Recently Released TSB Reports
- ISSUE 2/2011
- Copyright and Credits
- Guest Editorial
- Flight Operations
- Maintenance and Certification
- Recently Released TSB Reports
- Accident Synopses
- Debrief: MET Towers: A Collision Can Happen and it Has Happened...
- The First Defence (poster)
- Take Five: Carburator Icing
- Full HTML Version
- PDF Version
- TSB Final Report A07W0003—Loss of Control—Marginal Weather
- TSB Final Report A07W0099—Load Shift/Loss of Control on Takeoff
- TSB Final Report A07W0150—Power Loss
- TSB Final Report A07P0295—Hot Air Balloon Accident
- TSB Final Report A08A0007—Hard Landing—Power Recovery Autorotation
- TSB Final Report A08H0002—Runway Incursion
- TSB Final Report A08P0242—Uncontrolled Descent into Terrain
The following summaries are extracted from Final Reports issued by the Transportation Safety Board of Canada (TSB). They have been de-identified and include the TSB’s synopsis and selected findings. Some excerpts from the analysis section may be included, where needed, to better understand the findings. For more information, contact the TSB or visit their Web site at www.tsb.gc.ca. —Ed.
On January 3, 2007, a Cessna A185F departed Yellowknife, N.W.T., at 1019 Mountain Standard Time (MST), with a pilot and three passengers on board, for a round trip flight to Blatchford Lake Lodge, approximately 53 NM southeast. The aircraft was on a company flight itinerary with an estimated time of arrival of 1100. When there was no contact from the pilot by 1300, a communication search and track crawl was conducted by company aircraft, but this was unsuccessful in locating the aircraft. No emergency locator transmitter signal was detected at any time. At 1513, the company reported the aircraft overdue to the flight service station. An active search by the rescue coordination centre was conducted using a number of aircraft. The wreckage of the aircraft was found at 1215, January 4, 2007, on the ice at Blatchford Lake. The pilot and two passengers had sustained fatal injuries, one passenger had sustained serious injuries, and the aircraft was substantially damaged.
It was determined that the aircraft stalled while in a left turn at low level. With the forward visibility through the windshield obscured by ice, the pilot was most likely flying with attitude references through his left side window. In a left turn, the descending left wing would have obstructed his visibility, leaving only a view of the snow-covered lake surface below. The conditions would have been conducive to a whiteout situation, whereby the snow-covered lake surface would blend with a snowy, obscured ceiling to disorient the pilot by eliminating all horizon references. The pilot’s manoeuvring speed was unknown, but entering a turn would have increased the stall speed, as would the effect of the ice on the wings. The use of flaps would have decreased his stall speed, but the flaps had not been deployed. The stall warning had not activated to warn of the impending stall.
The calculated aircraft weight at impact was just below the maximum gross weight; however, the amount of additional weight of the airframe ice was not quantified. The centre of gravity (CG) was at or slightly aft of the aft limit. This configuration would not have created a problem under normal flight conditions, but the aft CG would have increased the difficulty in recovering from a stall.
Under the operator’s Transport Canada exemption for operations below 1 000 ft AGL with less than two miles of flight visibility, the pilot had to be trained in the use of a global positioning system (GPS) receiver. There is no record of his having received the required instruction. The coordinates entered for the lodge were about a mile east of the lodge, and the pilot had turned northeast (away from the lodge) before reaching this waypoint. There is a probability that the pilot abandoned the use of the GPS when he reached the north shore of the lake, and turned left to follow the shore of the lake for navigation, since his visual reference was out his left side window with his windshield obscured by ice. His subsequent flight path continued to track eastward away from the GPS waypoint and away from the lodge, until the aircraft crashed.
Map of area
The pilot was required to have had a minimum of 500 hours in operations under Section 700 of the CARs or equivalent to qualify for low-level/limited visibility flight. He had about 16 hours commercial (Section 700 of the CARs) flying time with about 1500 hours of non-commercial single-engine flying time. He had completed his low-level flying training, but did not adhere to the operations manual requirements that specified that the aircraft was to be operated at 80 knots indicated airspeed (KIAS) with 10° of flap. The aircraft airspeeds varied from 130 KIAS to 77 KIAS, and flaps were not deployed.
