Report: Canadair RJ uncommanded roll on takeoff in icing conditions

April 15, 2011

The CRJ shortly before Stick pusher activates (graphic from AIBN animation)

AIBN Norway published the final report of their investigation into an serious incident involving a Cimber Air Denmark Canadair CRJ200LR Regional Jet, January 2008. During take-off, immediately after lift-off, the aircraft suddenly lost lift on the right wing. The wing dropped, sending the aircraft into an uncontrolled 40-degree bank. The stall protection system activated, and the crew regained control 

On 31 January 2008, at 17:21 hours, a serious aircraft incident took place during take-off from runway 19L at Oslo Airport Gardermoen (ENGM). A Canadair CRJ200LR aircraft with two pilots and two cabin crew members on board suddenly lost lift on the right wing, causing the wing to drop and sending the aircraft into an uncontrolled 40-degree bank immediately after lift-off. The stall protection system activated, and the crew regained control and continued as scheduled to Copenhagen.
The investigation has shown that prescribed de-icing took place 15 minutes prior to departure, and that the wings were not cold-soaked in advance. Weather conditions were temperature at freezing, 15 kt wind and continuous precipitation in the form of aggregated, wet snowflakes. The runway was covered by slush and wet snow which had fallen after the runway had been cleared of snow and sanded 30 minutes earlier. Unintentionally, due to distraction, the system for heating the leading edge of the wing was not switched on prior to take-off. The nose wheel was lifted from the ground at the correct speed, but at a higher than recommended rotation rate.
This incident is one in a number of similar cases. From 2002 to 2008, six CL-600 series aircraft were involved in accidents during winter conditions. The wing of the aircraft type has proven to be especially sensitive to contamination on the leading edge. After the accidents, a number of measures have been implemented to ensure that the wing is clean during take-off, and to ensure that the pilots use the correct take-off technique.

The AIBN believes that the safety measures that have been introduced have not resulted in a definitive solution to the problem. When the de-icing fluid runs off during take-off, it is essential that the leading edge of the wing is heated. On take-off from contaminated runways, spray from the nose wheel will envelop the aircraft’s wing root. This source of contamination hits an aerodynamically critical area on the wing, and comes in addition to the precipitation which can adhere to the wing and disturb the airflow. The AIBN believes that it is not sufficient to depend solely on ”soft” safety barriers such as check lists and memory when the position of one switch (Wing Anti-Ice ON) can be critical to prevent a catastrophic accident during take-off. Technical or physical safety barriers in the form of design changes, automatic systems or automatic warning systems are, in the opinion of the Accident Investigation Board, necessary to obtain adequate reduction in accident risk. Alternatively, more severe restrictions for winter operations with the affected aircraft models must be introduced.

The Accident Investigation Board issues four safety recommendations.

More information:

AIB Norway: report released on A321 runway skid

March 11, 2010

The Accident Investigation Board of Norway published its final report of their investigation into a serious incident involving an Airbus A321 at Sandefjord Airport Torp (ENTO), Norway.

An Airbus A321, registration OY-VKA and flight number VKG866, flew from Tenerife Airport (GCTS) to Sandefjord Airport Torp (ENTO) on 26th of March 2006. The flight was operated by My Travel Airways Scandinavia.
The first officer was Pilot Flying (PF) and the commander was Pilot Not Flying (PNF). The crew reviewed updated weather and runway status before commencing the approach to ENTO. Air Traffic Information Services (ATIS) indicated dry runway and Braking Action (BA) GOOD.
When checking in on Tower frequency, the crew was informed that the runway was contaminated by 8 mm wet snow with a measured (Friction Coefficient, FC) of 32-33-31. These numbers indicated a MEDIUM BA.
The crew requested wind information in order to check for any crosswind or tailwind limitations. They made a mental consideration regarding the landing conditions and decided that it was acceptable to perform the landing. The airplane got high on the glide slope after passing 250 ft Radio Height. This resulted in a touch down approximately 780 metres from the threshold. After landing the crew experienced POOR braking action and suspected auto brake failure. The first officer performed maximum manual braking without noticing any BA. After landing the crew experienced POOR BA and suspected a brake failure. The commander took control, pulled the Park Brake (PB) and steered the aircraft with Nose Wheel Steering (NWS) towards the left side of the runway with guidance from the first officer.
The effect of the PB and NWS was that the aircraft skidded sideways towards the end of the runway 18. This resulted in increased deceleration and the aircraft stopped at the very end of the hard surfaced runway, with the nose wheel against a concrete antennae base.
The crew advised the TWR about the anticipated runway excursion while the aircraft skidded towards the end. This allowed the TWR to alert the fire and rescue crew even before the aircraft had stopped. The fire and rescue service functioned as expected.
No persons were injured and the aircraft got some skin and nose wheel damage. The commander shut down the engines and evacuated the passengers through the forward left cabin door. The passengers were transported to the terminal building by buses while the crew remained in the aircraft being towed to the terminal.

AIBN issued three safety recommendations to MyTravel Scandinavia (now Thomas Cook Airlines Scandinavia) and two recommendations to Sandefjord Airport Torp, related to operations on contaminated runways.

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