Date & Time: Feb 25, 2009 at 1026 LT
Type of aircraft:
Boeing 737-800
Operator:
Registration:
TC-JGE
Survivors:
Yes
Schedule:
Istanbul - Amsterdam
MSN:
29789/1065
YOM:
2002
Flight number:
TK1951
Region:
Europe
Crew on board:
7
Crew fatalities:
4
Pax on board:
128
Pax fatalities:
5
Other fatalities:
0
Total fatalities:
9
Captain / Total flying hours:
17000
Captain / Total hours on type:
10885
Copilot / Total flying hours:
4146
Copilot / Total hours on type:
44
Circumstances:
On final approach, the aircraft hit the ground 1,5 km short of runway 18R. At least 9 pax were fatally injured. The aircraft broke into three pieces.
Causes:
During the accident flight, while executing the approach by means of the instrument landing system with the right autopilot engaged, the left radio altimeter system showed an incorrect height of -8 feet on the left primary flight display. This incorrect value of -8 feet resulted in activation of the ‘retard flare’ mode of the auto-throttle, whereby the thrust of both engines was reduced to a minimal value (approach idle) in preparation for the last phase of the landing. Due to the approach heading and altitude provided to the crew by air traffic control, the localiser signal was intercepted at 5.5 NM from the runway threshold with the result that the glide slope had to be intercepted from above. This obscured the fact that the auto-throttle had entered the retard flare mode. In addition, it increased the crew’s workload. When the aircraft passed 1000 feet height, the approach was not stabilized so the crew should have initiated a go around. The right autopilot (using data from the right radio altimeter) followed the glide slope signal. As the airspeed continued to drop, the aircraft’s pitch attitude kept increasing. The crew failed to recognize the airspeed decay and the pitch increase until the moment the stick shaker was activated. Subsequently the approach to stall recovery procedure was not executed properly, causing the aircraft to stall and crash.