Northwest Territories

These are the factors that were found to have caused or contributed to this occurrence:
- During departure, the captain intentionally kept a low pitch attitude and a high airspeed to remove possible snow accumulation on the aircraft. As a result, the aircraft’s departure profile was closer to the ground than it would be on a standard departure.
- When the captain and first officer attempted to raise the landing gear, the combination of an outside air temperature colder than approximately −20 °C and the air load on the landing gear from the increased speed resulted in one of the main landing gear units, likely the left unit, not fully retracting.
- Following the first officer’s call to reduce airspeed, the captain reduced engine power to reduce the aircraft’s speed and allow the main landing gear to fully retract. As a result of the decreased power, the aircraft entered an inadvertent descent at 140 feet above ground level.
- The captain and first officer were likely preoccupied with the abnormal main landing gear indication and the aircraft’s airspeed and did not notice the aircraft’s loss of altitude until immediately before impact. As a result, the aircraft impacted trees and terrain 10 seconds after the descent began.

Findings as to causes and contributing factors:
- The oversight mechanisms employed by Air Tindi were unable to detect the drift away from standard operating procedures, and deviations by pilots, including the conduct of improvised instrument approaches in instrument meteorological conditions, were not addressed.
- The flight crew’s decision to depart on the day’s flights and continue flying in deteriorating weather was influenced by both the flight crew’s past successful experiences in similar conditions and by a plan continuation bias, which led to a reduced perception of risk associated with continuing this visual flight rules flight in instrument meteorological conditions.
- The flight crew’s overreliance on the electronic flight bags for situational awareness contributed to their decision to continue operating visually in instrument meteorological conditions.
- While conducting an improvised instrument approach in an area of reduced visibility, the flight crew intentionally descended below 50 feet above ground level without sufficient visual reference to the surface and the aircraft impacted rising terrain.

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.
- For undetermined reasons, the left-side attitude indicator failed in flight.
- Although just before take off the crew acknowledged that the right-side attitude indicator was not operative, they expected it to become operative at some point in the flight. As a result, they did not refer to the minimum equipment list, and departed into instrument meteorological conditions with an inoperative attitude indicator.
- The crew’s threat and error management was not effective in mitigating the risk associated with the unserviceable right-side attitude indicator.
- The crew’s crew resource management was not effective, resulting in a breakdown in verbal communication, a loss of situation awareness, and the aircraft entering an unsafe condition.
- The captain did not have recent experience in flying partial panel. As a result, the remaining instruments were not used effectively and the aircraft departed controlled flight and entered a spiral dive.
- The captain and first officer likely experienced spatial disorientation.
- Once the aircraft emerged below the cloud layer at approximately 2000 feet above ground, the crew were unable to recover control of the aircraft in enough time and with enough altitude to avoid an impact with terrain.

Findings as to risk:
These are conditions, unsafe acts or safety deficiencies that were found not to be a factor in this occurrence but could have adverse consequences in future occurrences.
- If flight crews do not use the guidance material provided in the minimum equipment list when aircraft systems are unserviceable, there is a risk that the aircraft will be operated without systems that are critical to safe aircraft operation.
- If flight crews do not use all available resources at their disposal, a loss in situation awareness can occur, which can increase the risk of an accident.

Other findings:
These items could enhance safety, resolve an issue of controversy, or provide a data point for future safety studies.
- A review of Air Tindi Ltd.'s pilot training program revealed that all regulatory requirements were being met or exceeded.

Buffalo Airways’ initial investigation revealed the engine oil scavenge pump had failed. No TSB-BST investigation was conducted on the event.

Findings as to causes and contributing factors:
1. Not using all enroute information led the pilot to underestimate the severity and duration of the icing conditions that would be encountered.
2. Inadequate awareness of aircraft limitations in icing conditions and incomplete weight-and-balance calculations led to the aircraft being dispatched in an overweight state for the forecast icing conditions. The aircraft centre of gravity was not within limits, and this led to a condition that increased stall speed and reduced aircraft climb performance.
3. The pilot’s expectation that the flight was being undertaken at altitudes where it should have been possible to avoid icing or to move quickly to an altitude without icing conditions led to his decision to continue operation of the aircraft in icing conditions that exceeded the aircraft’s performance capabilities.
4. The severity of the icing conditions encountered and the duration of the exposure resulted in reductions in aerodynamic performance, making it impossible to prevent descent of the aircraft.
5. The inability to arrest descent of the aircraft resulted in the forced landing on the surface of Great Slave Lake and the collision with terrain.
6. The Type C pilot self-dispatch system employed by Air Tindi did not have quality assurance oversight or adequate support systems. This contributed to the aircraft being dispatched in conditions not suitable for safe flight.
Findings as to risk:
1. If passenger briefings on cabin door operations are ineffective, there is a risk of passenger egress in an accident being compromised, affecting survivability.
2. If survival equipment is stowed in a location that may be inaccessible following an accident, such as the belly pod, there is a risk of survival being compromised if search and rescue is delayed.
Other findings:
1. The aircraft was under control and in a level attitude when it contacted the ice. This minimized structural damage and increased survivability for the aircraft’s occupants.
2. The survival skills of the crew and passengers were indispensable in a situation in which access to the survival equipment on the aircraft was limited.

