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# Settle an argument

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# Settle an argument

7th Jan 2008, 06:16

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Settle an argument

Help me settle an argument please....

What would V1 and Vr be on an empty B777 on an ISA standard day?

Thanks.......

http://www.tv3.co.nz/Video/Motorspor...ID=43036#video
7th Jan 2008, 09:31

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What's the argument?

V speeds are based on lots of different factors. It's like asking "How long is a piece of string?"
7th Jan 2008, 13:36

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You will need to state from where, what runway and if you are going to "D" rate or not and by what.
I might still have missed something as l not from the pointed end.
7th Jan 2008, 14:12

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Not a Boeing man (yet) so I don't have accurate figures but an empty a/c at sea level on a standard day, assuming you don't have runway length/terrain/obstruction problems will be limited to the min speeds based on a percentage of Vmcg/Vmca (Min Vr is 1.05 Vmca etc.)
Figures I see vary from 112 Kts to 130 Kts depending on type, 772-773ER.

Confused? ....... I am
7th Jan 2008, 15:49

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further complicated by the fact that Vr on the classic 300 is also determined by tail clearance. This means that on a non-limiting runway, when V2 is optimised, then Vr is also increased to increase the available wt.
Also true on the 300-er but to a much lesser degree because of the semi-levered gear and the electronic tail-bumper, which decrease Vr by about 10kts for the same wt. or about 10 extra tons in a limited case for the same Vr.
In a light 200 (220t) 22 c non limiting runway flap 5 with V2 optimising
V1 145
Vr 146
V2 150
but the permentations are great
Vr/V2 ratio higher in the 300
7th Jan 2008, 19:51

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I was selling a car...

Someone said, 'How many miles has it got?'

'How many would you like it to have?'

(A bit like V-speeds on a big jet on a long runway...)

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