Originally Posted by Bumblebee
Using improved climb procedures, perhaps the 0-wind Vr may occur at the furthest point down the runway at which the climb gradient permits you to achieve the screen height, or meet other over-riding obstacle-clearance requirements?
Does it follow that with a tailwind, you might therefore need Vr to occur earlier along the runway for the same weight (a few knots less) to achieve the screen/obstacle clearance gradient required?
Bumblebee
Thanks for taking the time to help out here. I'm on paternity leave at the mo and don't have the AAs to hand, but certainly I think you're right when it comes to the more 'restrictive' airfields (the ones with a 5 or 6kt drop in Vr). And the bonkersly long unrestricted airfields which also have a drop in Vr (albeit only a couple of kts at these places) I guess I'm going to have to put down to the fine tuning of calculations
And a quick question for non 737 drivers - does this phenomenon happen with your aircraft Improved Climb performance tables as well?