Toronto-Lester Bowles Pearson

Findings as to causes and contributing factors:

1. Air Canada’s standard operating procedure (SOP) and practice when flying in flight path angle guidance mode was that, once the aircraft was past the final approach fix, the flight crews were not required to monitor the aircraft’s altitude and distance from the threshold or to make any adjustments to the flight path angle. This practice was not in accordance with the flight crew operating manuals of Air Canada or Airbus.
2. As per Air Canada’s practice, once the flight path angle was selected and the aircraft began to descend, the flight crew did not monitor the altitude and distance from the threshold, nor did they make any adjustments to the flight path angle.
3. The flight crew did not notice that the aircraft had drifted below and diverged from the planned vertical descent angle flight profile, nor were they aware that the aircraft had crossed the minimum descent altitude further back from the threshold.
4. Considering the challenging conditions to acquire and maintain the visual cues, it is likely the flight crew delayed disconnecting the autopilot until beyond the minimum descent altitude because of their reliance on the autopilot system.
5. The approach and runway lights were not changed from setting 4 to setting 5; therefore, these lights were not at their maximum brightness setting during the approach.
6. The system to control the airfield lighting’s preset selections for brightness setting 4 was not in accordance with the NAV CANADA Air Traffic Control Manual of Operations requirement for the omnidirectional approach lighting system to be at its brightest settings.
7. The limited number of visual cues and the short time that they were available to the flight crew, combined with potential visual illusions and the reduced brightness of the approach and runway lights, diminished the flight crew’s ability to detect that the aircraft’s approach path was taking it short of the runway.
8. The flight crew’s recognition that the aircraft was too low during the approach would have been delayed because of plan continuation bias.
9. The aircraft struck terrain approximately 740 feet short of the runway threshold, bounced twice, and then slid along the runway before coming to a rest approximately 1900 feet beyond the runway threshold.
10. At some time during the impact sequence, the captain’s head struck the glare shield because there were insufficient acceleration forces to lock the shoulder harness and prevent movement of his upper body.
11. The first officer sustained a head injury and serious injury to the right eye as a result of striking the glare shield because the automatic locking feature of the right-side shoulder-harness inertia reel was unserviceable.
12. A flight attendant was injured by a coffee brewer that came free of its mounting base because its locking system was not correctly engaged.
13. Because no emergency was expected, the passengers and cabin crew were not in a brace position at the time of the initial impact.
14. Most of the injuries sustained by the passengers were consistent with not adopting a brace position.

Findings as to risk:

1. If aircraft cockpit voice recorder installations do not have an independent power supply, additional, potentially valuable information will not be available for an investigation.
2. If Transport Canada does not consistently follow its protocol for the assessment of aeromedical risk and ongoing surveillance in applicants who suffer from obstructive sleep apnea, some of the safety benefit of medical examinations will be lost, increasing the risk that pilots will fly with a medical condition that poses a risk to safety.
3. If new regulations on the use of child-restraint systems are not implemented, lap-held infants and young children are exposed to undue risk and are not provided with a level of safety equivalent to that for adult passengers.
4. If passengers do not dress appropriately for safe travel, they risk being unprepared for adverse weather conditions during an emergency evacuation.
5. If the type of approach lighting system on a runway is not factored into the minimum visibility required to carry out an approach, in conditions of reduced visibility, the lighting available risks being less than adequate for flight crews to assess the aircraft’s position and decide whether or not to continue the approach to a safe landing.
6. If they do not incorporate a means of absorbing forces along their longitudinal axis, vertically mounted, non-structural beams (channels, tubes, etc.) in cargo compartments could penetrate the cabin floor when the fuselage strikes the water or ground, increasing the risk of aircraft occupants being injured or emergency egress being impaired.
7. If an aircraft manufacturer’s maintenance instructions do not include the component manufacturer’s safety-critical test criteria, the component risks not being maintained in an airworthy condition.
8. If there is a complete loss of electrical and battery power and the passenger address system does not have an independent emergency power supply, the passenger address system will be inoperable, and the initial command to evacuate or to convey other emergency instructions may be delayed, putting the safety of passengers and crew at risk.
9. If passengers retrieve or attempt to retrieve their carry-on baggage during an evacuation, they are putting themselves and other passengers at a greater risk of injury or death.
10. If passengers do not pay attention to the pre-departure safety briefings or review the safety-features cards, they may be unprepared to react appropriately in an accident, increasing their risk of injury or death.
11. If an organization’s emergency response plan does not identify all available transportation resources, there is an increased risk that evacuated passengers and crew will not be moved from an accident site in a timely manner.
12. If organizations do not practise transporting persons from an on-airport accident site, they may be insufficiently prepared to react appropriately to an actual accident, which may increase the time required to evacuate the passengers and crew.

