On Thursday 20 January 2005 20:16, Andy Ross wrote: > Lee Elliott wrote: > > I don't think it quite reaches it's altitude performance yet > > (I've been thinking about a PR version sometime). However, > > I once got the YF-23 > 200,000 ft (and still climbing at a > > fair lick). > > YASim's atmosphere model table stops at FL620. It doesn't try > to extrapolate and just clamps the air density outside that > range, so you were cheating badly by getting to that altitude. > :) > > Andy
Ta for that. IIRC the reduction in rate of climb did seem to level out at some point - at FL620 it would seem. Although I don't know the YF-23's max ceiling I'd expect it to be > 62,000 ft so perhaps this problem with the fdm isn't quite as bad as I thought it was. At the time I was using a 'mach-climb' hold AP function. Basically, this tries to get the max rate of climb while maintaining a set mach speed by increasing the target rate of climb when the target mach is exceeded in a sort of feed-back loop. It seems to work well if it's engaged while the a/c is below the target mach but it's not so good if the a/c is already travelling at the target mach. Something to look into some day... LeeE _______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
