Definition
A vertical or near-vertical structural member used as a mounting point or support. In aviation, a mast typically refers to a small upright fitting on the aircraft's exterior used to mount an antenna, a pitot tube, or other sensing or communication device, or to a support structure inside a component such as a helicopter rotor mast that transmits drive from the transmission to the rotor head.
Plain English
An upright post or shaft used either to hold something out into the airflow (like an antenna or pitot tube) or to carry rotational drive up to a helicopter's rotor.
Context Anchor
Seen in aircraft maintenance descriptions, helicopter rotor system discussions, and preflight inspections of external mounted equipment.
Derivation
From the Old English 'mæst,' meaning the upright pole on a ship that carries the sails. The aviation use keeps the same idea: an upright support that holds something important above or away from the main structure.
Why Pilots Care
Mast condition directly affects rotor balance, vibration levels, and flight safety; damage or misalignment can lead to severe handling problems.
Intuition Check
Mast does not only mean the pole on a sailboat. In aviation, it means a support or shaft on an aircraft, often connected to mounted equipment or a helicopter rotor system.
Example Sentence 1
During preflight, the pilot checked that the pitot mast was clear of any cover or obstruction.
Example Sentence 2
Excessive vibration was traced to a worn bearing on the main rotor mast.