Crash of an Antonov AN-148-100B in Stepanovskoye: 71 killed

Date & Time: Feb 11, 2018 at 1427 LT
Type of aircraft:
Operator:
Registration:
RA-61704
Flight Phase:
Survivors:
No
Schedule:
Moscow – Orsk
MSN:
27015040004
YOM:
2010
Flight number:
6W703
Country:
Region:
Crew on board:
6
Crew fatalities:
Pax on board:
65
Pax fatalities:
Other fatalities:
Total fatalities:
71
Captain / Total flying hours:
5039
Captain / Total hours on type:
1323.00
Copilot / Total flying hours:
860
Copilot / Total hours on type:
720
Aircraft flight hours:
16249
Aircraft flight cycles:
8397
Circumstances:
The twin engine aircraft departed runway 14R at Moscow-Domodedovo Airport at 1421LT. Six minutes later, while climbing to an altitude of 6,000 feet in light snow showers, the airplane descended then disintegrated in a snow covered field located in Argunovo, about 37 km southeast of the Airport, one minute later. The aircraft was totally destroyed and debris were scattered on more than one km. All 71 occupants were killed. Both recording systems have been recovered. A day after the crash, Russian Authorities confirmed that the aircraft was intact until the final impact with the ground. Preliminary reports indicates speed variations on all three ASI's three minutes after rotation. 50 seconds after the automatic pilot was disconnected, the airplane experienced vertical loads between 0,5 and 1,5 G. then pitched down to an angle of 35°. Five seconds prior to impact, the airplane banked right to 25°. Preliminary investigations shows that the incorrect data on ASI's was caused by icing of the Pitot tubes as the heating systems was off, apparently because the crew failed to activate it.
Probable cause:
The accident was the consequence of erroneous actions on part of the crew while climbing in instrument meteorological conditions at unreliable readings of instrument speed caused by icing (blockage with ice) of all three Pitot tubes. This caused the aircraft to become uncontrollable, enter a dive and eventually collide with the ground. The accident was then considered as a loss of control in flight (LOC-I). The investigation revealed systemic weaknesses in the identification of hazards and risk control, the inoperability of the airline's flight safety management system and the lack of control over the level of training of crew members by aviation authorities at all levels, which led to the issuance of certificates of aviation personnel and the admission to the flights of the crew, which did not fully meet the qualification requirements. The following contributing factors were reported:
- Hurry of the crew in preparation for the flight due to the late arrival of the aircraft from the previous flight and attempts to "catch up" with the time,
- Skipping by the crew of the operation to switch on the Pitot tube heating before takeoff and failing to comply with the section of the check list "BEFORE TAKE-OFF", which provides for the control of this action,
- Design features of the An-148 aircraft in terms of the restrictions on the duration of Pitot tube heating operation on the ground, which led to the need to carry out operations to control the inclusion of Pitot tube heating and compliance with the principle of "dark cockpit" in a separate section of the "BEFORE THE FLIGHT" check list, which is performed immediately before the start of the takeoff run, which creates additional risks of missing these operations. These actions are provided in the section "ON THE RUNWAY START",
- Systematic failure of the airline's crews to comply with the "dark cockpit" principle and the requirements of the radar, which contributed to "getting used" to the takeoff with the presence of emergency and warning messages on the Integrated system and alarm indicator (KISS) and did not allow to identify the fact that the Pitot tube heating was not included. In the accident flight before takeoff, six warning messages were displayed on the KISS, including three messages about the absence of Pitot tube heating,
- Design features of the An-148 aircraft, connected with the impossibility to disable the display of a number of warning messages on the KISS even when performing the whole range of works provided for by the MMEL while ensuring the flight with delayed defects,
- Low safety culture in the airline, which was manifested in: systematic failure to record in the flight log the failures detected during the flight, as well as in the performance of flights with the failures not eliminated and/or not included in the list of delayed failures, accompanied by the corresponding messages on the KISS,
- Failure to take necessary measures in case of detection of previous facts of untimely activation of Pitot tube heating by crews based on the results of express analysis of flight information,
- Unreadiness of the crew to take actions in case of triggering the alarm "Speed of Emergency" due to the lack of appropriate theoretical training in the airline and the impossibility to work out this special situation on the flight simulation device and / or during airfield training and, as a consequence, failure to comply with the procedures provided for after triggering of this alarm,
- Absence of federal aviation regulations for certification of flight simulators, the development of which is provided for by the Air Code of the Russian Federation,
- Approval for the existing AN-148 flight simulators of the IFC Training LLC and the CTC of the Saint-Petersburg State University of Civil Aviation without taking into account their actual capabilities to reproduce special flight cases, as well as the provisions of FAR-128,
- Absence of specific values of flight parameters (engine operation mode, pitch and roll angles, etc.) in the aircraft's flight manual, which must be maintained by the crew of the airspeed alarm system, as well as absence of the situation with unreliable instrument speed readings (Unreliable Airspeed Procedure) in the list of special flight cases,
- Increased psycho-emotional tension of crew members at the final stage of the flight due to inability to understand the causes of speed fluctuations and, as a consequence, the captain falling under the influence of the "tunnel effect" with the formation of the dominating factor of speed control according to the "own" (left) airspeed indicator without a comprehensive assessment of flight parameters,
- Insufficient training of pilots in the field of human factor, methods of threat and error control and management of crew resources,
- Individual psychological peculiarities of pilots (for the captain - reduction of intellectual and behavioral flexibility, fixation on their own position with the inability (impossibility) to "hear" prompts from the second pilot; for the second pilot - violation of the organization and sequence of actions), which in a stressful situation in the absence of proper level of management of the crew resources came to the fore; loss of the captain's psychological performance (psychological stupor, psychological incapacitation), which resulted in complete loss of spatial orientation and did not allow reacting to correct prompts and actions of the co-pilot, including when triggering the PULL UP warning of the EGPWS system,
- Absence of psychological incapacitation criteria in the airline's AFM, which prevented the second pilot from taking more drastic measures,
- High annual leave arrears for special conditions, which could lead to fatigue and negatively affect the performance of the captain,
- Operation of the aircraft control system in the longitudinal channel in the reconfiguration mode with unreliable signals of instrument speed, not described in the operational documentation, related to a double increase in the transfer coefficient from the hand wheel to the steering wheel in the flight configuration and constant deviation of the steering wheel for diving (without deviation of the steering wheel) for about 60 seconds, which reduced the time required for the crew to recognize the situation.
Final Report:

