Just reading a Terry Pratchett, I was reminded of another element of the 'fool' or a joker type routine, with a link to this case:
In Morris Dancing:
Quote:
Many sides have one or more fools. A fool will usually be extravagantly dressed, and communicate directly with the audience in speech or mime. The fool will often dance around and even through a dance without appearing really to be a part of it, but it takes a talented dancer to pull off such fooling while actually adding to and not distracting from the main dance set.
http://en.wikipedia.org/wiki/Morris_dance#TerminologyKen, I don't think it has anything to do with the Joker fuel level call, apart from, as you suggest, the term being familiar from that source (the other source, cards and card games - being alien to the pilot mentality of course.

). IIRC, the joker routine is
followed by the last Balbo pass and then the Balbo breaks into sections, usually fours for passes and finally pair landings.
Regards,