Definition
A device used in a helicopter engine fuel control system that automatically increases fuel flow to the engine as collective pitch is raised, preventing rotor RPM from drooping (decreasing) under the increased load. It links collective pitch input to throttle adjustment so the engine maintains constant RPM as power demand changes.
Plain English
A mechanism that automatically adds power to the engine when the pilot demands more lift, so the rotor blades don't slow down.
Context Anchor
Seen in helicopter powerplant and rotor RPM control discussions, especially when learning how the engine responds to collective movement.
Derivation
Droop' here means a drop or sag in rotor RPM under load, like a flag drooping. 'Compensator' means something that offsets or makes up for a problem. Together: a device that compensates for the tendency of rotor RPM to droop when the pilot pulls more pitch.
Why Pilots Care
Prevents rotor RPM decay during collective increases, maintaining lift and control authority.
Intuition Check
Do not read “droop” as a bent or sagging aircraft part. Here, “droop” means a drop in rotor RPM, and the compensator helps prevent or reduce that drop.
Example Sentence 1
When the pilot raised the collective to begin a climb, the droop compensator automatically increased fuel flow to keep rotor RPM steady.
Example Sentence 2
During a hover, the droop compensator prevented RPM droop when the helicopter was loaded with additional weight.