I've always wondered why PMDG hadn't included numbers on the ND Compass rose that tilted with the arc. I've seen this on numerous other add-on aircraft. The other day, I discovered something that my eye has always missed in the PMDG menu - "Conformal magnetic heading digits". I said "Oh! Yes!", but my happiness was short lived - I was greeted by an FPS warning, and when I returned to the panel, my FPS were halved! I noticed the FPS warning in the manual, but I'm still not able to understand why it would have such an impact on FPS. I've seen this on numerous other add-ons which didn't seem to have much of an impact. Is this something specific to the 747 compass rose?Thanks in advance for any explanation :)Best Regards,Robin Bilgil

Robin,The gauge has to do a bunch of extra math to account for the tilted digits, that's why FPS drops...

"ND Compass rose that tilted with the arc"What's that mean? What does it look like?Paul

The compass ring is suspended in a liquid to dampen oscillation and it tilts when accelerated vertically or laterally. Turbulence will cause them to wobble, and there are errors in the magnetic heading when turning or changing speed. Flying on compass only takes some practice, and comparing the compass to the gyros is best done with straight, level and constant speed.

Thanks for that, but why was he mentioning the compas on the ND? I don't think that the ND would be prone to the same errors!!Paul

LOLSorry for the misunderstanding guys -I'm talking about the rotating "heading arc" or "compass rose" as it is called, on the navigation display:http://img77.imageshack.us/img77/4259/ndxa0.jpgAs seen in the picture, the numbers conform to the circular rose. In the PMDG 747, selecting this option reduces the FPS by about half - and hence my question, since I have seen this feature on aircraft almost as or just as complex as the 747 without an apparent FPS hit, and heck even the default FS Boeing 747-400 has it.Best Regards,Robin Bilgil

I put my two cents in not knowing the issue... sorry. The 737NG doesn't have this feature... and I never noticed it missing.