Originally Posted by
main_dog
I have noticed that the 744 fuel totalizer tends to slightly over-read in descent and under-read in a climb. Next time at TOD take a look at the totalizer, it occasionally creeps up by a couple hundred Kgs as you pitch down. In a go-around, conversely, it begins to under-read.
I once made the mistake of glancing at the totalizer on the lower Eicas during a go-around and was a bit concerned to see almost a ton less than I was expecting... as soon as we levelled off at MAP altitude it started to creep back to where it should have been. I do believe this effect is more pronounced for tank 2 and 3 readings.
Perhaps this is what the FCTM refers to as "Fuel Sloshing".
Taken as only part of a procedure for determining if a Fuel Leak exists:
"Some fuel-related checklists (for example, FUEL IMBAL) list reasons that a fuel leak should be suspected. This list is not exhaustive and, in all cases the flight crew should use their knowledge of the fuel system and current operating conditions to determine whether a fuel leak should be suspected. Some reasons are:
• The total fuel remaining on EICAS is less than the planned fuel remaining. The total fuel can be less than planned fuel for a number of reasons, such as a fuel leak, unforecast headwinds, fuel sloshing (such as from high angles of pitch). Sloshing fuel would be a temporary effect. Flight crews should consider these when deciding whether or not to suspect a fuel leak.
• An engine has excessive fuel flow. A faulty fuel flow meter......"