Final answer:
When an aircraft loses radio communications, an alternating red and green light signal from the air traffic control tower indicates that the pilot should wait and not make any movements. The pilot should communicate their intentions by other means and remain stationary until further instruction.
Step-by-step explanation:
In aviation, when an aircraft loses radio communications with the air traffic control tower, the tower can use light signals to communicate with the pilot. An alternating red and green light signal indicates that the pilot should wait and not make any movements on the runway or in the air. It signals that there is a communication problem, and the pilot should communicate their intentions by other means. The pilot should remain stationary until receiving further instruction.