Definition
An engine-driven fuel pump that automatically adjusts its output pressure in response to changes in atmospheric or engine inlet air pressure, so that the fuel pressure delivered to the carburetor or fuel control unit remains correct relative to the surrounding air pressure as altitude changes.
Plain English
A fuel pump that senses how much air pressure is around it and adjusts its own pressure to match, so the engine keeps getting the right amount of fuel as the airplane climbs or descends.
Context Anchor
Seen in aircraft fuel system descriptions, maintenance manuals, and engine fuel pressure checks.
Derivation
Compensated comes from the Latin compensare, meaning 'to balance' or 'to make up for.' The pump is named for what it does: it balances out the effect of changing air pressure so the fuel system keeps working correctly at any altitude.
Why Pilots Care
Prevents fuel starvation or mixture problems caused by altitude-induced pressure changes, supporting reliable engine operation throughout the flight envelope.
Analogy
Think of it like someone adjusting the pressure on a garden hose as the water demand changes, so the spray stays steady instead of becoming too weak or too strong.
Intuition Check
Compensated does not mean the pump has been paid for or simply repaired. Here it means the pump automatically adjusts one pressure to match changes in another pressure.
Example Sentence 1
The compensated fuel pump maintains the correct fuel pressure at the carburetor as the aircraft climbs to higher altitudes.
Example Sentence 2
The pilot noticed smooth engine operation after climb because the compensated fuel pump continued to supply the correct fuel volume as outside pressure dropped.