Yukon

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. During the final moments of the flight, the aircraft’s right turn in excess of 45° of bank, while it was operating at a low height above the ground and just above the calculated stall speed, likely resulted in the aircraft entering an aerodynamic stall, with insufficient height to recover before impacting the terrain.
2. The stainless steel belt in the left AOA transmitter experienced a fatigue crack likely attributed to the wet-etch design process. Owing to the fact that the belt is an on condition component, the fatigue cracking went undetected until the belt failed at, or just before, takeoff on the occurrence flight, causing the AOA transmitter to transmit a false stall signal when the aircraft became airborne.
3. While attempting to align the aircraft for landing, the pilot experienced attentional narrowing due to an intense stress reaction in response to a surprise event. As a result, the pilot's attention was focused outside the aircraft, and the pilot unknowingly placed the aircraft in a flight regime that likely resulted in an aerodynamic stall at a very low height above ground.
4. The Royal Canadian Mounted Police's training for stall warning system malfunctions on the PC-12 focused solely on an inadvertent pusher activation. As a result, the occurrence pilot did not fully understand the symptoms of a false stall warning or the options available to mitigate the risks associated with this emergency.
5. The PC-12 pilot operating handbook provided limited guidance with regard to the potential use of the AURAL WARN INHIBIT switch during emergency situations. As a result, the occurrence pilot was unaware that this switch could be used during highworkload situations to quickly eliminate the false aural stall warning that was a distraction for the duration of the flight.

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. The pilot’s decision making was influenced by several biases and, as a result, the flight departed and subsequently continued into poor weather conditions in mountainous terrain.
2. The high speed at low altitude and low forward visibility reduced the opportunities for the pilot to take alternative action to avoid terrain.
3. Within the box canyon, the canyon floor elevation increased abruptly within less than 1 NM and the low visibility prevented the pilot from detecting this and taking sufficient actions to prevent collision with terrain.
4. When the pilot turned into the box canyon, the terrain awareness and warning system aural alerts were ineffective in warning the pilot about the rising terrain either because he had already heard multiple similar alerts in the preceding minutes, or because he had silenced the alerts.

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.
1. If administrative safety defences are not used as intended, it increases the risk that the hazards associated with the flight will not be identified and mitigated.

Other findings:
These items could enhance safety, resolve an issue of controversy, or provide a data point for future safety studies.
1. The pilot held a valid instrument rating and the aircraft was equipped to fly in instrument meteorological conditions. However, there were no scenarios in the pilot’s flying history on the Cessna 208B Grand Caravan or in his training where a transition from visual flight rules to a flight under instrument flight rules in an emergency was performed.

The aircraft departed controlled flight for reasons which could not be determined, and broke up due to high speed.

Findings as to Causes and Contributing Factors:
1. The aircraft was loaded in a manner that resulted in the centre of gravity being aft of the rearward limit.
2. Because the cargo was not properly secured, it shifted towards the rear of the aircraft, resulting in the centre of gravity moving further aft, causing the aircraft to pitch up and stall.

Findings as to Causes and Contributing Factors:
1. The meat was loaded into the aircraft on a slippery surface and not adequately secured.
2. The manner in which the meat was loaded and secured most likely allowed the load to shift to the rear of the cabin during take-off. This rearward shift resulted in the loss of pitch control and an aerodynamic stall from which the pilot could not recover.
Other Findings:
1. The aircraft's C of G was most likely at or aft of the aft limit before engine start.