The Flight
The aircraft departed Feilding Aerodrome on a visual flight rules flight to Paraparaumu, with a normal flight time of about 17 minutes. On board were the pilot and his two sons, aged 7 and 5 years. Earlier that evening, the pilot, his wife, and four children had attended the pilot's farewell work function in Palmerston North. Afterwards, they went to Feilding Aerodrome, where the pilot prepared ZK-TZC for the flight. His wife observed him carry out a pre-flight inspection, including checking the fuel. She noted that the pilot seemed normal and gave no indication of any issues with himself or the aircraft. She did not see the taxi but watched the take-off on runway 10, which she considered normal. She then drove to Paraparaumu with her two younger children.
An aviation enthusiast living near the aerodrome boundary watched ZK-TZC taxi and take off immediately without a ground run. He also considered the take-off and departure normal. Radar data showed that after take-off, the aircraft turned right, climbed to 1000 feet above mean sea level (amsl), and headed towards Paraparaumu. About 2.7 nautical miles from Feilding Aerodrome and approximately 1.3 nautical miles northwest of Palmerston North Aerodrome, it turned left, descended, and headed back to Feilding. The descent rate was about 500 feet per minute to 400 feet amsl. At 400 feet amsl (about 200 feet above ground), the aircraft passed east of the aerodrome and joined a left downwind for runway 10, spaced about 0.3 nautical miles laterally at an initial height of 400 feet amsl.
Loss of Control and Impact
During a left turn at low height during an apparent approach to land on runway 10 with the undercarriage and flaps extended, ZK-TZC departed controlled flight. The aircraft first rotated away from the aerodrome before striking the ground in a nose-down attitude. All three occupants were killed in the impact.
Witness Observations
Two witnesses about 3.5 km southeast of Palmerston North Aerodrome saw the aircraft at normal height shortly before it turned back towards Feilding. They reported seeing darkish grey smoke behind the aircraft shortly before the turn. Another witness near Palmerston North recalled seeing the aircraft in level flight at about 1000 feet before it rolled quickly into a steep left turn and headed back. He thought one or both engines were running unevenly but saw no smoke. He lost sight of the aircraft near Feilding and noted it was getting dark with a high cloud base and gusty winds.
A witness on a road from Feilding Aerodrome to Palmerston North saw the aircraft fly low over his car. He observed the undercarriage extend then retract and noted the left propeller was stationary, while the other engine sounded normal. The aircraft continued towards Feilding Aerodrome and crossed the eastern end of the runway. He thought it was trying to turn and seemed low and slow, with no smoke visible.
The aviation enthusiast saw ZK-TZC return and fly a left downwind for runway 10. He noted the left propeller was feathered and not turning, and the right engine sounded normal. He saw no smoke and could not recall the undercarriage or flap positions. Another witness near the threshold of runway 10 heard the aircraft overhead, sounding very low and loud, as if the engine was at maximum power, steady and not intermittent.
A couple living on the approach path heard the aircraft from a northerly direction; the engine sounded under heavy load, making a loud, steady noise like a topdressing aircraft. The noise stopped abruptly when they heard a loud thump. An eyewitness to the crash saw the aircraft at treetop height turning left to land. The aircraft nosed up sharply, then suddenly reversed direction before nosing down and hitting the ground nose first. She described the aircraft snapping in half on impact.
Probable Cause
The official findings identified that the pilot chose an improper course of action and flew an improbable circuit in attempting to land ZK-TZC back at the departure aerodrome with one engine inoperative, which led to the accident. No conclusive reason was found for the left propeller being feathered.