Crash of a Cessna 208B Grand Caravan in Akobo: 1 killed

Date & Time: Jan 7, 2018 at 1645 LT
Type of aircraft:
Operator:
Registration:
5Y-FDC
Flight Phase:
Survivors:
Yes
Schedule:
Akobo – Juba
MSN:
208B-1280
YOM:
2007
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
9
Pax fatalities:
Other fatalities:
Total fatalities:
1
Circumstances:
In unclear circumstances, the single engine aircraft crashed while taking off from Akobo Airstrip. It struck a house and several cows before coming to rest, bursting into flames. One person on the ground was killed while all 11 occupants escaped uninjured. The aircraft was totally destroyed by a post crash fire.

Crash of a PZL-Mielec AN-2TP in La Paragua

Date & Time: Jan 6, 2018
Type of aircraft:
Operator:
Registration:
YV1944
Flight Phase:
Flight Type:
Survivors:
Yes
Schedule:
La Paragua - Canaima
MSN:
1G185-58
YOM:
1980
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
0
Circumstances:
Shortly after takeoff, while in initial climb, the single engine aircraft stalled and crashed in a prairie, bursting into flames. Both pilots were seriously injured and the aircraft was totally destroyed by a post crash fire.

Crash of a Cessna (DMI) Falcon 402 on Bazaruto Island

Date & Time: Jan 2, 2018 at 1145 LT
Type of aircraft:
Operator:
Registration:
ZU-MDI
Flight Phase:
Survivors:
Yes
Schedule:
Bazaruto Island - Vilanculos
MSN:
402B-0207
YOM:
1972
Country:
Region:
Crew on board:
1
Crew fatalities:
Pax on board:
6
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
3291
Captain / Total hours on type:
215.00
Aircraft flight hours:
1068
Circumstances:
The single engine airplane was departing Bazaruto Island on a flight to Vilanculos, carrying six passengers and one pilot. During the takeoff roll on runway 20, after a course of about 400 metres, the aircraft started to veer to the left, departed the runway despite successive attempt to correct the flight trajectory. The aircraft crashed into bushed and came to rest in the opposite direction of the takeoff, some 60 metres from the runway centerline.
Probable cause:
The most likely cause of this accident was human failure. The following contributing factors were identified:
- The fact that the pilot has exceeded the aircraft's capacity from 8 (1+7) to 10 (1+9), associated with prevailing meteorological conditions, may have influenced the attitude of the aircraft during take-off.
- The fact that the pilot did not properly follow the pre-flight procedures, given the hurry he showed at departure and being distracted at the time of the pre-flight inspection may have contributed to forgetting to remove the lock) of the Vertical Stabilizer.
- The fact that the pilot probably did not remove the Lock of the Vertical Stabilizer caused it to remain fixed in its position and could not give the directional control to the aircraft.
Final Report:

