Guys, and gals.With the default 737, I see three speeds:IAS, which we all know about,GS, on the Garmin which is cool too.....,....but what's the speed on the compass area meant to indicate?Let me be more specific.I'm humming along towards my local, thinking it's hard to believe pilots get paid for this lark, and when approaching the ILS I switch from GPS to NAV.IAS is 250, and the speed on the compass is the same as the speed on the GPS (242).When I flick to NAV, the speed on the compass ( can't think of the tech name right now )changes from 242 to 421kts.What is the 421kts meant to be? What does this speed indicate??Look forward to words of wisdom.And yes, I know why pilots get paid what they do, so no jumping down my throat please!!CheersTim

I haven't messed with the default 737, but I'm guessing it's a DME readout. You can get your GS from a DME station, but it only works when flying directly to or from the station. If you're not flying direct to or from the station, it will not display an accurate speed.