As I said in post 2 I have this problem now and again. I also have had the problem of the FMC changing the path on the VIC SID's on Rwy 4R out of LIPZ. If IRC then the jumping route stopped after I had entered all the required perf info. So maybe it lacks enough info to calc correctly.

I had this too, a couple of times, in the original release. Haven't seen it since HF2, though. To fix it I down-selected the waypoint at LSK 1 (LEGS page) and up-selected it right back, i.e. making the FMC re-calculate. Each time I saw it, this made it go away.

I saw it too; and I found that the reason was really due to the coincidence between the T/D and the waipoint displayed.. I think that always the T/D varies a little due to wind, ground speed or another factors, something like decimals of a mile, always; in every flight, even when you think the T/D is fixed on an specific position, it is varying a little, something not visible to our eyes; but, in this case, the waypoint was, by coincidence, located just in the middle of this small variance, forcing the T/D to move ahead and move after the waypoint; if that waypoint was not present, it should vary decimals of a mile too, but should not be noted by the pilot; Regards Marcelo Monteiro

I get this too, on every flight, using ASE or not in Europe and Oz.

Guys, This kind of thing is never going to be completely fixable - the calculations that determine the T/C and T/D points and even the magenta line itself are dynamic equations that are constantly changing. What happens here is that the value is flipping between two different equation solutions for the T/D position. We have video evidence from the real airplane that this sort of thing can actually happen - the magenta line flicks back and forth between two different turn prediction solutions, that kind of thing. These are not flawless systems, even in the real world - it's always an approximation of what the airplane will actually do. You have to realize too that the real thing has multiple dedicated computers/CPUs that do nothing but these types of predictions. We have to optimize our calculations so that it doesn't completely destroy the framerate - just the reality of the FSX/Windows environment.

I have seen this type of anomally many times in the RW. FMC software is not without "bugs" either !!More often than not, they are not really bugs at all but pure mathematical complications. Airlines are notified by Boeing with such issues regularly. Fred.

Good hear it is normal. And I saw FMC recalculating T/D frequently but this is a surprise which RW FMC does this, too.Well, as it is in my mind that FMC path is only for prediction purpose and crew is responsible for entire flight, it is okay :) But as RW computers improved, I believe NGX could be, too.

I have seen this too but i think it might have to do with ASE. When it happens i looked at the winddirection and it was in a loop or a dejavu changing things between 300-340/25m/s in a pattern. Might be a bad connection to FSX with ASE via Sim connect ? Just a thought if the wind has a role in this /Michael