One of the FS9 panels has just such a gauge. It indicates whether you're on standard or QNH.
Gerry Winskill FrankTurley@xxxxxxx wrote:
My brain woke up this morning with a wizzo idea to help decrepit pilots like me, why not a cockpit indicator which warned you that you were passing through the transistion level and need to reset the altitude gauge? I searched through the FSX variable list looking for something like transition level, but failed. I then had a quick hunt through the FSX events list, and found - Barometric - Syncs altimeter setting to sea level pressure, or 29.92 if above 18,000 feet. From that I assume that the transition level is hard wired into the code at 18,000 feet. OK for the USA I guess. Frank T.