Crash of a Cessna 208B Grand Caravan in Punta Islita: 12 killed

Date & Time: Dec 31, 2017 at 1216 LT
Type of aircraft:
Operator:
Registration:
TI-BEI
Flight Phase:
Survivors:
No
Schedule:
Punta Islita – San José
MSN:
208B-0900
YOM:
2001
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
10
Pax fatalities:
Other fatalities:
Total fatalities:
12
Captain / Total flying hours:
14508
Captain / Total hours on type:
11587.00
Copilot / Total flying hours:
453
Aircraft flight hours:
12073
Circumstances:
The two pilots were conducting a commercial charter flight to take 10 passengers to an international airport for connecting flights. The flight departed a nontower-controlled airport that was in a valley surrounded on all sides by rising terrain, with the exception of the area beyond the departure end of runway 21, which led directly toward the Pacific Ocean. The accident airplane was the second of a flight of two; the first airplane departed runway 3 about 15 minutes before the accident airplane and made an immediate right turn to the east/southeast after takeoff, following a pass in the hills over lower terrain that provided time for the airplane to climb over the mountains. Both a witness and surveillance video footage from the airport indicated that, 15 minutes later, the accident airplane also departed from runway 3 but instead continued on runway heading, then entered a left turn and descended into terrain. Analysis of the video determined that the airplane reached a maximum bank angle of about 75° and an airspeed below the airplane's published aerodynamic stall speed before impact. Examination of the airplane was limited due to impact and postcrash fire damage; however, no defects consistent with a preimpact failure or malfunction were observed, and the engine exhibited signatures consistent with production of power during impact. The captain was appropriately rated and had extensive experience in the accident airplane make and model. He had been employed by the accident operator for about a year in 2006 and had recently been re-hired by the operator; however, records provided by the operator did not indicate that he had completed all of the training and check flights required by the operator's General Operations Manual (GOM). The first officer was appropriately rated but had little experience in the accident airplane. The GOM also stated that pilots would receive additional, airport-specific training before operating to or from airports with special characteristics; however, the operator provided no listing of such airports, including the airport from which the accident flight departed. The pilots' experience at the departure airport could not be determined. It is possible the psychiatric diagnoses in 2011 were correct and the pilot suffered from a number of conditions which can cause a variety of symptoms. However, given the extremely limited information, what his symptoms were around the time of the accident, whether they were being addressed or effectively treated, and what his mental state was at the time could not be determined from the available information. Therefore, whether or not the pilot's medical or psychological conditions or their treatment played a role in the accident circumstances could not be determined by this investigation. There were no weather reporting facilities in the vicinity of the airport. Although the airport was equipped with two frames for windsocks, no windsocks were installed at the time of the accident to aid pilots in determining wind direction and intensity. Although a takeoff from runway 21 afforded the most favorable terrain since the airplane would fly over lower terrain to the ocean, it is possible that a significant enough tailwind existed for runway 21 that the pilots believed the airplane's maximum tailwind takeoff limitation may be exceeded and chose to depart from runway 3 in the absence of any information regarding the wind velocity. Performance calculations showed that the airplane would have been able to take off with up to a 10-kt tailwind, which was the manufacturer limitation for tailwind takeoffs. The witness who saw the accident reported that he spoke with the pilots of both airplanes before the flights departed and that the pilots acknowledged the need to use the eastern pass in order to clear terrain when departing from runway 3. The reason that the flight crew of the accident airplane failed to use this path after takeoff could