Receiver‐Only Acknowledgment

To obtain acknowledgment from an aircraft equipped with receiver only, request the aircraft to do the following:

1. Fixed‐wing aircraft:
   1. Between sunrise and sunset:
      1. Move ailerons or rudders while on the ground.
      2. Rock wings while in flight.
   2. Between sunset and sunrise: Flash navigation or landing lights.
2. Helicopters:
   1. Between sunrise and sunset:
      1. While hovering, either turn the helicopter toward the controlling facility and flash the landing light or rock the tip path plane.
      2. While in flight, either flash the landing light or rock the tip path plane.
   2. Between sunset and sunrise: Flash landing light or search light.

      TBL 3-2-1 ATC Light Signals

      Meaning
      Color and type of signal	Aircraft on the ground	Aircraft in flight	Movement of vehicles, equipment and personnel
      Steady green	Cleared for takeoff	Cleared to land	Cleared to cross; proceed; go
      Flashing green	Cleared to taxi	Return for landing (to be followed by steady green at the proper time)	Not applicable
      Steady red	Stop	Give way to other aircraft and continue circling	Stop
      Flashing red	Taxi clear of landing area or runway in use	Airport unsafe- Do not land	Clear the taxiway/runway
      Flashing white	Return to starting point on airport	Not applicable	Return to starting point on airport
      Alternating red and green	General Warning Signal- Exercise Extreme Caution	General Warning Signal- Exercise Extreme Caution	General Warning Signal- Exercise Extreme Caution