I've been told that if you have work in a particular location of greater than 21 days then that is considered to be your 'work location' for tax purposes.
So from the way I understand it, if you were on a 3 week assignment and flew back home weekends, no problem there.
But if that was a 4 week assignment then any personal fly backs would be considered a taxable benefit. Your initial flight there and back is tax deductible though.
Ah ha!! I stand corrected! Thanks - now I understand.