The equation I've posted above didn't help much, especially since the default AP speed hold logic still relies on the "faulty" IAS indication and thus can hardly be synched with it.

 

I've therefor needed to scale the IAS indication, too.

 

 

[airspeed_indicators]
airspeed_indicator.0=0.96418733,1

 

In my test scenario (ISA, FL190), I now have a perfect match between target TAS (456) and the associated IAS (350).

The equation I've posted above didn't help much, especially since the default AP speed hold logic still relies on the "faulty" IAS indication and thus can hardly be synched with it.

 

I've therefor needed to scale the IAS indication, too.

[airspeed_indicators]
airspeed_indicator.0=0.96418733,1

In my test scenario (ISA, FL190), I now have a perfect match between target TAS (456) and the associated IAS (350).

ISA at FL190 SAT -23°c,  for an IAS of 350kt you should have a TAS of 470kt(Checked with my computers Jeppesen and Mercator)

ISA at FL190 SAT -23°c,  for an IAS of 350kt you should have a TAS of 470kt(Checked with my computers Jeppesen and Mercator)

 

350 KEAS - 471 KTAS

350 KCAS - 456 KTAS

 

(With: http://www.aerospaceweb.org/design/scripts/atmosphere/ )

 

I suppose that the instruments in a real aircraft display CAS?

No in a real aircraft we read the IAS. You all guys see things in a too much theoretical way. Perf charts always show IAS because it's a speed the aircraft "feels"(Normally there is a very small discrepancy between IAS and CAS around 1 to 2 kts)). Even at high altitude we use IAS in conjunction with Mach number to check accuracy between them and the performance charts(TAS vary according to temperature)and as a flight engineerDC8, DC10) it was my job among other things to check that. There is a chart, I've it , which gives the connection between IAS and Mach number for a given FL. This chart apply whatever the plane. We never use KEAS. If you don't have a flight computer you should buy one it worth the price, I use mines when I play FSX.

 

Regards

FSX isn't real life though and, at times, behaves fairly oddly.

 

My reference is this cruise chart, which, at FL330, associates 278 KIAS with 456 KTAS:

http://www.afva.net/gallery/afv/0x95a.jpg

 

Investing a few more seconds into the Wiki article on ASIs, I come to the conclusion that the discrepancy between instrument-indicated and FSX-indicated airspeed is most likely a (poor?) implementation of positioning error.

https://en.wikipedia.org/wiki/Position_error

 

Anyway, my ASI now works as it's supposed to and that's good.

Yes Bjoern! As you said FSX is not real life, it's a game, a very good game but with its limitations. But even with that limitations, as a former airman I trully enjoy it. I spent all my carrier flying big birds that's why I enjoy now virtually flying Do-27, An-2, twins like Cheyenne or Duke...I did a lot of real simulator too and trust me FSX is not so bad :wink: .

 

Cheers