2 useful documents:
http://www.caa.co.uk/docs/33/CAAPaper2005_04.pdf
http://www.fatiguescience.com/assets...ol-Fatigue.pdf
Second one in particular.
22 hours of "wakefulness" puts you past the equivalent UK drink drive limit.
just because you are "Knackered" and not "Fatigued" does not mean you will not make serious flight safety critical mistakes.
How many on here crew in at 2200-0100 and havent managed to sleep prior to reporting for duty? WHats that, 14 hours awake already? Add the 14 hours you will be at work for and all of a sudden, you are in quite a dangerous place.
The CAA pdf has some details of QinetiQ wakefulness model which is again useful to look at. Pages 13-14 refer.
As an aside, how many companies here permit single pilot flightdeck ops in the cruise in the case of extreme tiredness? The caa report identifies rest on a bunk provides a much better solution than sleep in the seat...