Search

27th of July 2010

With a take-off weight of 248.307 kilograms (of which 79.247 kilograms of cargo), a McDonnel Douglas MD-11F took off from Frankfurt (Germany) with Riyadh (Saudi Arabia) as its destination on this day in 2010. Two crew operated the flight, with the captain as pilot monitoring (PM) and the first officer as pilot flying (PF). The en-route section of the flight was uneventful.

The wreckage of the aircraft after the fire was extinguished. (© AP Photo)


The weather was good at Riyadh airport at the time of the aircraft's arrival;

Wind - 340º at 14 knots

Clouds - none

Visibility - good

Temperature - 39ºC

Dew point - 6ºC

QNH - 10o6 hPa

ATC vectored the aircraft for an ILS approach to runway 33L. the crew had determined that for a landing weight of 207.000 kilograms) the Reference Approach Speed (Vref) was 158 knots. The approach was flown with the Auto Pilot and AutoThrottle System switched off.

The #3 engine (© GACA)


Until 25 seconds before touchdown, the aircraft was stabilised on the localiser and glideslope. At that time it dipped half a dot below the glide slope. (the aircraft was slightly lower than it should have been). The indicated airspeed fluctuated between 160 and 170 knots. The ground speed slowly increased to 176 knots at touchdown. The PF flared the aircraft ~2 seconds before touchdown, when ~25 feet above the runway. The first touchdown (945 feet from the threshold) at a vertical speed of 780 ft/min, giving a load factor of 2.1g.

The aircraft bounced back into the air with the spoilers deployed as a result of the main-wheel spin-up. The PM Pushed the nose down, resulting in a second touchdown at a vertical speed of 660 ft/min, giving a load factor of 3.0g. A second bounce occurred, and again the PM pushed the nose down a third and final touchdown occurred. This touchdown was at a vertical speed of 1020 ft/min, giving a loaf factor of 4.4.g.

The damaged center section of the aircraft (© GACA) At this point, the aft fuselage ruptured behind the wing trailing edge. Two fuel lines (one fuel line to the number 2 engine/Auxiliary Power Unit (APU) and, a transfer line to the tail fuel tank) were severed and fuel spilt within the left-hand wheel well. A fire ignited and travelled to the upper cargo area. While the captain attempted to main control the first officer made a Mayday call at the request of the captain. The aircraft departed the paved surface of the runway to the left, at that time the nose gear collapsed. 8800 feet from the threshold and 300 feet from the runway center line the aircraft came to a stop. The crew performed the necessary emergency shutdown checks and evacuated the aircraft. Both crew members were taken to the hospital with varying injuries. Airport firefighters quickly extinguished the fire. The aircraft was destroyed.

The fire damaged center section of the aircraft (Source; baaa-arco.com © Unknown) An investigation into the accident was launched by the General Authority of Civil Aviation of Saudi Arabia (GACA). After ~18 months they published their final report (available for your reference by clicking here). The following findings related to the cause of the accident were identified in the report;

  1. The flight crew did not recognize the increasing sink rate on short final.

  2. The First officer delayed the flare prior to the initial touchdown, thus resulting in a bounce.

  3. The flight crew did not recognize the bounce.

  4. The Captain attempted to take control of the aircraft without alerting the First Officer resulting in both flight crews acting simultaneously on the control column.

  5. During the first bounce, the Captain made an inappropriate, large nose-down column input that resulted in the second bounce and a hard landing in a flat pitch attitude.

  6. The flight crew responded to the bounces by using exaggerated control inputs.

  7. The company bounced-landing procedure was not applied by the flight crew.

A list of 9 (nine) safety recommendations concluded the report.






86 views0 comments

Recent Posts

See All