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porcupine1
11-23-2004, 11:23 PM
does anyone know the formula/equation to figure Tas by useing Ias and alititude?
I know there is a chart but it is in meters, I am wondering about the actual math behind it
Thanks in advance.

porcupine1
11-23-2004, 11:23 PM
does anyone know the formula/equation to figure Tas by useing Ias and alititude?
I know there is a chart but it is in meters, I am wondering about the actual math behind it
Thanks in advance.

Stanger_361st
11-23-2004, 11:31 PM
Tas=IAS plus 2% for every thousand feet.
I believe this will work. This is for imperial.

WUAF_Badsight
11-23-2004, 11:48 PM
http://www.csgnetwork.com/tasinfocalc.html

porcupine1
11-24-2004, 12:22 AM
Spot on guys!!
thanks a bunch

VR_Cutter
11-24-2004, 06:34 AM
I have detailed IAS/TAS charts in both meters and feet. If anyone would like a copy just message me.

Bearcat99
11-24-2004, 06:46 AM
Go to the Essentials thread... I added a link to a conversion utility thanks to the 310th VFS.

TacticalYak3
11-24-2004, 09:55 AM
If you have FB there's a chart on one of the discs that you can print off.

mortoma
11-24-2004, 10:14 AM
The normal shortcut message will only get you close, but for all practical purposes close enough in th game. But the 'real' method takes into account your current density altitude, which can make a difference sometimes. I guess in the game we'll just consider everything is in standard conditions??

effte
11-25-2004, 07:06 AM
And here's the full version (http://www.nar-associates.com/technical-flying/airspeed/airspeed_wide.pdf), seems right from a quick read-through.

Rules of thumb, such as the 2% one mentioned above and apparently used for the Java calculator, are just that and will not provide absolutely correct results, although most of the time usable ones... but not always even the latter.

Not_Cheating
11-25-2004, 07:40 AM
For an easy IAS to TAS conversion that is pretty close take your IAS and add 1/2 of your flight level. this is for feet. If you are at 12,000 feet, this is flight level 120. If you are at 33,000 feet this is FL330. If you are going 250 KIAS at 18,000 feet add 1/2 of your flight level to your indicated airspeed or 1/2 of FL 180 = 90. 250+90=340 KTAS. 6000 feet is FL060. 1/2 of 60 is 30 + your indicated= your TAS! This is what we use in the Air National Guard KC-135.

Tocca4
11-25-2004, 12:05 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Not_Cheating:
For an easy IAS to TAS conversion that is pretty close take your IAS and add 1/2 of your flight level. this is for feet. If you are at 12,000 feet, this is flight level 120. If you are at 33,000 feet this is FL330. If you are going 250 KIAS at 18,000 feet add 1/2 of your flight level to your indicated airspeed or 1/2 of FL 180 = 90. 250+90=340 KTAS. 6000 feet is FL060. 1/2 of 60 is 30 + your indicated= your TAS! This is what we use in the Air National Guard KC-135. <HR></BLOCKQUOTE>

I don't really understand. With this method, the only thing you can calculate is the TAS when you're doing 250KIAS...or?
250+(1/2 of 180)=340
but going at 500KIAS
500+(1/2 of 180)=590 which is far from correct!

Or am i misunderstanding something?

TacticalYak3
11-25-2004, 12:30 PM
psst . . . just print the chart, keep it handy, try to fly at a pre-determined height and distance, make slight modifications if necessary . . . bombs away!

Fliger747
11-25-2004, 03:05 PM
About the only time this will be of interest is if you are test flying or navigating by deduced reconing. The airplane always stalls and is limited and flown by indicated airspeed, as wimpy as it seems at altitude.

Go down to the local pilot shop (if there is one) and get a wizzwheel, great for all of those convesions and usually has a small 'plotter' on the back to help find the 'boat'.

The atmosphere (standard conditions) halves it's pressure about every 18,000 ft. Towards the poles conditions are very non-standard and this changes a lot! Almost none of these complications are modeled in the sim.

JimmyGiro
11-25-2004, 05:44 PM
Try this:

TAS = IAS(Alt./15250)+IAS

VF15_Muto
11-25-2004, 10:41 PM
The precise real-world equations are:

TAS = (IAS * (Alt/1000 * ADAF)) + IAS
IAS = TAS / (((Alt/1000) * ADAF) + 1)

where ADAF = Air Density Adjustment Factor

Air Density is a function of temperature, pressure and relative humidity and the ADAF will change as those factors change, but none of this is modeled in IL2/PF.

Air Density is modeled in CFS2, with the default (i.e. no temperature or dewpoint info in the mission file) Air Density curve following International Standard Atmosphere parameters. Put hot and humid conditions in your CFS2 mission, and your TAS can change by 5% for a given IAS versus the ISA standard day, which, for a 2-hour flight over open water, can put you off course by 20 nautical miles at 200 knots.

Which, if realism is your concern, could make all the difference between a successful mission and complete disaster in the Pacific.

S~!
VF15_Muto

Fliger747
11-25-2004, 10:55 PM
For those who do care about NAVIGATION, go see the VF-15 site, some good information!

Since the game here seems to have everything in True North and no lat/long, (and a few other things) some steps are simplified.