Profit Max
There is no total safety. And indeed, a decision needs to be made as to what the acceptable level is. However, your numbers are way off. We are talking about a current safety of 99.99999% (this is the percentage of flights without fatal accidents).
Thanks, I am aware of those figures, I replied to a post which discounted the TOTAL safety and suggested to stay in bed.
Now, your suggestion regarding grounding a/c with inoperable T/R, this is the same issue. If the airline knows that more of their a/c will be on the ground because of inoperable T/R, it will have to buy more a/c to be on standby. This costs money. And passengers are not prepared to pay for it.
Or the airline will better mantain the TR or the design will imply less failures...to keep the aircraft flying longer
Ask yourself: When you bought a car, why did you go for the Golf, and not the high-security S-class Mercedes? Shouldn't you have if you aim for total security?
Do I have such option when I buy an airline ticket?
In a nutshell, the risk of flying is tiny, and a lot less than driving, cycling or just walking in a city.
So forget about the crash investigation, the risk is tiny and therefore we shouldn't worry about anything.
So why are there accident investigations? To find about the causes of accidents. If there is a cheap way of making flying more secure, you can bet that it will be implemented. If it is expensive, it will only be implemented if the costs outweigh the benefits.
My understanding is that is not implemented if the safety is of 99.99999%, not because of costs outweighing the benefits. What you are saying could be considered
professional negligence.
AN
edit to correct typing errors