Originally Posted by
testpanel
Hi all,
Just a question on a T/O in flex.
Do you have to adjust the V1/Vr speeds?
If so, why?
Thanks!
Yes, you may have to adjust the scheduled speeds (including V2 as well as V1 and Vr).
It depends on the particulars of your aircraft and the degree to which you are trying to optimise the performance from the specific runway.
Suppose, for example, your aircraft is constrained by V2min rather than any Vr-based considerations. You leave V2 set at V2min. But now the a/c is slower to accelerate (lower thrust). So a higher Vr may be required to ensure that the minimum V2 is achieved at the right height. This in turn may permit a higher V1 to be selected, if it was constrained by V1.