The company operations manual specified that the Cessna 185 will not depart into forecast icing conditions. Freezing fog and patchy moderate mixed icing was forecast for the destination area when the aircraft departed, and the pilot report from 0651 reported rime ice upon entering clouds at 1 100 ft ASL. After departure, the pilot had initially climbed to 1 400 ft ASL, then began a continuous descent to about 1 000 ft ASL near his destination. He had encountered icing conditions as forecast and reported, as evidenced by the ice remaining on the airframe after the occurrence. The aircraft was not equipped or approved to operate in icing conditions.
The cargo and baggage was not secured, nor was there any means on board for securing the baggage and cargo to the tie-down rings. Because the primary impact was oriented vertically, the unsecured items probably did not project into the cabin and passengers. It could not be determined whether the baggage carried in the passengers’ laps contributed to the severity of their injuries. The survivor was the passenger without baggage in his lap.
Search and rescue (SAR) efforts were delayed for several hours because the emergency locator transmitter (ELT) did not function. The unit was capable of operating, but the impact activation switch (G switch) was oriented to sense a forward impact, not a vertical (downward) impact.
Findings as to causes and contributing factors
The aircraft stalled at an altitude too low for the pilot to recover.
The aircraft’s stall speed and stall recovery characteristics were affected by the left turn, airframe icing, and the aft centre of gravity loading.
The pilot’s visibility was compromised by the marginal weather conditions and an ice-covered windshield, with a probability that the pilot had entered white-out conditions.
Findings as to risk
The pilot self-dispatched on a flight that was not in accordance with the requirements outlined in the company operations manual. He continued the flight after encountering conditions beyond his capabilities in regards to training, equipment, and operating conditions.
The baggage and cargo were not secured, and there were no means on board for securing the baggage and cargo to the tie-down rings.
Two of the passengers were carrying unsecured baggage in their laps.
- The pilot had not been trained in the use of the GPS as required by regulation for low-level flight/limited visibility flight.
On June 2, 2007, a de Havilland DHC-3T Turbo Otter had been loaded with a cargo of lumber at Mayo, Y.T. The aircraft was taxied to the threshold of Runway 06 and the pilot began the take-off roll at 1755 Pacific Daylight Time (PDT). At liftoff, the aircraft entered an extreme nose-up attitude and began to rotate to the right. Shortly thereafter, the aircraft struck the airport ramp. The pilot, who was the sole occupant of the aircraft, was fatally injured. A small post-impact fire was extinguished by first responders.
The aircraft was loaded with a mixture of rough and finished lumber weighing approximately 2 213 lbs. The cargo was composed of six 16-ft rough beams measuring 7 ½ in. by 7 ½ in., a selection of 16-ft rough lumber, and a selection of 10-, 12- and 14-ft finished boards. The lumber was loaded so that all the boards were flush with the front of the cabin. At rest, the aircraft described a 9 degree nose-up attitude, resulting in the cargo being loaded in an “uphill” manner while the aircraft was on the ground (see figure 1). Before the occurrence flight, several loads of lumber had been hauled to the same destination.
Figure 1: de Havilland DHC-3T Turbo Otter
The load was secured with a single one-inch cargo strap that was placed over the lumber. The strap was fastened to tie-down points located ahead of the rear cargo doors. The floor of the aircraft was plywood. The maximum aft centre of gravity (CG) limit was determined to be 152.2 in. The CG of the occurrence aircraft was calculated to be 154.8 in. aft of the datum, 2.6 in. behind the rearward limit.
There are several documented accidents in the TSB database where the cargo has shifted and resulted in loss of control accidents.
A85Q0057 – Two fatalities. A float-equipped Cessna 305C stalled with an aft CG and unsecured load.
A00C0059 – Two fatalities. A DC-3 lost control during a go-around procedure. The aircraft had CG aft of the rear limit, and the cargo was inadequately secured.
A01W0239 – Three fatalities. A Beech UC45-J lost control after takeoff with an inadequately secured load of moose meat.
