Definition
An electrical relay or solenoid designed to be energized only for short periods of time, not continuously. Its coil is built to handle the heat produced during brief operation, and would overheat and fail if left energized for extended periods. Common examples in aircraft include the starter solenoid and landing gear motor relays, which carry heavy current for a few seconds at a time.
Plain English
An electrical switch that's only meant to be turned on for short bursts. If you leave it on too long, it will overheat and burn out.
Context Anchor
Seen in aircraft electrical system and starter circuit descriptions, especially in maintenance manuals and parts specifications.
Derivation
Intermittent comes from the Latin intermittere, meaning to leave off or pause. The term signals that the device is built to work in short bursts with rest periods between, not run steadily.
Why Pilots Care
Prevents overheating and premature failure in starter and retraction systems that draw high current only briefly.
Analogy
It is like a doorbell button: it is meant to be pressed briefly, not held down for minutes at a time.
Intuition Check
Intermittent does not mean the part works unpredictably. Here it means the part is designed for short on-times with rest time between them.
Example Sentence 1
The starter solenoid is an intermittent-duty relay, so the pilot's operating handbook limits cranking to ten seconds followed by a cooling period.
Example Sentence 2
Landing gear solenoids are typically intermittent-duty units because they operate for just a few seconds during extension or retraction.