SteveR - yes, that's always the trouble with these sorts of things: remembering the ones that are useful to us correctly! I was not aware of the origin of the expression; thanks for that
barbox - not sure that I can elaborate. This was purely a copy and paste from AOPA's web site, and in particular their Pilots' Handbook. The original link is
http://www.aopa.org/members/files/ha...n_3.html#rules However, this will be of no use to you unless you are a member.
Regards,
David.