Malaysian Airline System Flight 653

Malaysian Airline System Flight 653 (MH653) was a scheduled domestic flight from Penang to Kuala Lumpur in Malaysia, operated by Malaysian Airline System (MAS). On the evening of 4 December 1977, the Boeing 737-200 aircraft flying the service crashed at Tanjung Kupang, Johor, Malaysia, while purportedly being diverted by hijackers to Singapore. It was the first fatal air crash for Malaysia Airlines (as the airline is now known), with all 93 passengers and 7 crew killed. It is also the deadliest aviation disaster to occur on Malaysian soil. The flight was apparently hijacked as soon as it reached cruise altitude. The circumstances in which the hijacking and subsequent crash occurred remain unsolved.

Aircraft
The aircraft involved was a Boeing 737-2H6 registered as It had been delivered new to MAS in September 1972 with registration

Sequence of events
Flight 653 departed from Runway 22 at Penang International Airport at exactly 19:21 for Kuala Lumpur's Subang Airport (now known as Sultan Abdul Aziz Shah Airport).

Captain GK Ganjoor and First Officer Karamuzaman Jali were making landing preparations at 19:54, while at an altitude of 4000 feet over Batu Arang and descending toward Runway 33 at Subang Airport, when the crew reported to Subang Tower that an "unidentified hijacker" was on board, after someone knocked on the cockpit doors. Subsequently, the pilots were forced to cut off all communications by one or more hijackers who suddenly barged into the cockpit. The tower immediately notified the authorities, who made emergency preparations at the airport.

A few minutes later, the crew radioed: "We're now proceeding to Singapore. Good night." In the last few minutes of the tapes from the cockpit voice recorder, investigators heard conversation between the pilots and the hijackers about how the aircraft would run out of fuel before it could make it to Singapore, followed by a series of gunshots. They concluded that both the pilot and co-pilot were fatally shot by the hijacker, which left the plane "professionally uncontrolled". At 20:15, all communication with the aircraft was lost. At 20:36, the residents of Kampong Ladang, Tanjung Kupang in Johor reported hearing explosions and seeing burning wreckage in a swamp. The wreckage was later identified as the aircraft; it had hit the ground at a near-vertical angle at a very high speed. There were no survivors.

Investigation and aftermath
The full circumstances of the hijacking and crash were never solved. An analysis by Malaysia's Department of Civil Aviation of evidence from the investigation concludes that: All recovered remains were x-rayed in an attempt to discover evidence of a projectile or weapon, but no such evidence was ever found. The remains of the victims were interred in a mass burial.
 * The aircraft was "hijacked by person or persons unknown", who were determined not to land at Kuala Lumpur
 * The crew "carried out their hijack procedures properly and correctly... throughout the flight."
 * The hijackers incapacitated the crew as the aircraft descended in its approach to Singapore
 * There was no explosion, fire, or structural failure prior to impact
 * Unusual pitching – up and down – movements occurred in the aircraft's final moments in the air. These manoeuvres were the result of the actions of person or persons unknown and developed until the aircraft's trajectory became unrecoverable, resulting in its impact with the ground

After the incident, the Aviation Security Unit of the Airport Standard Division of the Department of Civil Aviation Malaysia was established.

Passengers and crew
Passengers included the Malaysian Agricultural Minister, Dato' Ali Haji Ahmad; Public Works Department Head, Dato' Mahfuz Khalid; and Cuban Ambassador to Japan, Mario García Incháustegui.

The numbers and nationalities of the passengers and crew appear in the table below: