The aircraft had been re-built during April, 1968 and a maintenance release inspection had been carried out
on 30th August, 1969. The aircraft had flown 129 hours since the re-building and had done 140 landings. At
the time of the accident it had flown some 35 hours since the issue of the maintenance release. The aircraft
was engaged in a period of circuits and landings and after touching down on the fourth landing, the pilot-incommand
took over the controls in order to demonstrate crosswind technique. He applied full engine power
for a go-around and at a speed of about 40 knots the starboard undercarriage leg collapsed, the nose of the
aircraft dropped and it slewed to the right. The aircraft came to rest on its nose and starboard wing heading
some 90 degrees to the right of the intended take-off path.
The undercarriage had collapsed because of the fatigue failure of the lug of the eye bolt supporting the upper
end of the starboard radius rod. Examination showed that the pivot bolt and probably the eye bolt itself had
been tightened to an extent which prevented the pivotal movement of these components and an abnormal load
would therefore have been imposed on the eye bolt lug during ground operation of the aircraft.