What is a clearance void time?

• A. The time until which a clearance is valid.
• B. The time until which a clearance is valid; ensures pilots depart or reattempt clearance within a defined window.
• C. The time at which a clearance becomes effective.
• D. The time after which a clearance is canceled.

Answer: (B)

A clearance void time is the deadline by which you must begin acting on an ATC clearance. It sets a defined window to depart or reattempt the clearance. If you haven’t started the clearance by that moment, the clearance is considered void and you’d need to contact ATC to obtain a new clearance. This keeps traffic flowing and prevents pilots from holding onto an old clearance indefinitely. It’s not simply the moment a clearance becomes effective, nor merely a blanket cancellation; it’s the explicit time limit for initiating the cleared action.