Block Time

Block time (also called chock-to-chock time) is the total elapsed time from the moment an aircraft first moves under its own power for the purpose of flight (blocks off / chocks removed) until it comes to rest at the destination parking position and the engines are shut down (blocks on / chocks placed).

Block time includes taxi time at departure, flight time (wheels-off to wheels-on), and taxi time at arrival. It is distinct from flight time, which only measures airborne time. Block time is the standard measure used for:

• Airline scheduling and published timetables
• Crew duty time and flight time limitations
• Aircraft utilization metrics
• Maintenance interval tracking (some checks are based on flight hours, others on cycles or calendar time)

The difference between scheduled block time and actual block time is a key airline performance metric, as consistent delays indicate operational issues.