Findings as to causes and contributing factors:
1. During approach to landing on the previous flight, the right-wing leading-edge and wing tip were damaged by impact with several trees.
2. The damage to the aircraft was not evaluated or inspected by qualified personnel prior to take-off.
3. Cumulative unmanaged stressors disrupted the pilot’s processing of safety-critical information, and likely contributed to an unsafe decision to depart with a damaged, uninspected aircraft.
4. The aircraft was operated in a damaged condition and departed controlled flight likely due to interference between parts of the failing wing tip, acting under air loads, and the right aileron.
Findings as to risk:
Not applicable.
Other findings:
1. The emergency locator transmitter did not activate, due to crash damage and submersion in water.
2. The aircraft was not fitted with FM radio equipment that is usually carried by aircraft servicing the lodge. Lodge personnel did not have a means to contact the pilot once the aircraft moved away from the dock.

Findings as to causes and contributing factors:
1. An accurate take-off weight and balance calculation was not completed prior to departure, resulting in an aircraft weight that exceeded its maximum certified takeoff weight.
2. The right engine number 1 cylinder failed during the take-off sequence due to a preexisting fatigue crack, resulting in an engine fire.
3. After the right propeller’s feathering mechanism was activated, the propeller never achieved a fully feathered condition likely due to a seized bearing in the feathering pump.
4. The windmilling right propeller caused an increase in drag which, combined with the overweight condition, contributed to the aircraft’s inability to maintain altitude, and the aircraft collided with terrain short of the runway.
5. The operator’s safety management system was ineffective at identifying and correcting unsafe operating practices.
6. Transport Canada’s surveillance activities did not identify the operator’s unsafe operating practices related to weight and balance and net take-off flight path calculations. Consequently, these unsafe practices persisted.
Findings as to risk:
1. If companies do not adhere to operational procedures in their operations manual, there is a risk that the safety of flight cannot be assured.
2. If Transport Canada does not adopt a balanced approach that combines inspections for compliance with audits of safety management processes, unsafe operating practices may not be identified, thereby increasing the risk of accidents.
3. If cockpit or data recordings are not available to an investigation, this may preclude the identification and communication of safety deficiencies to advance transportation safety.
Other findings:
1. Current Canadian Aviation Regulations permit a transport category piston-powered aircraft to carry passengers without a flight data recorder or cockpit voice recorder.
2. The crew resource management component of the flight attendant’s training had not been completed.

Findings as to causes and contributing factors:
The aircraft was flown at low altitude into an area of low forward visibility during a day VFR flight, which prevented the pilot from seeing and avoiding terrain.
The concentrations of cannabinoids were sufficient to have caused impairment in pilot performance and decision-making on the accident flight.
Findings as to risk:
Installation instructions for the ELT did not provide a means of determining the necessary degree of strap tightness to prevent the ELT from being ejected from its mount during an accident. Resultant damages to the ELT and antenna connections could preclude transmission of an effective signal, affecting search and rescue of the aircraft and occupants.
Flying beyond gliding distance of land without personal floatation devices on board exposes the occupants to hypothermia and/or drowning in the event of a ditching.
Other findings:
Earlier on the day of the accident, the pilot flew the route from Fort Simpson to Yellowknife in cloud on a visual flight rules flight plan in controlled airspace.
With the ELT unable to transmit a useable signal, the SkyTrac system in C GATV was instrumental in locating the accident site. This reduced the search time, and allowed for timely rescue of the seriously injured survivors.

Findings as to Causes and Contributing Factors:
1. Airspeed fluctuations at touchdown, coupled with gusty wind conditions, caused a bounced landing.
2. Improper go-around techniques during the recovery from the bounced landing resulted in a loss of control.
3. It is possible that confused crew coordination during the attempted go-around contributed to the loss of control.