A06P0095 – One serious injury. A Cessna 185B aft CG aggravated by a possible load shift in turbulent conditions led to a loss of control.
The aircraft was loaded in a manner that resulted in the CG being aft of the rearward limit. The smooth surface of the finished lumber provided less friction against the plywood cabin floor. The cargo was only secured with one lateral strap and it is likely that the shorter finished boards moved aft during the taxi and take-off roll, which would result in a significant rearward shift of the CG.
The rearward shift of the CG during the taxi and take-off roll resulted in the aircraft pitching nose up, stalling and entering an incipient spin from which the pilot was not able to recover.
Findings as to causes and contributing factors
The aircraft was loaded in a manner that resulted in the centre of gravity being aft of the rearward limit.
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.
On August 30, 2007, the TSB issued Safety Advisory A07W0099-D1-A1 (Inadequate Cargo Restraint) to Transport Canada. The safety advisory suggested that Transport Canada may wish to inform industry of the significance of load shifting on aircraft performance and the need to effectively secure cargo in order to reduce the risk of in-flight load shift. The advisory was published in the Aviation Safety Letter, issue 2/2008.
On August 12, 2007, a Bell 206B Jet Ranger helicopter was over Abraham Lake, Alta., on final approach to the Cline River heliport (CCR5), at approximately 1420 Mountain Daylight Time (MDT) when the engine (Rolls-Royce/Allison 250-C20B) decelerated and flamed out. The pilot entered autorotation and the helicopter descended into the lake, rolled onto the right side, and sank close to shore. The pilot and the passenger in the left cabin seat evacuated the wreckage without assistance. The passenger in the right cabin seat required the pilot’s assistance to release the lap belt and exit the wreckage after the cabin became submerged. All three occupants sustained minor injuries. The helicopter was substantially damaged and there was no post-impact fire.
The engine lost power and flamed out for undetermined reasons. While no discrepancies that would have prevented normal operation of the engine were identified during bench testing of the Bendix fuel control components, small amounts of unidentified solid contamination were found in several components after disassembly. While small amounts of solid contamination were present, the fuel system components functioned satisfactorily during bench testing; therefore, the possibility that contamination contributed to the loss of power could not be proven or ruled out.
The fuel load on the helicopter at the time of the occurrence could not be determined with certainty, and water contamination was present throughout the engine and airframe fuel systems when the wreckage was recovered. The fuel cell was breached during the accident, which would have allowed water to flow into the fuel cell after the wreckage became submerged. With collective twist grip in the ground idle position and the engine fuel check valve leaking at low pressure, water may have been distributed throughout the fuel system by the boost pumps after the fuel cell filled with water, before the battery became discharged.
Several maintenance-related anomalies were identified during the examination of the engine and airframe. The missing engine data plate, the absence of a current engine log, and the installation of an incorrect power turbine governor (PTG) were indicative of administrative deficiencies, specifically maintenance tracking and record keeping, within the company maintenance program. The leaking compressor discharge pressure (Pc) pneumatic tube, the lack of continuous torque paint on the PTG “B” nuts, the crack in the reducing-tee in the fuel cell, and the internal leak in the check valve assembly in the fuel control unit (FCU) to fuel nozzle fuel line were further indications of weak maintenance practices. While none of these anomalies could be linked directly to the loss of engine power, their presence indicated that maintenance on the helicopter was not being accomplished fully in accordance with the maintenance control manual (MCM) from the contracted Approved Maintenance Organization (AMO), or the operator’s MCM.
Findings as to causes and contributing factors
The engine lost power and flamed out for undetermined reasons on approach to the Cline River helipad and the helicopter ditched in Abraham Lake.
The approach was conducted over water, toward a sloping shoreline that exposed the helicopter to an adverse forced landing environment.
Findings as to risk
Small amounts of unidentified solid contamination were found in several engine fuel system components after disassembly, creating the potential for fuel flow anomalies to occur within the engine fuel system.
A small air leak was present in the Pc tube, situated between the governor and the FCU, at the “B” nut on the aft side of the governor tee. There was a risk of engine deceleration had the leak rate increased.
