23rd of February 2018, contaminated wing, Blog #736
- V2Aviation
- Feb 23
- 3 min read
The owner of a Beechcraft King Air B100 (King Air) planned to take nine of his family members on a flight from Abbotsford Airport (BC, Canada) to San Bernardino International Airport (CA, USA).
Moderate to heavy snow was falling, with a temperature of -2 ºC and a 10-knot wind. The weather conditions were not hindering the to the pilot and passengers as the aircraft was preflighted, refueled, loaded and boarded inside a heated hangar.
At 1121 lt. (local time), the pilot called the Abbotsford air traffic control (ATC) tower to ask whether he could receive an early clearance while the aircraft was still in the hangar. The pilot was concerned that, with the heavy snowfall, the aircraft would be covered in snow if the flight experienced any delay in receiving the IFR clearance. Because the pilot’s flight plan was not yet in the system, the pilot told the controller he would call back in 10 to 15 minutes for his clearance.
Just under 20 minutes later, the pilot called ATC back and requested clearance over the phone; however, the controller was unsure if that was allowed. The pilot then told the controller that he would have the aircraft towed out and would call on the radio for the clearance. The pilot also mentioned the snow accumulation and his concern about the possibility of having to wait for a clearance in the falling snow. The controller informed the pilot that there was one.
With all passengers and pilot onboard, the aircraft was towed out of the hangar at 11.50 lt. into the snow.
Four minutes later, the engine start procedures were completed, and both engines were running. The pilot received the IFR clearance and started to taxi towards runway 07 at Abbotsford Airport.
At 12.03 lt, 13 minutes after leaving the hangar, the aircraft rolled onto the snow-covered runway 07 and continued for a rolling take-off.
Once airborne, the landing gear was selected up. While the landing gear retracted, the aircraft rolled to the left, reaching a bank of ~30º. The pilot applied right aileron, and the aircraft returned to a near wings-level attitude. In order to make an immediate off-field emergency landing, the pilot retarded the power levers and then applied forward pressure on the control column to land the aircraft. The aircraft struck terrain between Runway 07 and Taxiway C. The aircraft slid across the snow-covered ground for approximately 760 feet before coming to rest in a field, within the airport perimeter. Once the aircraft came to rest, the pilot moved the FUEL CUTOFF & FEATHER levers to the FUEL CUTOFF & FEATHER position and ordered the passengers to evacuate the aircraft. The pilot then exited the cockpit and opened the cabin door to help all the passengers exit the aircraft. After all the occupants had exited the aircraft, airport rescue and firefighting personnel arrived on scene.
The pilot and five of the passennor injuries. The aircraft was destroyed by impact forces; the impact was hard enough to automatically activate the aircraft's Emergency Locator Transmitter.
The accident was investigated by the Transportation Safety Board of Canada (TSB). In their report, the TSB listed several findings as to the cause and contributing factors:
The occurrence aircraft exited a warm hangar and was exposed to 14 minutes of heavy snow in below-freezing conditions. This resulted in a condition highly conducive to severe ground icing.
As the aircraft climbed out of ground effect on takeoff, it experienced an aerodynamic stall as a result of wing contamination.
The pilot’s decision-making was affected by continuation bias, which resulted in the pilot attempting a takeoff with an aircraft contaminated with ice and snow adhering to its critical surfaces.
The pilot and the passenger seated in the right-hand crew seat were not wearing the available shoulder harnesses. As a result, they sustained serious head injuries during the impact sequence.
During the impact sequence, the cargo restraint system used to secure the baggage in the rear baggage compartment failed, causing some of the baggage to injure passengers seated in the rear of the aircraft cabin.
The full TSB report, which served as a source for this blog, can be accessed by clicking on the .pdf file below:
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