Incident Overview
On 15 August 2019, a McDonnell Douglas MD-11-F (registration N270UP) operated a flight from Cologne Bonn Airport (EDDK) to Warsaw Chopin Airport (EPWA). While cruising at flight level 330, the crew received a FADEC1 MAINT, ENG 2 alert. They performed the FADEC MAINT checklist from the Quick Reference Handbook (QRH) to secure the engine. Despite completing the checklist, the crew observed a loss of fuel flow indication. During descent into Warsaw, engine 2 experienced a decrease in rpm and subsequently shut down automatically. The crew executed the ENGINE SHUT DOWN IN FLIGHT checklist and declared an emergency with air traffic control.
Landing and Fire
The aircraft landed uneventfully on runway 33, escorted by emergency services. After vacating the runway via taxiway Sierra 2, the tower controller informed the crew that flames were visible from the exhaust of engine 2. Although the cockpit did not indicate an engine fire, the crew performed the engine fire extinguishing procedure. The airport fire brigade also engaged in external fire suppression.
Investigation Findings
The Polish State Commission on Aircraft Accident Investigation (PKBWL) determined that the incident resulted from a maintenance error during an overhaul of the fuel metering unit (FMU), part number 801000-4, serial number F28648, conducted by Aero Accessories FMU. A spring seat of the fuel metering valve was incorrectly installed in the port of the Minimum Pressurization and Shutoff Valve (MPSOV). This misassembly caused abnormal operation of the fuel metering valve, which subsequently could not fully shut off fuel flow after the crew initiated the ENGINE SHUT DOWN IN FLIGHT procedure. The continued fuel flow likely sustained the engine fire after landing.
Preventive Actions
The PKBWL accepted preventive measures proposed by the aircraft operator. These include: (a) implementing supervisory oversight during assembly to prevent incorrect installation of critical components, and (b) strengthening resource control to prevent unauthorized availability or use of incorrect or additional components.
No further safety recommendations were formulated.