What happened
On 2 February 2005, a Piper PA34-200T Seneca II, registration ZK-FMW, was operating a scheduled air transport charter flight. The mission, which included a scenic component, was traveling from Ardmore to Taupo with one pilot and two passengers on board.
During the flight, the aircraft performed an instrument approach toward Taupo Aerodrome. While executing the approach, the aircraft deviated to the left of the established final approach track. At approximately 1154, the aircraft struck Mount Tauhara, located roughly 8 km northeast of the aerodrome. The impact resulted in the destruction of the aircraft and three fatalities.
The investigation
The investigation examined the flight path, meteorological conditions, and the pilot's medical status. Investigators analyzed the aircraft's navigation equipment, specifically the automatic direction-finder (ADF) and non-directional beacon (NDB) usage.
Toxicology reports revealed that the pilot had traces of THC-COOH, a metabolite of cannabis, in his system. Experts determined this likely indicated cannabis consumption between 12 and 24 hours prior to the accident. While the presence of the metabolite was confirmed, investigators could not definitively conclude that the substance caused the flight deviation, as the physiological effects of cannabis vary significantly.
Findings
- The aircraft experienced a controlled flight into terrain after deviating from the published approach path.
- The pilot's blood contained metabolites indicating cannabis use within the previous day, though its direct impact on flight performance remained unproven.
- The aircraft lacked modern terrain awareness technology that might have alerted the crew to the proximity of the mountain.