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Old 20th Aug 2011, 11:58
  #59 (permalink)  
john_tullamarine
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When V1 = VR, in what cases it can be ASD limited ?

Anytime that ASD happens to be the limiting case. The point being made is that the various limitations are applied separately and whichever is limiting for the particular takeoff sets the RTOW.

If ASDA is not infinite, at least it is enough,.

Fair comment

I always thought that choosing "maximum V1" is done so that we have more chances to stop and stay on the ground rather than taking off.

Not necessarily .. and the other consideration is whether it is a good idea to make a non-limiting ASD situation limiting by pushing the V1 up as high as possible on the day.

Running to maximum V1 gets you to VR in the shortest distance which benefits the go case. Reducing to a low V1 pushes the TOD out for the benefit of a more relaxed ASD.

In some cases V1 is simply ridiculous.

If you have a lot of spare runway in front of you then, consistent with the data presented, you have the option of increasing V1 as you might see fit. Be wary of brake energy limits ...

The thinking is made before the event.

And that is the basis for risk managing SOPs.
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