There was a crack in the end flare on the main fuel line in the fuel cell, where the line attached to the reducer tee-fitting on the aft boost pump. At low fuel levels, the engine-driven fuel pump can draw air into the system if the boost pumps become inoperative.
The wrong PTG was installed on the engine, creating a situation of potentially degraded engine performance.
The engine check valve assembly, located in the fuel line between the FCU and the fuel nozzle, had a substantial internal leak, increasing the risk of drainage of fuel into the combustion case when the engine was not operating.
The torque paint on the PTG “B” nuts was discontinuous, leaving no way to confirm visually any loosening of the “B” nuts.
The company did not maintain current engine technical records in accordance with the requirements of Section 605 of the Canadian Aviation Regulations (CARs).
Each parameter of engine data acquisition unit (DAU) data was being averaged and recorded once per minute, which reduced the amount and usefulness of the data for accident investigation purposes.
A functioning crash-protected cockpit video digital recorder (CVDR) may have allowed investigators to reconstruct the flight sufficiently to better understand the circumstances that led to the accident.
Safety action taken
Following the accident, Transport Canada completed a limited combined regulatory inspection of the operator’s field operation base at the Cline River Heliport. A more in-depth inspection was subsequently carried out by Transport Canada Aircraft Maintenance and Manufacturing (AMM). There were 10 inspection findings in total, most identifying administrative deficiencies. The specialty areas that had findings were quality assurance (QA), technical records, sample aircraft for conformance, maintenance planning, defect recording, rectification, deferral and control procedures, and technical dispatch procedures. The operator responded immediately by implementing a comprehensive corrective action plan (CAP). An aviation consulting company was contracted to assist in dealing with and rectifying the deficiencies.
As a follow-up to this occurrence, the parts supplier who shipped an incorrect PTG to the operator conducted an internal review of the circumstances leading to this incorrect shipment. The review employed a Maintenance Error Decision Aid (MEDA) process. The review resulted in four internal MEDA recommendations for error prevention:
Encourage the customer to identify the part number required, and provide a purchase order when ordering parts.
Ensure that parts requests are entered electronically, so as to provide an electronic trail to enable checking of parts prior to shipment.
Ensure that the parts are correctly identified before removing them from inventory.
Additional human factors training for the employee involved. As a follow-up to this occurrence, the contracted AMO provided additional individual staff training, in accordance with the Maintenance Policy Manual (MPM), as necessary to upgrade the knowledge and understanding of the requirements of the MPM with regards to receiving of
As a follow-up to this occurrence, the contracted AMO provided additional individual staff training, in accordance with the Maintenance Policy Manual (MPM), as necessary to upgrade the knowledge and understanding of the requirements of the MPM with regards to receiving of parts. As well, an MPM amendment was generated to address the use of owner-supplied parts.
On August 24, 2007, at about 1900 Pacific Daylight Time (PDT), an Aerostar S77A hot air balloon was being prepared to launch for a sightseeing flight from a field near the Hazelmere trailer park in Surrey, B.C. The balloon was operated under a Special Flight Operating Certificate from Transport Canada (TC) and was loaded with a pilot and 12 passengers in the balloon’s basket. It was fastened to its trailer by a strap to prevent the balloon from ascending prematurely.
An intense, uncontrolled, propane-fuelled fire occurred. The pilot ordered the passengers to evacuate the basket and then proceeded to evacuate himself. The balloon rose to the limit of its tethering strap. Some of the passengers still on board jumped from the burning basket as the balloon climbed. The fire affected the tethering strap and it failed from tensile overstress and the balloon climbed without control. The balloon continued to climb until the envelope collapsed and the burning wreckage fell into a nearby trailer park, setting three mobile homes and two vehicles on fire. Two passengers, who did not evacuate the basket, were fatally injured. Several other passengers suffered serious injuries, some with serious burns. The pilot suffered burns. No persons on the ground were injured. Three mobile homes, two vehicles, and the balloon were destroyed.
