Plain English Meaning
A small sensor that feels the sharp jolt of a crash and switches the emergency beacon on by itself, so it works even if the pilot is unable to.
Full Definition
A device installed in an aircraft that detects the sudden deceleration or impact forces of a crash and automatically triggers the Emergency Locator Transmitter (ELT) to begin broadcasting a distress signal.
Context Anchor
Seen in discussions of Emergency Locator Transmitters, especially how an ELT activates after an accident or hard impact.
Why Pilots Care
It ensures the ELT sends a distress signal without any action from the pilot, speeding up search and rescue after an accident.
Intuition Check
A crash sensor does not decide whether an event is officially a crash. It reacts to strong impact or sudden stopping forces that are large enough to trigger the ELT.
Example Sentence 1
After the hard landing, the mechanic inspected the ELT to make sure the crash sensor hadn't been triggered.
Example Sentence 2
During inspection the mechanic checked that the crash sensor would trigger the ELT under simulated high-impact conditions.