Recently Released TSB Reports


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. We encourage our readers to read the complete reports on the TSB Web site. For more information, contact the TSB or visit their Web site at http://www.tsb.gc.ca/. -Ed.

TSB Final Report A04P0314-Collision with Water

On August 13, 2004, a Robinson R-22 Beta helicopter was on a short, daytime, VFR flight from Campbell River, B.C., to a private airstrip near McIvor Lake, B.C. As the helicopter approached McIvor Lake, the engine noise increased with increased engine rpm, and the helicopter pitched up, and then entered a steep descent. The helicopter remained both directionally and laterally stable as it descended toward the lake. There were some popping or banging noises heard during the descent. In the latter stages of the descent, the forward motion of the helicopter slowed, and the vertical descent rate increased. There was no apparent flare before water contact, and the helicopter struck the lake surface with high vertical velocity and low rotor rpm. The helicopter sank in about 30 ft of water. The pilot, who was the sole occupant of the helicopter, was fatally injured. The accident occurred at approximately 12:32 Pacific Daylight Time (PDT).

Findings as to causes and contributing factors

  1. At some point after installation, both V-drive belts were subjected to changes in dimension, probably as a result of shrinkage due to excess heat. Any changes to belt length would increase the risk of the belts coming off the sheaves and disconnecting the engine from the rotor system.
  2. Corrosion on an in-line fuse end, and improper connection of the fuse holder, raised the resistance in the electrical circuit to the belt-tensioner and slowed the operation of the belt-tension actuator motor. This slower operation would have caused an increase in tensioning time and in belt temperature during engagement/disengagement, which likely precipitated the belt shrinkage.
  3. During the latter stages of the autorotation, the helicopter’s main-rotor rpm was allowed to drop below safe limits, resulting in insufficient rotor energy to arrest the descent.

Findings as to risk

  1. Use of a work-around procedure to engage the actuator motor (tapping the motor) increases the risk of component failure and, in this case, masked the actual cause of the engagement problem.
  2. Use of a 10-amp fuse in place of the required 1.5-amp fuse in the electrical circuit to the belt-tension actuator motor eliminated the intended defence and, under certain circumstances, could have allowed the actuator to over-tension and damage the belts.

TSB Final Report A05O0112-Mis-Rigged Elevator Trim Tabs

On June 2, 2005, a Raytheon 800XP aircraft was on its first flight following painting and reassembly at an aircraft repair facility. The aircraft departed Peterborough, Ont., for Buffalo, N.Y. During the initial climb, as the aircraft speed neared 190 knots indicated airspeed (KIAS), the aircraft ran out of nose-down trim authority. The speed was kept below 190 KIAS, and the crew hand-flew, diverting to the Lester B. Pearson International Airport in Toronto, Ont., to inspect the aircraft. During the approach to Toronto, the rudder began to vibrate and seize, and the flight crew declared an emergency. The aircraft landed at approximately 13:48 Eastern Daylight Time (EDT) without further incident. An inspection revealed that the elevator trim controls were incorrectly rigged.

Circle shows the trim tab with the rigging pin in place. The trim tab should be flush with the elevator, not 1/4 in. down

Circle shows the trim tab with the rigging pin in place. The trim tab should be flush with the elevator, not 1/4 in. down

Findings as to causes and contributing factors

  1. The elevator trim tabs were not rigged in accordance with the aircraft maintenance manual, resulting in a mis-rigged condition and a lack of sufficient nosedown trim authority.
  2. Maintenance was performed without adherence to the applicable standards of airworthiness, as required by section 571.02 of the Canadian Aviation Regulations (CARs).
  3. The independent control inspection was not carried out in accordance with the standards described in the CARs or Airworthiness Notice (AN), resulting in the mis-rigged controls being undetected.
  4. Incorrect maintenance release statements were entered in the aircraft documents.

Safety action taken

As a precautionary measure, Transport Canada issued a notice of suspension to the aircraft repair facility on June 10, 2005; conducted a special audit on June 14, 2005; and issued an amended suspension on June 21, 2005. On June 27, 2005, Transport Canada rescinded the notice of suspension, subsequent to immediate corrective actions being implemented.

On August 22, 2005, Transport Canada received a corrective action plan from the aircraft repair facility, which addressed long-term corrective actions.