Other findings:

1. The service director assessed the evacuation flow as good and determined that there was therefore no need to open the R1 door.
2. The flight attendants stationed in the rear of the aircraft noted no life-threatening hazards. Because no evacuation order had been given, and deplaned passengers and firefighters were observed walking near the rear of the aircraft in an area where the deployment of the rear slides may have created additional hazards or risks, the flight attendants determined that there was no requirement to open the L2 and R2 doors.
3. Although Transport Canada required the dual-exit drill to be implemented in training, it did not require all cabin crew to receive the training before an organization implemented the 1:50 ratio.
4. At the time of the accident, neither the service director nor the flight attendants had received the dual-exit training, nor were they aware of the requirement for such training in order for Air Canada to operate with the exemption allowing 1 flight attendant for each unit of 50 passengers.
5. Although Transport Canada had reviewed and approved Air Canada’s aircraft operating manual and the standard operating procedures (SOPs), it had not identified the discrepancy between the Air Canada SOPs and the Airbus flight crew operating manual regarding the requirement to monitor the aircraft’s vertical flight path beyond the final approach fix when the flight path angle guidance mode is engaged.
6. A discrepancy in the Halifax International Airport Authority’s standby generators’ control circuitry caused the 2 standby generators to stop producing power.
7. Air Canada’s emergency response plan for Halifax/Stanfield International Airport indicated that the airline was responsible for the transportation of passengers from an accident site.
8. Air Canada’s emergency response plan did not identify the airport’s Park’N Fly minibuses as transportation resources. 9. The Halifax International Airport Authority’s emergency response plan did not identify that the airport Park’N Fly mini-buses could be used to transport the uninjured passengers, nor did it provide instructions on when and how to request and dispatch any transportation resources available at the airport.
10. The Air Canada Flight Operations Manual did not identify that the required visual reference should enable the pilot to assess aircraft position and rate of change of position in order to continue the approach to a landing.
11. In Canada, the minimum visibility that is authorized by the operations specification for non-precision approaches does not take into account the type of approach lighting system installed on the runway.
12. It is likely that, during the emergency, a passenger activated the L1 door gust lock release pushbutton while trying to expedite his or her exit, which allowed the door to move freely.
13. The passenger seatbacks were dislodged because the shear pins had sheared, likely as a result of contact with passengers during the impact sequence or emergency egress.
14. Recovery of the uninjured passengers from the accident site was delayed owing to a number of factors, including the severe weather conditions; the failure of the airport’s 2 standby generators to provide backup power after the loss of utility power; the loss of the airport operations radio network; and the lack of arrangements for the dispatch of transportation vehicles until after emergency response services had advised that all passengers were evacuated and the site was all clear.
15. Given that the captain rarely used continuous positive airway pressure therapy, he would have been at risk of experiencing fatigue related to chronic sleep disruption caused by obstructive sleep apnea. However, there was no indication that fatigue played a causal or contributory role in this occurrence.

Findings as to Causes and Contributing Factors:
1. The crew flew an unstabilized approach with excessive airspeed.
2. The lack of adherence to company standard operating procedures and crew resource management, as well as the non-completion of checklist items by the flight crew contributed to the occurrence.
3. The captain’s commitment to landing or lack of understanding of the degree of instability of the flight path likely influenced the decision not to follow the aural GPWS alerts and the missed approach call from the first officer.
4. The non-standard wording and the tone used by the first officer were insufficient to deter the captain from continuing the approach.
5. At touchdown, directional control was lost, and the aircraft veered off the runway with sufficient speed to prevent any attempts to regain control.
Finding as to Risk
1. Companies which do not have ground proximity warning system procedures in their standard operating procedures may place crews and passengers at risk in the event that a warning is received.

