If you like puzzles, this may interest you:My Wife at the moment is on US Airways flight 391 from KCLT to KLAS, an Airbus 321.I decided to duplicate the flight with FS2004 simulation and fly along with her from the data displayed by the FlightAware site: http://flightaware.com/live/flight/AWE391I selected the PSS/IFDG Airbus 321. I set my takeoff time to match her real time. I also matched the flight path of flight 391 as closely as possible. I was unable to find the waypoints for the Zaver One Departure (SID) in FSNav, FSC, or the FMC, so I interprelated the SID as closely as possible. All on route waypoints are the same, as well as the TYSSN TWO Arrival (STAR) within 20 miles of arrival into KLAS (not there yet, so that is academic to the observation so far.)Now the observation. 1. I have flown for about 3 and 1/2 hours with a bit over 1 hour to go.2. I show that I have 508 miles to go, FlightAware shows that my wife has 503 miles to go, so I know our speeds are virtually the same.3. My FS2004 true airspeed on my panel gauge reads 457 knots, FlightAware scheduled speed is 462 knots, (assumed tp be TAS with no wind), again pretty well close enough.4. However, on my panel my IAS is 290 knots pretty much as expected, but, Ground Speed is 408 knots.5. FlightAware data says actual speed is 368 knots (Assumed to be the ground speed of flight 391).If this assumption is correct, something is not telling the truth, as there is a 40 knot difference between my panel indicated ground speed, and that of FlightAware data. Yet the real time distance to go after 3 and 1/2 hours shows that the real ground speed between the two is just about on the money.How about that? Any idieas?Respectfully:RTH

Weather.. the winds aloft gives you other GS and so then what you have in FS, FS weather may be close, but cannot be exact as in real life.

Flight aware mat not be showing accurate speeds.

Flight aware mat not be showing accurate speeds.

Yea, thats probably it. Over the years, I've seen some strange readings from flightaware.