Have heard that
"halve your groundspeed, multiply that by 10" will keep you pretty close to a 3deg slope.
also
5x your groundspeed = required ROD for a 3 degree approach.
the above are the same, just depends on how good you are at maths!!!
sorry if someone has mentioned it and i've missed it and am repeating!
DAR, you said "you only have too much fuel when you are on fire"...
.....or if you have a boss like mine that books too many people on a flight in the heaviest aircraft and you are already on min fuel and get an earbashing from them because you 'have too much and we havn't had this problem before'.....
