Aero Commander accident in the past - Reason for in-flight break-up.
The Aero Commander has an unmistakeable howling engine noise while climbing. I first heard, then saw, an Aero Commander climbing away from Essendon to the north-east this morning Monday 30 September. The weather over the Melbourne area was overcast with very strong gusting northerlies and the Aero Commander was making slow headway. Soon it would be over high terrain and although I haven't seen the flight forecast experience says it is probably moderate to severe turbulence below 10,000 ft over the ranges.
It got me thinking about the Aero Commander that broke up in mid-air on the same route as todays flight I saw. That was quite a few years ago and the circumstances leading to the in-flight break up could not be satisfactorily explained by ATSB. The sequence of break-up was explained after the wreckage was examined. Apparently there was no sign of structural failure that initiated the disaster. Whatever happened it was quite sudden and may have been caused by pilot input in turbulence. A radar picture revealed a series of sharp turns and loss of altitude before the break up started to occur. Hundreds of Aero Commanders and other general aviation light twins would have flown over the same route in the same conditions over many years yet none came to grief.
I wondered what really happened and no doubt many other people wondered the same thing. The ATSB report was, as usual, bland and gave no Most Probable Cause -other than a forensic examination of the break up sequence. I have always considered it a pity that ATSB are constrained by their legislation not to state a Most Probable Cause of an accident, if the facts cannot be proven with certainty.
I understand the American NTSB are required by law to give a Most Probable Cause if they are unable to pin down what actually happened to cause the accident sequence.
In the case of the Aero Commander crash in question, the pilot and her passenger were killed. Accidents involving in-flight control surface failures have often been caused by over-controlling by flight crew. The American Airlines A300 rudder fin failure was caused by over-controlling on the rudder by the first officer for example.
I wondered if over controlling by the Aero Commander pilot in severe turbulence - or even by her passenger somehow on the controls with her in fright - may have been a Most probable Cause? Something happened and few have talked about it...