An alternating red and green light signal from the control tower means which of the following?

• A. Land immediately
• B. Exercise extreme caution
• C. Hold position
• D. Contact ATC

Answer: (B)

An alternating red and green light from the tower is a special caution signal. It tells you to exercise extreme caution and proceed only as directed by ATC, because there may be hazards or unusual conditions on the airfield. It isn’t a command to land immediately, nor a simple hold signal, and it doesn’t replace radio contact—you should follow ATC instructions and stay alert for further guidance.