Thompson

Findings as to causes and contributing factors:
1. The left engine low oil pressure indications during the previous and the occurrence flights were likely the result of a steady oil leak past the rear turbine air-oil seal assembly.
2. The loss of engine oil pressure resulted in a loss of propeller control authority on landing and the upset of the aircraft.
3. After consultation with maintenance, the crew considered the risks associated with landing single engine and without hydraulic pressure for the nose-wheel steering, and decided to continue the flight with both engines running, even though this was not consistent with the QRH procedures for low oil pressure indications.
4. Carbon deposits that accumulated within the inside diameter of the bellows convolutions interfered with the bellows’ ability to expand and to provide a positive seal against the rotor seal.

Findings as to risk:
1. If Canadian Aviation Regulations (CARs) subparts 703 and 704 operators do not provide initial or recurrent crew resource management training to pilots, these pilots may not be prepared to avoid, trap, or mitigate crew errors encountered during flight.
2. If operators of the SA227-AC Metro III aircraft rely solely on the emergency procedures listed in the aircraft flight manual, continued engine operation with low oil pressure may result in loss of control of the aircraft.
3. If an engine is not allowed to sufficiently cool down prior to shutdown, oil that remains trapped within hot areas of the engine may heat up to a point where the oil decomposes, creating a carbon deposit.
4. If flight data, voice, and video recordings are not available to an investigation, the identification and communication of safety deficiencies to advance transportation safety may be precluded.

Other findings:
1. The investigation was unable to determine the length of cooldown periods for the occurrence aircraft. However, a random sampling of engine shutdowns for similar company aircraft showed that 50% had not completed the full 3-minute cooldown period.
2. Despite having received limited crew resource management (CRM).

Findings as to causes and contributing factors:
1. Delivery of the incorrect type of aircraft fuel caused loss of power from both engines, necessitating a forced landing.
2. The fueling operation was not adequately supervised by the flight crew.
3. A reduced-diameter spout was installed that enabled the delivery of Jet-A1 fuel into the AVGAS fuel filler openings.
4. The fuel slip indicating that Jet-A1 fuel had been delivered was not available for scrutiny by the crew.

Findings as to risk:
1. If administrative and physical defences against errors in aviation fuel operations are circumvented or disabled, there is a risk that the incorrect type of fuel will be delivered.
2. If a reduced-diameter spout is available to accommodate non-standard fuel filler openings, there is an increased risk that Jet-A1 fuel can be dispensed into an aircraft that requires AVGAS.

Other findings:
1. Aircraft that were manufactured prior to the current airworthiness standards, or that have been modified by the installation of turbine engines, may have fuel filler openings that do not meet the dimension requirements.
2. The airworthiness standards for rotorcraft do not specify the size of fuel filler openings.
3. The use of all of the available restraint systems in the aircraft contributed to the survival of the occupants.
4. There was no post-crash fire, likely due to the separation of the battery from the aircraft and to the rain-saturated crash site.
5. The absence of a post-impact fire contributed to the survival of all of the aircraft's occupants.

Failure of the right main gear for unknown reasons.

Findings as to Causes and Contributing Factors:
1. The crew conducted an Area Navigation (RNAV) approach for which they were not trained, with an aircraft that was not properly equipped nor approved for such purpose.
2. The aircraft descended 300 feet below the minimum descent altitude (MDA) as a result of a number of lapses, errors and adaptations which, when combined, resulted in the mismanaged approach.
3. The aural warning on the aircraft’s altitude alerter had been silenced prior to the approach, which precluded it from alerting the crew when the aircraft descended below minimum descent altitude.
4. The SkyNorth standard operating procedures for conducting a non-precision approach were not followed, which resulted in the aircraft descending below the minimum descent altitude. During the ensuing missed approach, the aircraft struck trees.
Findings as to Risk:
1. The lack of a more-structured training environment and the type of supervisory flying provided increased the risk that deviations from standard operating procedures (SOPs) would not be identified.
2. There are several instrument approach procedures in Canada that contain step-down fixes that are not displayed on global positioning system (GPS) units. This may increase the risk of collision with obstacles during step-downs on approaches.

Findings as to Causes and Contributing Factors:
1. An electrical short circuit in the cockpit pedestal area produced flames and smoke, which induced the crew to take emergency action.
2. The detrimental effects of aging on the wires involved may have been a factor in this electrical arc event.
3. The crew elected to return to the airport at low level in an environment with inadequate visual references. As a result, control of the aircraft was lost at an altitude from which a recovery was not possible.
Findings as to Risk:
1. The actions specified in the standard operating procedures (SOP) do not include procedures for an electrical fire encountered at low altitude at night, which could lead to a loss of control.
2. Visual inspection procedures in accordance with normal phase inspection requirements may be inadequate to detect defects progressing within wiring bundles, increasing the risk of electrical fires.
3. In the event of an in-flight cockpit pedestal fire, the first officer does not have ready access to available fire extinguishers, reducing the likelihood of successfully fighting a fire of this nature.
4. Sealed in plastic containers and stored behind each pilot seat, the oxygen masks and goggles are time consuming to access and cumbersome to apply and activate. This could increase the probability of injury or incapacitation through extended exposure to smoke or fumes, or could deter crews from using them, especially during periods of high cockpit workload.
Other Finding:
1. A failure of the hot-mic recording function of the cockpit voice recorder (CVR) had gone undetected and information that would have been helpful to the investigation was not available.

The flight crew lost altitude awareness during the localizer back course approach and allowed the aircraft to descend below a mandatory level-off altitude. Contributing factors to this occurrence were the crew's deviation from a published approach procedure, ineffective in-flight monitoring of the approach, rapidly developing localized fog conditions, and, probably, pilot fatigue.

Fire in engine n°1 after takeoff and failure of the fire extinguisher system.

Engine problems of unknown origin.

Loss of control on final caused by an engine failure.