Definition
A light gun signal transmitted from the control tower to an aircraft that has lost radio communication. To an aircraft in flight, a flashing green light means 'return for landing' (to be followed by a steady green at the proper time). To an aircraft on the ground, it means 'cleared to taxi.'
Plain English
When the tower can't talk to you on the radio, they aim a bright lamp at you and flash a green light. If you're flying, it means come back and land — wait for a steady green before actually touching down. If you're on the ground, it means you're allowed to taxi.
Context Anchor
Used in lost communication procedures when the control tower communicates with an aircraft by aiming colored light signals instead of using radio calls.
Derivation
“Flashing” means turning on and off repeatedly. “Green” is commonly used as a permission color, but in aviation the exact permission depends on whether the aircraft is on the ground or in the air.
Why Pilots Care
Enables continued safe movement without radio contact.
Grounding Statement
Picture the tower aiming a blinking green light at your aircraft because you cannot hear or answer radio instructions.
Intuition Check
Do not assume flashing green simply means “go” in every situation. On the ground it means cleared to taxi; in flight it means return for landing and wait for a steady green before landing.
Example Sentence 1
After the radio went silent, the tower aimed a flashing green light at the aircraft, signaling the pilot to return to the airport for landing.
Example Sentence 2
Seeing the flashing green while in the pattern, the pilot turned back to land at the departure airport.