David Megginson wrote: > According to the YASim config file, it has the pilot and a passenger > at 180lb each, and something labelled "cockpit" (baggage?) at 200lb. > Both fuel tanks are full.
The "cockpit" ballast that you see is intended to represent the panel, control column, instruments, seats, etc... Basically, everything that isn't part of the airframe. The tail of the plane is a hollow tube, but the front has stuff in it. If you leave the mass distribution as-is, YASim will weight all sections of the fuselage equally and you'll have a tail-heavy plane that flips backwards on its gear. :) Is it really 200 pounds? Dunno. I just fiddled with it until the c.g. behavior looked right, as measured by "does the plane sit nicely on its gear"? The mass distribution computation needs some tuning; other things that are currently wrongish: + The fuselage is assumed to be a straight tube, despite the fact that all meaningful ones are fatter (i.e. heavier) in the middle. + The "wing" objects (including the tail) are given weight distributions proportional to their areas. The main wing is thicker than the tail surfaces, but typically not by the n^8 rule you'd get if it was shrunk to the tail size. So tail weights tend to be overstated, and the plane ends up tail-heavy again. On all the current models, I've fixed the c.g. issues by fiddling with ballast. It would be nice to have a "mass compiler" that did something closer to the Right Thing from the beggining. As far as the tanks go, there is a "/yasim/fuel-fraction" property that you can use to diddle the amount of fuel at startup. The 172 won't notice, but the other aircraft (especially the 747) feel very different with full fuel vs. empty tanks. Andy -- Andrew J. Ross NextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com "Men go crazy in conflagrations. They only get better one by one." - Sting (misquoted) _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
