Accident Overview
An aircraft engaged in an aerial topdressing operation on a farm near Matamata crashed on its 14th flight of the day. The flight was part of a routine sowing of superphosphate and lime mixed with other ingredients. After approximately two hours of normal operations, a break was taken to replenish the fertilizer bin from a truck, during which the aircraft was refueled. Following the truck's departure, the aircraft was loaded with 22 hundredweight (cwt) of fertilizer mixture and commenced its next sortie.
Sequence of Events
The loader driver lost sight of the aircraft after takeoff and was reloading for the next flight when he noticed the fertilizer truck had stopped halfway down the farm road. The truck driver ran back to report that the aircraft had crashed. The wreckage was found on the side of a gully about 250 metres from the end of the airstrip. The aircraft was completely wrecked but there was no fire. The pilot was killed instantly.
Flight Path and Impact
Evidence indicated that the aircraft failed to attain takeoff speed. It lifted off briefly, then settled back, striking the rear fuselage heavily against the ground. It then ran through the fence at the end of the strip in a nose-high attitude. The aircraft became airborne again, collided with a tree while in a 90-degree bank to the right, and dived steeply into the gully.
Weather Conditions
The weather was partly cloudy with a northerly wind of 3 to 5 knots. Visibility was good. The investigation concluded that weather did not appear to be a factor.
Investigation Findings
The investigator determined that the aircraft was grossly overloaded and that its center of gravity (C of G) was 28 mm beyond the aft limit. This overloading was attributed to approximately 200 kg (3.92 cwt) of fertilizer remaining in the hopper from previous flights, combined with the weighing equipment on the loader under-reading. When both the pilot and loader driver believed the load was 22 cwt, the estimated hopper load was actually 27.68 cwt.