What happened
On February 15, 2013, an Embraer EMB-500 business jet was performing a commercial flight from Kortrijk-Wevelgem, Belgium, to Berlin-Schönefeld, Germany. During the final approach to runway 07L, the aircraft entered a stall while attempting to flare for landing. The aircraft rolled, struck the ground with its left wing, and came to a stop on the right side of the runway. There were no injuries among the two pilots and one passenger on board, though the aircraft sustained heavy damage and damage was also caused to airport facilities.
As the aircraft descended through 3,0 and 1,400 feet AMSL, it flew through clouds in conditions that included moderate icing. Despite the ATIS information indicating icing below 3,000 feet, the crew did not activate the wing and horizontal stabilizer de-ice system. Additionally, the crew continued the approach despite not meeting the requirements for a stabilized approach, having accepted a higher approach speed from Air Traffic Control that was inappropriate for the aircraft's category in icing conditions.
The investigation
The BFU investigation examined the cockpit voice data recorder (CVDR) and radar data to reconstruct the flight path and crew actions. The investigators analyzed the aircraft's ice and rain protection systems, the stall warning and protection system (SWPS), and the crew's adherence to Standard Operating Procedures (SOPs). The investigation also reviewed previous flights by the same operator to determine if the failure to use de-icing equipment was an isolated incident. The BFU also looked into the interaction between Air Traffic Control (ATC) speed assignments and the aircraft's performance capabilities in icing conditions.
Findings
- The crew failed to activate the Wing and Horizontal Stabilizer De-Ice System despite being in known icing conditions, which allowed ice to accumulate on the wings and tail.
- The accumulation of ice rendered the Stall Warning and Protection System (SWPS) ineffective.
- The aircraft was flying at an approach speed that was too low for the icing conditions during the flare.
- The crew's decision to maintain a higher speed requested by ATC increased workload and prevented a stabilized approach.
- A contributing factor was the crew's insufficient knowledge regarding the relationship between the Ice Protection System and the Stall Warning and Protection System.
Safety action
- The BFU issued a recommendation to the Belgian aviation authority to ensure operators strictly adhere to SOPs and stabilized approach criteria.
- Recommendations were made to EASA and ANAC to ensure aircraft manufacturers update pilot training syllabi to clearly explain the functions and management of the Ice Protection and SWPS.
- A recommendation was issued to Deutsche Flugsicherung (DFS) to consider aircraft approach categories and safety gates when assigning approach speeds to pilots.