Occurrence Classification Policy

Purpose

To establish the classes of transportation occurrences to be investigated (pursuant to Section 8(1)(b) of the CTAISB Act) and to set the criteria for investigations within each class.

Background

Approximately 4,000 transportation occurrences are reported to the TSB each year in accordance with its mandatory reporting requirements. Practical considerations dictate that only a small proportion of these be investigated. From time to time, a transportation disaster or a particularly troubling safety issue will warrant a public inquiry. Numerous occurrences warrant a TSB investigation in that they offer potential for acquiring new knowledge of the underlying safety deficiencies compromising safe transportation operations. But most reported occurrences by themselves offer little scope for adding to the Board's knowledge of the underlying safety deficiencies. However, a broad examination of sets of such occurrences involving similar phenomena or contributory factors is at times warranted.

Effective resource management and the advancement of transportation safety will depend upon the Board's timely identification of individual occurrences, as well as unsafe situations or conditions, with potential for significant safety payoff.

Factors affecting the Occurrence Classification Policy

Resources

Sound management practice requires that the balance of resources be applied against expected transportation safety payoff, whether for individual investigations or for groups of investigations aimed at the resolution of significant safety issues.

Obligations and commitments

Canada is signatory to several international agreements pertaining to the conduct of investigations. In addition, the TSB is party to several less formal agreements for the provision of services to particular nations or provinces. The TSB strives to meet such obligations and commitments.

Canadian interests

Sometimes Canadian-manufactured transportation products, Canadian carriers, or large numbers of Canadian citizens travelling with foreign carriers are involved in major occurrences outside of Canada. The TSB must be prepared to provide a fair analysis of occurrences where Canadian products, services, or citizens are involved.

Public expectation

Following spectacular or particularly tragic occurrences, there is a public expectation that action will be taken by the government to prevent recurrence. The TSB must endeavour to maintain public confidence that accidents in the federally regulated, national transportation system will be independently and competently investigated -- regardless of the mode.

TSB experience

In its first five years of operation, the Board carried out enough studies and other analyses of significant safety issues to determine that a larger portion of its efforts should be devoted to the identification of safety deficiencies through the analysis of other than single events.

Classification criteria

The primary criterion for determining if an occurrence in any mode will be investigated is whether or not such analysis is likely to lead to a reduction of risk to persons, property, or the environment. (Considerations for the assessment of risk are outlined in Appendix B). Other criteria include:

  • Consideration of any TSB obligations or commitments under international agreements, assistance to the provinces or other nations, etc.
  • Consideration of the degree of public expectation of a TSB investigation—whether from a general public concern or concern for Canadian products, services, or citizens abroad.

Policy

Classes of occurrences

The Board will focus its efforts on occurrences in the federally regulated, commercial transportation sector. Each transportation occurrence will be assigned to one of the following classes of occurrences:

Class 1 occurrences (public inquiry)

When the Board deems it necessary, the Board will conduct public inquiries into transportation occurrences that it is investigating (be they accidents or incidents; or situations or conditions that, if left unattended, could induce an accident). In determining whether to conduct a public inquiry, the Board will consider the following:

  • the potential for reducing the risk to persons, property, or the environment;
  • whether an inquiry would uncover facts that might not otherwise be made known;
  • whether an inquiry would result in quicker remedial action;
  • the actual or potential extent of injuries and/or loss of life;
  • the degree of public interest in and concern about public safety; or
  • the possible involvement of an arm of government.

Class 2 occurrences (individual occurrence investigation)

An individual occurrence shall be investigated when

  1. there is a high probability of advancing Canadian transportation safety in that there is significant potential for reducing the risk to persons, property, or the environment; or
  2. the Governor in Council so requests (pursuant to Section 14(1) of the CTAISB Act).

Class 3 occurrences (individual occurrence investigation)

Individual occurrences that do not meet the criteria of Class 2 occurrences may be investigated when

  1. there is significant public expectation that the TSB should independently make findings as to cause(s) and contributing factors; or
  2. there is potential for better understanding the latent unsafe conditions contributing to a significant safety issue; or
  3. a government representative so requests (pursuant to Section 14(2) of the CTAISB Act); or
  4. the Board must do so to meet its obligations or commitments.

Class 4 occurrences (safety issue investigation)

Multiple occurrences, which the Board deems to be indicative of significant unsafe situations or conditions, will be subject to a safety issue investigation when

  1. there is a high probability of advancing Canadian transportation safety by reducing the risk to persons, property, or the environment; or
  2. in the Board's opinion, there is widespread public expectation that the TSB should independently analyse a particular safety issue.

(Activities of this type will generally be based on a significant safety issue previously identified by the Board in consultation with the transportation community and the public.)

Class 5 occurrences (data collection)

Data pertaining to occurrences that do not meet the criteria of classes 1 through 4 will be recorded in suitable scope and detail for possible safety analysis, statistical reporting, or archival purposes.

Notes

Generally, the Board will not participate in the investigation of foreign occurrences unless there is a high probability of advancing Canadian transportation safety; and, generally, it will not investigate industrial-type occurrences (i.e. those not directly related to the transportation aspects of operations).

