Canada

Findings as to Causes and Contributing Factors:
1. The downwind condition on approach contributed to the aircraft landing long and with a high ground speed. This, in combination with hydroplaning, prevented the crew from stopping the aircraft in the runway length remaining.
2. When the decision to abort the landing was made, there was insufficient distance remaining for the aircraft to accelerate to a sufficient airspeed to lift off.
3. The overrun area for Runway 09 complied with regulatory standards, but the obstacles and terrain contour beyond the overrun area contributed to the fatality, the severity of injuries, and damage to the aircraft.
Finding as to Risk:
1. Alert Service Bulletin A25-1124A (dated 01 June 2000), which recommended replacing the inertia reel aluminum shaft with a steel shaft, was not completed, thus resulting in the risk of failure increasing over time.
Other Findings:
1. The weather station at the Powell River Airport does not have any air–ground communication capability with which to pass the flight crew timely wind updates.
2. The decision to make a second approach was consistent with normal industry practice, in that the crew could continue with the intent to land while maintaining the option to break off the approach if they assessed that the conditions were becoming unsafe.

Findings as to Causes and Contributing Factors:
1. The engine lost power when a compressor turbine blade failed as a result of the overstress extension of a fatigue-generated crack. The fracture initiated at a metallurgical anomaly in the parent blade material and progressed, eventually resulting in blade failure due to overstress rupture.
2. The combination of aircraft position at the time of the engine failure, the lack of equipment enabling the pilot to locate and identify high terrain, and the resultant manoeuvring required to avoid entering instrument flight conditions likely prevented the pilot from attempting to glide to the nearest airfield.
Findings as to Risk:
1. Single-engine instrument flight rules (SEIFR) operations in designated mountainous regions have unique obstacle risks in the event of an engine failure. Canadian equipment requirements for such operations do not currently include independent terrain mapping, such as terrain awareness and warning systems (TAWS).
2. Airline operators are not currently required to conduct any additional route evaluation or structuring to ensure that the risk of an off-field landing is minimized during SEIFR operations.
3. Pilots involved in commercial SEIFR operations do not receive training in how to conduct a forced landing under instrument flight conditions; such training would likely improve a pilotís ability to respond to an engine failure when operating in instrument meteorological conditions (IMC).
4. Mean time between failure (MTBF) calculations do not take into account In Flight Shut Downs (IFSDs) not directly attributable to the engine itself; it may be more appropriate to monitor all IFSD events.
5. The design of the Cessna 208B Caravan fuel shutoff valves increases the risk that the valves will open on impact, allowing fuel spillage and increasing the potential for fire.
Other Finding:
1. Sonicblue Airways was not providing downloaded engine parameter data for engine condition trend monitoring (ECTM) evaluation at appropriate intervals.

Findings as to Causes and Contributing Factors:
1. Airworthiness Directive AD 48-12-01 mandates the replacement of the potentially hazardous fuel line, but the line had not been replaced on this aircraft.
2. A fuel leak from the main fuel inlet line in the engine compartment of this cargo DC-4 caused an in-flight fire that spread into the nacelle and wing.
3. The fuel-fed fire burned for an extended period of time because turning the fuel selector off is not required as part of the primary Engine Fire Checklist.

Findings as to Causes and Contributing Factors:
1. During the take-off, the left engine combustion chamber plenum split open due to a fatigue crack. The rupture was so extensive that the engine flamed out.
2. The crew did not feather the left engine or retract the flaps, and the aircraft entered a moderate left-hand turn after take-off; the resulting drag caused the aircraft to descend until it contacted trees.
3. The first officer’s flying skills may have been challenged during the handling of the engine failure, and the checklist was conducted out of sequence, suggesting that there may have been uncertainty in the cockpit. A contributing factor may have been the captain’s unfamiliarity with handling an emergency from the right seat.
4. The use of flap 20 for take-off, although in accordance with company policy, contributed to the difficulty in handling the aircraft during the emergency.
Findings as to Risk:
1. The TPE331 series engine plenum is prone to developing cracks at bosses, particularly in areas where two bosses are in close proximity and a reinforcing weld has been made. Cracks that develop in this area cannot necessarily be detected by visual inspections or even by fluorescent dye-penetrant inspections (FPIs).
2. Because the wing was wet and the air temperature was at 0°C, it is possible that ice may have formed on top of the wing during the take-off, degrading the wing’s ability to generate lift.
3. Being required to conduct only flap 20 take-offs increases the risk of an accident in the event of an engine problem immediately after take-off.
Other Finding:
1. The plenum manufactured with a single machined casting, incorporating the P3 and bleed air bosses, is an improvement over the non-single casting boss plenum; however, cracks may still develop at bosses elsewhere on the plenum.

Findings as to Causes and Contributing Factors:
1. The aircraft departed at a weight exceeding the maximum take-off weight and the maximum weight for operation in icing conditions.
2. After departure from Winnipeg, the aircraft encountered in-flight icing conditions in which the aircraftís performance deteriorated until the aircraft was unable to maintain altitude.
3. During the attempt to return to the Winnipeg International Airport, the pilot lost control of the aircraft, likely with little or no warning, at an altitude from which recovery was not possible.
Findings as to Risk:
1. Aviation weather forecasts incorporate generic icing forecasts that may not accurately predict the effects of icing conditions on particular aircraft. As a result, specific aircraft types may experience more significant detrimental effects from icing than forecasts indicate.
2. Bulk loading prevented determining the cargo weight in each zone, resulting in a risk that the individual zone weight limits could have been exceeded.
3. The aircraftís centre of gravity (CG) could not be accurately determined, and may have been in the extrapolated shaded warning area on the CG limit chart. Although it was determined that the CG was likely forward of the maximum allowable aft CG, bulk loading increased the risk that the CG could have exceeded the maximum allowable aft CG.
4. The incorrect tare weight on the Toronto cargo container presented a risk that other aircraft carrying cargo from that container could have been inadvertently overloaded.
Other Findings:
1. The pilotís weather information package was incomplete and had to be updated by a telephone briefing.
2. The operatorís pilots were not pressured to avoid using aircraft de-icing facilities or to depart with aircraft unserviceabilities.
3. The aircraft departed Winnipeg without significant contamination of its critical surfaces.
4. The biological material on board the aircraft was disposed of after the accident, with no indication that any of the material had been released into the ground or the atmosphere.
5. The fact that the aircraft was not equipped with flight data recorder or cockpit voice recorder equipment limited the information available for the occurrence investigation and the scope of the investigation.

Finding as to Causes and Contributing Factors:
1. The pilot attempted to cross the mountain ridge in adverse weather, and the aircraft stalled at an altitude from which recovery was not possible. Loss of visual references, strong updrafts, moderate to severe turbulence and possible wind shear likely contributed to the onset of the aerodynamic stall.
Other Finding:
1. Had this been a survivable accident, rescue efforts may have been compromised by a lack of communication. A satellite phone provides a more effective means of communication when in remote areas.