Saskatchewan

On 13 December 2017, an Avions de Transport Régional ATR 42-320 aircraft (registration C-GWEA, serial number 240), operated by West Wind Aviation L.P. (West Wind), was scheduled for a series of instrument flight rules flights from Saskatoon through northern Saskatchewan as flight WEW282. When the flight crew and dispatcher held a briefing for the day’s flights, they became aware of forecast icing along the route of flight. Although both the flight crew and the dispatcher were aware of the forecast ground icing, the decision was made to continue with the day’s planned route to several remote airports that had insufficient de-icing facilities. The aircraft flew from Saskatoon/John G. Diefenbaker International (CYXE) to Prince Albert (Glass Field) Airport (CYPA) without difficulty, and, after a stop of about 1 hour, proceeded on toward Fond-du-Lac Airport (CZFD). On approach to Fond-du-Lac Airport, the aircraft encountered some in-flight icing, and the crew activated the aircraft’s anti-icing and de-icing systems. Although the aircraft’s ice protection systems were activated, the aircraft’s de-icing boots were not designed to shed all of the ice that can accumulate, and the anti-icing systems did not prevent ice accumulation on unprotected surfaces. As a result, some residual ice began to accumulate on the aircraft. The flight crew were aware of the ice; however, there were no handling anomalies noted during the approach. Consequently, they likely did not assess that the residual ice was severe enough to have a significant effect on aircraft performance. The crew continued the approach and landed at Fond-du-Lac Airport at 1724 Central Standard Time. According to post-accident analysis of the data from the flight data recorder, the aircraft’s drag and lift performance was degraded by 28% and 10%, respectively, shortly before landing at Fond-du-Lac Airport. This indicated that the aircraft had significant residual ice adhering to its structure upon arrival. However, this data was not available to the flight crew at the time of landing. The aircraft was on the ground at Fond-du-Lac Airport for approximately 48 minutes. The next flight was destined for Stony Rapids Airport (CYSF), Saskatchewan, with 3 crew members (2 pilots and 1 flight attendant) and 22 passengers on board. Although there was no observable precipitation or fog while the aircraft was on the ground, weather conditions were conducive to ice or frost formation. This, combined with the residual mixed ice on the aircraft, which acted as nucleation sites that allowed the formation of ice crystals, resulted in the formation of additional ice or frost on the aircraft’s critical surfaces. Once the passengers had boarded the aircraft, the first officer completed an external inspection of the aircraft. However, because the available inspection equipment was inadequate, the first officer’s ice inspection consisted only of walking around the aircraft and looking at the left wing from the top of the stairs at the left rear door, without the use of a flashlight on the dimly lit apron. Although he was unaware of the full extent of the ice and the ongoing accretion, the first officer did inform the captain that there was some ice on the aircraft. The captain did not inspect the aircraft himself, nor did he attempt to have it de-iced; rather, he and the first officer continued with departure preparations. Company departures from remote airports, such as Fond-du-Lac, with some amount of surface contamination on the aircraft’s critical surfaces had become common practice, in part due to the inadequacy of de-icing equipment or services at these locations. The past success of these adaptations resulted in this unsafe practice becoming normalized and this normalization influenced the flight crew’s decision to depart. Although the flight crew were aware of icing on the aircraft’s critical surfaces, they decided that the occurrence departure could be accomplished safely. Their decision to continue with the original plan to depart was influenced by continuation bias, as they perceived the initial and sustained cues that supported their plan as more compelling than the later cues that suggested another course of action. At 1812 Central Standard Time, in the hours of darkness, the aircraft began its take-off roll on Runway 28, and, 30 seconds later, it was airborne. As a result of the ice that remained on the aircraft following the approach and the additional ice that had accreted during the ground stop, the aircraft’s drag was increased by 58% and its lift was decreased by 25% during the takeoff. Despite this degraded performance, the aircraft initially climbed; however, immediately after liftoff, the aircraft began to roll to the left without any pilot input. This roll was as a result of asymmetric lift distribution due to uneven ice contamination on the aircraft. Following the uncommanded roll, the captain reacted as if the aircraft was an uncontaminated ATR 42, with the expectation of normal handling qualities and dynamic response characteristics; however, due to the contamination, the aircraft had diminished roll damping resulting in unexpected handling qualities and dynamic response. Although the investigation determined that the ailerons had sufficient roll control authority to counteract the asymmetric lift, due to the unexpected handling qualities and dynamic response, the roll disturbance developed into an oscillation with growing magnitude and control in the roll axis was lost. This loss of control in the roll axis, which corresponds with the known risks associated with taking off with ice contamination, ultimately led to the aircraft colliding with terrain 17 seconds after takeoff. The aircraft collided with the ground in a relatively level pitch, with a bank angle of 30° left. As a result of the sudden vertical deceleration upon contact with the ground, the aircraft suffered significant damage, which varied in severity at different locations on the aircraft due to impact angle and variability in structural design. The design standards for transport category aircraft in effect at the time the ATR 42 was certified did not specify minimum loads that a fuselage structure must be able to tolerate and remain survivable, or minimum loads for fuselage impact energy absorption. As a result, the ATR 42 was not designed with these crashworthy principles in mind. The main landing gear at the bottom of the centre fuselage section was rigid, and, on impact, did not absorb or attenuate much of the load. The impact-induced acceleration was not attenuated because the landing gear housing did not deform. This unattenuated acceleration resulted in a large inertial load from the wing, causing the wing support structure to fail and the wing to collapse into the cabin. The reduced survivable space between the floor above the main landing gear and the collapsed upper fuselage caused crushing injuries, such as major head, body, and leg trauma, to passengers in the middle-forward left section of the aircraft. Of the 3 passengers in this area, 2 experienced, serious life-changing injuries, and 1 passenger subsequently died. The collapse of part of the floor structure compromised the restraint systems, limiting the protection afforded to the aircraft occupants when they were experiencing vertical, longitudinal, and lateral forces. This resulted in serious velocity-related injuries and impeded their ability to take post-crash survival actions in a timely manner. Unaware of the danger, most passengers in this occurrence did not brace for impact. Because their torsos were unrestrained, they received injuries consistent with jackknifing and flailing, such as hitting the seat in front of them. As a result of unapproved repairs, the flight attendant seat failed on impact, resulting in injuries that impeded her ability to perform evacuation and survival actions in a timely manner. Although the TSB has previously recommended the development and use of child restraints aboard commercial aircraft, planned regulations have yet to be implemented by Transport Canada. As a result, the occurrence aircraft was not equipped with these devices, and an infant passenger who was unrestrained received flailing and crushing injuries during the accident sequence. By the time the aircraft came to a rest, all occupants had received injuries. Passengers began to call for help within minutes of the impact, using their cell phones. Numerous people from the nearby community received the messages and quickly set out to help. The passengers and crew began to evacuate, but they experienced significant difficulties as a result of the aircraft damage. It took approximately 20 minutes for the first 17 passengers to evacuate, and the remaining passengers much longer; it took as long as 3 hours to extricate 1 passenger, who required rescuer assistance. As a result of the accident, 9 passengers and 1 crew member received serious injuries, and the remaining 13 passengers and 2 crew members received minor injuries. One of the passengers who had received serious injuries died 12 days after the accident. There was no post-impact fire, and the emergency locator activated on impact.