An occurrence will not be classified until sufficient facts are available to assess the potential for safety payoff. This may require deployment of TSB investigators to the occurrence site to evaluate physical evidence, review documents, interviewing personnel or witnesses, etc. During this period, investigators may exercise the powers of an investigator established in the CTAISB Act.

When practicable, an individual occurrence will be classified within 72 hours of the initial occurrence notification. In general, an occurrence can be reclassified based on the perceived potential for significant safety outcome. However, no classified occurrence can be downgraded to Class 5.

The investigative response for each class of occurrence will be in accordance with standard operating procedures prescribed in the manuals of investigation operations.

Appendix A – Definitions of « accident » and « incident » for each mode

All reportable occurrences must be identified as an accident or an incident in the transportation occurrence modal database using the following definitions which are based upon the Transportation Safety Board Regulations SOR/2014-37.

A1 – Aviation Accident

An aviation accident means an occurrence resulting directly from the operation of an aircraft in which:

  1.  a person is killed or sustains a serious injury as a result of:
    1. being on board the aircraft,
    2. coming into direct contact with any part of the aircraft, including parts that have become detached from the aircraft, or
    3. being directly exposed to jet blast, rotor down wash or propeller wash;
  2. the aircraft sustains structural failure or damage that adversely affects the aircraft's structural strength, performance or flight characteristics and would normally require major repair or replacement of any affected component, except for:
    1. engine failure or damage, when the damage is limited to the engine, its cowlings or accessories, or
    2. damage limited to propellers, wing tips, antennae, tires, brakes, fairings or small dents or puncture holes in the aircraft's skin; or
  3. the aircraft is missing or inaccessible.

A2 – Aviation Incident

An aviation incident means an occurrence resulting directly from the operation of an aircraft having a maximum certificated take-off weight greater than 2 250 kg, or of an aircraft being operated under an air operator certificate issued under Part VII of the Canadian Aviation Regulations in which:

  1. an engine fails or is shut down as a precautionary measure;
  2. a power train transmission gearbox malfunction occurs;
  3. smoke is detected or a fire occurs on board;
  4. difficulties in controlling the aircraft are encountered owing to any aircraft system malfunction, weather phenomena, wake turbulence, uncontrolled vibrations or operations outside the flight envelope;
  5. the aircraft fails to remain within the intended landing or take-off area, lands with all or part of the landing gear retracted or drags a wing tip, an engine pod or any other part of the aircraft;
  6. a crew member whose duties are directly related to the safe operation of the aircraft is unable to perform their duties as a result of a physical incapacitation which poses a threat to the safety of persons, property or the environment;
  7. depressurization of the aircraft occurs that requires an emergency descent;
  8. a fuel shortage occurs that requires a diversion or requires approach and landing priority at the destination of the aircraft;
  9. the aircraft is refuelled with the incorrect type of fuel or contaminated fuel;
  10. a minor collision, a risk of collision or a loss of separation occurs;
  11. a crew member declares an emergency or indicates an emergency that requires priority handling by air traffic services or the standing by of emergency response services;
  12. a slung load is released unintentionally or as a precautionary or emergency measure from the aircraft; or
  13. any dangerous goods are released in or from the aircraft.

A3 – Marine Accident

A marine accident means an occurrence resulting directly from the operation of a ship, other than a pleasure craft, in which:

  1.  a person is killed or sustains a serious injury as a result of
    1. boarding, being on board or falling overboard from the ship, or
    2. coming into direct contact with any part of the ship or its contents;
  2. the ship
    1. sinks, founders or capsizes,
    2. is involved in a collision,
    3. sustains a fire or an explosion,
    4. goes aground,
    5. sustains damage that affects its seaworthiness or renders it unfit for its purpose, or
    6. is missing or abandoned.

A4 – Marine Incident

A marine incident means an occurrence resulting directly from the operation of a ship, other than a pleasure craft, in which:

  1.  a person falls overboard from the ship;
  2. a crew member whose duties are directly related to the safe operation of the ship is unable to perform their duties as a result of a physical incapacitation which poses a threat to the safety of persons, property or the environment;
  3. the ship
    1. is involved in a risk of a collision,
    2. makes unforeseen contact with the bottom without going aground,
    3. is anchored, grounded or beached to avoid an occurrence,
    4. fouls a utility cable or pipe, or an underwater pipeline,
    5. sustains a total failure of:
      1. the navigation equipment if the failure poses a threat to the safety of any person, property or the environment,
      2. the main or auxiliary machinery, or
      3. the propulsion, steering, or deck machinery if the failure poses a threat to the safety of any person, property or the environment,
      4. all or part of the ship's cargo shifts or falls overboard; or
      5. there is an accidental release on board or from the ship consisting of a quantity of dangerous goods or an emission of radiation that is greater than the quantity or emission levels specified in Part 8 of the Transportation of Dangerous Goods Regulations.

A5 – Pipeline Accident

A pipeline accident means an occurrence resulting directly from the operation of a pipeline in which:

  1.  a person is killed or sustains a serious injury;
  2. the safe operation of the pipeline is affected by:
    1. damage sustained when another object came into contact with it, or
    2. a fire or explosion or an ignition that is not associated with normal pipeline operations; or
  3. there is a release of a commodity from the line pipe body.

