This accident occured on 02/25/2009. A 737-800 crashed short of the runway.
It's still very early in the investigation, but there has been some initial information released. Keep in mind that it usually takes a year or so for an investigation to be completed and this information is subject to change during that investigation.
On 3/04/2009, the Dutch Safety Board issued an initial safety report indicating that one of the altimeters failed (the one of the pilot side) and this appears to have caused the autopilot to believe the aircraft was 8 feet AGL when it was really at 1950 feet AGL. (The pilots altimeter is the one used by the autopilot for receiving data.) The autopilot then apparantly reduced power to the engines setting the plane up for an immediate landing. This caused the plane to stall and crash short of the runway.
The first officer had the controls and his altimeter was showing 1950 AGL.
So we have what appears to be a typical approach situtation in that we as commercial airline pilots are trained to trust our instruments and use the autopilot down to autopilot minimums. This is all well and good until something doesn't function properly.
A simple faulty altimeter appears to have taken down an airliner. Within 100 seconds of this simple altimeter failing, the plane had crashed. This simple altimeter failure appears to have been missed by the pilot, the first officer and a check pilot sitting in the cockpit. It's obviously easy to miss with everything going on in the cockpit during an approach. (Especially when we might not be actively looking for such a failure)
Five passengers (sitting in business class) and 4 crew (including both pilots and the check pilot) were killed. Three of the five passengers killed were Boeing engineers that just happened to be on the doomed flight.
Eighty passengers were injured. The plane was destroyed as it broke into 3 pieces. Fortunately there was no fire and 122 passengers and 3 crew survived.
Here are some pictures of the downed aircraft:
The report from the Dutch Safety Board can be found here:
What can we as pilots learn from this?
There will probably be some examination in the next few months on how autopilots are being used and how we are being trained to use them.
There have now been two recent crashes where the autopilot is a focus of a plane crash investigation.
In this Turkish Airlines case, the Dutch Safety board considered the matter so important that they released their initial findings quickly and issued a warning to Boeing with the following statement:
"The Board is of the opinion that extra attention is needed for the role of the radio altimeter when using the automatic pilot and the automatic throttle system. The Board has issued a warning for Boeing today requesting extra attention to a part of a manual for the Boeing 737, in which is stated that in case of malfunction of the radio altimeter(s), the automatic pilot and throttle system that are connected to this may not be used for approach and landing. The Board would like Boeing to consider an investigation into whether this procedure is also applicable during flight."
As commercial pilots, we need to make sure that we are aware of this type of possible failure during an approach.