When I was crewing and flying left seat in 'Fling-Wings it was called running out of blade.(where you can no longer sustain a hover) That point where full pitch was not enough to provide positive lift in the less dense atmosphere. This altitude changes depending on the loaded weight of the A/C, ambient air temp, (OAT) and barometric pressure. You CAN fly above this altitude in some rotary wing A/C, those equipped with Horizontal stabilizers to provide vertical lift in conjunction with forward speed (more speed = more lift) they just can't hover or land at that altitude. I doubt that the Mavic could reach the stated 5000 meter serviceable ceiling from any lower altitude before running out of power, due to the motors drawing more and more power to maintain lift, until they were at full throttle just to maintain a hover, although if you are going to try do it in the winter when the air is denser.