Aviation Procedures and Decision Guidelines for Accident/Incident Categorisation

Aviation

Procedures

The Transport Safety Investigation Act 2003 forms the basis of procedures followed by the Bureau. The ATSB uses the categories below when prioritising its aviation investigations to meet international obligations and achieve the most important safety outcomes within its given budget.

Decision Guidelines for Accident/Incident Categorisation

The ATSB is resourced each year to undertake a finite number of aviation investigations. It is acknowledged, however, that an occurrence with a large number of deaths would represent a major accident and supplementary funding may be required.

In categorising aviation transport safety matters and selecting which of those the ATSB should investigate, the decision-makers must consider:

1. The potential safety value that may be gained by conducting an investigation
2. On board fatalities and/or serious passenger injuries, and provision of support to state coroners
3. The public profile of the occurrence
4. The extent of resources available and projected to be available and, in the event of conflicting priorities,
5. Any risks associated with not investigating
6. The requirement under s21(2) of the TSI Act for the Executive Director to publish reasons (justification) for discontinuing an investigation where an investigation has already commenced.

The priorities applied when considering the initiation of an aviation investigation reflect the ATSB’s primary focus on enhancing safety with respect to fare paying passengers. Subject to the considerations detailed above, the ATSB will allocate its resources in line with the following priorities:

1. Passenger transport – large aircraft
2. Passenger transport – small aircraft:

• RPT and charter on small aircraft
• Humanitarian aerial work (for example, RFDS, SAR flights)

3. Commercial (that is, fare paying) recreation (for example, joy flights)
4. Flying training
5. Aerial work with participating passengers (for example, news reporters, geological surveys)
6. Other aerial work:

• Non-passenger carrying aerial work (for example, agriculture, cargo)
• Private transport/personal business

7. High risk personal recreation/sports aviation/experimental aircraft operations.

The decision to investigate will also have regard as to whether, in the absence of an ATSB investigation, a credible safety investigation is likely.

In view of these considerations, initiation of a formal ATSB investigation can only be made at or above Team Leader level after discussion and agreement with the Deputy Director and Executive Director. Each investigation will be categorised on a scale of 1 to 5 (see below).

Following the initial assessment of an occurrence, and the allocation of an investigation level a decision will be made whether or not to conduct an on-scene investigation. Subsequently an investigation may be upgraded or downgraded. The decision to upgrade (and commit extra resources) or to downgrade must be made at Deputy Director level after discussion with the Executive Director. Any decision to discontinue an investigation must be endorsed by the Executive Director.

The following guidance on the categorisation of aviation transport safety matters is intended to serve as a suggested starting point based on initial information. This guidance is not intended to cover all possible scenarios but illustrates a broad range of typical events. It is expected that judgment will be required in order to categorise some events which do not neatly fit these categories or where the circumstances, potential safety value and available resources suggest that they should be assigned a different level.

Level 1

• An accident involving one or more High Capacity Air Transport (scheduled and non-scheduled) passenger aircraft with fatalities.
• An accident involving one or more High Capacity Air Transport (scheduled and non-scheduled) passenger aircraft without fatalities
  • where there was a significant risk of fatalities or serious injuries and a substantial commitment of investigative resources is likely to significantly mitigate future High Capacity Air Transport accidents.
• A serious incident (as defined by ICAO see Attachments A & B) involving one or more High Capacity Air Transport (scheduled and non-scheduled) passenger aircraft
  • where there was a significant risk of fatalities or serious injuries and a substantial commitment of investigative resources is likely to significantly mitigate future High Capacity Air Transport (scheduled and non-scheduled) accidents.

Level 2

• An accident involving one or more High Capacity Air Transport cargo aircraft with fatalities and serious injuries.
• An accident involving one or more High Capacity Air Transport cargo aircraft without fatalities and serious injuries
  • where there was a significant risk of fatalities or serious injuries and a substantial commitment of investigative resources is likely to significantly mitigate future High Capacity Air Transport cargo aircraft accidents.
• An accident involving one or more Low Capacity Air Transport (scheduled) passenger aircraft with a significant number of fatalities (for example, it may involve more than five fatalities) and serious injuries.
• An accident involving one or more Low Capacity Air Transport (scheduled) passenger aircraft without fatalities or with a relatively low level of fatalities (eg less than five) and serious injuries
  • where there was a significant risk of more fatalities or serious injuries and a substantial commitment of investigative resources is likely to significantly mitigate future Low Capacity Air Transport (scheduled) accidents.
• A serious incident (as defined by ICAO see Attachments A & B) involving one or more Low Capacity Air Transport (scheduled) passenger aircraft
  • where there was a significant risk of multiple fatalities (eg more than five) and serious injuries and a substantial commitment of investigative resources is likely to significantly mitigate future Low Capacity Air Transport (scheduled) accidents.
• An accident involving one or more Low Capacity charter (non-scheduled) aircraft with fare-paying passengers and multiple fatalities and serious injuries (for example it may involve more than five fatalities)
  • where a substantial commitment of investigative resources is likely to significantly mitigate future Low Capacity Air Transport (scheduled) and charter (non-scheduled) accidents.