Balloon lifting trailer
The balloon was originally manufactured with two burners and three 23-gallon capacity propane cylinders installed in the basket. The pilot/owner had replaced the two burners with a three-burner installation which was approved by the manufacturer as part of the type design of the aircraft. He had also installed a fourth cylinder, of 15-gallon capacity, in the basket. This modification was not approved by the manufacturer as part of the type design, nor was it approved by TC. No documentation was produced by the operator to show that this installation was performed or signed-off by an aircraft maintenance engineer (AME). The pilot had instituted the practice of using an auxiliary 10-gallon portable cylinder for initial filling of the envelope with hot air. It was not installed, but placed in the basket for the hot inflation, and removed when its propane was exhausted. The manufacturer was not aware of this practice.
The aircraft journey log indicated that the balloon had flown approximately 1272 hours since manufacture. The balloon was being maintained by an AME who had been performing the 100-hour inspections for the past 14 years. If the balloon required maintenance as a result of these inspections, it was sent to a repair facility. The AME who performed the 100-hour inspections was unable to provide any documentation of work performed during the past 14 years.
The number 4 cylinder fuel line was not secured, unlike the standard fuel lines which were routed along the basket uprights and placed inside leather sleeves to minimize their exposure and stresses. The tank valve of the number 4 cylinder was the only tank valve determined to be open, therefore the number 4 cylinder was the fuel source for the fire. As burner C had metallic remains of the full length of the number 4 fuel line connected to it, the number 4 fuel line must have become disconnected at the number 4 cylinder tank valve. The pop and hiss sounds heard by both the pilot and ground crewman are explained by the fuel line disconnecting and propane under pressure being expelled. Ignition was probably provided by the test burn which had just been made or by the pilot light, as the loose fuel line whipped around and propane discharged from the number 4 cylinder under pressure.
The pilot’s practice was to coil the number 4 cylinder fuel line around the cylinder when not in use. That practice, in addition to the practice of connecting and disconnecting the line during every flight, probably led to more stress on the tank valve/fuel line connection. This extra wear and tear likely led to the hose pulling out of its end fitting.
As the number 4 cylinder was the source of the propane fuelling the fire, closing that cylinder’s tank valve would have removed the fuel source and likely extinguished the fire. However, considering the ferocity of the fire, this was not practical. An emergency fuel shut-off, such as is generally provided in other aircraft fuel systems, was not fitted.
S77A modified configuration
The basket was the largest available for this balloon and calculations indicate that the gross weight, with twelve passengers on board, was substantially greater than the maximum allowable gross weight. This increased weight meant more lift was required. More fuel would therefore have to be burned to create the hot air for the added lift. The original configuration of the fuel system did not provide sufficient fuel at the increased weight for the average flight duration. The operator had modified the balloon with a fourth fuel cylinder to provide greater lift and flight time.
Contrary to the airworthiness limitation in the manufacturer’s Continued Airworthiness Instructions, envelope repairs comprised more than 65 per cent of the envelope.
Although the operator was operating under a valid TC special flight operations certificate (SFOC) stating that it was adequately equipped and able to conduct a safe balloon operation carrying fare-paying passengers, no inspection of the company was ever made to support this statement. The SFOC has no expiry date and there are no audits of balloon operators. Had there been periodic inspections by TC, the owner’s modifications to the balloon’s configuration and variations from the manufacturer’s Continued Airworthiness Instructions may have been raised as safety concerns.
S77A manufacturer’s three-burner configuration
Findings as to causes and contributing factors
The fuel line connecting the number 4 cylinder to burner C became disconnected at the tank valve connection, probably due to a combination of age, wear, handling, and allowing propane under pressure to be expelled. The propane was ignited either by flame from the test burn just made from burner C or from the pilot light.
As there was no emergency fuel shut-off and the number 4 tank valve was open, propane continued to be expelled through the number 4 tank valve, thus feeding the fire.
Modification of the balloon from the manufacturer’s configuration by the addition of cylinder number 4 and the use of an additional auxiliary cylinder (number 5) for initial envelope hot inflation contributed to the likelihood of hose/valve discontinuity because of extra wear and handling.