not be determined. It is likely that, after entering the valley ahead of the runway, with rising terrain and peaks that likely exceeded the climb capability of the airplane, they attempted to execute a left turn to exit the valley toward lower terrain. During the steep turn, the pilots failed to maintain adequate airspeed and exceeded the airplane's critical angle of attack, which resulted in an aerodynamic stall and impact with terrain. Performance calculations using weights that would allow the airplane to operate within manufacturer weight and balance limitations at the time of the accident indicated that it was unlikely that the airplane would have had sufficient climb performance to clear the terrain north of the airport. However, the airplane would likely have had sufficient climb performance to clear terrain east of the airport had the crew performed a right turn immediately after takeoff like the previous airplane.
Probable cause:
The flight crew's failure to maintain airspeed while maneuvering to exit an area of rising terrain, which resulted in an exceedance of the airplane's critical angle of attack and an aerodynamic stall. Contributing to the accident was the flight crew's decision to continue the takeoff toward rising terrain that likely exceeded the airplane's climb capability, the lack of adequate weather reporting available for wind determination, and the lack of documented training for an airport requiring a non-standard departure.
Final Report:

Crash of a Cessna 340 in Bartow: 5 killed

Date & Time: Dec 24, 2017 at 0717 LT
Type of aircraft:
Registration:
N247AT
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Bartow – Key West
MSN:
340-0214
YOM:
1973
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
4
Pax fatalities:
Other fatalities:
Total fatalities:
5
Captain / Total flying hours:
1600
Aircraft flight hours:
1607
Circumstances:
The instrument-rated private pilot and four passengers boarded the multiengine airplane inside a hangar. The pilot then requested that the airplane be towed from the hangar to the ramp, since he did not want to hit anything on the ramp while taxiing in the dense fog. Witnesses heard the pre-takeoff engine run-up toward the end of the runway but could not see the airplane as it departed; the engines sounded normal during the run-up and takeoff. A witness video recorded the takeoff but the airplane was not visible due to the dense fog. During the takeoff roll the airplane's tires chirped, which is consistent with the wheels touching down on the runway with a side load. The video ended before the accident occurred. The witnesses stated that the takeoff continued and then they heard the airplane impact the ground and saw an explosion. The weather conditions at the time of the accident included visibility less than 1/4 mile in fog and an overcast ceiling at 300 ft above ground level. The airplane's weight at the time of the accident was about 105 lbs over the maximum takeoff weight, which exceeded the center of gravity moment envelope. The excess weight would have likely extended the takeoff roll, decreased the climb rate, and increased the amount of elevator pressure required to lift off of the runway. A majority of the airplane was consumed by postcrash fire. The ground impact marks and wreckage distribution were consistent with the airplane rolling left over the departure end of the runway and impacting the ground inverted in a nearly vertical, nose-low attitude. Examination of the engines revealed operating signatures consistent with takeoff power at the time of impact. The elevator trim tab and actuator were found beyond their full up travel limits and the trim cable exhibited tension overload separations near the actuator. It is likely that, when the cable separated in overload, the chain turned the sprocket and extended the actuator rod beyond full travel. No anomalies were observed with the airframe, engines, or cockpit instrumentation that would have precluded normal operation. The investigation was unable to determine the status of the autopilot during the accident takeoff. Based on the evidence it's likely that when the airplane entered instrument meteorological conditions the pilot experienced spatial disorientation, which resulted in a loss of control and descent into terrain.
Probable cause:
The pilot's loss of control due to spatial disorientation during takeoff in instrument meteorological conditions.
Final Report:

