The Fuel Quantity Indicators may fool you during climb/go-around

[pelmet]

I have seen warning in some Boeing manuals about this. Sometimes we would get low quantity messages on a certain type on departure at light weights and minimal fuel for short flights.

I think 3800 kg is not a lot for a 787 on landing and perhaps they would have declared a PAN PAN anyways but here is an example of the fuel quantity guage indication possibly misleading the crew on even the most modern of aircraft. And I believe the newer types use sound waves which I suppose is more accurate, but obviously not as accurate as one might think. Maybe best to wait a minute or two for level flight and a more accurate indication.

"C-FNOG, a Boeing 787-9 aircraft operated by Air Canada, was conducting flight ACA859 from London/Heathrow (EGLL), UK to Toronto/Lester B. Pearson Intl (CYYZ), ON. During the final approach to CYYZ, ATC instructed the flight crew to perform a go-around due to traffic on the runway. Prior to the go-around, the fuel quantity was indicating 4800 kgs. However, with the increased pitch up during the climb, the fuel quantity was observed to display 3200 kgs. The flight crew declared a PAN PAN, and the aircraft returned to land without further incident with ARFF standing by. When the aircraft reached the gate at the terminal, the fuel quantity displayed 3800 kgs."

[goingnowherefast]

Every plane I've flown with reasonably accurate fuel gauges does this. Over-reads in descent and under reads in climb.

Comes with experience on type, sometimes all you need to do is wait till in level flight again, and the pucker factor lessens. I'd imagine the FMS has a fuel totalizer feature too, but that's not as easily seen.

Not going to criticize a crew for declaring a Pan Pan though. Fuel is a pretty important part of staying aloft.