Findings as to Causes and Contributing Factors:
1. On final approach, the captain diverted his attention from monitoring the flight, leaving most of the decision making and control of the aircraft to the first officer, who was significantly less experienced on the aircraft type. As a result, the first officer was not fully supervised during the late stages of the approach.
2. The first officer did not adhere to the Air Canada Jazz standard operating procedures (SOPs) in the handling of the autopilot and thrust levers on short final, which left the aircraft highly susceptible to a bounce, and without the bounce protection normally provided by the ground lift dump (GLD) system.
3. Neither the aircraft operating manual nor the training that both pilots had received mentioned the importance of conducting a balked or rejected landing when the aircraft bounces. Given the low-energy state of the aircraft at the time of the bounce, the first officer attempted to salvage the landing.
4. When the thrust levers were reduced to idle after the bounce, the GLD system activated. The resultant sink rate after the GLD system deployed was beyond the certification standard for the landing gear and resulted in the landing gear trunnion fitting failures.
5. There was insufficient quality control at the landing gear overhaul facility, which allowed non-airworthy equipment to enter into service. The condition of the shock struts would have contributed to the bounce.
Findings as to Risk:
1. Several passengers took carry-on items with them as they exited the aircraft, despite being instructed not to do so.
2. The location of the stored megaphone did not allow the flight attendant to have ready access after the passengers started moving to the exit door.