Crash of a Cessna 207 Skywagon near Playa del Carmen

Date & Time: Dec 21, 2017 at 0950 LT
Operator:
Registration:
XA-UHL
Flight Phase:
Survivors:
Yes
Schedule:
Playa del Carmen – Chichén Itzá
MSN:
207-0261
YOM:
1974
Country:
Crew on board:
1
Crew fatalities:
Pax on board:
4
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
1506
Captain / Total hours on type:
37.00
Aircraft flight hours:
5090
Circumstances:
Few minutes after takeoff from Playa del Carmen, while flying at an altitude of 1,500 feet, the engine lost power and failed. The pilot attempted to make an emergency landing when the aircraft collided with trees and crashed in a wooded area located 18 km from its departure point. The pilot and all four passengers, a British family on vacations, were uninjured. The aircraft was damaged beyond repair.
Probable cause:
Engine failure caused by an oil leak following the failure of the 5th cylinder.
Final Report:

Crash of a Cessna 402C in Bahía Solano

Date & Time: Dec 20, 2017 at 0955 LT
Type of aircraft:
Operator:
Registration:
HK-4417
Flight Phase:
Survivors:
Yes
Schedule:
Bahía Solano – Quibdó
MSN:
402C-0020
YOM:
1979
Country:
Crew on board:
2
Crew fatalities:
Pax on board:
7
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
2901
Captain / Total hours on type:
1050.00
Copilot / Total flying hours:
675
Copilot / Total hours on type:
430
Aircraft flight hours:
9711
Circumstances:
The twin engine aircraft was departing Bahía Solano-José Celestino Mutis Airport on a flight to Quibdó, carrying seven passengers and two pilots. During the takeoff roll on runway 36, the airplane deviated to the right and veered off runway. While contacting soft ground, the right main gear collapsed. The aircraft rotated and came to rest in a grassy area about 5 metres to the right of the runway. All 9 occupants evacuated safely and the aircraft was damaged beyond repair.
Probable cause:
A loss of control during the takeoff roll as a result of inappropriate techniques on the part of the pilot-in-command who suffered a loss of situational awareness by not detecting the deviation in a timely manner.
The following contributing factors were identified:
- Inadequate crew decisions to apply appropriate corrective actions,
- Inadequate crew training program,
- Poor operational supervision on part of the operator.
Final Report:

Crash of a PZL-Mielec AN-2MS in Naryan-Mar: 4 killed

Date & Time: Dec 19, 2017 at 1027 LT
Type of aircraft:
Operator:
Registration:
RA-01460
Flight Phase:
Survivors:
Yes
Schedule:
Narian-Mar – Kharuta
MSN:
1G231-51
YOM:
1988
Flight number:
NYA9280
Country:
Region:
Crew on board:
2
Crew fatalities:
Pax on board:
11
Pax fatalities:
Other fatalities:
Total fatalities:
4
Captain / Total flying hours:
2342
Captain / Total hours on type:
25.00
Copilot / Total flying hours:
6146
Copilot / Total hours on type:
434
Aircraft flight hours:
14767
Circumstances:
The single engine aircraft (an Antonov An-2TP that was converted in 2014 with a TPE331 turbine engine) departed Naryan-Mar Airport on a schedule service (flight NYA9280) to Kharuta, Republic of Komi, carrying 11 passengers and two pilots. Shortly after takeoff, while climbing to a height of 30-40 metres, the aircraft entered an excessive nose-up attitude then rolled to the right, stalled and crashed in a snow covered field. A passengers was killed and 12 other occupants were injured. In the evening, two other passengers died and a fourth passed away on 10 January 2018.
Probable cause:
Loss of control during initial climb due to the combination of an excessive weight (the total weight of the aircraft was 42 kilos above MTOW) and a CofG that was too far aft, well above the permissible limit (32%). Poor flight preparation.
Final Report:

Crash of an ATR42-320 in Fond-du-Lac: 1 killed

Date & Time: Dec 13, 2017 at 1812 LT
Type of aircraft:
Operator:
Registration:
C-GWEA
Flight Phase:
Survivors:
Yes
Schedule:
Saskatoon – Prince Albert – Fond-du-Lac – Stony Rapids
MSN:
240
YOM:
1991
Flight number:
WEW280
Country:
Crew on board:
3
Crew fatalities:
Pax on board:
22
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
5990
Captain / Total hours on type:
1500.00
Copilot / Total flying hours:
15769
Copilot / Total hours on type:
7930
Aircraft flight hours:
26481
Aircraft flight cycles:
32051
Circumstances:
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.
Probable cause:
Findings as to causes and contributing factors:
These are conditions, acts or safety deficiencies that were found to have caused or contributed to this occurrence.
1. When West Wind commenced operations into Fond-du-Lac Airport (CZFD) in 2014, no effective risk controls were in place to mitigate the potential hazard of ground icing at CZFD.
2. 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.
3. Although the aircraft’s ice-protection systems were activated on the approach to CZFD, 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.
4. Although the flight crew were aware of the ice, there were no handling anomalies noted on the approach. Consequently, the crew likely did not assess that the residual ice was severe enough to have a significant effect on aircraft performance. Subsequently, without any further discussion about the icing, the crew continued the approach and landed at CZFD.
5. Weather conditions on the ground were conducive to ice or frost formation, and this, combined with the nucleation sites provided by the residual mixed ice on the aircraft, resulted in the formation of additional ice or frost on the aircraft’s critical surfaces.
6. Because the available inspection equipment was inadequate, the first officer’s ice inspection consisted only of walking around the aircraft on a dimly lit apron, without a flashlight, and looking at the left wing from the top of the stairs at the left rear entry door (L2). As a result, the full extent of the residual ice and ongoing accretion was unknown to the flight crew.
7. Departing from remote airports, such as CZFD, 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 the unsafe practice becoming normalized and this normalization influenced the flight crew’s decision to depart.
8. 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.
9. 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.
10. During the takeoff, despite the degraded performance, the aircraft initially climbed; however, immediately after lift off, 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.
11. 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.
12. Although the investigation determined 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.
13. 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.
14. The aircraft collided with the ground in 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 because of the impact angle and the variability in structural design.
15. 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.
16. On impact, the 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.
17. 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 died.
18. The collapse of part of the floor structure compromised the restraint systems, limiting the protection afforded to the occupants when they were experiencing vertical, longitudinal, and lateral forces. This resulted in serious velocity-related injuries and impeded their ability to take post-impact survival actions in a timely manner.
19. Most passengers in this occurrence did not brace before impact. Because their torsos were unrestrained, they received injuries consistent with jackknifing and flailing, such as hitting the seat in front of them.
20. Given that regulations requiring the use of child-restraint systems have yet to be implemented, the aircraft was not equipped with these devices. As a result, the infant passenger was unrestrained and received flail and crushing injuries. 21. 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.
Final Report: