VC10 pilots? Messing around!? I don't believe it!
I think possibly our meanest trick was on a female American Air Force Captain, who came for a trip with us one day - I was still a copilot at the time. The aircraft captain swapped badges with the air engineer, whilst I swapped with the navigator and we all moved to the appropriate seats, having already done the cockpit checks before she arrived. She had not been in the cockpit long before the following conversation ensued:
'Hey, Captain, didn't you say I could have a go at flying this thing today?'
'Did I? I don't remember that.'
'Yeh, in the bar last night - right after that idiot sang Rhinestone Cowboy on the karaoke'
'Oh I remember. So I did. Well, OK then, but so long as you do exactly what I say.'
There proceeded to be a swap of seats followed by a similar conversation between myself and the navigator and another seat swap. As far as our passenger was concerned, she was now sat between the two pilots, who were occupying the navigator and air engineer positions, whilst the two rear crew guys were in the pilots' seats.
We then made a big show of fumbling through the checks (which had already been done) and she laughed along with us, expecting us to change back before the aircraft started moving. She started to turn white as we weaved our way along the taxiway and out onto the runway. I think what really tipped her into petrified mode was during the take off run, when the air engineer (who she thought was the captain) screamed 'PULL BACK! PULL BACK!' as we reached rotate speed. The aircraft staggered into the air and for the next 3 hours she must have spent much of the time in shock as we continued the farce right through to the most hair raising landing I think she will ever see ... that is assuming of course that she ever set foot on an aircraft again.