What happened
During an approach to Tauranga Airport under adverse weather conditions, a twin engine aircraft collided with the slope of Mt Ngatamahinerua. The impact occurred approximately 30 km west of the destination airport. The collision resulted in the total destruction of the airframe and caused 23 fatalities, with no survivors among the occupants.
Findings
Investigations into the accident identified a powerful downward air current located on the lee side of the Kaimai Range, near the Gordon quarry, as the primary factor. This downdraft forced the aircraft below the height of the surrounding mountain crests. Within this area, the aircraft encountered severe turbulence that prevented the pilot from maintaining control or regaining sufficient altitude to clear the terrain.
Several contributing factors were also noted during the inquiry:
- The pilot was not aware of his precise geographical position, which led to an early descent.
- Despite the navigational error, the descent was performed at an altitude that met the official minimum safe altitude requirements for that sector.
- Aviation authorities had categorized the Kaimai Range as non-mountainous terrain, which influenced the calculation of safe flight altitudes for the route.
- An inaccurate meteorological forecast regarding upper-level winds between Whenuapai and Tauranga provided misleading information for the flight.