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Not following ascent/descent path


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15 minutes ago, Mathijs Kok said:

Not all airlines allow crew to change CI that easy, lol.

Of course not, money talks! But there is another factor, it's named delays...... or not.

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vor 15 Stunden , Mathijs Kok sagte:

You don't happen to know the cost index? That affects these things (not too much btw).

 

There will be a new build with rather big changes in how flight paths are followed next week. Its now in test (we did find two people who had issues that were reliably repeatable)

 

Will this new build solve the high ascent/descent rates in certain flight modes/phases?

br

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4 hours ago, Joan Alonso said:

I saw Dave's stream yesterday. I don' know if he was flying with the updated files on the A321, but even the big one of the family performed a terrific climb.

 

Yes, it was the latest (Beta) files.

 

To be honest, I've never experienced the climb/descent issue (under the release version or subsequent updates), but I can still see how the changes affected the performance and it was SPLENDID! 

 

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Funny enough, I was one of those users that read this thread thinking what the other users possibly do wrong. Until I used the A319 with CFM engines for the first time myself. All my flights so far with the A319 were with the IAE engines and I never had issues with climb or descent rates, this weekend I did a flight with the CFM variant and observed the same. Rocketing into the sky initially when activating VNAV (more than 6000ft/min). Then, later on, when Pro-ATC/x told me to initiate my descent at a rather ridiculous position (more than 200nm out of my destination), also descent rates with more than 5000ft/min, resulting in overspeed. While the latter was obviously bad piloting, the ridiculous high climb rates were not.

 

It seemed to me that those high climb rates were only due to the fact that I was levelling off at 6000ft, 250kts. Then, when I entered 20000ft as new altitude and pushed the button, the autopilot first increased the throttle to climb power, this resulted in a huge acceleration (as I was levelled off), then the autopilot initiated the climb and of course, with such a huge acceleration, the initial climb rate went up to 6000ft until there was negative acceleration. The autopilot then gradually reduced the V/S, undershoot a little bit but finally managed to maintain a reasonable climb rate.

 

Verdict: probably it is not related to the engine variant but to the level off. However, I think that those initial climb rates are slightly exaggerated, no? I hope the next patch will reduce this effect a little bit.

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  • Aerosoft

We do have an update pending that has shown to remove (or at least reduce) this effect for the users who suffer from it. It's part of the A320/A321 release (today) so we will take a day to get feedback from that before sending it to the  A318/A319.

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Personally, I think that the easiest way to fix this would be to turn around the logic: simply first let the Airbus initiate the climb and put a lag phase into the adjustment of the throttle setting. This would result in an instant negative acceleration preventing high climb rates until the throttle is increased and the engines spool up... But, if I give that "solution" a second thought, I am pretty sure that you already implemented it that way ;-)

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6 minutes ago, Mathijs Kok said:

We are pretty sure now the issue is in the prediction code. That seems to lead to different results on different machines.  The changes we now made are trying to prevent that.

 

Well, this is a good news!

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  • 3 weeks later...

I've also experienced problems with the vertical navigation logic (hereafter called VNAV) with the Pro series, having bought the family bundle about a week ago. Interestingly, I haven't seen any particularly abnormal climb performances, but the descent profile certainly needs a complete overhaul. I'm still enjoying the aircraft, because while awaiting a fix from Aerosoft, I use selected descent with VS which thanks to my many thousands of hours on different sim platforms (FSX, FSW, X-Plane and P3D) makes me hit the FAP/FAF every time.

 

I think the VNAV descent sets itself up for trouble mainly because it calculates the T/D wrong, too hot (close) to the airport/runway. My experience with the A3XX Pro is around 100-110 NM from RWY, which is too little and leads to vertical speeds in excess of 3,000 feet per minute. From a passenger comfort and safety point of view, it's unwise to chase aggressive descent profiles (> 3000 fpm for longer periods of time). In addition to getting too close to RWY, the aircraft also goes into panic mode when flying certain segments of a STAR, eg. the RIPAM 4M for RWY 19R at ENGM. This STAR has waypoints with ALT constraints 9000A. When flying the 320, I was at the GM432 at 9,000, then the aircraft panicked because the next WPT was BAVAD 5,000A, 9 NM away, resulting in a dive-descent at close to 6,000 fpm, an overshot (or undershot?) of the altitude, resulting in the aircraft starting to climb again in order to reach 5,000...

