I want to be able to calculate accurate V speeds based on weight, weather conditions, etc....Is there a program that will help or does anyone know how to do it manually? Any help is greatly appreciated!!!

Hello nigel,It would help to know what aircraft you are refering to ,as every plane is different?Most payware aircraft now have in depth manuals including speed charts, and also you may be able to find some speed charts for some of the freeware models here at Avsim. On another note you would want to add half the wind component to your calculated V Speeds. For example say you have a calculated VR speed of 128 with a headwind of 10kts you would then add 5kts to your VR speed making it 133.Hope some of this helps.CyberSimmer

where did you find that information?? is there an online resource where I can learn that?? what about a 45 degree crosswind?? How would I know how much of a component to use for that??The main aircraft I fly in FSX is the default lear 45 and the Cessna Caravan so I would be looking to use those as an example.

>where did you find that information?? is there an online>resource where I can learn that?? what about a 45 degree>crosswind?? How would I know how much of a component to use>for that??>>The main aircraft I fly in FSX is the default lear 45 and the>Cessna Caravan so I would be looking to use those as an>example. Srry I cant provide you with a direct link for the information you require. Best I can suggest is that you do a search in the Avsim File Library under miscellaneous ,and or Utilities for each aircraft you fly. Also it should not matter under what Flight Sim version you search under as any speed charts would apply to all Flight Sims!I do know that some good fellows have provided us with some aircraft manuals here at Avsim just gotta do some searching:)As far as the crosswind Vspeed goes: the same rule would apply.Regards,CyberSimmer

thanks for your help. I have doen some searching with little luck. As Joe Dirt would say, I will keep on keeping on!!

For example say you have a>calculated VR speed of 128 with a headwind of 10kts you would>then add 5kts to your VR speed making it 133.>>Hope some of this helps.>>CyberSimmerSay what? Why would headwind change your Vr speed? You generally may add half the gust speed if there is a gust. Is that what you mean?Manny

Nigel,Search the Avsim library using my last name. You'll find documents that will help you determine "generic V-Speeds". In real-life, airlines have takeoff charts / calculations for specific airports and runways that take into consideration numerous factors such as elevation, obstacles, runway slope, runway length, etc. Though hard to read, I have an example of such a chart in my A300 performance pdf showing the specific v-speeds to use when departing runway 15L at Toulouse.Hope this helps.Matt Zagoren

cool, thanks for the suggestion. I will see what I can find. The way you detailed it is how I wanted to do it but, generic will work fine too. I just get tired of guessing and pulling back on the stick only to find nothing happens...then the aircraft leaps into the air and I climb out at 4000 fpm!! Does anyone know if there is a flight calculator or anything that will handle this task?? I bought the aerosoft flight calc but, it doesnt do takeoff or landing data.

>I want to be able to calculate accurate V speeds based on>weight, weather conditions, etc....Is there a program that>will help or does anyone know how to do it manually? Any help>is greatly appreciated!!!Vertical speed = ((Thrust - Drag) * (True air speed)) / WeightorVertical speed = (excess power required for level flight) / WeightHowever there are some slight differences between propeller and jet aircraft.This website might be of interest to you.http://www.luizmonteiro.com/Index.htm

actually, I was looking for V1 Vr V2 Vref etc...not vertical speed...however, that site is great for many different types of calculations.

The V speeds are constants, based on equations derived from basic performance characteristics of each aircraft in question. I'm not in front of my simming rig right now, but EVERY FS aircraft has the v-speeds shown somewhere - ususally on the kneeboard, if not there then in the aircraft information in the Learning Centre.For more accurate calculations you need the actual charts and graphs for the aircraft in question - and a hope that the FS flight model is close to realistic. Most aren't.Allcott

even if there were such a program, it would be illegal to use :-) the first source for v-speed look-up is the POH. it usually is the last source, too, being the only source. insurance companies tend to take precedence over physics research in this world :-)get the POHv-speeds are also marked on the airspeed indicator. those that are not can be figured by interpolation, using the time-hallowed "just-about-so" method ;-)

Nigel,I think its in here.V speeds are factors multiplied by the stall speed which is a function of weight and configuration:http://perso.orange.fr/hsors/FS_Soft/aerolinks.htmlIan

Too true. Stall speeds are determined by practice during the test phase when the plane is "in Beta" ;-)In fact, I even consider trim values, V speeds and maneuver speeds as well as limit speeds to be by far the most important numbers of all (right after the values of necessary fuel on board ;-) ). Then for me come the numbers for the engine (e.g. EGT, max temps,...), then pressurization parameters (aircraft at FL360 don't fly well with dead personnel on board ;-) ).And here's where the gaming crowd gets separated from the "real simmers": in real life, I wouldn't even think of moving any plane without having trim, V speed and maneuver speed tables ready at hand. And because the gaming sector is the bigger one in FS, the major part of planes has no such tables available, even many add-on developers never publish them.The numbers are strictly individual to every single airplane type, and often hard to find, and more often badly simulated in FS (if at all).Andreas