Possible scenarios discussed on cause of Turkish plane crash

At least nine people were killed and 84 injured when a Boeing 737-800 operated by Turkish Airlines crash-landed Wednesday in a field near Amsterdam's main airport, Schiphol, splitting into three parts.

The flight data and voice recorders, recovered late on Wednesday, will be key to determining the cause of the crash of an airplane with a good safety record, flown by a well-respected airline, landing at one of the world's most modern airports.

This is the fourth serious accident since August 2008, when a Spanair MD-80 crashed on take off in Madrid, the others being the Hudson River crash and the fatal Continental Airlines crash at Buffalo, New York on Feb. 12.

The fact that the plane did not catch fire has persuaded some commentators to question how much fuel was onboard the aircraft.

Here are the major scenarios and possibilities circulating in Turkey:

1) VORTEX: A Boeing 777, operated by KLM, landed just ahead of the crashed Turkish Airliner. Experts say the vortex the Boeing 777 created may have jeopardized the landing of the Turkish Airlines plane. Some 54 accidents have so far been caused by vortexes.

2) ENGINE FAILURE: Some passengers said they saw smoke rising from the left engine of the plane. Although it is not confirmed, media reports suggest the plane asked for an emergency landing. Photos from the crash scene showed one of the engines lying on the ground far from the wreckage. But it is unclear whether the engine broke away from the plane before or after the crash.

3) STALL: The plane might have unexpectedly lost speed as it was descending. The possible causes are numerous, and can include a loss of engine power due to either a lack of fuel, ice, a bird strike or a control problem, experts believe.

4) WINDSHEAR: This could be a possible cause for the crash. Windshear is a difference in wind speed and direction over a relatively short distance in the atmosphere.