Model Mach speed setting

[Red Eye]

I've been flying a F-100D by Kazunori Ito but it has a problem that it busts mach 1 at a low speed.

For example, at 25000 feet, it thinks mach is about 375 knots. It should be around 693 knots. It does scale the mach speed down as you increase altitude but it is very far off - almost by a factor of 2.

I've been through the air file (air edit), the configs and such but cannot find where I need to make the correction. I even looked into the guages and effects.

If someone can give me a clue what the variable may be named or where else to look, I'd appreciate it.

Thanks

[mgh]

The speed of sound is 601 kt at 25,000 ft - not 693 kt as you state.

Check www.tscm.com/mach-as.pdf for the correct values for Mach number and the conversion to to TAS and CAS (IAS).

[Red Eye]

Even if this is the case that the airspeed is a bit different, FS9 is activating the sonic boom effect, going to Mach 1.0 on the airspeed indicator much below that level.

I got my numbers from a java applet on the NASA web site where you input airspeed, altitude and it kicks back mach http://www.grc.nasa.gov/WWW/K-12/airplane/mach.html and I realize that other factors can cause the value to vary but it shouldn't be as far off as it is.

Thanks for the pointer to the PDF -- Interesting too.
Redeye