Definition
A shaped iron or steel piece attached to the inside of an electrical machine's frame (such as a generator, motor, or magneto) that concentrates and directs the magnetic field from the field coils across the air gap to the rotating armature.
Plain English
A curved metal piece inside a generator or motor that focuses the magnet's pull onto the spinning part in the middle. It acts like a guide that steers the magnetic force where it needs to go.
Context Anchor
Seen in aircraft magneto and ignition system descriptions during powerplant maintenance training.
Derivation
From the magnetic 'pole' (north or south end of a magnet) and 'shoe' meaning a fitted protective or shaping piece. The shape of the part — a curved cap fitted over the end of the field magnet — is what gives it the name 'shoe.'
Why Pilots Care
Intact pole shoes maintain strong spark output in magnetos; damage reduces ignition reliability and can cause engine roughness.
Intuition Check
Do not read shoe as footwear or pole as a stick. Here, pole means the end of a magnet, and shoe means the shaped metal piece fitted there to guide the magnetic field.
Example Sentence 1
During inspection of the starter generator, the technician checked the pole shoes for security and signs of wear.
Example Sentence 2
A cracked pole shoe was replaced to restore full generator performance before the next flight.