The Convair CV-580 pictured, made in 1952, and at the time owned by Air Freight NZ, crashed at 9:26 pm on 3 October 2003. Both crew members were killed.
A summary report from Aviation-Safety.net (there is a link to the full report):-
Convair 580 ZK-KFU was scheduled for 2 regular return night freight flights from Christchurch to Palmerston North. At 20:32 flight AF 642 started its takeoff from runway 20 on schedule and climbed to FL210. The flight progressed normally. At 21:13 the Wellington controller cleared the flight to descend initially to FL130 and later to FL110. After contacting Ohakea Control the crew were further cleared down to 7000 feet and were given vectors for the approach to Palmerston. The aircraft descended through an area of forecast severe icing, which was probably beyond the capabilities of the aircraft anti-icing system to prevent ice build-up on the wings and tailplane. The aircraft then probably stalled because of a rapid build-up of ice, pitching the aircraft nose down and probably disorientating the crew. Airspeed increased to 392 kts and the G loading was peaking at 3.21 G. The angle of bank was probably between 50° and 60°. Increasing torsional stress on the wing roots probably caused panels to buckle and separate. At an altitude of 6800 feet the wings and engines started to separate. Nine seconds later the remaining fuselage impacted the sea about vertically and at high speed.
PROBABLE CAUSE: The TAIC accident investigation report did not contain a probable cause.
A report on the NZ Herald website the night of the crash is here