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V speeds isn't to low?


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Hey, so i was doing some researchs into the web founding some fcom's, and noticed (if i read correct and interpret correct) that the v speeds, even full loaded, was too low, like... i was taking off yesterday with 190.2 tons, and a vr o 128, i have xplane 11 and jar designs a330 i did the same takeoff to compare and my v1 starts at 135 knots, my vr 142, my v2 145, and i noticed that the vspeeds of jar was too close of the fcom's i found 

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So, many users are telling your team that the aircraft rotates too low... i takeoff again with 190.2 tons complaining with this fcom, my vspeed 149 154 162, my rotate wasn't late the aircraft response normaly like ever other airbus i've fly in my life

 

image.thumb.png.56575a0a54482b27a017c153b2648416.png       the metar was, 320/16, 30,60in, -1 degree in a runway at 13 feet 

Only to complete this is an lutfhansa fcom, the link of the excel is: https://forums.x-plane.org/index.php?/files/file/49658-a330-flex-temp-calculator-xlsx/ (yes it is in the xplane forum, but isn't related direct to the xplane, taking in count that is take of oficial fcom)

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V speeds are always related to the circumstances surrounding the airport concerned. It isn’t simply a matter of runway length/temperature/QNH/ac weight. Obstacles, ASDA, contamination, and several other things are also taken into account. However, the speeds you quote do seem a bit low. From FlySmart (Airbus official performance software), using LHR27R as the departure airport and your weather data, the speeds derived are 156/156/158, and Config 1+F is the demanded configuration. 
 

Edit; for contrast, using runway 27 at KBOS with the same data, but wet, the figures are 129/133/141 and Config 2. The differences are down to it being a short runway (7000’), with no overrun, and with significant obstacles (ie the city of Boston) in the net take off flight path. 

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8 hours ago, TimC340 said:

V speeds are always related to the circumstances surrounding the airport concerned. It isn’t simply a matter of runway length/temperature/QNH/ac weight. Obstacles, ASDA, contamination, and several other things are also taken into account. However, the speeds you quote do seem a bit low. From FlySmart (Airbus official performance software), using LHR27R as the departure airport and your weather data, the speeds derived are 156/156/158, and Config 1+F is the demanded configuration. 
 

Edit; for contrast, using runway 27 at KBOS with the same data, but wet, the figures are 129/133/141 and Config 2. The differences are down to it being a short runway (7000’), with no overrun, and with significant obstacles (ie the city of Boston) in the net take off flight path. 

So i agree 100% with u, the vspeeds aren't constants, there are thousand of variables that influence's on the v1,vr,v2. Let's speak only of flaps 1+f, this table could seems a bit low for the results of FlySmart, but the original speeds>fcom that I found>FlySmart. Certainly we can't say what calculation is wrong, but seems to me that our researchs is more efficiently that aerosoft data base's

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I have no idea what source Aerosoft has used for its performance calculations. FlySmart is Airbus’s own performance tool. It’s not available to the public - if it were, it would cost many, many thousands of £/€/$. It is the basis on which all of our aircraft get airborne every day. As a current A330/340 pilot, I use it on every flight and obviously have to rely on its accuracy - we do not carry paper performance charts.

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