When producing estimates for Mil crossings, one quickly learned that an F-4/F-111 took 5 minutes to cover the length of a chinagraph pencil on the flat-top displays
s'funny - I always remember having to extract the RP estimates from the MYRIAD touchwire display for LJAO......
Not to mention 'all crossings via WOBUN' to the extent that RACAL produced a lovely miniature TRN-26 TACAN (anyone know what happened to it?) so that USAFE aircraft could route that way, accurate like!!