一伦敦前往北京航班出现故障，国航通报最新进展

Group 1 - The flight CA856 from London to Beijing experienced a mechanical failure during the flight, leading to a safe emergency landing as per protocol [1] - To ensure passenger service and support, the airline dispatched a replacement aircraft to the emergency landing airport to continue subsequent flight operations [1] - The replacement flight successfully arrived at Beijing Capital International Airport at 4:40 AM on August 27 [1]