Yes, dublinpilot is right. I am taking the p a bit. Only cos i was bored.
But, Its great that some of you fell for it. In a totally non offensive nice way of course.
It was a joke that the CAA examiner on my IR did to me. Except he kept me guessing for about 5 minutes why the pen made a different noise.
And if any of you say you are not going to try that out with people on a lovely summers day at your airfield, then you are a cad.