Sorry Snarlie,
I think that I might have been involved in that prank although it could have happened more than once. It was on the 033 radial in those days, you were going to the Magnus if I remember.
A short interview with Captain Smith ensued post flight but I didn't get into too much trouble because I was a lowly co pilot in those days. I felt bad though because I think I suggested it to the P1 and being a nice guy he went along with the plan.