Report: Boeing 737-800 struck runway construction markers on takeoff at Paris-CDG

August 30, 2011

Take-off trajectory of AMV6104 (source: BEA)

The French Bureau d’Enquêtes et d’Analyses (BEA) released the final report of their investigation into a serious incident in which a Boeing 737-800 struck runway construction markers on takeoff from Paris-CDG, France.

On August 17, 2008 at 00:57 local time, AMC Airlines Flight AMV6104 struck some provisional lights at the end  runway 27L at Paris-Charles de Gaulle Airport. Then, during the rotation, it destroyed some markers on the safety-barrier positioned in front of the construction zone. It took off before a provisional blast fence and continued its flight to its destination.
Repair works on runway 09R/27L were in progress between 4 and 20 August 2008. During this period, the last 1,240 metres of runway  27L were closed for flight operations. The AMC Airlines Boeing 737 commenced takeoff from after lining up from taxiway Y11, leaving 2360 metres for takeoff. This was reported to the crew by ground controller.

The crew had calculated takeoff parameters using a computer program, but the takeoff distance calculated by the program was not known to the crew.

BEA Concluded that:
The event was caused by the crew’s failure to take into account the length of the runway available for takeoff.
The following factors may have contributed to the event:

  • ˆ the inadequacy of the OPT utilisation procedures set up by the operator AMC to prevent such an error;
  • ˆ the impaired level of crew performance, specifically related to the pilots’ fatigue.
More information:

Report: Turkish Airlines B737-800 Schiphol accident report released

May 6, 2010

The Dutch Safety Board released its final report regarding their investigation into the fatal accident involving a Turkish Airlines Boeing 737-800 near Amsterdam-Schiphol Airport.

The Dutch Safety Board has reached the following main conclusion:
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 autothrottle, 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 localizer 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 autothrottle 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 stabilised 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 recognise 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.


Report: Spatial disorientation caused Kenya Airways B737-800 loss of control accident

April 28, 2010

Flight profile of flight KQ507 after takeoff from Douala

The fatal accident involving a Boeing 737-800 operated by Kenya Airways in May 2007 was caused by spatial disorientation and a loss of control, according to the Cameroon Civil Aviation Authority (CCAA) investigation.
The airplane crashed at night shortly after takeoff from Douala Airport (DLA), Cameroon, killing all 114 on board.

The CCAA report indicated that there was lack of crew coordination as flight KQ507 climbed into the dark knight. There were no external visual references, yet no instrument scanning was done. At 1000 feet climbing, the pilot flying released the flight controls for 55 seconds without having engaged the autopilot. The bank angle of the airplane increased continuously by itself very slowly up to 34 degrees right and the captain appears unaware of the airplane’s changing attitude.

Just before the “Bank Angle” warning sounds, the captain grabbed the controls, appeared confused about the attitude of the airplane, and made corrections in an erratic manner increasing the bank angle to 50 degrees right.

At about 50 degrees bank angle, the AP is engaged and the inclination tends to stabilize; then movements of the flight controls by the pilot resume and the bank angle increases towards 70 degrees right. A prolonged right rudder input brought the bank angle to beyond 90 degrees. The airplane descended in a spiral dive and crashed into a magrove swamp.

PROBABLE CAUSE: “The airplane crashed after loss of control by the crew as a result of spatial disorientation (non recognized or subtle type transitioning to recognized spatial disorientation), after a long slow roll, during which no instrument scanning was done, and in the absence of external visual references in a dark night.
Inadequate operational control, lack of crew coordination, coupled with the non-adherence to procedures of flight monitoring, confusion in the utilization of the AP, have also contributed to cause this situation.”


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