Bealzebub - my fault! I should have specified that the '1000kg' was for a 737 - roughly 6 times around!
I suspect the 747 fleets have their 'it is nice to have 5,000kg extra' people too
The problem is, Lou, where does one stop? Is '1000kg extra' (since it is a figure which in the example I quoted was plucked from thin air with no logic) - ENOUGH for a 737 or should he perhaps have taken 3000kg............. Not long before we have return fuel, perf permitting