PV> PV>> V1 speed may be choose between V1 mini and V1 maxi; and each
PV> PV>> airline choose high or low V1 for an airplane type.
I am not familiar with the option of each airline being able to choose 
between a V1 min and V1 max.  Here there is no such thing as high or low 
V1 for an airplane type.  I think we are both talking about the same 
thing and I honestly think that language interpretation is the key here.
PV> PV>> And, on a
PV> PV>> runway, if you can stop a 165 tons plane at V1=155 Kts, you can
PV> PV>> stop the same plane at 125 tons and 145 Kts, even the computed
PV> PV>> V1 is 140Kts
In the US this is the terms that I quoted to you earlier.  The term 
above here refers to the ability to stop an Airplane on the runway at a 
given weight with basically no other factors included.  No Runway 
limits, except slope, no ability to continue the T. O. etc.  We refer to 
that speed as Refusal Speed and refers only to the stopping ability of 
the airplane.
PV> JC> I'm not sure I fully understand your point but will try to
PV> JC> clarify. The definition of V1 is a "Speed to which you can
PV> JC> accelerate with both  engines operating to critical engine
PV> JC> failure speed and experience an engine failure and either
PV> JC> continue the takeoff or stop in the remaining distance".
And the key words here are "either continue the takeoff or stop in the 
remaining distance".  Not stopping alone but continue the take off as 
well.
PV>it's that.
PV>And, with actuals rules, we must have one V1.
This basically what I said at the beginning.
PV>But for a plane, a weight, a runway and day conditions we have a lot
PV>of speeds witch agree with the law, and we must choose only one
PV>speed.
An that's why in the US we choose V-1 as per the definition quoted above 
which gives us the option of either taking off or stopping in the 
remaining distance with an engine loss.  Now what I believe you are 
referring to is Refusal Speed to which we can accelerate to and stop the 
aircraft based on WT.  In the US and with US built aircraft this Speed V-
1 and balanced field length are the same and are the minimum allowed for 
certified operations hence the term "Balanced Field Length".  As the 
length of the R/W increases then you could in theory accelerate to a 
higher speed and stop (Refusal Speed) but with no aircraft malfunction 
it is a moot point as you would be airborne before that time.  Runway in 
excess of "Balanced Field Length" is what we call "Gravy"..(GBG)..
PV>And if you are below the runway weight limit, the higher V1 
PV>may be greater than
PV>the company choose. We can't know exactly it's value, but 
PV>we know higher weight
PV>V1 value. And I wrote that : if you can stop a 165 tons 
PV>plane at v1=155Kts, you
PV>can stop the same plane, at 125 tons at 145Kts, even the 
PV>choosen V1 is 140 Kts.
PV>Because we must choose a V1 among a lot of V1 that agree 
PV>the legal requirement.
Again apparently you are talking about the US term "Refusal Speed" 
(ability to stop only).  The "V-1 Speed" (ability to either stop or take 
off in remaining distance).
Believe me I understand what you are trying to say.....Jim.....
___
 X CMPQwk 1.4 #1684 X "You'll have to remove your Uniform and step back 
through".
--- Maximus/2 3.01
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