The flight departed from Kuala Lumpur International Airport on 8 March at 00:41 local time (16:41 UTC, 7 March) and was scheduled to land at Beijing Capital International Airport at 06:30 local time (22:30 UTC, 7 March). It ascended to its assigned cruise altitude of 35,000 feet (10,700 m) and was travelling at 471 knots (542 mph; 872 km/h) true airspeed when it ceased all communications and the transponder signal was lost. The aircraft's last known position on 8 March at 01:30 local time (17:30 UTC, 7 March) was 6°55′15″N 103°34′43″E, corresponding to the navigational waypoint IGARI, at which the aircraft was due to alter its course slightly eastward. The aircraft was also expected to contact air traffic control in Ho Chi Minh City as it passed into Vietnamese airspace just north of the point where contact was lost.[21][22] The New Straits Times reported on 9 March that the captain of another aircraft had attempted to reach the pilots of MH370 "just after 1:30 am" to relay Vietnamese Air Traffic Control's request for MH370 to contact it. The captain said he was able to establish contact but just heard "mumbling" and static.[23]
Malaysia Airlines issued a media statement at 07:24 confirming that contact had been lost at 02:40 and that search-and-rescue operations had begun.[24] It later emerged that Subang Air Traffic Control had lost contact with the aircraft at 01:22 and notified Malaysia Airlines at 02:40. Neither the crew nor the aircraft's onboard communication systems relayed a distress signal, indications of bad weather, or technical problems before vanishing from radar screens.[12]