You can see clearly on the PFD the plane is trying to meet the Alt Constraints of the STAR very nicely. In this case however I was told to descent to 6000 but I did most of my descent in Managed mode and it was working just fine, a few issues with speed going up and down, but that will be fixed soon I guess. This is really promising stuff and I am sure the TOC and TOD markers will be in place soon.
Again here you can see the plane following down the Alt constraints in managed mode, I had the Platform alt for ILS capture as per the charts. Yes I had to do a little bit of intervention but this is truly amazing to see now.
Yeah, one thing I noticed with the speed going up and down is because the airspeed constraints in the STAR doesn’t seem to be assigned to each waypoints within it.
Let’s take this, for example:
WPT A = 220 kts
WPT B = blank
WPT C = 200 kts
WPT D = blank
WPT E = blank
WPT F = 180 kts.
In this case, what happens is that when the aircraft has WPT A as the next waypoint to navigate to, the aircraft is able to slow down to match that constraint. Once it has passed WPT A the next is WPT B, and since that waypoint doesn’t have any airspeed constraint, the aircraft thinks there’s no more constraints, so it speeds up to 250 kts (assuming we’re already under 10,000 ft) or whichever managed airspeed is set in the Descent phase. Once it passes WPT B and towards WPT C, it then detects there’s an airspeed constraint and start slowing down to match it again. And this behaviour seems to continue as long as the next upcoming waypoint has a constraint set, otherwise it goes back to whichever airspeed it was flying unconstrained.
So from where I’m sitting, there’s only two options in this case, either:
The Navdata constraints need to be updated for every waypoint inside the STAR. This would mean for the above example, the waypoints and their constraints should look like this:
WPT A = 220 kts
WPT B = 220 kts
WPT C = 200 kts
WPT D = 200 kts
WPT E = 200 kts
WPT F = 180 kts
This way, as long as there’s both altitude and airspeed constraints in every single waypoint within a STAR, the current system in the A32NX can just follow it accordingly. Or…
Add extra logic in the aircraft systems where if you entered a STAR with an airspeed constraint, it will keep the last constraint even after they have passed that waypoint. Even if there’s no constraint in the next waypoint until it detects another constraint and the aircraft can slow down to match it again.
Yes I agree, I am not sure if it is Nav Data or something else. I tried the same approach with the Toliss A319, same NavData cycle and this did not happen as I expected, but you never know. I wanted to check just in case. I guess it is something they will be working on.
But either way, it is really nice to see this happening now, and great achievement for FBW. I mean once this is in place we are well on the way to one of the best planes in MSFS getting even better.
Yes. This is not fully taken care of at the moment. With the default FMS, we had several issues regarding speed constraints. We tried some solutions, but non worked 100%. The situation right now is the best we can do until VNAV implementation.
I think VNAV isn’t really released yet in experimental, altitude constraints have been working on a basic level for a while now (the plane seems to do an idle descent instead for now ?).
Seeing their amazing work on LNAV, I’m definitely excited for when they’ll update VNAV. The task at hand seems incredibly complex though, so we’ll probably have to remain patient for now.
Yes , but in managed mode I have not yet seen it until now try to follow all the waypoint constraints down to the FAF. It did it at times, but would soon just go to whatever alt I had set in the FCU, now it seems to try and meet the constraints. Its definitely not finished, but it is getting there, and still amazing to see.
Ok I see, but it’s doing nothing different than what it was doing already as far as vertical navigation is concerned. What you see is not vnav, it’s a basic implementation of a step descent from altitude X to altitude Y. Proper vnav requires a quite complex code which is not yet public.
I have not seen it follow ALT constraints before from around FL210 all the way down to the Platform Alt without it going very wrong. That is the beginnings of, I am not saying it is the full thing and I never did.
But if the Airbus is in managed mode, at FL210 and I set 2400 in the FCU and it meets and descends all through the way points without my intervention which is all I was saying, then please tell me what other mode of Vertical Navigation that is called?
I am saying that is a nice thing to see, before managed mode dropped you like a brick, or the last time I tried it.
So the key thing is the beginnings of, as I said!
I know its not VANV in its full capacity, and when did it start to do this bit I was talking about. I have only seen this behaviour in the last week or so.
