The current world record for absolute altitude achieved by a helicopter — 12,442 meters (40,820 feet), flown by a heavily modified SA 315 Lama — has stood for more than 45 years at this writing.
After starting the engine, they removed the starter motor to save weight.
Then when the engine flamed out at 40 squillion feet, they set the record for the world's highest autorotation, as there was no way to relight the engine.
PS you are too lazy to Gurgle the answer yourself?