AMF,
I agree with you, right up to the very last bit.
and the main breakdown leading to this CFIT wasn't R/T dicipline
The point of the document, and this branch of the discussion, is that poor R/T
by the controller was a major contribution. He did not follow the readback rules. If he did, he would have heard the fact that an enormous error had occured (how does anyone start a published procedure by blindly descending to 400'?) and he may have been able to save the day. He didn't listen to the readback properly.
I see the point of view you are expressing. It's just that over here we consider proper readback (and listenback) to be an improvement to safety that is big enough to not only make it worthwhile, but mandatory.
I appreciate the outstanding issues here (BOS); was poor R/T discipline a contributory factor? Don't know. Will it take a mid-air at a major US airport before someone decides that readback of clearances is mandatory in the US?
If the system is too clogged to allow readbacks, then the system needs changing. The UK is also suffering from this - in particular some London frequencies are too busy - but we will not scrap the readback rule because it is just too important. We have to improve the system by means of more controllers with more frequencies. As usual, money is the problem.
I particularly liked
this document, where this primary concern is one of liability, not safety! God bless Am.......
Stu