The Lawrence Bay Airways Ltd. float-equipped de Havilland DHC-2 (registration C-GUJX, serial number 1132) departed from a lake adjacent to a remote fishing cabin near Buss Lakes for a day visual flight rules flight to Southend, Saskatchewan, about 37 nautical miles (nm) southeast. There were 4 passengers and 1 pilot onboard. The aircraft crashed along the shoreline of another lake located about 2 nm southeast of its point of departure. The impact was severe and the 5 occupants were killed on impact. The emergency locator transmitter activated, and the aircraft was found partially submerged in shallow water with the right wing tip resting on the shore. There was no post-crash fire. The accident occurred during daylight hours at about 1111 Central Standard Time.

At 1503 Central Standard Time, the Construcciones Aeronauticas SA (CASA) C-212-CC40 (registration C-FDKM, serial number 196) operated by Fugro Aviation Canada Ltd., departed from Saskatoon/Diefenbaker International Airport, Saskatchewan, under visual flight rules for a geophysical survey flight to the east of Saskatoon. On board were 2 pilots and a survey equipment operator. At about 1814, the right engine lost power. The crew shut it down, carried out checklist procedures, and commenced an approach for Runway 27. When the flight was 3.5 nautical miles from the runway on final approach, the left engine lost power. The crew carried out a forced landing adjacent to Wanuskewin Road in Saskatoon. The aircraft impacted a concrete roadway noise abatement wall and was destroyed. The survey equipment operator sustained fatal injuries, the first officer sustained serious injuries, and the captain sustained minor injuries. No ELT signal was received.

