I know this was debated on the Flyer Forum, but I'd like to bring it up here too.



The M&B section includes the option to describe mass in terms of kg or lbs, but fuel figures are only available in litres and gallons. Could fuel flow options also include lbs and kgs please?

Aircraft with capacitance gauges and mass-flow meters have no need to think of fuel load in terms of volume. All of our company aircraft are calibrated in lbs (they're American after all), we effectively have no concept of volume. And why would you? Fuel is burned by mass, not volume. The volume of the fluid varies with temperature, so what you fill up with at the end of the day is not what you are left with the next morning! When we're refuelling, we do it watching the gauges so that we get the right mass of fuel on board, not volume.



I doubt any large piston or modern turbine aircraft consider fuel flow by volume - the quantities are so large that the errors would be huge - large aircraft talk about lbs, kgs... or tonnes of fuel!