What happened
On the afternoon of January 29, 1996, a Cessna 208 Caravan, registered ZK-SFA, crashed into the heavily forested eastern slopes of Mount Robertson. The aircraft was operating a scheduled service from Wellington, destined for Picton Aerodrome (Koromiko). During the flight, the aircraft impacted the terrain approximately 10 nautical miles northeast of Blenheim. While the pilot survived the impact, the accident resulted in five fatalities among the passengers on board.
The investigation
Investigators examined the circumstances leading to the impact, focusing on the flight conditions and the pilot's navigation during the final stages of the flight. The inquiry established that the aircraft was flying under a cloud layer at the time of the accident, which significantly restricted the pilot's ability to see the terrain ahead. The investigation also looked into the operational procedures of the carrier and the specific flight parameters, such as speed and visibility, during the descent toward Picton.
Findings
Several critical factors contributed to the accident, primarily centered on the pilot's decision making and a loss of situational awareness. The investigation determined that the aircraft descended beneath the cloud base, which led to the misidentification of various terrain features. This lack of visibility, combined with the high speed at which the aircraft was traveling, prevented the pilot from recognizing the approaching mountain. The sequence of events suggests that the combination of reduced visibility and insufficient forward sight made it impossible to avoid the wooded slopes.
Safety action
Following the investigation, three safety recommendations were issued to the operating company. These measures focused on the necessity of establishing formal operating procedures to prevent aircraft from drifting into high-altitude terrain. Furthermore, the findings highlighted the importance of ensuring pilots utilize all available navigational resources when flying under Visual Flight Rules (VFR). The recommendations also called for the formal documentation of recommended airspeeds and specific aircraft configurations to be used during VFR operations when visibility is compromised.