Following the occurrence and subsequent audit by Transport Canada, the aircraft repair facility hired a director of quality assurance and designated this person as the person responsible for maintenance (PRM). The company then amended or implemented various processes involving aircraft maintenance, as follows:

  • amended its quality assurance program to ensure closer scrutiny in all aspects of maintenance than was previously possible;
  • implemented a process for regular discussions on process control;
  • implemented the process of a full control-travel check before disassembly; consequently, this process revealed that many aircraft that had been received to work on had controls that were not rigged within the specified limits;
  • implemented additional training on human factors, improving the reporting of potential problems; and
  • the company is in the process of implementing a safety management system (SMS).

TSB Final Report A05O0115-Main Rotor Blade Failure

On June 10, 2005, a Bell Textron 212 helicopter was being ferried from Bolton, Ont., to Richmond, B.C. The recently-purchased helicopter was being flown by the company’s chief pilot with two passengers on board. At 12:20 Eastern Daylight Time (EDT), the helicopter was at an altitude of 1 500 ft above sea level (ASL) with an airspeed of 100 kt, when there was a series of loud bangs immediately followed by severe airframe vibrations. The pilot had difficulty controlling the helicopter for the next 10 to 15 seconds.

The pilot immediately lowered the collective, pulled back on the cyclic control, and brought the engine throttles to idle. He regained control of the helicopter, but the banging and vibrations continued. Every time one of the advancing main rotor blades came forward, it would climb off track abnormally. The vibrations and banging became more severe as the flight continued. The pilot proceeded toward a large ploughed field for an emergency landing. As the airspeed decreased, the helicopter became more controllable, and a successful landing was carried out. There were no injuries to the occupants. The helicopter was substantially damaged from the in-flight vibrations.

Post-flight inspection revealed that one of the main rotor blades had sustained damage. A small section of skin near the blade tip, aft of the spar doubler, on the lower surface of the rotor blade had debonded. The skin was raised and curled, but had not separated from the blade (see photo, next page). The debonded skin measured 25 in. by 2 in. between stations 263 and 288. In early 2005, the same blade had been damaged while the helicopter was parked in a hangar. The blade was then shipped to an authorized rotor blade repair shop. While paint was being stripped from the rotor blade in preparation for repair, deep corrosion pitting was discovered on the lower skin surface between stations 243 and 262, just inboard of where the debonding later occurred on the occurrence flight. Because the pitting pattern exceeded the allowable limits, the repair shop proposed a repair procedure to Bell Helicopter and received approval. The repair procedure included removing the damaged skin and replacing it with a bonded external doubler. The trailing edge trim tab was also replaced. The skin-to-inner core bonding procedure required using a bladder and heater blanket tool. This tool ensures proper curing of the adhesive by applying heat and pressure to the area being repaired. This type of repair is performed regularly to repair damaged rotor blades. The bladder and heater blanket tool that was used covered the rotor blade from its tip to a point inboard of the repair area, which included the area where the debonding took place on the June 10 flight. Following the repair using the bladder and heater blanket tool, the blade was in service for approximately four flight hours before the lower skin debonded on the occurrence flight at the spar doubler between stations 263 and 288.

Finding as to causes and contributing factors

  1. A section of the main rotor lower blade skin detached during flight, causing the helicopter to develop severe vibrations, and resulting in an emergency landing.

Finding as to risk

  1. The second area of blade damage likely occurred during the manufacturing process, but was not detected at that time. No information is available to assess how this type of damage affects blade integrity and the associated consequences during operations.

Other finding

  1. Although the detachment took place within the area where the bladder and heater blanket was used, the investigation could not confirm whether the heat and pressure cycle had any adverse effect on the section of blade that delaminated.

Debonded lower surface of rotor blade and repair area (blade resting upside down)

Debonded lower surface of rotor blade and repair area (blade resting upside down)

TSB Final Report A05W0127-Incorrect Loading/Centre of Gravity (C of G)

On June 24, 2005, a de Havilland DHC-3T (Turbo) Otter water-taxied from the company dock at Yellowknife, N.W.T., for a charter flight to Blachford Lake, N.W.T. The aircraft was loaded with two crew members, seven passengers, and 840 lbs of cargo. Before the flight, the pilot conducted a pre-flight passenger briefing, which included information about the location of life preservers and emergency exits. During the take-off run, at about 19:12 Mountain Daylight Time (MDT), the aircraft performed normally. It became airborne at about 55 mph, which is lower than the normal take-off speed of 60 mph.

The pilot applied forward control column to counter the pitch-up tendency, but there was no response. He then trimmed the nose forward, but the aircraft continued to pitch up until it stalled at about 50 ft above the water, and the left wing dropped. The aircraft struck the water in the East Bay of Great Slave Lake in a nose-down, 45° left bank attitude. On impact, the left wing and left float detached from the aircraft, and the aircraft came to rest on its left side. The crew was able to evacuate the passengers before the aircraft submerged, and local boaters assisted in the rescue. There were no serious injuries to the crew or passengers. The aircraft suffered substantial damage.

