What do you remember about how to communicate with ATC if you lose radio comms or need to fly an aircraft without a radio? We all learned about light gun signals as student pilots, but we seldom quiz ourselves to check our retention.
Let’s face it, if you had a real-world radio failure tomorrow and the tower was trying to communicate with you by flashing a light gun your way, would you know what they were trying to say or how to respond?
If not, the good news is, you aren’t alone, and it’s easy to fix the problem. Step 1 is to set ourselves up for no radio (NORDO) success by flying with an easily accessible light gun signal cheat sheet like the one printed on this deluxe VFR pilot kneeboard. Step 2 is a quick refresher on what light gun signals are, what they mean, and how to respond.
Ready? Let’s get started.
What Are Light Gun Signals?
The FAA Pilot/Controller Glossary describes light guns as “A handheld directional light signaling device which emits a brilliant narrow beam of white, green, or red light as selected by the tower controller.”
The glossary goes on to explain that “the color and type of light transmitted can be used to approve or disapprove anticipated pilot actions where radio communication is not available.”
The signals produced by the light gun are used “for controlling traffic operating in the vicinity of the airport and on the airport movement area.”
What Do Light Gun Signals Mean?
The signals from a light gun mean different things depending on the color, whether the light is solid or flashing, and whether the plane receiving the signal is in the air or on the ground. All light gun signs tell a pilot to either take or not take each type of action.
Keep reading for a quick refresher on the meaning of light signals for both ground-based and airborne planes.
Light Gun Signals for Aircraft on the Ground
Planes on the ground can receive any one of six different light gun signals. The signals and their corresponding meanings are:
Aircraft is cleared for takeoff. A steady green light means that the runway in front of you is free of traffic and you may take off.
Cleared for taxi. Once you receive a flashing green light, you are cleared to taxi. Remember to hold for takeoff until you receive a steady green light.
Stop. Hold your position and wait for further instructions.
Taxi clear of runway in use. A flashing red light is typically used to advise pilots who have just landed to take the nearest possible taxiway and clear the active runway for other incoming traffic.
Return to starting point on airport. A flashing white light can be used when the airfield is currently too busy to support no radio (NORDO) operations, and the controller needs you to park until traffic slows down and they can fit you in.
Alternating Red and Green Flashes
Exercise extreme caution. The FAA has advised controllers that the alternating red and green signal should be used when:
- Aircraft are converging and a collision hazard exists.
- Mechanical trouble exists of which the pilot might not be aware.
- Other hazardous conditions are present which call for intensified pilot or operator alertness. These conditions may include obstructions, soft field, ice on the runway, etc.
The FAA’s brief also notes: “The warning signal is not a prohibitive signal and can be followed by any other light signal, as circumstances permit.”
Light Gun Signals for Aircraft in Flight
Planes in the air can receive any one of five different light gun signals. The signals and their corresponding meanings are:
Cleared to land. Once you receive a steady green light, this counts as a clearance to land. The controller is indicating the runway will be unoccupied and you are authorized to land on it.
Return for landing. If you receive a flashing green light when approaching the airfield, the controller is instructing you to do a go-around because you are not yet cleared to land but should be cleared shortly. Remain in the pattern and watch for the steady green light that clears you to land.
Give way and continue circling. Typically, an aircraft without radio communications will be allowed to land as soon as possible, but there may be a situation where another aircraft needs to come in first on the same runway. If you see a steady red light when approaching the runway, locate the other involved aircraft and remain clear. Allow them to land first while you circle and wait for the steady green light.
Airport unsafe, do not land. A flashing red light is a catch-all way for a controller to indicate to an incoming NORDO pilot that some form of hazard on the runway or at the airport is making it unsafe for you to land. As the pilot in command, you can go around, try lining up for another runway, or choose to divert to another airport. Depending on your situation, you may need to visually assess the situation and then land anyway in the case of a dire emergency.
Flashing white lights are not used to signal aircraft in flight.
Alternating Red and Green Flashes
Exercise extreme caution. See detailed description above in the “Light Gun Signals for Aircraft on the Ground” section.
How to Respond to Light Gun Signals from ATC
You’ve received and understood the light signal message from ATC. Now what? How do you signal your response without a radio? Just like the predetermined light signal codes, the FAA has developed a standardized aircraft response.
Airplanes flying during the day should acknowledge the signals by moving ailerons and rudders to rock the wings. Pilots on the ground during daylight hours should also acknowledge by moving ailerons and rudders so the controller will see the control surfaces moving in response to the light signals.
At night, light gun signal acknowledgements should be made by flashing landing lights or navigation lights off and on twice whether you are on the ground or in the air.
Want to refresh yourself on other signs and signals? Here are some articles we think you’ll find useful:
- Airport Runway Lights: Spacing and Colors (All the Details)
- How to Read Airport Signs (Everything You Need to Know)
Have you ever needed to rely on light gun signals during a takeoff or landing? We’d love to hear about it! Share your story in the comments below.