 

Generally speaking, and in my opinion (formed by flying a huge fleet of various aircraft), not many devs can write the code necessary for a fully realistic VNAV logic, and often it's the descent profile that seems to be the most difficult to get right. I will refrain from giving any examples, but they are prominent devs... My purpose with this post is to be constructive and to help Aerosoft, a fantastic developer/publisher, so you can solve this little problem once and for all. You've already got the most stunning sim creation of an Airbus I've ever seen, both exterior and interior with industry-leading 3D modelling and texturing. My advice for the vertical descent logic is as follows: Have the T/D 130-160 NM out, calculating vertical speeds between 100 and 3,000 fpm, with up to 4,000 possible (add drag visible on PFD) for a short period of time with airbrake deployed to regain profile in situations with strong tail wind component. Look at which constraints are more important than others, and don't forget to calculate/include time for the 10,000/250 overall constraint (and yes, the real aircraft will try to fix this on its own, pitching the nose up to shed speed). Have the aircraft at FAF altitude (ready for GS interception, as dialled in by the pilot) a couple of miles before rather than after the actual point.

 

Lastly, and once again in my opinion, the banking speed of the aircraft is a little too fast and abrupt. It needs to bank more slowly, adding to realism and immersion. And yes, banking more slowly means starting the turn a little earlier, both in and out of the arc.

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1 hour ago, parsec71 said:

I've also experienced problems with the vertical navigation logic (hereafter called VNAV) with the Pro series, having bought the family bundle about a week ago. Interestingly, I haven't seen any particularly abnormal climb performances, but the descent profile certainly needs a complete overhaul. I'm still enjoying the aircraft, because while awaiting a fix from Aerosoft, I use selected descent with VS which thanks to my many thousands of hours on different sim platforms (FSX, FSW, X-Plane and P3D) makes me hit the FAP/FAF every time.

 

I think the VNAV descent sets itself up for trouble mainly because it calculates the T/D wrong, too hot (close) to the airport/runway. My experience with the A3XX Pro is around 100-110 NM from RWY, which is too little and leads to vertical speeds in excess of 3,000 feet per minute. From a passenger comfort and safety point of view, it's unwise to chase aggressive descent profiles (> 3000 fpm for longer periods of time). In addition to getting too close to RWY, the aircraft also goes into panic mode when flying certain segments of a STAR, eg. the RIPAM 4M for RWY 19R at ENGM. This STAR has waypoints with ALT constraints 9000A. When flying the 320, I was at the GM432 at 9,000, then the aircraft panicked because the next WPT was BAVAD 5,000A, 9 NM away, resulting in a dive-descent at close to 6,000 fpm, an overshot (or undershot?) of the altitude, resulting in the aircraft starting to climb again in order to reach 5,000...

 

Generally speaking, and in my opinion (formed by flying a huge fleet of various aircraft), not many devs can write the code necessary for a fully realistic VNAV logic, and often it's the descent profile that seems to be the most difficult to get right. I will refrain from giving any examples, but they are prominent devs... My purpose with this post is to be constructive and to help Aerosoft, a fantastic developer/publisher, so you can solve this little problem once and for all. You've already got the most stunning sim creation of an Airbus I've ever seen, both exterior and interior with industry-leading 3D modelling and texturing. My advice for the vertical descent logic is as follows: Have the T/D 130-160 NM out, calculating vertical speeds between 100 and 3,000 fpm, with up to 4,000 possible (add drag visible on PFD) for a short period of time with airbrake deployed to regain profile in situations with strong tail wind component. Look at which constraints are more important than others, and don't forget to calculate/include time for the 10,000/250 overall constraint (and yes, the real aircraft will try to fix this on its own, pitching the nose up to shed speed). Have the aircraft at FAF altitude (ready for GS interception, as dialled in by the pilot) a couple of miles before rather than after the actual point.

 

Lastly, and once again in my opinion, the banking speed of the aircraft is a little too fast and abrupt. It needs to bank more slowly, adding to realism and immersion. And yes, banking more slowly means starting the turn a little earlier, both in and out of the arc.

 

We are aware and have already been working on these issues. Have you tried the experimental update?  It's available via the AS Updater.  More fine tuning to be done, but I think you'll be pleased with the update.

 

 

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Dave, hello

I am currently running on ver 1.2.1.0

My Updater is not indicating an experimental update that you allude to.

I gather it is yet to come.  For your information.

 

You guys are doing great work in this area.  Appreciated

Cheers

Jock

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11 minutes ago, Jockos said:

Dave, hello

I am currently running on ver 1.2.1.0

My Updater is not indicating an experimental update that you allude to.

I gather it is yet to come.  For your information.

 

You guys are doing great work in this area.  Appreciated

Cheers

Jock

 

Actually, I believe that is the correct update, I was out for the past few days and still catching up a little.

 

Even though we are still fine tuning (I was testing a potential change this afternoon), the version that you have should be a vast improvement with a highly stable VNAV Descent. Do me a favor, and if you haven't please use the Fuel Manager to create a fuel load for the aircraft, load that via MDCU#3, ensure that you have the ZFW and fuel entries filled in on the INIT Page 2, and update your winds prior to departure.  Then let me know how the VNAV worked for you.

 

Looking foward to hearing back from you.

 

Best wishes.

 

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