Level 3

• An accident involving one or more Low Capacity Air Transport passenger (scheduled) or charter (non-scheduled) aircraft with fatalities and/or serious injuries not classified as a level 2 investigation.
• An accident involving Air Transport cargo operations with fatalities.
• An accident involving one or more training aircraft with fatalities.
• An accident (as defined by ICAO, see Attachment A) without fatalities involving one or more High or Low Capacity Air Transport aircraft not classified as a level 1 or 2 investigation and where investigation is likely to significantly mitigate future accidents.
• An accident involving one or more general aviation aircraft (other than sport aviation) with fatalities.
• An accident involving one or more charter or other general aviation aircraft
  • where there was a significant risk of fatalities or serious injuries and a substantial commitment of investigative resources would significantly mitigate accidents.
• A serious incident (as defined by ICAO see Attachments A & B) involving one or more High or Low Capacity Air Transport passenger aircraft not classified as a level 1 or 2 investigation and where investigation is likely to significantly mitigate future accidents.
• A serious incident (as defined by ICAO see Attachments A & B) involving one or more Air Transport cargo, charter or training aircraft where investigation is likely to significantly mitigate future accidents.
• An incident involving one or more High or Low Capacity Air Transport aircraft where investigation is likely to significantly mitigate future accidents.

Level 4

• An accident involving a foreign aircraft covered by Article 26 of the Chicago Convention that is not being investigated as level 1, 2, or 3.
• An accident (as defined by ICAO, see Attachment A) involving one or more charter or general aviation aircraft (other than sport aviation) without fatalities
  • where a limited commitment of investigative resources could significantly mitigate future aviation accidents.
• An accident or serious incident (as defined by ICAO, see Attachments A & B) involving Australian designed and manufactured aircraft types on the Australian Register with international safety implications not being investigated as level 1, 2, or 3.
• An accident or serious incident (as defined by ICAO, see Attachments A & B) involving one or more High or Low Capacity Air Transport aircraft not being investigated as level 1, 2, or 3.
• A serious incident (as defined by ICAO, see Attachments A & B) involving one or more non Air Transport aircraft
  • where a limited commitment of investigative resources could significantly mitigate future accidents.

Level 5

• An accident (including with fatalities) or serious incident involving a sport aviation aircraft unless foreign and required to be investigated under Article 26 of the Chicago Convention.
• An accident involving aircraft without fatalities
  • where the potential safety lessons do not, after initial review, justify the commitment of investigative resources. Basic incident data will be filed for statistical purposes.
• A serious incident or incident involving aircraft
  • where the potential safety lessons do not, after initial review, justify the commitment of investigative resources. Basic incident data will be filed for statistical purposes.

Attachment A

ICAO definitions for aircraft accidents and serious incidents

Accident. An occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight until such time as all such persons have disembarked, in which:

a) a person is fatally or seriously injured as a result of:

being in the aircraft, or
direct contact with any part of the aircraft, including parts which have become detached from the aircraft, or
direct exposure to jet blast,
except when the injuries are from natural causes, self-inflicted or inflicted by other persons, or when the injuries are to stowaways hiding outside the areas normally available to the passengers and crew; or

b) the aircraft sustains damage or structural failure which:

adversely affects the structural strength, performance or flight characteristics of the aircraft, and
would normally require major repair or replacement of the affected component,

except for engine failure or damage, when the damage is limited to the engine, its cowlings or accessories; or for damage limited to propellers, wing tips, antennas, tires, brakes, fairings, small dents or puncture holes in the aircraft skin; or

c) the aircraft is missing or is completely inaccessible.

Note 1. For statistical uniformity only, an injury resulting in death within thirty days of the date of the accident is classified as a fatal injury by ICAO.

Note 2. An aircraft is considered to be missing when the official search has been terminated and the wreckage has not been located.

Serious incident. An incident involving circumstances indicating that an accident nearly occurred.

Note 1. The difference between an accident and a serious incident lies only in the result.

Note 2. ICAO examples of serious incidents can be found in Attachment B.

Attachment B

List of examples of serious incidents

The incidents listed are typical examples of incidents that are likely to be serious incidents. The list is not exhaustive and only serves as guidance to the definition of serious incident.

• Near collisions requiring an avoidance manoeuvre to avoid a collision or an unsafe situation or when an avoidance action would have been appropriate.
• Controlled flight into terrain only marginally avoided.
• Aborted take-offs on a closed or engaged runway.
• Take-offs from a closed or engaged runway with marginal separation from obstacle(s).
• Landings or attempted landings on a closed or engaged runway.
• Gross failures to achieve predicted performance during take-off or initial climb.
• Fires and smoke in the passenger compartment, in cargo compartments or engine fires, even though such fires were extinguished by the use of extinguishing agents.
• Events requiring the emergency use of oxygen by the flight crew.
• Aircraft structural failures or engine disintegrations not classified as an accident.
• Multiple malfunctions of one or more aircraft systems seriously affecting the operation of the aircraft.
• Flight crew incapacitation in flight.
• Fuel quantity requiring the declaration of an emergency by the pilot.
• Take-off or landing incidents. Incidents such as undershooting, overrunning or running off the side of runways.
• System failures, weather phenomena, operations outside the approved flight envelope or other occurrences which could have caused difficulties controlling the aircraft.
• Failures of more than one system in a redundancy system mandatory for flight guidance and navigation.

Safety Action Statements

Safety Action Statements contain details of any ATSB safety outputs or other safety actions. ATSB safety outputs include Recommendations and Safety Advisory Notices. Recommendations and Safety Advisory Notices issued prior to the release of the final report are published in the final investigation report together with any responses. The final report will also contain any necessary Recommendations and Safety Advisory Notices. Safety Actions taken by organisations other than the ATSB, which were initiated as a result of the investigation (referred to as Local Actions), are also published in the final report. The ATSB encourages organisations to take safety action ahead of a final report which reduces the need to make Recommendations and leads to more timely improvement.