The meaning of the undefined term ‘accident’ in Article 17(1) of the Montreal Convention 1999 (MC99) has been unclear in Chinese cases for several years. In 2020, for the first time, the appellate court in Qatar Airways Group Q.C.S.C. v. Zhao et al. (‘Zhao’) defined ‘accident’ with the meaning almost the same as the one defined by the US Supreme Court in Air France v. Saks, yet concluded that the passenger’s death onboard the aircraft which was not timely detected by the carrier constituted an Article 17 ‘accident’, and held the carrier liable, even if the death caused by the passenger’s acute heart and respiratory failure was due to natural causes. The Zhao ruling also contains unsatisfactory rationales as reflected in the court’s inconsistent and controversial approaches in identifying the ‘accident’. After explaining the representative practice in other MC99 jurisdictions regarding the meaning of ‘accident’, this article introduces the Zhao case and discusses three unresolved issues pertaining to the Zhao ruling, namely the misidentification of death per se as an ‘accident’, the tendency and ambiguity of identifying the carrier’s omissions as de facto ‘accidents’ and, the flawed application of the Saks test in identifying some usual and expected conditions in normal flight activities as de facto ‘accidents’. It concludes that though the Zhao ruling can serve as an example to show the trend of acknowledging the Saks definition in Chinese practice, the meaning of ‘accident’ in a case regarding passenger death onboard the aircraft remains unsettled.