MD11 Relief Pilot and Dispatcher reported an engine compressor stall during takeoff. The flight crew contacted Dispatch and Maintenance and decided to return to the departure airport after dumping fuel.
Synopsis
MD11 Relief Pilot and Dispatcher reported an engine compressor stall during takeoff. The flight crew contacted Dispatch and Maintenance and decided to return to the departure airport after dumping fuel.
Narrative
At approximately 1;000 ft AGL; we heard a Big Bang; thinking it was a bird. Then 2-3 seconds later; heard another bang; followed by another. I looked up and saw #1 engine N1 RPM roll back and recovering. I scanned rest of engine parameters-all appeared normal except EVM Comp at 1.9; TURB at 1.3. I called out to the Captain compressor stall #1 engine. He reached up to reduce power; but engine had already recovered. At this point he hands me the checklist to run for Compressor stall. We completed checklist and they made call to ATC. ATC gave us a level off of FL100. During climb; Captain completed after takeoff checklist. We discussed options; with major concern of taking a suspect engine over water on a 9+30 hour flight. Captain directed me to contact Dispatch and Maintenance Control to inform and discuss options. Maintenance Control suggested a return to ZZZZ for inspection. Captain made decision to return but first we had to dump fuel to landing weight. Takeoff weight was heavy. ATC gave us vectors north towards coast and we were about FL200. Completed dumping and flew full stop landing to Rwy XXR with no further problems encountered.Cause: Unknown mechanical issue with #1 engine.
Second reporter narrative
The crew of Aircraft X called on SATCOM to advised that they had a compressor stall on the #1 engine at takeoff. Cause: Aircraft X suffered a compressor stall on the #1 engine while taking off from ZZZZ. Maintenance Control was conferenced in and they advised the crew to return to ZZZZ. The crew advised that they did not want to declare an emergency. The crew advise that they needed to dump 130.0K of fuel to get below landing weight.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.