What happened
On the night of 3 October 2003, a Convair 580, registration ZK-KFU, was operating a scheduled freight service from Christchurch to Palmerston North. The flight, operated by Air Freight New Zealand, proceeded normally across the Cook Strait. However, while descending through the area, the aircraft was observed on radar performing a tightening left turn before suddenly disappearing from screens.
Subsequent investigations revealed that the aircraft had struck the ocean approximately 10 km north of Paraparaumu Aerodrome. The impact occurred at high speed and in a near-vertical orientation. The two fatalities involved were both members of the flight crew.
The investigation
Investigators analyzed radar data, flight recorder information, and meteorological reports to reconstruct the final moments of the flight. The investigation focused on the aircraft's trajectory after crossing the Cook Strait and its descent through changing weather conditions. The inquiry examined the aircraft's performance, the presence of icing, and the adequacy of the onboard flight recorders and communication systems.
Findings
Evidence suggests that after crossing the Cook Strait, the aircraft likely encountered severe icing while descending. It is believed that the airframe became heavily encrusted with ice, leading to a loss of aerodynamic performance. The aircraft subsequently entered a stall and became trapped in a spiral dive. The structural integrity of the plane failed during the descent, resulting in the in-flight break-up of the Convair 580.
Safety action
Following the accident, several safety concerns were addressed, including:
- The necessity for pilots and operators to maintain a deeper understanding of the hazards associated with aircraft icing.
- The importance of utilizing air reports (AIREPs) to alert the aviation community to dangerous meteorological conditions.
- The need for improved documentation for IFR and night freight operators regarding adverse weather encounters.
- The requirement for better tracking capabilities for underwater location beacons to assist in search operations.