Definition
A signal sent by pressing the push-to-talk switch on the aircraft microphone five times within five seconds on the assigned Common Traffic Advisory Frequency (CTAF) to activate or set pilot-controlled airport lighting to its highest available intensity. At airports with this system, three clicks selects low intensity, five clicks selects medium intensity, and seven clicks selects high intensity, with each new keying resetting the lighting timer (typically 15 minutes).
Plain English
Tapping the radio's transmit button five times in a row turns the runway and approach lights up to medium brightness at airports where pilots control the lights themselves by radio.
Context Anchor
Seen in night operations at airports where pilots can turn on or adjust runway lights using the aircraft radio.
Why Pilots Care
It lets a pilot turn on runway lights without help from anyone on the ground, making night landings safer at remote or unattended airports.
Intuition Check
This does not mean saying “click” into the microphone or making a sound with your voice. It means pressing and releasing the radio transmit button five times on the correct frequency.
Example Sentence 1
On final approach to the unattended field, the pilot keyed the mic five times to bring the runway lights up to medium intensity.
Example Sentence 2
Before taxiing back for takeoff at the unlit airport the pilot used five microphone clicks to confirm the lights would stay on long enough for departure.