Narrative:Twin Pioneer JZ-PPX took off from Mokmer at 09:30 for a local training flight. Takeoffs and landings were practiced and after some time the captain requested and received permission to carry out manoeuvres outside the circuit. During one of these manoeuvres, a right-hand turn, the right wing broke off. The aircraft lost control and spiralled down into the sea. The wreckage stayed afloat for a while and sank.
PROBABLE CAUSE: "The Commission is of the opinion that, on the ground of the available evidence of the accident with the Twin Pioneer G-AOEO, the accident with the JZ-PPX has to be put down with to certainty nearing probability to the failure of the V-brace strut due to fatigue, because both aeroplanes were equipped with the same type of liftstrut and V-brace construction and because both aeroplanes were used in the same manner. The JZ-PPX carried out many instruction flights at a low altitude, many take-offs and landings, many manoeuvres with high flight loads, possibly up to the maximum loads. The G-AOEO also carried out many demonstration flights at a low altitude with man take-offs and landings, many manoeuvres, also with possibly maximum loads. The term of life of the V-brace as declared by the manufacturer, was based on conditions of flight which are not in agreement with the reality. During a meeting at September 6, 1957, Mr MacCallum of Scottish Aviation Ltd. gave a value of 4000hrs which raised a discussion. The Commission is aware of the fact that he cannot give a positive opinion upon the cause of the accident because there are no silent witnesses present, but nevertheless is of the opinion that there is a close conformity with the accident of the G-AOEO."
Loss of control
» NRC Handelsblad Overzeese Weekeditie xx.09.1958 (p.11)
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Biak-Mokmer Airport to Biak-Mokmer Airport as the crow flies is 0 km (0 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Networkĺs opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.