B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 30; Flight Crew Total 22000; Flight Crew Type 150
Troubleshooting; Situational Awareness; Distraction; Workload
Aircraft Equipment Problem Critical
Flight Crew Became Reoriented; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
After takeoff; during climb at about 600 FT; noticed left engine overheat and overspeed. Retarded throttle and continued climb. Also got a 'Thrust Asym Prot' EICAS message. [Advised ATC] initially and performed both checklists. Contacted Dispatch; Maintenance Control and the Duty Officer. After discussions with all; initially according to our checklist and the Duty Officer; we could have continued the flight since engine was now running normally. However; after Maintenance Control recovered engine overheat and overspeed parameters; it was decided to return to the departure airport. Dispatch recommended returning because we had burned fuel and there were very few options on our route to go for refueling. Our primary concern was engine condition. We climbed to FL240; jettisoned fuel for landing. We returned to the departure airport for a normal two engine landing.
Preflight planning; pushback; start and taxi were perfectly normal.  Weather was perfect.  With the Captain flying and I monitoring; we were cleared for takeoff.  After rotation and gear retraction at approximately 500 feet; the N1 and EGT displays of the left engine surged and turned red.  There were no other physical or aural indications present.  The captain retarded the left throttle and we continued straight ahead to 3;000' and engaged the autopilot.  The overtemp/overspeed indications ceased when the throttle was retarded.  We [advised ATC] and entered holding.  After consultation with dispatch/Maintenance Control/Duty Officer via satellite phone; it was determined that continued flight was not advisable.  We climbed to FL240 and dumped 140;000 pounds of fuel.  We then returned to the departure airport and landed uneventfully.
B777 flight crew reported left engine N1 overspeed and EGT overtemp after takeoff that resulted in a return to the departure airport.