The redundant backup of aircraft equipment is fully considered at the beginning of the design of modern civil aircraft,allowing the air carrier to continue operation with inoperative aircraft equipment in accordance with MEL and improving the efficiency of aircraft use and the normal operation of the aircraft.Although this state of the aircraft is guaranteed at an acceptable level of safety,it always comes along with some limitations or adjustments of standard operating procedures.The dispatcher should match and evacuate the limitations and adjustments with the actual operating route to ensure the comprehensive risk identification and effective response measures.This article explores a typical case of retaining and releasing the aircraft with single air conditioning pack,analyse the operational limitations and develops targeted measures to ensure the operational safety.