The post-mortem toxicology results for the pilot in the Carterton hot air balloon showed that he had a positive result for tetrahydrocannabinol (a constituent of cannabis). It was likely that this was due to 2 factors: first, the pilot smoking cannabis shortly before the accident flight; and, second, residual tetrahydrocannabinol, from ingesting cannabis over a longer term, redistributing in the pilot’s blood after his death.
The Commission found that the accident was caused by errors of judgement by the pilot. It also found that it could not exclude the possibility that the pilot's performance had been impaired as a result of ingesting cannabis.
This is not the first time that the Commission has inquired into occurrences where persons operating aircraft, vessels or rail vehicles, or where persons performing functions directly relevant to the operation of these, have tested positive for performance-impairing substances such as illicit drugs and alcohol. The Commission is increasingly seeing more occurrences where the use of performance-impairing substances is a feature.
Unless this safety issue is properly addressed, further occurrences where the use of performance-impairing substances is a contributing factor will occur. Legislative or regulatory reform in this area is necessary.
The Commission, therefore, recommends that the Secretary for Transport complete, as a matter of priority, all necessary work that will support the introduction of appropriate legislation or rules that will:
- prescribe allowable maximum levels for alcohol
- prohibit persons from operating an aircraft, vessel or rail vehicle if they are impaired by drugs
- require operators to implement drug and alcohol detection and deterrence regimes, including random testing
- prescribe post-occurrence testing requirements for drugs and alcohol.
This legislation or these rules should apply:
- across the aviation, maritime and rail transport modes
- to persons operating an aircraft or a marine craft for recreational purposes.