Fuel Dump: Quantity lost

[tncmdream]

Hello,

I would simply like to know how is the fuel dump loss calculated?
In other words, the quantity of fuel loss per minute, or/and second.

Good day

[dusk2dawn]

The value for dump / min is stated in the a/c manual.

[Bullethead]

G'day tncmdream,

On the a/c I fly at the moment, B767, the fuel jettison rate is about 1200kgs per minute, but the strange thing is that you can only jettison from the centre tank and with full wing tanks and a normal zero fuel weight you will still be above max landing weight. So land anyhow if you have to.

The B747 has a much more involved jettison system and the jettison rate varies depending on how much fuel you have and where it is. IIRC the max rate is about 4000kgs per minute. So to jettison down to max landing weight could take nearly half an hour if you had full tanks.

The jettison systems are arranged so that you can't jettison all your fuel, a good idea, by limiting the tanks you can jettison from or having a standpipe in the tank/s so you can't jettison below that level.

Regards,
BH.

[westinghouse]

hi,

A330/A340 dumps from the innners aprox 1000kg/min excluding the fuel burn from the engines.
can be done at any altitude.

bye.

[ETOPS]

the max rate is about 4000kgs per minute

You actually get about 2000kg/min on average as the rate drops considerably during jettison. Figure on about 50 minutes to get down to 40 tonnes.....:hmm: