IAS - TAS correction

[jf1981]

Hi

I'm looking forward how to have TAS out of IAS. Based on manual informations or sharts, I have for example our ot 180 mph at 10,000 ft an estimated TAS of 210 mph.

This turns out to be quite underestimated. When I travel, I record times much less than expected for a given distance.

For example, I expected a little bit more than 10 minutes travelling time between Gatwick and Holam airfields at 180 IAS 10,000 ft. It took 8 minutes.

I can't see the true figure since the full screen mode does'nt show TAS either !

Any idea about this error ?

Regards

[Viper2000]

Wind?

[jf1981]

Originally Posted by Viper2000

Wind?

I'll do further trials to check this.

[Remo]

Originally Posted by jf1981

I'll do further trials to check this.

Try running the same route in both directions..

The average should cancel out wind (only roughly though)

[jf1981]

It's not wind. I get roughly same flight time in both directions at level namely Milestone-Gatwick 12 mins at boost 1 lb/sqft and 10,000 ft level, 190 IAS which is about 35 miles.

I guess my initial figure was quite wrong due to error in translation of IAS to TAS during climbing.

Must be my fault. I'll have to sort this out later.

Latest figure seems quite correct, I don't think there was a lot of wind on that map given they have simulated wind in the game.

Regards

[1.JaVA_Platypus]

180mph IAS on 10.000 Feet should be 216 Mph. But indeed, if you are descending or ascending, the TAS will be diffrent. And for Dead reckoning navigation, you should use Ground Speed. So wind direction and speed should be calculated as well.

TAS increases by 2% for every 1000 Feet. This is a rule of thumb wich can be used for speeds below 400km/h 248Mph or 216Kts.

When done properly, Dead reckonging can give immense satisfaction! If only we could get the level autopilot to work in COD....