• The safe operation of UAS is as important as that of manned aircraft, and third-party injury and damage to la property can be just as severe when caused by either type of aircraft.
Proper investigation of each accident, serious incident or other occurrence is absolutely necessary in order to identify causal factors and to prevent repetition. Similarly, the sharing of safety related information is critical in reducing the number of occurrences. The limited operational experience with UAS in civil applications makes such investigation particularly relevant.
• This Chapter outlines the principles that must be employed with regard to the reporting and further investigation of occurrences involving the operation of all civilian unmanned aircraft within UK airspace; it also covers occurrences involving UK-registered unmanned aircraft that take place within the airspace of other nations.
• The current UK definitions of Accident” and ‘Serious Incident’ originate from Regulation (EU), which in turn are directly linked to the ICAO Annex 13 definitions.
• An Accident is defined as: ‘An occurrence associated with the operation of an aircraft which, in the case of a manned aircraft, takes place between the time any person boards the aircraft with the intention of flight until such times as all such persons have disembarked or, in the case of an unmanned aircraft, takes place between the time the aircraft is ready to move with the purpose of flight until such time it comes to rest at the end of the flight and the primary propulsion system is shut down, 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
⁃ 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 a single engine (including its cowlings or damage, when the damage is limited to a single engine (including its cowlings or accessories), to propellers, wing tips, antennas, probes, vanes, tires, brakes, wheels, fairings, panels, landing gear doors, windscreens, the aircraft skin (such as small dents or puncture holes) or minor damages to main rotor blades, tail rotor blades, landing gear, and those resulting from hail or bird strike (including holes in the radome); or
⁃ the aircraft is missing or is completely inaccessible.’
• A Serious Incident is defined as: ‘An incident involving circumstances indicating that there was a high probability of an accident and associated with the operation of an aircraft which, in the case of a manned aircraft, takes place between the times any person boards the aircraft with the intention or flight until such time as all such persons have disembarked or, in the case of an unmanned aircraft, takes place between the time the aircraft is ready to move with the purpose of flight until such time it comes to rest at the end of the flight and the primary propulsion system is shut down.’
NOTE: The difference between an accident and a serious incident lies only in the result.
• A Reportable Occurrence is defined as: ‘Any incident which endangers or which, if not corrected, would endanger an aircraft, its occupants or any other person.’
• Any person involved (as defined under Regulation EU) who has knowledge of the occurrence of an accident or serious incident in UK airspace must report it to the AAIB. Such persons include (but are not limited to) the owner, operator and pilot of a UAS.
• All other occurrences must be reported under the CCA Mandatory Occurrence Reporting Scheme.
• The following aircraft categories are specifically covered by the MOR Scheme (i.e. all occurrences must be reported):
⁃ any aircraft operated under an Air Operator’s Certificate grandee by the CAA;
⁃ any turbine-powered aircraft which has a Certificate of Airworthiness issued by the CAA.
• Although these categories would appear to exclude the vast majority of UAS applications, all occurrences related to UAS operations which are considered to have endangered, or might have endangered, any aircraft (including the subject unmanned aircraft) or any person or property, must still be reported to the CAA via the MOR Scheme. This applies equally to all UAS categories, regardless of the aircraft’s mass or certification state. It also includes UK registered UAS operating outside UK airspace.
• Appendix B to CAP 382 lists the types of occurrence that are likely to fall into the definition of a ‘reportable occurrence’. Whilst some of the listed occurrences would clearly only apply to manned aviation, many will apply equally to UAS, in modes that are UAS specific. In addition to those listed in CAP 382, other, more UAS-specific, reportable occurrences include events such as:
⁃ Loss of control/datalink – where that loss resulted in an event that was potentially prejudicial to the safety of other airspace users or third parties.
⁃ Navigation failures;
⁃ Pilot station configuration changes/errors: between Pilot Stations; transfer to/from launch control / mission control stations; display failures.
⁃ Crew Resource Management (CRM) failures/confusion;
⁃ Structural damage/heavy landings;
⁃ Flight programming errors (e.g. incorrect speed programmed);
⁃ Any incident that injures a third party.