What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On January 29, 2021, about 10:49 pacific standard time, a Boeing 767-338, registration number, N363CMprivacy data omitted, and powered by
Two general electric (ge) CF6-80C2-B6 turbofan engines, experienced a right (no. 2) engine fire during climb from los angeles international airport (lax), los angles, California. A diversion to the Ontario international airport (ont), Ontario, California for an uneventful single engine landing was made. The incident flight was a 14 code of federal regulations (CFR) part 129 cargo flight from lax to the Mexico
City international airport (mex), Mexico city, Mexico.
A post landing inspection revealed extensive damage to the #2 engine, and minor damage to the aiframe to include punctures to the right aileron and rear cargo door.
Based on dfdr data, the engine operated in a high unbalanced condition (>5 cu's) for approximately 4 minutes, then continued windmilling for at least 40 minutes near 2.5 cu's.
The most likely failure scenario as of the date of this report is as follows:
1. Low pressure turbine (lpt) stage 5 nozzle liberated two airfoils.
2. This failure led to secondary damage to lpt stage 4 & 5.
3. Rotor imbalance occurs that is calculated at 50 cu's, over 10 times what the FDR can record and the equivalent of a fan blade out (FBO) event.
4. Lpt stages 1, 2 and 3 sustain severe rub damage from contact and airfoils crack midspan.
5. Accessory gearbox transverse linkage breaks, causing oil line to fracture and an oil-fed fire to start.
This event is considered a contained engine failure, and all engine controls and fire supression systems worked as expected.
The engine had logged 54,187 hours since new (20,656 cycles), but only 1,649 hours (669 cycles) since last overhaul.
As the FAA filed it
ON JANUARY 29, 2021, ABOUT 10:49 PACIFIC STANDARD TIME, A BOEING 767-338, REGISTRATION NUMBER, N363CM^PRIVACY DATA OMITTED^, AND POWERED BY
TWO GENERAL ELECTRIC (GE) CF6-80C2-B6 TURBOFAN ENGINES, EXPERIENCED A RIGHT (NO. 2) ENGINE FIRE DURING CLIMB FROM LOS ANGELES INTERNATIONAL AIRPORT (LAX), LOS ANGLES, CALIFORNIA. A DIVERSION TO THE ONTARIO INTERNATIONAL AIRPORT (ONT), ONTARIO, CALIFORNIA FOR AN UNEVENTFUL SINGLE ENGINE LANDING WAS MADE. THE INCIDENT FLIGHT WAS A 14 CODE OF FEDERAL REGULATIONS (CFR) PART 129 CARGO FLIGHT FROM LAX TO THE MEXICO
CITY INTERNATIONAL AIRPORT (MEX), MEXICO CITY, MEXICO.
A POST LANDING INSPECTION REVEALED EXTENSIVE DAMAGE TO THE #2 ENGINE, AND MINOR DAMAGE TO THE AIFRAME TO INCLUDE PUNCTURES TO THE RIGHT AILERON AND REAR CARGO DOOR.
BASED ON DFDR DATA, THE ENGINE OPERATED IN A HIGH UNBALANCED CONDITION (>5 CU'S) FOR APPROXIMATELY 4 MINUTES, THEN CONTINUED WINDMILLING FOR AT LEAST 40 MINUTES NEAR 2.5 CU'S.
THE MOST LIKELY FAILURE SCENARIO AS OF THE DATE OF THIS REPORT IS AS FOLLOWS:
1. LOW PRESSURE TURBINE (LPT) STAGE 5 NOZZLE LIBERATED TWO AIRFOILS.
2. THIS FAILURE LED TO SECONDARY DAMAGE TO LPT STAGE 4 & 5.
3. ROTOR IMBALANCE OCCURS THAT IS CALCULATED AT 50 CU'S, OVER 10 TIMES WHAT THE FDR CAN RECORD AND THE EQUIVALENT OF A FAN BLADE OUT (FBO) EVENT.
4. LPT STAGES 1, 2 AND 3 SUSTAIN SEVERE RUB DAMAGE FROM CONTACT AND AIRFOILS CRACK MIDSPAN.
5. ACCESSORY GEARBOX TRANSVERSE LINKAGE BREAKS, CAUSING OIL LINE TO FRACTURE AND AN OIL-FED FIRE TO START.
THIS EVENT IS CONSIDERED A CONTAINED ENGINE FAILURE, AND ALL ENGINE CONTROLS AND FIRE SUPRESSION SYSTEMS WORKED AS EXPECTED.
THE ENGINE HAD LOGGED 54,187 HOURS SINCE NEW (20,656 CYCLES), BUT ONLY 1,649 HOURS (669 CYCLES) SINCE LAST OVERHAUL.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.