Hi, thanks for your prompt feedback.
You'll get the same result if you do MZFW (237) -DOW (200)= 37 t. That's all you get as a payload
But if you've got a large amount of fuel then it is possible that your upper limit will be less than the MZFW limit of (237). Thats why Box C helps in determining the allowed traffic load.
Using your example let's say you've got 37 t actual payload. The question here is can you uplift more fuel and so how much?
Yes you can uplift 3 more tons of fuel. In this case your ZFW will be 237 and your upper limit will be Box B of 270. Therefore max fuel can be 33 tons.
However fuel is not an issue as I already mentioned that Box C will change and go up with increase in fuel.
Firstly let's increase our payload by 8T. What is the Col C figure now? What is the 'controlling' ie lowest perf figure? There is no clue yet that we have exceeded our MZFW from this column.
There is a clue. As I mentioned earlier, when you increase the payload by 8T your TOW will become 268, exceeding the Box C by 1 ton. This is the clue that you have exceeded the Max ZFW Limit.
The figure does NOT change with payload increase
Thats what helps in getting the clue
Once you get the clue then you can verify it by claculating in any way and find that MZFW limit has been exceeded. Only this point makes me
assume that may be this was the reason that the expert who left the stand introduced the term "limit".
Much easier to ignore the word 'Limit'
on my end, no problem
