Definition
A handheld, high-intensity directional signaling device used by air traffic controllers in the control tower to communicate with aircraft when normal two-way radio communication is not available. The light gun projects a focused beam that can be aimed at a specific aircraft, and the color and steadiness of the light convey standardized instructions for ground and flight operations.
Plain English
A focused, colored spotlight that the tower aims at an aircraft to give it instructions when the radio isn't working. The color of the light, and whether it is steady or flashing, tells the pilot what to do.
Context Anchor
Seen in airport operations, especially when an aircraft has lost radio contact with the control tower or is operating without a radio.
Derivation
“Light” means visible brightness, and “gun” here means a device aimed in a chosen direction. In aviation, a light gun is not a weapon; it is a signal light that can be pointed at a specific aircraft or vehicle.
Why Pilots Care
Provides a reliable backup method for receiving takeoff, landing, and taxi clearances when radios are inoperative.
Intuition Check
Do not read “gun” as a firearm here. A light gun is an aimed signal lamp used to communicate with colored light.
Example Sentence 1
After his radio failed on downwind, the pilot watched for a steady green light gun signal from the tower clearing him to land.
Example Sentence 2
At the non-towered airport the specialist used the light gun to signal a flashing red light, telling us to stop taxiing and hold position.