Pilot Controlled Lighting
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Pilot Controlled Lighting (PCL), also known as Aircraft Radio Control of Aerodrome Lighting (ARCAL) or Pilot Activated Lighting (PAL), is a system which allows aircraft pilots to control the lighting of an airport or airfield's, approach lights, runway edge lights, and taxiways via radio. PCL systems are most common at non-towered or little-used airfields where it is neither economical to light the runways all night, nor to provide staff to turn the runway lighting on and off. PCL enables pilots to control the lighting only when required, saving electricity and reducing light pollution.
If the airfield supports PCL, the pilot sets the radio to the ARCAL frequency for the airport, which is usually the same as the UNICOM/CTAF frequency (for example Smiths Falls-Montague Airport hosts separate Unicom and ARCAL frequencies). The systems are typically operated by clicking the radio microphone talk button.
PCL systems usually have three settings:
- Low intensity: Three clicks within seven seconds
- Medium intensity: Five clicks within seven seconds
- High intensity: Seven clicks within seven seconds
When the system is activated, a 15-minute countdown starts, after which the lights turn off. While the lights are on, whenever a lighting command is issued, whether it changes the lighting intensity or not, the 15-minute countdown is reset. At some airfields, special lights may blink for ten seconds to warn pilots before the lights shut off.
When using PCL, it is strongly recommended that aircraft on final approach to the airfield issue a fresh lighting command, even if the lights are already on (especially if the lights were activated by another aircraft). This is so that the lighting does not turn off at a critical moment (such as when crossing the runway threshold).