Operation at a weight greater than the maximum gross weight required more fuel which resulted in modifications being made to the balloon’s configuration.
Lack of oversight by the regulator allowed the modifications to the balloon’s configuration and variations from the manufacturer’s continued airworthiness limitations to go unchallenged.
The strap securing the balloon to the trailer was made of a synthetic material which was susceptible to heat damage and failed in tensile overstress, releasing the balloon with two passengers still on board.
During the initial envelope inflation, the balloon was fastened to its trailer, which was in turn attached to a pick-up truck. When the fire started and people began to evacuate the basket, the balloon began to rise because the emergency deflation system had not been activated. As people continued to evacuate the basket, they had to jump from a considerable height. Some suffered more serious injuries as a result of striking the trailer.
The safety briefing given to passengers prior to their boarding the balloon did not adequately explain how they were to exit the balloon basket in the event of an emergency.
Finding as to risk
- The use of a home-made manifold to refuel all five cylinders at once allowed the escape of a significant amount of propane once the tank valves were closed, after the tanks were filled. This posed a risk of fire at the service station.
- Repairs to the fabric of the balloon envelope were in excess of 65 per cent, contrary to the airworthiness limitation in the manufacturer’s Continued Airworthiness Instructions.
On January 10, 2008, a Eurocopter AS 350 BA helicopter, with two pilots on board, departed the St. John’s International Airport, N.L. to conduct annual recurrent training. Upon arriving in the training area at 1433 Newfoundland Standard Time (NST) at approximately 600 ft above ground level, the training pilot retarded the fuel flow control lever to simulate an engine failure. The pilot commenced an autorotation. Nearing the end of the exercise, the fuel flow control lever was advanced to restore power to the engine with a view to executing an overshoot. The engine (a Turbomeca Arriel 1B, serial number 4193) did not spool up as expected. The pilot continued the autorotation, contacting the ground at a high rate of descent. Both pilots sustained serious injuries; the helicopter was destroyed.
Findings as to causes and contributing factors
The lack of explicit instructions prohibiting power recovery autorotations in the AS 350 rotorcraft flight manual (RFM) resulted in the operator’s training pilots adapting a practice of fuel flow control lever (FFCL) operation that was contrary to the manufacturer’s intent.
The training pilot retarded the FFCL with the intention of executing a power recovery autorotation. The engine did not respond as anticipated when the FFCL was advanced for the overshoot and a high rate of descent ensued.
The autorotation was flown at a higher-thanrecommended airspeed which, coupled with the steep turn, increased the rate of descent. This high rate of descent could not be arrested prior to contact with the ground because of the low-energy state of the main rotor.
Both pilots suffered severe back injuries due to the hard landing. Neither pilot was wearing a shoulder harness; this likely contributed to the severity of their injuries.
The training pilot suffered severe facial injuries. He was not wearing a helmet; this likely contributed to the severity of his injuries.
The other pilot was wearing this helmet and did not incur
head injuries; scarring on his helmet indicates contact with
the helicopter structure during impact sequence.
Finding as to risk
- Practice autorotations over unsuitable terrain could result in injury and aircraft damage should a forced landing be required.
- While the rotor RPM was within the autorotation range, it was not set at its optimum setting, reducing the energy state of the rotor.
Safety action taken
The operator has issued the following safety memos:
Shoulder harness—addressed to all pilots, advising that the use of the shoulder harness is mandatory.
Autorotation in AS 350-series helicopters—addressed to all pilots, advising them that unless intending to do a full-on practice autorotation, manipulation of the throttle in flight is not authorized. This includes power recoveries and surprise autorotations.
Autorotation RPM verification—addressed to all pilots and maintenance engineers, instructing them to record all required parameters, such as weight, altitude, temperature, speed, and rotor RPM, anytime autorotation RPM verification flights have been conducted.
The company has implemented a policy of cost sharing and interest-free loans to facilitate flight helmet purchase by the company’s pilots. Many pilots have taken advantage of this offer and more pilots are now wearing helmets during flight operations.
