Aircraft Weights (Zero-Fuel etc)

[pcoltas]

This is really confusing me.

If an Aircraft has an empty weight of 12 tonnes and a zero fuel weight of 17 tonnes, what is the max payload it can carry?

I would say 5 tonnes, zero fuel weight - empty weight. Is this right?

Then it says the maximum take off weight is 21 tonnes. So does this mean that the maximum fuel weight is 21-17 = 4 tonnes?

Because the question says calculate the lift generate by the aircraft in kN after the aircraft has used 22,000lbs of fuel.

But 22,000lbs = 10 (metric) tonnes? How can it use this if the max fuel weight is 4 tonnes?

Its probably just me misinterpreting something but any help would be greatly appreciated

Thanks in advance

[Alex Whittingham]

Answered on Tech Log, where you put the duplicate post.