My Avmed lectures are a bit of a hazy memory sharpend, but 62,000' in an unpressurised a/c, even with a pressure breathing mask would seem to me to present some physiological problems. I recall being told on here that the Canberra guys who set up the world altitude record of over 70,000' in the 50's wore a suit rather like that subsequently worn by U2 pilots. I assume you were in normal flying suits, so were there any after affects?