing shutdown and disembark without emergency evacuation procedures. Emergency services performed a visual and thermal inspection upon arrival, confirming no ongoing hazard.
Emergency Response and Ground Operations
Airport Rescue and Firefighting (ARFF) units responded promptly, positioning along runway 18C during the aircraft’s final approach. Upon landing, fire crews observed charred components in the engine nacelle but no flames or smoke.
The aircraft was towed to a secure FedEx ramp for engineering evaluation. The runway was inspected for debris and damage, but none was found. Airport operations resumed normal service within minutes of the incident aircraft’s removal.
FedEx maintenance teams coordinated with GE Aerospace for teardown and analysis of the affected engine.
Investigation Outcome and Industry Impact
The NTSB formally categorised the event as an “accident” due to the engine fire and systems failure. Their final report, released on 1 May 2025, concluded the probable cause as:
“A high-pressure fuel leak from a gap in the bolted flange interface between the main fuel pump’s fuel crossover supply tube and the hydromechanical unit idler adapter pad, resulting in fuel escape and ignition.”
Contributing factors were extensive and systemic, including:
Manufacturing non-conformance: Avio Aero’s deviation from GE design without authorisation. Insert installation failure: Improperly seated and protruding steel inserts prevented proper sealing. Undetected production deviation: GE Aerospace’s failure to identify the issue during adapter quality reviews.
This accident exposes a critical failure of quality assurance processes across both component manufacture and OEM oversight.
Root Cause and Contributing Factors
The accident is a clear demonstration of how a small, undetected flaw in manufacturing can lead to significant flight risk. Key root causes:
Component defect: The non-compliant geometry and insert alignment led directly to flange bolt pullout. Ignition source proximity: The crossover tube’s location near the engine heat shield ensured leaked fuel would ignite quickly. Quality control breakdown: Both Avio Aero and GE failed to detect or document the unauthorised design deviation. No systemic traceability: Avio Aero lacked records explaining the deviation or confirming GE’s approval, suggesting a procedural bypass.
The investigation also highlighted how automated machining processes—when not verified—can quietly introduce systemic flaws into multiple units.
Safety Recommendations and Mitigations
The NTSB did not issue formal urgent safety recommendations but emphasised a need for enhanced manufacturing controls and part conformance audits. Recommended actions include:
Full fleetwide inspection of similar HMU idler adapters for improper insert installations. Enhanced traceability and quality sign-off procedures between suppliers and OEMs. Re-evaluation of fuel crossover tube clamp load tolerances and joint integrity under vibration. Training enhancements for quality assurance staff on inspection of insert seating and adapter pad integrity.
GE Aerospace and FedEx have both committed to full compliance with any applicable ADs or service bulletins arising from the event.
Conclusion
The engine fire aboard FedEx flight FX541 was swiftly and professionally managed by the flight crew, demonstrating textbook execution of in-flight emergency procedures. However, the root cause of the incident—a flawed manufacturing process undetected by multiple layers of oversight—reveals a deeper concern for supply chain assurance and component reliability in modern turbofan engines.
The aircraft returned to service fourteen days later following engine replacement and airworthiness evaluation. No injuries occurred, but the event served as a critical reminder of the cascading risk that a single misaligned bolt can represent in high-energy systems like jet propulsion.
Disclaimer
This article is based on publicly available information and reports at the time of writing. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided.
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