On 21 March 2022, soon after entering the Guangzhou radar control area level at the equivalent of FL290, a Boeing 737-800 was observed, contrary to clearance, to begin a sustained and very rapid descent without contacting ATC. After disappearing from radar, it was subsequently found to have impacted terrain at high speed which destroyed the aircraft and caused the deaths of all 123 occupants. The Investigation has commenced and both severely damaged flight recorders have been recovered. Analysis of recovered data is believed not to indicate an airworthiness-related explanation but this has not been confirmed by the responsible Investigation Agency.