What is indicated by all lights being on while crossing a runway?

When all lights are on while crossing a runway, it indicates that the engines are running. This situation typically signifies that the aircraft is ready for takeoff or is preparing to move onto the runway. The illumination of all lights serves as a safety precaution, alerting air traffic control and other aircraft in the vicinity that the plane is operational and that caution is required when approaching the runway or other aircraft.

In aviation operations, the illumination of these lights communicates that the aircraft is actively engaged and preparing to taxi, takeoff, or possibly execute a landing. Therefore, this understanding reinforces the notion that the engines must be running to activate these signals, ensuring safety protocols are adhered to.

This scenario highlights the importance of visual signals in managing ground and flight operations at an airport, as they play a crucial role in maintaining awareness among pilots and air traffic controllers.