Aircraft wreckage during recovery

Aircraft wreckage during recovery

Findings as to causes and contributing factors

  1. The aircraft was loaded in such a manner that the C of G was beyond the rearward limit. This resulted in the aircraft’s aerodynamic pitch control limitation being exceeded.
  2. A weight and balance report was not completed by the pilot prior to departure; consequently, he was unaware of the severity of the aft C of G position.

Finding as to risk

  1. The weight of the passengers was underestimated due to the use of standard weights. This increased the potential of inadvertently loading the aircraft in excess of its maximum certified take-off weight (MCTOW).

Safety action taken

The operator adopted the following action items and policy changes to address the issues identified in the course of the investigation:

  • It will no longer use fuel as ballast to adjust the weight and balance of an aircraft when towing.
  • It increased operational oversight and conducted pilot briefings to ensure weight and balance calculations are completed prior to departure.
  • It adopted and implemented a new procedure for weight and balance calculation.
  • It elected to adjust the Transport Canada standard weights. The standard passenger weights will not be discounted for the lack of carry-on baggage. Adult male passengers will be assigned the standard weight of 200 lbs in the summer and 206 lbs in the winter. Adult female passengers will be assessed as 165 and 171 lbs, respectively, for summer and winter weights. The carry-on baggage that is not allowed within the passenger compartment will be weighed as part of the cargo and stowed in the cargo compartment.

TSB Final Report A05O0125-Power Loss and Collision with Terrain

On June 25, 2005, a Progressive Aerodyne, Inc. SeaRey amphibious aircraft (referred to here as SR 1) was taking part in the Canadian Aviation Expo at the Oshawa, Ont., airport. The flight was planned as part of a two-plane demonstration with another SeaRey aircraft (SR 2). The plan was to take off in formation, with the SR 1 leading, climb to 1 000 ft above ground level (AGL), turn left, and join a left downwind leg for Runway 30. When south of the airport, the aircraft were to split and perform a coordinated series of non-aerobatic manoeuvres that had been briefed and practised. Before takeoff, SR 1 had radio problems, so SR 2 led the takeoff, and SR 1 was in a right-echelon wingman position. The aircraft were cleared to take off in formation on Runway 30 from the intersection of Runway 04/22. After takeoff, the lead aircraft climbed out the extended centreline of the runway. SR 1 made a left turn as if leaving the formation toward the southwest, then turned to the right to again follow the lead aircraft. SR 1 then pitched nose up, and appeared to stall and spin to the left. The propeller was turning as the aircraft descended. The aircraft continued in a descending turn to the left until it struck the ground in a residential construction area. The aircraft was destroyed, and the pilot was fatally injured. There was no post-impact fire.

Ground and flight path of occurrence aircraft, as illustrated in the TSB Final Report

Ground and flight path of occurrence aircraft, as illustrated in the TSB Final Report

Findings as to causes and contributing factors

  1. Discrepancies in the fuel system most likely allowed air into the fuel line, causing a partial loss of engine power.
  2. While the pilot was turning back toward the airport, the flaps were raised, probably inadvertently, causing an increased rate of descent so that the pilot had insufficient altitude to manoeuvre to an open area for landing.
  3. The aircraft struck a concrete sewer casement, causing high deceleration and overloading the common attachment point of the seat and shoulder belts. As a result, the pilot struck the instrument panel and received fatal injuries.

Safety action taken

The Canadian distributor of SeaRey aircraft has taken the following safety actions:

  • Information describing the dangers of using the Ray Allen Company G205 stick grip to actuate trim and flaps has been posted on the SeaRey technical Web site (a private Web site from which SeaRey owners and operators in North America, Europe, and Australia have access to technical assistance in building, operating, and maintaining their aircraft).
  • The Recreational Aircraft Association has been asked to warn its members about the use of Ray Allen Company stick grips, and to contact the Ray Allen Company for a solution to the problem of inadvertent activation by incorporating switch guards on stick grips.
  • A recommendation has been posted on the SeaRey technical Web site that fuel manifolds with return-to-tank fuel lines be incorporated into all Rotax installations.
  • The Canadian distributor for Rotax engines has been asked to request Bombardier-Rotax GmbH to configure new engines with a fuel manifold with return-to-tank fuel lines.
  • A recommendation has been posted on the SeaRey technical Web site that auxiliary fuel pumps be incorporated in all high-engine/low-tank Rotax 912 installations for the following reasons:
    • They provide a backup pump to supply the carburettor float bowls if the engine-driven pump should fail.
    • They prevent low pressure (suction) upstream from the engine-driven pump, perhaps helping to prevent air from entering the fuel line at a loose fitting, and possibly preventing the formation of a vapour lock.
    • They provide a way to pressurize the fuel lines during pre-flight to check for fuel leaks.

