Fletcher FU-24

The lone pine tree which the aircraft struck was probably obscured due to the position of the sun and shadow, making it difficult for the pilot to detect. Damage to the aileron control system resulted from the collision, and prevented the pilot from turning away from the ridge he had been sowing. Due to the impaired controllability the pilot was unable to recover from a steep left-banked turn, and the aircraft stalled and collided heavily with the face of the ridge in a nose-down attitude.

The following findings were reported:
- The pilot suffered an acute myocardial infarction while in flight,
- The effects of the myocardial infarction probably led initially to loss of situational awareness and loss of control of the aircraft,
- The pilot may have realised at a late stage that a collision with the ground was imminent, but was unable to recover from the situation in time to avoid it.

Pilot incapacitation was the probable cause of this accident. The incapacitation of this pilot was an unusual event, and could not have been predicted or prevented by any reasonable or effective medical screening process.

The following findings were reported:
- During a turning manoeuvre at a low height, the aircraft stalled and squashed onto the ground in a wing level attitude, at a high rate of descent,
- The height of the aircraft above the ground at the time afforded the pilot little opportunity for recovery,
- The pilot probably reverted to an unsafe flying practice he had adopted during his earlier training,
- The unsafe practice had been recognised by a previous instructor who, when not successful in correcting it, had discontinued the pilot's training,
- The final instructor had no reason to be concerned about the pilot's flying as he had exhibited no dangerous trends and flew as instructed,
- Had the final instructor been aware of a previous trait of the pilot to perform unsafe manoeuvres he might have been able to correct it,
- The causal factors in this accident were a lack of continuity in training records, pressure the pilot believed he was under to achieve maximum productivity in his flying with a minimum of delay, the pilot's apparent refusal to accept cautions in relation to his ability, and the Fletcher aircraft's performance during the execution of a limit manoeuvre too close to terrain.

The position of the turn towards the higher ground may have deprived the pilot of a visual horizon causing him to fly too slowly and the plane to stall and spin. No technical anomalies were found on the aircraft.

No firm reason for the pilot to abandon his sowing run and make a steep turn away from the ridge could be found. It was noted that the change of heading took the plane on a course towards the sun and also a 100- feet-tall tree that may have caused the pilot to take abrupt avoiding action, causing the plane to stall and fall into an incipient spin from which control could not be regained owing to the limited height available.

An injector was completely blocked by a grain of sand which caused a significant power loss just after takeoff.