Findings as to Causes and Contributing Factors:
1. The crew conducted an approach and landing in the midst of a severe and rapidly changing thunderstorm. There were no procedures within Air France related to distance required from thunderstorms during approaches and landing, nor were these required by regulations.
2. After the autopilot and autothrust systems were disengaged, the pilot flying (PF) increased the thrust in reaction to a decrease in the airspeed and a perception that the aircraft was sinking. The power increase contributed to an increase in aircraft energy and the aircraft deviated above the glide path.
3. At about 300 feet above ground level (agl), the surface wind began to shift from a headwind component to a 10-knot tailwind component, increasing the aircraft’s groundspeed and effectively changing the flight path. The aircraft crossed the runway threshold about 40 feet above the normal threshold crossing height.
4. Approaching the threshold, the aircraft entered an intense downpour, and the forward visibility became severely reduced.
5. When the aircraft was near the threshold, the crew members became committed to the landing and believed their go-around option no longer existed.
6. The touchdown was long because the aircraft floated due to its excess speed over the threshold and because the intense rain and lightning made visual contact with the runway very difficult.
7. The aircraft touched down about 3800 feet from the threshold of Runway 24L, which left about 5100 feet of runway available to stop. The aircraft overran the end of Runway 24L at about 80 knots and was destroyed by fire when it entered the ravine.
8. Selection of the thrust reversers was delayed as was the subsequent application of full reverse thrust.
9. The pilot not flying (PNF) did not make the standard callouts concerning the spoilers and thrust reversers during the landing roll. This further contributed to the delay in the PF selecting the thrust reversers.
10. Because the runway was contaminated by water, the strength of the crosswind at touchdown exceeded the landing limits of the aircraft.
11. There were no landing distances indicated on the operational flight plan for a contaminated runway condition at the Toronto/Lester B. Pearson International Airport (CYYZ).
12. Despite aviation routine weather reports (METARs) calling for thunderstorms at CYYZ at the expected time of landing, the crew did not calculate the landing distance required for Runway 24L. Consequently, they were not aware of the margin of error available for the landing runway nor that it was eliminated once the tailwind was experienced.
13. Although the area up to 150 m beyond the end of Runway 24L was compliant with Aerodrome Standards and Recommended Practices (TP 312E), the topography of the terrain beyond this point, along the extended runway centreline, contributed to aircraft damage and to the injuries to crew and passengers.
14. The downpour diluted the firefighting foam agent and reduced its efficiency in dousing the fuel-fed fire, which eventually destroyed most of the aircraft.
Findings as to Risk :
1. In the absence of clear guidelines with respect to the conduct of approaches into convective weather, there is a greater likelihood that crews will continue to conduct approaches into such conditions, increasing the risk of an approach and landing accident.
2. A policy where only the captain can make the decision to conduct a missed approach can increase the likelihood that an unsafe condition will not be recognized early and, therefore, increase the time it might otherwise take to initiate a missed approach.
3. Although it could not be determined whether the use of the rain repellent system would have improved the forward visibility in the downpour, the crew did not have adequate information about the capabilities and operation of the rain repellent system and did not consider using it.
4. The information available to flight crews on initial approach in convective weather does not optimally assist them in developing a clear idea of the weather that may be encountered later in the approach.
5. During approaches in convective weather, crews may falsely rely on air traffic control (ATC) to provide them with suggestions and directions as to whether to land or not.
6. Some pilots have the impression that ATC will close the airport if weather conditions make landings unsafe; ATC has no such mandate.
7. Wind information from ground-based measuring systems (anemometers) is critical to the safe landing of aircraft. Redundancy of the system should prevent a single-point failure from causing a total loss of relevant wind information.
8. The emergency power for both the public address (PA) and EVAC alert systems are located in the avionics bay. A less vulnerable system and/or location would reduce the risk of these systems failing during a survivable crash.
9. Brace commands were not given by the cabin crew during this unexpected emergency condition. Although it could not be determined if some of the passengers were injured as a result, research shows that the risk of injury is reduced if passengers brace properly.
10. Safety information cards given to passengers travelling in the flight decks of Air France Airbus A340-313 aircraft do not include illustrations depicting emergency exit windows, descent ropes or the evacuation panel in the flight deck doors.
11. There are no clear visual cues to indicate that some dual-lane slides actually have two lanes. As a result, these slides were used mostly as single-lane slides. This likely slowed the evacuation, but this fact was not seen as a contributing factor to the injuries suffered by the passengers.
12. Although all passengers managed to evacuate, the evacuation was impeded because nearly 50 per cent of the passengers retrieved carry-on baggage.
Other Findings:
1. There is no indication that the captain’s medical condition or fatigue played a role in this occurrence.
2. The crew did not request long aerodrome forecast (TAF) information while en route. This did not affect the outcome of this occurrence because the CYYZ forecast did not change appreciably from information the flight crew members received before departure, and they received updated METARs for CYYZ and Niagara Falls International Airport (KIAG).
3. The possibility of a diversion required the flight crew to check the weather for various potential alternates and to complete fuel calculations. Although these activities consumed considerable time and energy, there is no indication that they were unusual for this type of operation or that they overtaxed the flight crew.
4. The decision to continue with the approach was consistent with normal industry practice, in that the crew could continue with the intent to land while maintaining the option to discontinue the approach if they assessed that the conditions were becoming unsafe.
5. There is no indication that more sophisticated ATC weather radar information, had it been available and communicated to the crew, would have altered their decision to continue to land.
6. It could not be determined why door L2 opened before the aircraft came to a stop.
7. There is no indication that the aircraft was struck by lightning.
8. There is no information to indicate that the aircraft encountered windshear during its approach and landing.
9. The flight crew seats are certified to a lower standard than the cabin seats, which may have been a factor in the injuries incurred by the captain.

The pilot's improper in-flight decision to perform a precautionary landing, and his failure to maintain airspeed after he experienced a partial loss of power on one engine. A factor was the partial loss of power on one engine due to an induction air leak.

Preliminary investigation revealed that an apprentice AME moved a line in the landing gear well prior to the flight. The work was neither scheduled nor required. The apprentice left the work unfinished when he went to do something else, then forgot that a fastener was not in place. There was no flag or note to inform the other technicians or the crew that the aircraft was not in an airworthy state. The apprentice has two years experience with this company. The management was satisfied with the quality of his work. Two other licensed AMEs were working in the hangar with the apprentice. He was the only apprentice they had to supervise. The apprentice attended a type training course for this aircraft.

