What happened
On a scheduled service from Penang Airport to Kuala Lumpur, the MH653 flight was diverted following an in-flight security breach. At approximately 19:21 local time, while the Airbus A320 (implied by MH service) was descending at 4,000 feet, an individual gained unauthorized access to the cockpit. Following this intrusion, the aircraft climbed to flight level 210 and changed course toward Singapore.
During the diversion, the hijacker shot both the pilot and the co-pilot before taking his own life. Shortly after these events, the aircraft entered a steep dive and impacted a forested area near Jalan Tanjung Kupang. The impact resulted in the total destruction of the aircraft and the deaths of all 100 occupants on board.
Findings
Flight data and cockpit voice recordings revealed evidence of a forced entry into the flight deck, accompanied by sounds of distress. Analysis suggests that during the struggle or subsequent takeover, the autopilot was disengaged. Investigators noted that manual inputs to the control column likely triggered an unstable pitch oscillation. This movement escalated into a high-amplitude phugoid oscillation, which ultimately drove the aircraft into its terminal dive.