Thread: Engine Rumour
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Old 24th Oct 2015, 21:56
  #3 (permalink)  
Join Date: Aug 2004
Location: Melbourne, Australia
Posts: 8,417
This rumour has the ring of truth since there is at least one moron in CASA who already thought up and promulgated hard time propeller overhauls as well as control cable replacements.

These actions might be necessary but only on the basis of a major research project that:

(1) Examines a statistically valid sample of of engines, propellers, cables, etc., then,

(2) Produces a statistically valid relationship between component age and catastrophic failure probability, and finally,

(3) Mathematically tests the hypothesis that "there is an X% probability that catastrophic failure will occur after Y years", then

(4) model the expected change in failure rates as a result of proposed regulation, taking into account costs and appropriate risk management principles.

The final step (4) needs to also account for "infant mortality" which in my opinion is not inconsiderable when it comes to engines and other components, where the simple acts of removal, overhaul and reinstallation introduce more failure points.

And finally if all this work had been done,, which it hasn't, and supported the current CASA conclusions, which it doesn't, then the FAA would have mandated the replacement or overhaul periods at least Fifty years ago, which it didn't.

Speaking as someone who did this type of work for Six years at Ansett, by hand without benefit of computer, in the old days.
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