A6 – Pipeline Incident

A pipeline incident means an occurrence resulting directly from the operation of a pipeline in which:

  1.  an event or an operational malfunction results in:
    1. an unintended or uncontrolled release of gas,
    2. an unintended or uncontrolled release of HVP hydrocarbons,
    3. an unintended or uncontained release of LVP hydrocarbons in excess of 1.5 m3, or
    4. an unintended or uncontrolled release of a commodity other than gas, HVP hydrocarbons or LVP hydrocarbon;
  2. the pipeline is operated beyond design limits or any operating restrictions imposed by the National Energy Board;
  3. the pipeline restricts the safe operation of any mode of transportation;
  4. an unauthorized third party activity within the safety zone poses a threat to the safe operation of the pipeline;
  5. a geotechnical, hydraulic or environmental activity poses a threat to the safe operation of the pipeline;
  6. the operation of a portion of the pipeline is interrupted as a result of a situation or condition that poses a threat to any person, property or the environment; or
  7. an unintended fire or explosion has occurred that poses a threat to any person, property or the environment.

A7 – Railway Accident

A railway accident means an occurrence resulting directly from the operation of rolling stock, in which:

  1.  a person is killed or sustains a serious injury as a result of:
    1. getting on or off or being on board the rolling stock, or
    2. coming into contact with any part of the rolling stock or its contents;
  2. the rolling stock or its contents:
    1. are involved in a collision and/or a derailment resulting in damages to rolling stock and/or track infrastructure,
    2. sustain damage that affects the safe operation of the rolling stock,
    3. cause or sustain a fire or explosion,
    4. cause damage to the railway that poses a threat to the safe passage of rolling stock or to the safety of any person, property or the environment, or
  3. there is an accidental release on board or from a rolling stock consisting of a quantity of dangerous goods or an emission of radiation that is greater than the quantity or emission level specified in Part 8 of the Transportation of Dangerous Goods Regulations resulting from damage to the containment system.

A8 – Railway Incident

A railway incident means an occurrence resulting directly from the operation of rolling stock, in which:

  1.  the rolling stock is involved in a minor collision and/or minor derailment (1 - 2 cars) resulting in no damages;
  2. a risk of collision occurs between rolling stock;
  3. an unprotected main track switch or subdivision track switch is left in an abnormal position;
  4. a railway signal displays a less restrictive indication than that required for the intended movement of rolling stock;
  5. rolling stock occupies a main track or subdivision track, or track work takes place, in contravention of the Rules or any regulations made under the Railway Safety Act;
  6. rolling stock passes a signal indicating stop in contravention of the Rules or any regulations made under the Railway Safety Act;
  7. there is an unplanned and uncontrolled movement of rolling stock;
  8. a crew member whose duties are directly related to the safe operation of the rolling stock is unable to perform their duties as a result of a physical incapacitation which poses a threat to the safety of persons, property or the environment; or
  9. there is an accidental release on board or from a rolling stock consisting of a quantity of dangerous goods or an emission of radiation that is greater than specified in Part 8 of the Transportation of Dangerous Goods Regulations.

Appendix B

Risk assessment considerations

If the general criteria apply, then, before the decision is made to investigate an occurrence, further analysis will be conducted using the risk assessment considerations that follow. These take into account the probability of future occurrences resulting in adverse consequences and the potential nature of those consequences.

In assessing the probability of adverse consequences, the following sorts of considerations will be evaluated:

  • Is there a history of occurrences like this one or is this an isolated occurrence?
  • How many pieces of equipment or kilometers of pipeline are there that might have similar defects?
  • How many operating or maintenance personnel are following or are subject to the practices or procedures in question?
  • What percentage of the time is the suspect equipment or the questionable procedure or practice in use?
  • To what extent are there organizational, management, or regulatory implications which might reflect larger systemic problems posing a threat to public safety?

In assessing the consequences of occurrence, consideration is given to such questions as:

  • How many lives are at risk? Fare-paying passengers? Transportation employees? Bystanders or general public?
  • What could be the extent of further property damage? Direct property loss to the operator? Damage to adjacent infrastructure? Third-party collateral damage?
  • What could be the environmental impact? Dangerous commodity spill? Physical disruption of natural habitat?
  • What is the potential impact on carriers? On commercial operations? Physical disruption of infrastructure? Corporate viability? Financial markets?
  • What could be the public and media interpretation? What might be the political implications? Internationally? Nationally? Locally?

Sometimes, although there is little doubt that an unsafe condition with unacceptable risk exists, the potential for further practical safety action is limited. Thus, in addition to assessing the risks, the potential for meaningful, timely safety action will be considered. To determine the potential safety value of an investigation or study, the following questions should be considered:

  • To what extent are the related safety hazards already well known or being attended to?
  • Could this occurrence shed new light on an old problem?
  • Has the TSB identified this issue as one warranting extra attention? Board Safety Concern? Significant Safety Issue? Safety Study?