I opened my copy a few days ago, and was surprised to find it in mint, unread, condition. Obviously one I had bought to replace a "borrowed" copy that was never returned. I last read it many years ago, as a young airline pilot. Now, as a long-retired airrline pilot, I can relate much better. Among other things, never mistrust the sixth sense. Even if everything is going fine, instruments etc reading normally, if you have that "feeling something is wrong" you can bet something is.