Whatunion should read Catch 22.
That is unfortunate Whirly, but scary to think that anyone of the sort of experience to be instructing cannot cope with the situation! What if he found himself in my situation in one of our PA-28s, where the ASI was under-reading? OK, I could land it fast at Bournemouth and accept the long float, but don't we teach our students to fly the attitude (how do you think I knew it was underreading)? Don't we get them to practice circuits with no speed reference, just using the RPM, the 'picture' and the feel?
Even on an R22 a pitot blockage must be an issue of concern.