LNAV with SU2 still pretty wormy

[Guest Bill Kingsford]

I noticed that the FMS in SU2 still can't track a course centerline. Rather, the FMS flies the great circle route between waypoints and acculumates cross track error depending on the distance from the programmed waypoint. I find that LNAV course intercepts are still VERY rough unless you baby the aircraft to within at least .5 miles of the course centerline on an intercept of :)The flight dynammics model is really nice though, a lot has been accomplished here, nice pitch control especially. I now have enough directional control and rudder effectiveness to make decent crosswind landings too, that's wonderful! In SU1 it was near impossible to land and roll out on the centerline with significant crosswind.-Bill Kingsford"The Kingsford Edge"

[rsrandazzo 6,353]

Bill-What you are seeing here is actually a difference between what is calculated for the route centerline- and what is drawn...We have a rather significant calculation system for the route the airplane flies- but the route path being drawn is using a more simplified set of mathematics (The AFDS and the FMC path calculations are not entirely conincident and use slightly different methodologies still...) We are moving in that direction, however- and we felt that it was important to include the rounded corners, holds, etc- even if you might see some discrepencies in the track centerline...If we draw/fly all the courses as a simple plumb-line between the two points- it's very easy to keep the airplane on centerline- but it is not very pretty nor does it lend itself to later acuracy enhancements we have coming...So stay tuned... lots of stuff we're still discovering how to do!In the mean time, those curves and holds look pretty good, eh? Lots work whent into that mix...

[Guest Bill Kingsford]

Hi Robert,Yes, I have to admit that the holds are done beautifully, no other add-on can even come close to the PMDG 737 in this regard. I understand that this is a very complex issue though and I think it's great how you guys continue to research and develop this technology further.The visual model is beautiful as are the new flight dynamics, both works of art in of themselves. All in all it's an amazing accomplishment and I enjoy it very much. Happy Holidays!-Bill Kingsford"The Kingsford Edge"