Eurocopter has developed a proposed supplement for the AS 350 RFM that deals with engine emergencies training procedures. The proposal provides explicit instructions on the procedure to be followed for practice autorotations, for both FFCL and twist grip engine controls. Regulatory approval is pending.
On July 28, 2008, a Boeing 737-700 was on a scheduled flight from Toronto Lester B. Pearson International Airport (LBPIA), Ont., to Vancouver, B.C. At approximately 1141:50 Eastern Standard Time (EST), the north ground controller, believing that Runway 15 right/33 left (15R/33L) was under the control of the north ground position, cleared three emergency services vehicles to enter Runway 15R/33L en route to the fire training area. At 1142:27, the Boeing 737 was cleared for takeoff from Runway 33L. The aircraft was approximately one-third of the way down the runway when the vehicles entered Runway 15R. The flight became airborne approximately 2500 ft from the vehicles.
Toronto LPBIA diagram
When a tower controller is about to begin operations on another runway, a request for its ownership and control is made. When a tower controller is finished using a runway, its ownership and control is usually transferred to the ground controller. In this occurrence, the north tower controller needed the ownership and control of Runway 05 to accommodate impending arrivals, but still needed ownership and control of Runway 33L to accommodate the delayed departure of the Boeing 737. Ownership and control of Runway 05 had been transferred to the north tower controller, but ownership and control of Runway 33L had not been relinquished to the north ground position.
The north ground controller expected ownership and control of Runway 33L to be relinquished to the north ground position when ownership and control of Runway 05 was transferred to the north tower controller. The sighting of Tech 37 on Runway 33L by the north ground controller likely confirmed in the mind of the north ground controller that Runway 33L was no longer in use for aircraft departures and was indeed under north ground control. Moreover, the location of the north ground controller position in the tower made surveillance of the south end of Runway 33L problematic and likely prevented the north ground controller from seeing the Boeing 737 near the threshold.
Runway ownership and control transfer is accomplished verbally. There is no visual indication or process to inform controllers of runway ownership, nor is there any physical act performed to confirm controller ownership of runways when changing runway operations.
Convinced that the north ground position had ownership and control of Runway 33L, the north ground controller cleared the aircraft rescue and firefighting (ARFF) vehicles onto the runway, leading to the conflict with the Boeing 737.
The north service road provides access from the north fire hall to the fire training area as well as to many other areas around the airport without the need for vehicles to traverse airport manoeuvring areas utilised by aircraft. There was no operational need, in this instance, for the ARFF vehicles to be present on the airport manoeuvring area en route to the fire training area.
Finding as to causes and contributing factors
- Believing Runway 33L to be under the control of the north ground position, the north ground controller cleared the ARFF vehicles onto that runway, leading to a conflict with the departing Boeing 737.
Findings as to risk
The absence of an effective method for indicating runway ownership and control increases the likelihood of incursions.
Where ARFF vehicles do not need to use the runways, their unnecessary presence on a runway increases the risk of incursions, especially during a runway change.
Safety action taken
NAV CANADA reviewed its procedures involving runway ownership. As a result, a new runway surface indicator (RSI) was designed and implemented in early September 2008. This system operates within EXCDS (extended computer display system), allowing visibility at all positions within Toronto tower, as well as a recording of all actions associated with the application. Both the EXCDS and phraseology manuals have been updated to reflect the current standard of operation.
The Greater Toronto Airports Authority (GTAA) initiated a communication process to assist in mitigating risk, which requires emergency services to notify NAV CANADA prior to conducting training exercises that involve crossing the airfield. The GTAA will monitor this process to ensure ongoing effectiveness. These on-field training exercises are deemed to be essential for vehicle operators to ensure that they maintain a level of proficiency to minimize the risk of an incursion.
The GTAA reiterated that airport traffic directives and the associated airport vehicle operator’s permit (AVOP) training program indicate and inform AVOP applicants that the service roads should be used whenever possible and that an operational need is required to be present in the manoeuvring area.
