If you are a single ship full-stop landing on the hot side of the runway, when are you permitted to cross to the cold side?

The correct answer emphasizes the importance of communication and procedural safety in aviation operations. Being cleared by the Runway Safety Unit (RSU) indicates that it is safe for you to cross from the hot side of the runway to the cold side. This clearance is a critical step for ensuring that the entire air traffic scenario is under control and that there are no conflicts with other aircraft, whether they are landing, taking off, or taxiing.

The role of the RSU is to maintain safe operations on and around the runway, and their clearance signifies that all conditions are favorable for crossing without posing a hazard to yourself or other aircraft. It is essential to have explicit permission before crossing to minimize the risk of accidents and ensure that all parties are aware of your intentions.

This process also reinforces the broader aviation principle of following established protocols and communication channels, which is vital for maintaining safety in aircraft operations.