Dumb Question
Thanks all for your replies. I'm glad one or two of you have at least confirmed what I was worried about; namely, that the transponder info is only as good as your instrument info, and that if you do have a static/pitot fault then ATC are going to be just as mis-informed as you are.
I guess if you were caught in the same situation as the Peruvian 757 was, you would whip out the QRH and choose the appropriate thrust setting and attitude for flight. Those guys got the stick shaker and yet chose to believe that they were still too fast. Whenever I watch that programme I always wonder why they didn't trust it.
Then again, I suppose we can all be Monday morning quarterbacks.
Thanks again,
Birky