On August 3, 2008, a U.S.-registered Beech 65-A90 King Air took off from Pitt Meadows Airport, B.C., with the pilot and seven parachutists for a local sky diving flight. At 1521 Pacific Daylight Time (PDT), as the aircraft was climbing through 3 900 ft above sea level, the pilot reported an engine failure and turned back towards Pitt Meadows Airport for a landing on Runway 08R. The airport could not be reached and a forced landing was carried out in a cranberry field, 400 m west of the airport. On touchdown, the aircraft struck an earthen berm, bounced, and struck the terrain again. On its second impact, the left wing dug into the soft peat, spinning the aircraft 180 degrees. Four of the parachutists received serious injuries and the aircraft was substantially damaged. There was no fire and the occupants were evacuated. The emergency locator transmitter functioned at impact and was turned off by first responders.
Aircraft Information and Operation Approval
The aircraft was heavily modified, in accordance with a Federal Aviation Administration (FAA) approval, to enable parachuting operations. Since February 2003, the aircraft had been registered in the United States and was being operated seasonally in Canada under the Free Trade Agreement (FTA) with a Canadian Foreign Air Operator Certificate-FTA (CFAOC-FTA). The CFAOCFTA was issued annually by Transport Canada (TC) for parachute jumping operations, recognizing the certificate of authorization issued by the FAA to the operator. At the time of the accident, the parachuting company was using the aircraft for revenue parachute jumping activities.
Left engine drive splines and coupling
Close-up of external spline wear
It was concluded that mechanical failure of the left-hand engine fuel pump drive splines resulted in the loss of power from that engine. The bang, the shuddering, and the yaw to the right that was experienced may have been caused by the left-hand engine fuel pump drive splines disengaging momentarily and then re-engaging. This disengagement would have caused the engine to flameout, and the re-engagement would have caused a relight with a corresponding bang. This would have been accompanied by a surge of power which could have caused the aircraft to yaw to the right.
A sudden yaw to the right is normally associated with a right-engine power loss. Although the pilot verified the engines’ instruments, he did not correctly identify the left engine as the failed engine. This was likely due in part to the horizontal layout of engine instrumentation that makes timely engine malfunction identification difficult. Moreover, the pilot had not received any training on the King Air for over two years, decreasing his ability to react appropriately. This resulted in the pilot erroneously shutting down the operating engine.
Because the engines were being operated “on condition,” the left engine was operated more than 800 hours past the time before overhaul (TBO) required by the engine manufacturer. Had the 3600-hour overhaul been accomplished, or the phase inspection completed as required in the maintenance instructions, the spline wear and corrosion should have been detected.
The general condition of the aircraft, the condition of the fuel systems, the engine TBO over-run, and the missed inspection items demonstrated inadequate maintenance. The regulatory oversight in place was inadequate because the inspection carried out by the FAA in April 2008 did not identify any of these issues. Furthermore, TC did not carry out any inspections of this operation.
Findings as to causes and contributing factors
The general condition of the aircraft, the engine TBO over-run and the missed inspection items demonstrated inadequate maintenance that was not detected by regulatory oversight.
The TBO over-run and missed inspections resulted in excessive spline wear in the left engine-driven fuel pump going undetected.
The left engine lost power due to mechanical failure of the engine fuel pump drive splines.
The horizontal engine instrument arrangement and the lack of recent emergency training made quick engine malfunction identification difficult. This resulted in the pilot shutting down the wrong engine, causing a dualengine power loss and a forced landing.
Not using the restraint devices contributed to the seriousness of injuries to some passengers.
Finding as to risk
- There is a risk to passengers if TC does not verify that holders of CFAOC-FTA meet airworthiness and operational requirements.
Safety action taken
After the accident, the aircraft owner requested that a sister aircraft have its fuel system inspected while undergoing maintenance at an approved maintenance organization in Calgary, Alta. Those inspections revealed numerous heavily corroded components and jelly formed by microbial growth. The fuel drained from the tanks and system was described as milky and was disposed of.
The Foreign Inspection Division has taken steps to ensure that the regions are notified of foreign air operators that have been issued a CFAOC-FTA for operations in Canada. Procedures will be documented in its staff instruction handbook indicating that the regions are to be notified by e-mail of a CFAOC-FTA operation with the location and dates.
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