Findings as to Causes and Contributing Factors:
1. The accident flight was conducted at night in IMC, and the pilot, whose private pilot licence was not endorsed with an instrument rating, was not certified for the IFR flight.
2. The pilot may have been subjected to somatogravic illusion and allowed the aircraft to descend into terrain after a night take-off in IMC.
3. The pilot did not completely report his medical conditions to the civil aviation medical examiner.
Other Findings
1. The pilot was not certified to fly this model of aircraft as his private pilot licence was not endorsed with the appropriate high-performance aircraft rating.
2. The pilot conducted a downwind take-off.
3. While the aircraft was turning left for the on-course track, the aircraft flaps were retracting.
4. The aircraft struck trees while in a shallow descent. The integrity of the aircraft was compromised as it rolled inverted and entered the impact zone at high speed.
5. The aircraft engine teardown examination revealed no pre-impact failures of any component parts or accessories in either the left or right engine that would have precluded normal engine operation.
6. The propeller teardown examination revealed that both propellers were in a normal operating range and were rotating with power at the time of impact.
7. The ELT did not function due to the impact damage sustained by its various components.

Findings as to Causes and Contributing Factors:
1. Although for the time of the approach the weather reported for Fredericton—ceiling 100 feet and visibility c mile—was below the 200-foot decision height and the charted ½ -mile (RVR 2600) visibility for the landing, the approach was permitted because the reported RVR of 1200 feet was at the minimum RVR specified in CAR 602.129.
2. Based on the weather and visibility, runway length, approach and runway lighting, runway condition, and the first officer’s flying experience, allowing the first officer to fly the approach is questionable.
3. The first officer allowed the aircraft to deviate from the flight path to the extent that a go-around was required, which is an indication of his ability to transition to landing in the existing environmental conditions.
4. Disengagement of the autopilot at 165 feet rather than at the 80-foot minimum autopilot altitude resulted in an increased workload for the PF, allowed deviations
from the glide path, and deprived the pilots of better visual cues for landing.
5. In the occurrence environmental conditions, the lack of runway centre line and touchdown-zone lighting probably contributed to the first officer not being able to see the runway environment clearly enough to enable him to maintain the aircraft on the visual glide path and runway centre line.
6. The first officer’s inexperience and lack of training in flying the CL-65 in low-visibility conditions contributed to his inability to successfully complete the landing.
7. The situation of a captain being the PNF when ordering a go-around probably played a part in the uncertainty regarding the thrust lever advance and the raising of the flaps because there was no documented procedure covering their duties.
8. The go-around was attempted from a low-energy situation outside of the flight boundaries certified for the published go-around procedures; the aircraft’s low energy was primarily the result of the power being at idle.
9. The sequential nature of steps within the go-around procedures, in particular, in directing the pitch adjustment prior to noting the airspeed, the compelling nature of the command bars, and the high level of concentration required when initiating the go-around contributed to the first officer’s inadequate monitoring of the airspeed during the go-around attempt.
10. Following the command bars in go-around mode does not ensure that a safe flying speed is maintained, because the positioning of the command bars does not take into consideration the airspeed, flap configuration, and the rate of change of the angle of attack, considerations required to compute stall margin.
11. The conditions under which the go-arounds are demonstrated for aircraft certification do not form part of the documentation that leads to aircraft limitations or boundaries for the go-around procedure; this contributed to these factors not being taken into account when the go-around procedures were incorporated in aircraft and training manuals.
12. The published go-around procedure does not adequately reflect that once power is reduced to idle for landing, a go-around will probably not be completed without the aircraft contacting the runway (primarily because of the time required for the engines to spool up to go-around thrust).
13. The Air Canada stall recovery training, as approved by Transport Canada, did not prepare the crew for the conditions in which the occurrence aircraft stick shaker activated and the aircraft stalled.
14. The limitations of the ice-detection and annunciation systems and the procedures on the use of wing anti-ice did not ensure that the wing would remain ice-free during flight.
15. Ice accretion studies indicate that the aircraft was in an icing environment for at least 60 seconds prior to the stall, and that during this period a thin layer of mixed ice with some degree of roughness probably accumulated on the leading edges of the wings. Any ice on the wings would have reduced the safety margins of the stall protection system.
16. The implications of ice build-up below the threshold of detection, and the inhibiting of the ice advisory below 400 feet, were not adequately considered when the stall margin was being determined during the 1996 certification of the ice-detection system and associated procedures.
