In the EC lorry drivers (for non-exempt road vehicles over 3.5 tonnes) are only allowed up to 4.5 hours continuous driving time without a break, up to 9 hrs in one day. This is presumably to prevent fatigue causing accidents. British domestic law I think allows up to 10 hours driving where the EC law doesn't cover, with a total of 11 hours "on duty", i.e. one hour not driving.
With this in mind, why would anyone experiment with hours longer than these in commercial aircraft?
Why weren't these fatigue tests done in the sim? Safer, but considerably more expensive I suppose...
B&t