Background
On the day of the accident, the pilot arranged to topdress properties for three clients, one of whom had three separate blocks to be treated. The pilot departed from Stratford Aerodrome at 0653 hours in ZK-LTF for the first airstrip, located approximately 7 km to the north-east.
Day's Operations
After an initial reconnaissance flight, topdressing began at 0722 and finished on the first block at 1034. The pilot then made brief landings at Stratford and another airstrip 11 km to the north before positioning the aircraft to a strip near Huiroa. The remainder of the day's work was carried out from this strip. Four blocks were treated: the first 8 km north-west, the second immediately north, the third 3 km west, and the last 4.5 km south adjacent to Strathmore Saddle. A reconnaissance of the fourth block was flown at 1518, but actual spreading did not commence until 1755. Two loads of urea were spread between 1755 and 1812, with a 12-minute pause until the final take-off at 1824. During this break, the last urea was loaded, fertiliser bins secured, and the loading vehicle parked. It is not known if refuelling occurred. The loader driver boarded the aircraft, apparently intending to accompany the pilot back to Stratford after the last drop.
Final Flight
At 1825, the pilot performed one run towards the south, made a left reversal turn, spread another swath on a northerly heading, and pulled up to commence another reversal turn to the left. At some time after this pull-up, the aircraft struck the ground heavily on a south-westerly heading, killing both occupants on impact. The accident occurred during evening civil twilight at approximately 1830 NZST, adjacent to Strathmore Saddle at an elevation of about 530 feet.
Search and Recovery
Later that evening, the pilot's wife reported the aircraft overdue. A ground search initially carried out by friends and associates found the wreckage and bodies of the crew about half an hour after midnight.
Investigation Findings
The official investigation concluded that the pilot was licensed, rated, and fit for the flights; the aircraft had a current Airworthiness Certificate and had been maintained properly; no pre-accident defect was found; the impact was consistent with partial recovery from a dive with insufficient height to do so; no conclusive reason could be found for the aircraft to be in that situation; light conditions were probably conducive to difficult height judgement; the pilot's judgement may have been further eroded by fatigue and a degree of carbon monoxide absorption; and the accident was not survivable.