When should checklists be started after landing?

Starting checklists after landing should be done once the aircraft has cleared the active runway because this is a critical time for ensuring safety and efficiency in operations. The active runway is where aircraft take off and land, and once an aircraft has exited it, the immediate risk of collision is significantly reduced.

Initiating checklists at this point allows the flight crew to begin a systematic review of procedures that pertain to the safe operation of the aircraft post-landing, including engine shutdown protocols, brake checks, and preparation for taxiing to the gate. This practice supports effective communication among the crew and helps to ensure that nothing is overlooked during the transition from flight operations to ground operations.

Other stages mentioned in the options occur after the aircraft has cleared the active runway. For instance, shutdown of engines or taxiing to the gate involves additional operational considerations that may distract from immediate post-landing procedures. Therefore, starting checklists after clearing the active runway allows the crew to focus on the key tasks required as part of their landing procedure safely.