I agree with what Jon has said--the pitch angle with the aircraft on the ground should be 5 degrees. If this is modeled, I don't think there's any other significant issue.
With regards to the pitch angle at cruise, I simply cannot see how you'd ever model that exactly. First of all, it is dependent upon several things: Airspeed, density altitude, aircraft loading and the general rigging of the aircraft, just to name a few. I have flown two nearly identical aircraft (both 172's) and can tell you that they each fly slightly differently--and the picture out the window is not exactly the same in both aircraft. Certainly the horizon intersects the side of the cowling (from the pilot's perspective) at about the same spot, but it isn't exact. And without looking at the XML properties for the 172P I cannot say; but where is the CG located for the current emulation? Is the aircraft modeled at maximum gross weight, or with only the pilot--and how heavy is the pilot? I am not trying to say that the picture out the window changes drastically with variations in loading, but it certainly *does* change somewhat. But more importantly however is that the control force required to maintain flight stability changes, as does the trim requiring to relieve those control forces. But if the emulation can be loaded in similar fashion to the real aircraft, with similar results (airspeed and power settings), then I submit that it's probably as close as you're ever going to get. The point here is that I do not believe there is any ONE right answer. If the emulation "flies" like the actual aircraft, then all is good. For example, if full throttle in the emulation gives the same approximate airspeed as in the real aircraft (about 115-120 knots, if memory serves); if a power setting of about 1900-2000rpm allows one to maintain an altitude of about 1500-2000 feet MSL at 90 knots; and if 1500-1600 RPM allows me to fly a 3-degree glideslope at about 90 knots with 10 degrees of flaps...then all is good. How much better can it get? (Having said this, I do think that the default 172P model in FG needs property value tweaks to increase realism; but that cannot be done to an accurate degree until a proper set of 3-axis flight controls are configured to the emulation. A joystick is simply not accurate enough to make the kinds of hair-splitting determinations we're talking about here, IMHO.) Incidentally, I did make contact with a friend that is sending me a copy of the entire set of drawings included in the 172P service manual. If they are of value and are of good quality, I will gladly scan them and post them for review. TB ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
