On Dec. 19, 1997, SilkAir Flight 185 took off from Indonesia, bound for Singapore. There were 97 passengers and seven crew on board as the flight lifted off at 3:37 p.m. local time.
Thirty-five minutes later, the aircraft mysteriously and suddenly dove vertically into Musi River in Sumatra. All on board perished.
The Indonesian government investigation said the cause of the crash was "inconclusive."
But the US National Transportation Safety Board, which worked jointly with the Indonesian team, concluded that the pilot committed suicide. In a letter to the Indonesian safety committee, the NTSB wrote:
The examination of all of the factual evidence is consistent with the conclusions that: 1) no airplane-related mechanical malfunctions or failures caused or contributed to the accident, and 2) the accident can be explained by intentional pilot action. Specifically, a) the accident airplane’s flight profile is consistent with sustained manual nose-down flight control inputs; b) the evidence suggests that the cockpit voice recorder (CVR) was intentionally disconnected; c) recovery of the airplane was possible but not attempted; and d) it is more likely that the nose-down flight control inputs were made by the captain than by the first officer.
There are a number of parallels that are now being drawn in online aviation forums between the Malaysia Airlines Flight 370 and the SilkAir 185 tragedy.
The only new information in the last 24 hours is that military radar tracks the aircraft making an abrupt change of course and flying for an hour and 10 minutes west over the Malaysia peninsula and into the Strait of Malacca. At that last known position, presumably when the military radar lost contact, the aircraft was at 29,500 feet, according to Malaysia's Air Force chief Rodzali Daud.
Why no radio communication? Why not transponder signal? Why no contact at all with the ground as the plane continued at just a few thousand feet below cruising altitude for more than an hour?
Most aviation professionals suggest that a flight crew member would know how to turn off or disable radio, transponder, and the Aircraft Communication Addressing and Reporting System (ACARS), the on-board systems monitoring equipment that transmits information back to the airline.
"Hijacking or a pilot going rogue would explain the transponder and ACARS not transmitting. If this is what actually happened, I fear the CVR and FDR would have been turned off also, thus giving the authorities very little chance of knowing what actually happened," writes "garpd," an aviation graphics designer in the UK on Airliners.net.
The Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR) could be turned off by tripping a circuit breaker. In the SilkAir investigation, the pilot was suspected of manually tripping the circuit breaker on the CVR and then, the FDR, thus eliminating any recording of events during the final minutes of that flight.
Malaysian authorities say they are now doing deeper background checks on passengers and crew.
"Maybe somebody on the flight has bought a huge sum of insurance, who wants family to gain from it or somebody who has owed somebody so much money, you know, we are looking at all possibilities," Malaysian police chief Khalid Abu Bakar told a news conference Monday. "We are looking very closely at the video footage taken at the KLIA (Kuala Lumpur International Airport), we are studying the behavioral pattern of all the passengers."
Again, there's the echo of SilkAir Flight 185.
Capt. Tsu Way Ming, the pilot of SilkAir 185 reportedly had $1 million in security trading losses 10 days before his last flight. He bought a life insurance policy the week before his last flight, according to Macarthur Job, who wrote about the incident for Flight Safety Australia in 2008.
But if the Malaysia Airlines flight was a planned suicide, why did whomever was at the controls turn the aircraft west and fly for at least another hour?
If it was a hijacking, then based on the original flight plan and fuel, the search area could be much larger – as large as 3,000 miles in diameter - or all the way to India or deep into China.
In the unusually long absence of information about the location of Malaysia Airlines Flight 370, speculation continues. And the search by authorities is turning inward – toward examining more closely the crew and passengers – for clues to the cause of the flight's disappearance.
[Editor's note: The original post incorrectly stated the year of the SilkAir Flight 185 crash.]