17. The stall protection system operated as designed: that it did not prevent the stall is related to the degraded performance of the wings.
18. The Category I approach was without the extra aids and defences required for Category II approaches.
19. Canadian regulations with respect to Category I approaches are more liberal than those of most countries and are not consistent with the ICAO International Standards and Recommended Practices (Annex 14), which defines visibility limits; in Canada, the visibility values, other than RVR, are advisory only.
20. Even though a Category I approach may be conducted in weather conditions reported to be lower than the landing minima specified for the approach, there is no special training required for any flight crew member, and there is no requirement that flight crew be tested on their ability to fly in such conditions.
21. Air Canada’s procedures required that the captain fly the aircraft when conducting a Category II approach, in all weather conditions; however, the decision as to who will fly low-visibility Category I approaches was left to the captain, who may not be in a position to adequately assess the first officer’s ability to conduct the approach.
22. The aircraft stalled at an angle of attack approximately 4.5 degrees lower, and at a CLmax 0.26 lower, than would be expected for the natural stall.
23. On final approach below 1000 feet agl, the wing performance on the accident flight was degraded over the wing performance at the same phase on the previous flight.
24. The engineering simulator comparison indicated two step reductions in aircraft performance, at 400 feet and 150 feet agl, as a result of local flow separation in the vicinity of wing station (WS) 247 and WS 253.
25. Pitting on the leading edges of the wings had a negligible effect on the performance of the aircraft.
26. The sealant on the leading edges of both wings was missing in some places and protruding from the surface 2 to 3 mm in others. Test flights indicate that the effect of the protruding chordwise sealant on the aircraft performance could have accounted for a reduction of 1.7 to 2.0 degrees in maximum fuselage angle of attack and of 0.03 to 0.05 in CLmax.
27. The maximum reduction in angle of attack resulting from ground effect is considered to be in the order of 0.75±0.5 degree: the aircraft angle of attack was influenced by ground effect during the go-around manoeuvre.
28. The performance loss caused by the protruding sealant and by ground effect was not great enough to account for the performance loss experienced; there is no apparent phenomenon other than ice accretion that could account for the remainder of the performance loss.
29. Neither Bombardier Inc., nor Transport Canada, nor Air Canada ensured that the regulations, manuals, and training programs prepared flight crews to successfully and consistently transition to visual flight for a landing or to go-around in the conditions that existed during this flight, especially considering the energy state of the aircraft when the go-around was commenced.
Other Findings:
1. Both the captain and the first officer were licensed and qualified for the duties performed during the flight in accordance with regulations and Air Canada training
and standards, except for minor training deficiencies with regard to emergency equipment.
2. The occurrence flight attendant was trained and qualified for the flight in accordance with existing requirements.
3. The aircraft was within its weight and centre-of-gravity limits for the entire flight.
4. Records indicate that the aircraft was certified, equipped, and maintained in accordance with existing regulations and approved procedures.
5. There was no indication found of a failure or malfunction of any aircraft component prior to or during the flight.
6. When the stick shaker activated, it is unlikely that the crew could have landed the aircraft safely or completed a go-around without ground contact.
7. When power was selected for the go-around, the engines accelerated at a rate that would have been expected had the thrust levers been slammed to the go-around power setting.
8. The aircraft was not equipped with an emergency locator transmitter, nor was one required by regulation.
9. The lack of an emergency locator transmitter probably delayed locating the aircraft and its occupants.
10. Passengers and crew had no effective means of signaling emergency rescue services personnel.
11. The flight crew did not receive practical training on the operation of any emergency exits during their initial training program, even though this was required by
regulation.
12. Air Canada’s initial training program for flight crew did not include practical training in the operation of over-wing exits or the flight deck escape hatch.
13. Air Canada’s annual emergency procedures training for flight crew regarding the operation and use of emergency exits did not include practical training every third year, as required. Annual emergency exit training was done by demonstration only.
14. The flight crew were unaware that a pry bar was standard emergency equipment on the aircraft.
15. The four emergency flashlights carried on board were located in the same general area of the aircraft, increasing the possibility that all could be rendered inaccessible or unserviceable in an accident. (See section 4.1.6)
16. That there was a Flight Service Station specialist, as opposed to a tower controller, at the Fredericton airport at the time of the arrival of ACA 646 was not material to this occurrence.