What requirement must be met concerning the altitude selector for takeoff?

The requirement that the altitude selector must correlate with the ATC clearance altitude is critical for ensuring compliance with air traffic control directives. This is essential to maintain safe and effective separation between aircraft as they take off and climb. By setting the altitude selector to match the clearances given by ATC, pilots can ensure that their intended flight path aligns with the air traffic management system, reducing the risk of altitude conflicts with other aircraft.

In addition, using the ATC clearance altitude helps in following predetermined airspace rules and regulations, contributing to overall safety in flying operations. This practice promotes disciplined flying and adherence to air traffic procedures, which is paramount, especially during critical phases of flight like takeoff.