Originally Posted by
Pilot DAR
So, I wonder to myself, if 1960's technology can include this simple protection against a second error, why would the RUN/CUTOFF switches of a very modern airliner have at least that protection. I presume that there must be a reason, but darned if I can imagine it!
I agree that it's much more difficult to design away the opportunity for deliberate malicious pilot action, though in the case of simply switching off one engine after another, the afore mentioned "confirm that you really want to do that" would give a second crew member a hope of acting to prevent the second malicious shut down. Heck my computer requires that I confirm I want to delete a file, it can't be that difficult.
I quoted two of your paragraphs which I think are pertenant to the design philosophy of current Boeing cut-off switches.
"
why would the RUN/CUTOFF switches of a very modern airliner NOT have at least that protection"
I'm assuming you intended to include the 'not' in your sentence, but I'm guessing the answer is, because this is the first time such an obscure event has occurred.
The possibility that it might happen, as is being contemplated now, had not been considered at the design stage.
"Heck my computer requires that I confirm I want to delete a file, it can't be that difficult."
Possibly the most intriguing sentence
yet, amongst the tens of thousands of contributions, in three hamster wheel threads that revolve around such a simple system.
Personally, I can think of no reasons why your logic should not be seriously considered, with a view to effectively mitigate against unintended actions, and also to somewhat frustrate any attempt at a deliberate action.
Some will probably think no improvement is necessary because nothing is infallible, and it could introduce unnecessary complications. They might also say the costs involved are not justified because the current risk is so small.
I'll stand down now, and leave this discussion to those who are directly involved, as my initial concerns have at least been recognised.
Thank you.