TSB Final Report A05P0184-Loss of Control

On August 2, 2005, an MD500D helicopter departed the Terrace Airport, B.C., at 15:59 Pacific Daylight Time (PDT), to retrieve a geological survey crew from a mountain 35 NM northwest of the Terrace Airport. The pick-up point was on a 25° slope within a bowl-like feature, commonly referred to as a cirque. The steepness of the slope required the pilot of the skid-equipped helicopter to conduct a toe-in procedure at the pick-up site. During the attempt, there was a loud bang, and the helicopter dropped tail-low. The helicopter subsequently began an uncontrolled right turn and struck the terrain 30 yd. downhill from the pick-up point.

The fuel cell compartments ruptured from impact forces, and a fire ensued. The geological survey crew assisted the pilot from the burning helicopter and performed emergency first aid until the air ambulance arrived at 18:40. The pilot, the sole occupant on board the helicopter, was seriously injured. There were no injuries to persons on the ground. The helicopter was destroyed by impact forces and the intense post-crash fire.

Tail rotor during post-accident examination

Tail rotor during post-accident examination

Findings as to causes and contributing factors

  1. The reason for the tail drop and corresponding tail rotor strike could not be determined.
  2. Once the tail rotor contacted the ground, the tail rotor drive shaft sheared and the helicopter began to yaw rapidly clockwise. Control of the helicopter was lost, and given the terrain, a successful emergency landing was not possible.
  3. The fuel tank ruptured during the crash sequence, spraying the cockpit area with fuel. This resulted in an intense post-crash fire, which severely injured the pilot and destroyed physical evidence.

TSB Final Report A05Q0208-Tree Impact Without Loss of Control

On November 5, 2005, a Cessna 172M was chartered by the Quebec ministère des Ressources naturelles et de la Faune (Department of Natural Resources and Wildlife) for night aerial surveillance of poaching activities. The pilot and two wildlife protection officers were on board. At about 21:45 Eastern Standard Time (EST), the aircraft took off from the Saint-Frédéric, Que., aerodrome for a VFR flight. Shortly after takeoff, due to foggy conditions, the chief of operations on board the aircraft redeployed the ground teams to an area more to the south of the surveillance area that was originally planned. The aircraft was reported missing at about 23:00 EST. It was found three days later in a wooded area 7 NM southwest of the Saint-Georges, Que., aerodrome. After striking the treetops, the aircraft crashed in an inverted position and caught fire. The three occupants sustained fatal injuries.

Debris

Finding as to causes and contributing factors

  1. The VFR night flight was conducted in marginal VFR conditions, at an altitude below the minimum obstacle clearance altitude (MOCA) prescribed by the Canadian Aviation Regulations (CARs) for night flight; the aircraft struck trees with no loss of control.

Findings as to risk

  1. The aircraft was not equipped with instruments that could have alerted the pilot before impact that the Cessna was close to the ground, nor are such on-board instruments required by the existing regulations.
  2. Although the regulatory requirements for flight following were complied with, the company was not aware of the aircraft’s take-off time, its flight itinerary, or its diversion to Saint-Georges.
  3. The aircraft proceeded towards Saint-Georges without the knowledge of the operator or the wildlife protection officers on the ground; as a result, the search took longer because the aircraft crashed outside the agreed surveillance area.
  4. The CARs do not require that a pilot’s work time as an instructor be recorded in a log. Consequently, although the pilot mentioned that he was tired before the flight, his level of fatigue could not be assessed due to a lack of information.

Other findings

  1. No emergency locator transmitter (ELT) signals were received because the ELT was destroyed after impact. If the aircraft had been equipped with an ELT model that transmits on the frequency 406 MHz, the emergency signal would have been picked up and instantly relayed to a ground station.
  2. The Quebec ministère des Ressources naturelles et de la Faune had not specified any meteorological or operational criteria for night aerial surveillance of poaching activities; consequently, the wildlife protection officers had no meteorological references to aid them in deciding whether the mission was feasible.

