airbus v speed determination
 

I found a very nice PDF file; Getting to grips with aircraft performance.

Please, go to

Getting to Grips With Aircraft Performance

to get the file.

If you go to page 199, looking at the first paragraph, line #3
says

"since v2 is assumed to be fixed,.....".

However, I do not see why the author suddenly assumes v2 as fixed.

any idea?

thanks in advance.

This document was published in Jan 2002. You took quite sometime to find it. Anyway now that you have it will give you good insight into what's it all about.
He is talking about increasing V2/Vs ratio. Since V2 is limited to a maximum value so cannot be increased so in a way fixed at max value and the increase in the ratio can only be affected by reducing Vs.

Thanks much.
I guess I was not desperate enough to read it early enough.
I thought V2 is still variable and the max value(becauese of V tire) is only the upper limit.

if the pdf file is still at hand....
 

please go to page 132

the author wrote:
"When CT is fixed and CF increases, it becomes interesting to decrease fuel consumption. Therefore, when CI decreases, Econ Mach decreases."

The above sentence sounds a bit awkward. I even looked up a dictionary for "interesting".

simyoke
This is due to translation from French. Interesting means necessary and sometimes they use the word important for significant.