well but it is very difficult to guard against all exceptional situation requiring some basic aviation skills. i think the point made is that you can fix leaks

well but it is very difficult to guard against all exceptional situation requiring some basic aviation skills. i think the point made is that you can fix leaks one by one, which takes a very long time, or you can know the abstraction layer below. fixing one leak and assuming there isn’t any other is not the right strategy, is my point.