Originally Posted by
Sunfish
If he really said that, then this is lunacy! The entire body of statistics including probability exists to stamp out this rubbish.
To put that another way, unless you have detailed knowledge of the population, you cannot make such sweeping statements. You don’t know if your apparent “cluster” of events is purely coincidental and that is even assuming there is a common cause, without knowing the baseline accident rate and the standard deviation.
Given what is called “infant mortality” in maintenance, CASAs new rules on Angel Flight may even increase the accident rate.
He really said that (if we assume - as is reasonable - that the Committee is quoting from evidence given by Dr Aleck to the Committee).
They can - and do - "make such sweeping statements" and go forth and make regulations on the basis of what may be a purely coincidental cluster. And in the case of the imposition of more maintenance requirements upon aircraft involved in Community Service Flights, there is no evidence of any causal connection between a lack of maintenance and either of the Angel Flight accidents but plenty of evidence to show that more time-based mandatory meddling increases the risk of 'infant mortality'.
The ghastly irony is that CASA has probably made CSFs more risky. Fortunately, for those exposed to the increased risks, the risks remain remote.
Why does CASA regulate in this way to achieve these outcomes? In the interests of "safety" of course.