Flight Crew Last 90 Days 18
Aircraft Equipment Problem Critical
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft
Max GW TO and First Officer was PF. Just after liftoff Number 3 engine had a compressor stall and over-temp of 745 degrees (PW engine). Also; abnormal loud sound (thump) with gear retraction. Flew engine out profile; requested vectors straight out; declared Mayday and ran ENG 3 EGT HI checklist and eng compressor stall checklist. Contacted Dispatch; dumped 125;000 [pounds] of fuel and got vectors for the ILS. Had another abnormal sound during gear extension. Compressor stalls again on Number 3 engine on final. Normal landing. Shut down engine 3 after clearing runway.
This was the F/O's leg. Engine start and taxi out normal. We had to hold short for approximately 10 minutes to burn down to Max T/O weight (reduced from 630.5 to 629.2 for MEL'd items.) T/O roll was uneventful until gear retraction. We encountered a violent compressor stall on Number 3 engine with a level 3 ENG 3 EGT HI Alert displayed (745 deg C). After selecting the Confirm Engine Out prompt we requested and proceeded straight out and leveled off to accelerate and clean up. After Slat Retract we ran the ENG _ EGT HI checklist and retarded the affected engine throttle to idle. (The Level Three Alert was displayed for about 90 seconds). The vibration stopped and the engine parameters all returned to normal for idle power on Number 3. We declared a MAYDAY with Tower and advised we would like to be vectored for fuel dumping and a return for landing. We elected to leave the engine running as indications were normal but not to push the throttle forward fearing the outcome. After climbing to the designated altitude (3300-3900 Meters) we initiated fuel dumping per the checklist from approximately 199.0K to 70.0K which brought us to approximately 493.0K GW. We were approximately 40 NM out and requested approach vectors. Prior to fuel dumping we SATCOM called Dispatch and advised them of our plan. We selected the divert prompt on ACARS and set up for an ILS to the longest runway. We requested a return to the airfield and shot the ILS approach (Approximately 490.0K). On short final we had another minor Compressor Stall event on engine Number 3 so on landing rollout we shut down engine Number 3. Fire crews were waiting for us and followed us to parking. The landing was very smooth and taxi in normal. On post flight no visible damage noted.
MD11 flight crew experiences compressor stalls and high EGT on the number three engine at gear retraction. An emergency is declared and fuel is dumped before returning for landing at maximum landing weight.