[danimalhanke]

When talking about TAS and IAS EVERYTHING is related to how many miles/kilometers you are travelling across the ground. (BTW today's lesson is free as I am a Certified Filght Instructor) Standard conversion charts will not be usable when flying because many different factors come into play when determining TAS. Things like density altitude, wind speed and heading etc. You CANNOT simply apply a standardrized conversion with so many variables. It is why pilots carry their trusty flight computer with them whenever they fly. So, if you do not know the density altitude, the wind speed and heading, performance curves for the particular acft you're flying then give up because it will NEVER come out right!!!!! One example: You're flying your 1964 Cessna 172 (which I own) at 91 knots into a head wind of 70 knots at a heading of 0 degrees and your density altitude is 29.92 then your TAS is 21 knots. See what I mean?
If you want more detailed explainations then simply google IAS vs TAS.

Indicated airspeed will differ from true airspeed at air densities other than some reference density. Air density is affected by temperature, moisture content, and altitude. Indicated airspeed is used in aircraft operation as the aircraft stalling speed and structural limiting speeds are dependent on indicated airspeed, irrespective of true airspeed. However, proper navigation via dead reckoning (without constant ground reference) requires the use of true airspeed and wind corrections.

Rules of thumb to estimating your TAS.
http://www.flightsimaviation.com/rule-o ... d_TAS.html

One more to show the futility of what you're attempting to do. At least you're trying! :lol:
http://www.auf.asn.au/groundschool/umodule2.html