The aircraft departed Kamsack, on an instrument flight rules flight to Saskatoon, Saskatchewan. The pilot and three passengers were on board. At takeoff from runway 34, the aircraft began rolling to the left. The aircraft initially climbed, then descended in a steep left bank and collided with terrain 200 feet to the left of the runway. A post-impact fire ignited immediately. Two passengers survived the impact with serious injuries and evacuated from the burning wreckage. The pilot and third passenger were fatally injured. The aircraft was destroyed by impact forces and the post-impact fire. The accident occurred during evening civil twilight at 2124 Central Standard Time.

The aircraft was taking off from a ski strip east of and parallel to Runway 36 at La Ronge. After the nose ski cleared the snow, the left wing rose and the aircraft veered to the right and the captain, who was the pilot flying, continued the take-off. The right ski, however, was still in contact with the snow. The aircraft became airborne briefly as it cleared a deep gully to the right of the runway. The aircraft remained in a steep right bank and the right wing contacted the snow-covered ground. The aircraft flew through a chain link fence and crashed into trees surrounding the airport. The five passengers and two crewmembers evacuated the aircraft with minor injuries. There was a small fire near the right engine exhaust that was immediately extinguished by the crew.

For unknown reasons, the aircraft made a wheels up landing and skidded on runway at Stony Rapids Airport before coming to rest. Both pilots were uninjured while the aircraft was damaged beyond repair.

The aircraft departed La Ronge, Saskatchewan, at 1930 central standard time under instrument flight rules to Sandy Bay, with two flight crew members and two emergency medical technicians aboard. TW350 was operating under Part VII, Subpart 3, Air Taxi Operations, of the Canadian Aviation Regulations. At 1948, air traffic control cleared TW350 out of controlled airspace via the Sandy Bay Runway 05 non-directional beacon approach. The crew flew the approach straight-in to Runway 05 and initiated a go-around from the landing flare. The aircraft did not maintain a positive rate of climb during the go-around and collided with trees just beyond the departure end of the runway. All four occupants survived the impact and evacuated the aircraft. The captain died of his injuries before rescuers arrived. Both emergency medical technicians were seriously injured, and the first officer received minor injuries. The aircraft sustained substantial damage from impact forces and was subsequently destroyed by a post-impact fire. The accident occurred at 2002 during the hours of darkness.

The aircraft was conducting stop-and-go landings on Runway 36 at the airport in La Ronge, Saskatchewan. On short final approach for the third landing, the aircraft developed a high sink rate, nearly striking the ground short of the runway. As the crew applied power to arrest the descent, the autofeather system feathered the left propeller and shut down the left engine. On touchdown, the aircraft bounced, the landing was rejected, and a go-around was attempted, but the aircraft did not attain the airspeed required to climb or maintain directional control. The aircraft subsequently entered a descending left-hand turn and crashed into a wooded area approximately one mile northwest of the airport. The first officer was killed and two other crew members sustained serious injuries. The aircraft sustained substantial damage. The accident occurred during daylight hours at 1245 central standard time.

A Beechcraft A100 King Air, C-GAPK was inbound to La Ronge Airport, SK (YVC), from Pinehouse Lake on a medevac flight. On descent into La Ronge the crew noticed ice building on the wing leading edges. At approximately 6 miles back on final the crew operated the wing de-ice boots, however a substantial amount of residual ice remained after application of the boots. It was reported that in the landing flare at about 100 knots, the aircraft experienced an ice-induced stall from an altitude of about 20 feet followed by a hard landing. The right wing and nacelle buckled forward and downward from the landing impact forces to the extent that the right propeller struck the runway surface while the aircraft was taxiing off the runway.

A Northern Dene Airways Ltd. Metro III (registration C-FIPW, serial number AC524), operating as Norcanair Flight KA1051, departed Stony Rapids, Saskatchewan, with two crew members and nine passengers on a day, visual flight rules flight to La Ronge, Saskatchewan. On arrival in La Ronge, at approximately 1410 central standard time, the crew completed the approach and landing checklists and confirmed the gear-down indication. The aircraft was landed in a crosswind on Runway 18 and touched down firmly, approximately 1000 feet from the threshold. On touchdown, the left wing dropped and the propeller made contact with the runway. The aircraft veered to the left side of the runway, despite full rudder and aileron deflection. The crew applied maximum right braking and shut down both engines. The aircraft departed the runway and travelled approximately 200 feet through the infield before the nose and right main gear were torn rearwards; the left gear collapsed into the wheel well. The aircraft slid on its belly before coming to rest approximately 300 feet off the side of the runway. Three of the passengers suffered minor injuries from the sudden stop associated with the final collapsing of the landing gear; the other passengers and the pilots were not injured.