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Settle an argument

Old 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?


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Old 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?"
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Old 7th Jan 2008, 13:36
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toolowtoofast, as reported by NSEU, you need to give more info.
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.
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Old 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
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Old 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
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Old 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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