Following MacBearo's idea about using the RAT for speed reference; a piece of bendy plastic affixed to the windscreen with a few engraved lines on it might do just as well, but would not be very scientific.
If the situation is as surmised, pitot icing follwed by an upset, then the ability to restore one's attitude becomes paramount. If all the sensors/instruments are giving erroneous/conflicting/confusing results then it is going to be next to impossible to establish which way is up.
Coupled with the piece of bendy plastic could be a small weight hanging on a strong thread attached to the the fwd glareshield! Remember, gravity sucks.
Cost; about 40 pence.
Last edited by rubik101; 30th Jun 2009 at 01:13.