B737 Classic Fuel gauge tolerances
The B737-200 FCOM included under the Fuel chapter that the fuel gauge accuracy tolerance was plus or minus three percent of the total fuel gauge contents. It meant that when operating into fuel reserves where for example you were down to 1500 kgs total fuel before landing, allowance must be made for the worst case of three percent gauge tolerance. That worked out for the main tanks of around 130 kgs per tank. So you planned to land with an extra 260 kgs over and above the 1500 kgs.
Request information if the 737NG series and the 737 Classics have similar fuel gauge tolerance as I cannot find it mentioned in the FCOM. How about the A320 as well?
Also with regards to calculation of (say) 30 minutes holding fuel as the basis a fixed reserve, I recall that figure was based upon fuel required for an ILS from the Outer Marker - plus one go-around and a circuit inside the outer marker, touch down and full reverse. It was anticipated the engines would flame out due to fuel exhaustion on completion of he landing roll.
Can anyone verify if that is correct keeping in mind these figures were from the FAA many years ago.