Canada

The aircraft was landed at a point from which it could not be stopped under the prevailing conditions. Contributing to the occurrence were the lack of immediate propeller ground fine pitch and the choice of runway 03 as the landing runway. A possible contributing factor was the inappropriate information in the then-current runway analysis manual.

On touchdown, the float(s) struck the water and caused a flying attitude that the pilot could not control before the right wing dug in and the aircraft overturned. Contributing to the accident were conflicting wind and water conditions at the time of the occurrence.

Findings as to Causes and Contributing Factors:
- The crew did not realize that the pull to the left and the extended take-off run were due to the left brakes' dragging, which led to overheating of the brake components.
- Dragging of the left brakes was most probably caused by an unidentified pressure locking factor upstream of the brakes on take-off. The dragging caused overheating and leakage, probably at one of the piston seals that retain the brake hydraulic fluid.
- When hydraulic fluid leaked onto the hot brake components, the fluid caught fire and initiated an intense fire in the left nacelle, leading to failure of the main hydraulic system.
- When the L WING OVHT light went out, the overheating problem appeared corrected; however, the fire continued to burn.
- The crew never realized that all of the problems were associated with a fire in the wheel well, and they did not realize how serious the situation was.
- The left wing was weakened by the wing/engine fire and failed, rendering the aircraft uncontrollable.
Findings as to Risk:
- Numerous previous instances of brake overheating or fire on SA226 and SA227 aircraft had the potential for equally tragic consequences. Not all crews flying this type of aircraft are aware of its history of numerous brake overheating or fire problems.
- The aircraft flight manual and the emergency procedures checklist provide no information on the possibility of brake overheating, precautions to prevent brake overheating, the symptoms that could indicate brake problems, or actions to take if overheated brakes are suspected.
- More stringent fire-blocking requirements would have retarded combustion of the seats, reducing the fire risk to the aircraft occupants.
- A mixture of the two types of hydraulic fluid lowered the temperature at which the fluid would ignite, that is, below the flashpoint of pure MIL-H-83282 fluid.
- The aircraft maintenance manual indicated that the two hydraulic fluids were compatible but did not mention that mixing them would reduce the fire resistance of the fluid.
Other Findings:
- The master cylinders were not all of the same part number, resulting in complex linkage and master cylinder adjustments, complicated overall brake system functioning, and difficult troubleshooting of the braking system. However, there was no indication that this circumstance caused residual brake pressure.
- The latest recommended master cylinders are required to be used only with specific brake assembly part numbers, thereby simplifying adjustments, functioning, and troubleshooting.
- Although the emergency checklist for overheating in the wing required extending the landing gear, the crew did not do this because the wing overheat light went out before the crew initiated the checklist.
- The effect of the fire in the wheel well made it difficult to move the ailerons, but the exact cause of the difficulty was not determined.

The pilot did not follow the prescribed emergency procedure for low oil pressure, and the engine failed before he could land safely. The pilot's decision making was influenced by his belief that the low oil pressure indications were not valid. The engine failed as a result of an interruption of oil flow to the first-stage planet gear assembly; the cause of the oil flow interruption could not be determined.

The crew did not refuel at Rouyn as planned, and did not have sufficient fuel to complete the segment. Contributing to the accident were the following: the crew did not fully understand the flight plan documents and did not calculate fuel consumption en route.

An unstabilized approach resulted in a heavy landing because the captain changed the configuration of the aircraft, and the high rate of descent that resulted was not arrested before contact was made with the runway surface. Contributing to the high rate of descent were the reduction of engine power to flight idle, airframe ice, and the time available for the final descent. Contributing to the damage on landing was the left to right movement of the aircraft.

A modification to the cabin heating unit inconsistent with the manufacturer's recommendations and aviation regulations caused an engine fire in the right engine cowl during the initial climb. The pilot shut down the engine, but the aircraft could not maintain a positive rate of climb and crashed to the ground.

The aircraft was inadvertently flown into trees and the ground, in controlled flight and dark ambient conditions, during a night departure because a positive rate of climb was not maintained after take off. Factors contributing to the accident were the pilot’s concentrating on blue line speed rather than maintaining a positive rate of climb, the dark ambient conditions, a departure profile into rising terrain, an overweight aircraft, and crew resource mismanagement.

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.

Findings as to Causes and Contributing Factors:
1. At the time of the occurrence, the base of the cloud at Little Grand Rapids was between 100 and 300 feet agl, with fog to the east of the airport, and the visibility was one to two miles.
2. The aircraft was flown in marginal weather at low level, below the minimum en route altitude for commuter operations and below the MDA for the NDB A approach at Little Grand Rapids. The MDA for the approach was 1 560 feet asl, 555 feet above the airport elevation.
3. While the aircraft was being manoeuvred at very low level in marginal weather, it descended after an abrupt turn, and flew, in controlled flight, into the terrain.
Other Findings:
1. At both take-off and landing, the aircraft was about 1 000 pounds heavier than the relevant maximum allowable weight.
2. The GPS installed in C-GVRO was not approved as a primary navigational aid. The available information indicates that the flight crew used the GPS as a primary navigational aid during the last approach to Little Grand Rapids.
3. The aircraft was not equipped with a GPWS, nor was it required to be by regulation.
4. The weight and balance report that was submitted to Transport Canada, required for the importation of C-GVRO, contained numerous discrepancies; the report was not reviewed for accuracy by Transport Canada.
5. The emergency locator transmitter (ELT) produced a very weak signal because the antenna cable had been installed with little slack, and it pulled out of the antenna fitting during impact.
6. It could not be determined whether the presence of carbon monoxide and diphenhydramine in the captain's body affected his decision making and level of alertness.
7. The company, which had been an air taxi operator, did not effectively manage either the addition of the more complex commuter operations or the introduction of the larger Bandeirante aircraft.
8. The difficulty that the company had in the transition to commuter operations and in the introduction of the Bandeirante aircraft was underestimated by Transport Canada.
9. There were inadequacies in TC=s oversight, whereby the post-certification audit of the company was not conducted, thus eliminating an important mechanism by which TC could have found, and addressed, the inadequate safety management practices, non-conformance with pilot training requirements, and related operating irregularities.
10. The pilots had passed their flying proficiency and medical tests, but they had not completed elements of pilot training requirements with respect to servicing and operational control and right seat conversion as prescribed by TC. Also, no company pilot had received required training in the use of onboard survival or emergency equipment.
11. There was no indication found of any pre-impact failure or malfunction of the airframe, flight controls, or engines.
12. The aircraft was not equipped with either a CVR or an FDR; TC had given the company an exemption to operate without a CVR until 01 August 1998, and the aircraft was not required to be equipped with an FDR.
13. The absence of recorders on this aircraft, which was configured to carry 20 people, left many of the otherwise ascertainable facts associated with the accident unknown and reduced the opportunity of uncovering risks to safety associated with the flight.
14. Conditions were conducive to the pilot experiencing a false sensation that the aircraft was climbing (somatogravic illusion) after increasing the engine power, and he may have been manoeuvring to avoid an abandoned fire tower.