translation of 1st text page of prelim report
"Today 4 March 2009 the Safety investigation board issues a warning for the aircraft manufacturer Boeing and its first findings about the terrible accident with the Boeing 737/800 of Turkish Airlines.
In this accident nine people dies (5 passengers and 4 crew) and 80 passengers were injured, of which 28 injured are still in several hospitals.
The aircraft was en route from Istanbul to Schiphol (on Wednesday 25 February 2009) and was expected to land on Schiphol at 10.40 hours.
The Boeing had a normal flight, during which until before the approach no problems have occurred.
In the cockpit there were three persons, the captain, who was seated on the left. To the right a first officer was seated, for whom this was a training flight. (The first officer had all the permits) In addition there was an extra first officer seated in the centre of the cockpit.
De crew contacted the ATC (Amsterdam Radar) at 10.04 hours and is transferred at 10.14 hours – before the landing- to Schiphol tower. The tower clears the Boeing to land on the Polderbaan 18R.
De Polderbaan is approached according to the set procedure and without any delay, in which frame the Boeing is cleared to descend to 2000 feet (about 700 meters) and is cleared to set in for the landing towards the Polderbaan.
This descend is executed with the aid of the automatic pilot, which is a usual practice at Turkish Airlines (this method can be executed by everyone, likewise a manual landing can for that matter).
From the voice recorder and the black box, which are both in the possession of the investigation board, it appears that in the approach at 1950 feet an anomaly occurred.
At an altitude of 1950 feet the left radio-altimeter suddenly (indicated and) passed on a change in altitude to the automatic piloting system. Namely that the aircraft was not positioned at an altitude of 1950 feet but at an altitude of minus 8 feet. This change influenced directly the auto throttle system with which more or less power is given during the approach.
The radio altimeter normally measures very precisely in which altitude an aircraft is positioned in relation to the ground and can register this from 2500 feet downwards. As has been said, the left radio altimeter is of great importance for giving the right power in case of an automated landing. A Boeing is equipped with two radio altimeters, a left and a right one. From the black box it shows that this anomaly occurred only in the left radio altimeter.
From the voice recorder it shows that the malfunctioning of the left radio altimeter has been signalled to the crew (namely via the warning signal "landing gear should be put down"). From the preliminary data it shows that this signal was not perceived as a problem. "