Safety action taken

As a result of the accident, the operator amended its company operations manual. The minimum altitude for anti-poaching surveillance flights is 1 000 ft above the maximum elevation figure (MEF).

As a result of the accident, the Quebec ministère des Ressources naturelles et de la Faune initiated an administrative investigation. An action plan was submitted, to include the following:

  • A safe work procedure was proposed to provide a better system for aerial surveillance operations. The procedure identifies the associated risks and the safety precautions to be considered for this type of operation. It also describes the training required for employees, and the equipment and work methods to ensure employee safety.
  • The guide concerning the use of aircraft at the Société de la faune et des parcs du Québec is being revised to include a section specifically for aerial surveillance operations by wildlife protection officers.
  • Communication systems for rapidly locating an employee in distress are under review.
  • A provincial operating procedure designed to improve monitoring of employee travel during work activities has been prepared.
  • Future operation plans for aerial anti-poaching activities will be governed by a new provincial operating procedure.
  • The Quebec ministère des Ressources naturelles et de la Faune has updated its safety guide for employees emergency plan for employees in distress.

TSB Final Report A05O0258- Loss of Control-Collision with Terrain

On November 20, 2005, the pilot of a privately-owned Ryan Aeronautical Navion B aircraft departed Burlington, Ont., under visual meteorological conditions (VMC), for a breakfast fly-in at Brantford, Ont. An en-route stop was made in Guelph, Ont., to pick up a passenger. At approximately 12:30 Eastern Standard Time (EST), the pilot and passenger boarded the aircraft and taxied for a departure from Brantford. The aircraft departed Runway 23 at the intersection of Taxiway Bravo, and climbed on the runway heading. During the climb, the engine failed, and the aircraft stalled and entered a spin. A single mayday call was heard on the Brantford UNICOM frequency. The aircraft struck the ground in a nose-down attitude, with the right wing striking first. The aircraft cart-wheeled and came to rest 94 ft from the initial impact point. The occupants were fatally injured. There was no post-impact fire.

Shown here are parts comprising the crankshaft (item 1) and parts of the engine to propeller reduction gearbox (items 2, 3, and 4). The failure location at the forward fillet radius to the number six connecting rod journal bearing is shown by the small arrow/

Shown here are parts comprising the crankshaft (item 1) and parts of the engine to propeller reduction gearbox (items 2, 3, and 4). The failure location at the forward fillet radius to the number six connecting rod journal bearing is shown by the small arrow.

Findings as to causes and contributing factors

  1. A fatigue crack developed in the engine crankshaft as a result of corrosion pitting and the absence of a case-hardened layer on the fillet radius of the number six connecting rod journal. The fatigue failure of this section of the engine crankshaft resulted in a complete loss of power.
  2. Control of the aircraft was not maintained during the power loss event, and consequently the airspeed decreased below a safe flying speed. The aircraft stalled and entered a spin from which there was insufficient altitude to recover.

Findings as to risk

  1. A previous propeller ground strike incident was not recorded in either the aircraft journey log or the technical logs, and there is no indication that theaircraft was inspected afterwards to determine its airworthiness.
  2. After the overhauled propeller was installed, the aircraft was flown five times before receiving a certified maintenance release. Until such a release is obtained, there is an increased risk that the aircraft may not be airworthy.
  3. Transport Canada recency requirements allow pilots to fly for extended periods of time without retraining in critical flight skills. The gradual erosion of these skills reduces a pilot’s preparedness to react appropriately during emergency situations.
  4. The fuel selector valve revealed internal leakage during testing. Although not a factor in this occurrence, continued use of a component for which the manufacturer has recommended replacement poses a risk to the safe operation of the aircraft.

Safety concern

Currently, the recency requirements in Canada allow pilots engaged in recreational flying to continue to exercise the privileges of a licence without having to regularly demonstrate proficiency to another qualified person. Therefore, a pilot may continue flying for years without reinforcing, through practice, those skills considered essential for the initial issuance of a licence (for example, dealing with an engine failure or landing in a crosswind).

In this occurrence, the pilot’s flying activity and attendance at the Transport Canada safety seminars exceeded the minimum requirements of sections 401.05 and 421.05 of the Canadian Aviation Regulation (CARs). However, it is unlikely that critical flight skills and emergency procedures were practised since his initial licensing in 1974. The absence of pilot recency is also listed as a finding in TSB report A05O0147.

The TSB is concerned that there is no requirement for a private pilot to participate in periodic recurrent flight training, such as a biennial flight review. This presents the risk that pilots will not be prepared to deal with unusual or critical flight situations when they arise.

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