Cessna T188C, VH-NAB

This Occurrence Brief has been compiled from information obtained from the pilot and aircraft operator. The ATSB did not conduct an on-site investigation.

The Cessna 188 was being used to spread insecticide over a cotton crop. Soon after take-off, and as the pilot was setting the aircraft up to conduct the initial spray run, the aircraft descended from a steep turn, into the crop and impacted heavily. Although the aircraft was substantially damaged, the pilot was not hurt. The weather conditions were CAVOK (cloud ceiling, visibility and general weather were suitable for visual flight) with a variable wind of about 3 to 5 kts. The temperature was reported as being about 26 degrees C.

The pilot gained an agricultural rating 8 months prior to the accident and had accumulated about 36 hours agricultural flying experience before the accident. She had about 15 hours experience on the aircraft type and was operating under the supervision of an experienced agricultural pilot.

The pilot reported the following information:
The aircraft had been loaded to within 0.6 kg of the maximum take-off weight.
Following the take-off, the aircraft 'felt heavy' but was climbing adequately.
During a steep turn towards the direction of the initial spray run, the aircraft began descending towards the ground.
The wings were levelled and full power applied but the engine did not appear to deliver full power.
Further turns were made to avoid wires and trees and then as the aircraft continued descending the wings were rolled level before the aircraft hit the ground.

A subsequent engineering inspection by the operator revealed that one of the magnetos had no defects, but the other magneto had badly worn or burnt breaker points. No other defects were found during the engineering inspection. The operator's engineering assessment determined that it was unlikely that the faulty magneto would have affected the ability of the engine to deliver full power.

The investigation could not determine why the aircraft failed to remain airborne, although the steep turn at high weight may have been a factor in the accident.