Definition
A pilot-controlled lighting system that allows the pilot to select one of three preset intensity levels for runway and approach lights by keying the aircraft's microphone on the published Common Traffic Advisory Frequency (CTAF). Typically, 7 clicks within 5 seconds selects the highest intensity, 5 clicks selects medium, and 3 clicks selects the lowest.
Plain English
At many smaller airports without a control tower, the pilot turns on the runway lights by clicking the microphone button. A 3-step system gives three brightness choices: high, medium, or low.
Context Anchor
Seen in night operations and airport lighting discussions, especially at airports where pilots turn on or adjust runway lights from the airplane.
Derivation
Here, “step” means a fixed level or increment, not a walking step or a procedure step. The term points to the three fixed brightness levels available in that lighting control system.
Why Pilots Care
Proper brightness selection improves visibility at night or in low visibility while preventing glare that can reduce contrast or temporarily blind the pilot.
Grounding Statement
At many smaller airports the pilot selects the intensity by keying the radio a specific number of times within a short window.
Intuition Check
Do not read “3-step control” as a three-part checklist. In this context, it means three selectable brightness levels for airport lights.
Example Sentence 1
Approaching the non-towered field at night, the pilot keyed the mic seven times on CTAF to bring the runway lights up to full intensity on the 3-step control.
Example Sentence 2
With the 3-step control set to medium, the runway edge lights provided enough illumination without creating distracting glare on the wet pavement.