I was introduced to it a couple of years ago when I started flying ex-mil jets.
Bingo rings are good for keeping you on top of your fuel requirement, especially when you depart the original plan.
It is a very useful system to use when "eyes down" time needs to be kept to a minimum (ie. low level fast jet).
Modern GA aircraft with fuel totalisers and gps charts etc etc would have no requirement to use this system, but the technique is always good to know.
Last edited by Squeegee Longtail; 14th January 2012 at 18:40.
Reason: typo