What position must arresting systems be in when controlled remotely by ATC?

When arresting systems are controlled remotely by Air Traffic Control (ATC), they must be in the retracted or down position. This positioning is crucial for ensuring that the arresting wires or other mechanisms are ready to engage aircraft if needed. The retracted position allows for the safe operation of the runway or taxi areas when the systems are not actively engaged. If an aircraft requires the use of these systems for emergency landings or to stop safely, having them down ensures they will function as intended.

In this context, the operational status of the systems being down signifies that they are poised for immediate use without posing any risk to other aircraft operations. The terms 'reclined', 'upright', 'operational', 'inactive', 'raised', and 'lowered' imply various states that do not convey the critical readiness factor that comes with a retracted or down position. Hence, ensuring that the arresting systems are reliably positioned to fulfill their function is vital for maintaining safety in operations around the runway and for landing aircraft.