While controlling at Bruggen during the Kosovo campaign late '91, i wondered why all og the Tonka crews would ask for a PAR at the end of the sortie but the VC10's would normally ask for an ILS, esp when the skys were gin clear with 40km vis. So, one morning at around 6am when we had all retired to the bar after a successful mission, i asked the pilot of a GR1 and the answer was quite simple. After an 7/12 - 8 hour sortie which included 2 refuellings in thunderstorms interspersed with a bombing run with some light flack, they were absolutely knackered and numb (physically and mentally) so when in contact with home ATC they would ask for a PAR because all they had to do was respond to up/down, left/right and look out approaching DH. They also trusted the Controllers to give them a good service
Of course, the VC10 crews had a slightly easier time of it and so still had a bit more in reserve.
So i guess there is a good reason for PAR. But while RPAR might be great on paper, it does occasionally jump from one ac to another and that needs sorted pronto. Problem is that the company say there is nothing wrong and that we got what we asked for. also while it has not been commissioned/fitted at Valley etc, we have already paid for them so tough accoding to one engineer!