Aircraft Doesn't Follow FP/Route, Only Flies Straight North

[kgaviation]

Mod Version

Describe the bug Upon engaging the AP after takeoff, the aircraft turns to a heading of 360 degrees and flies straight north. It doesn't follow the route or FP I created in the flight planning menu and ignores all other waypoints/fixes.

To Reproduce

1. Created IFR flight plan from KMCO-KLAS
2. Started cold and dark from the gate
3. After takeoff, engage the autopilot and let the aircraft climb to FL360 and follow the route/flight plan

Expected behavior

Aircraft should follow the route/flight plan and not just fly straight north and fly off course

Actual behavior

Started cold and dark from the gate at KMCO. After taking off, I engaged the AP, but it banked to the right and proceeded to fly on a straight north heading and did not follow the route I created or any waypoints/fixes.

References

Additional context

Was this working before/when did the issue start occurring? Yes, it worked correctly until the latest sim update on March 9.

Is this a problem in the vanilla unmodded game? No. I tried a flight in the default A320 and it did not have this problem.

Discord username (if different from GitHub):

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[iiTzHyper]

AP not following Flight Plan (leaking input value affect, but don’t disconnect the AP)

Workaround: Set dead-zones for your input device higher.

[Paytheon]

I have this problem but noticed the PERF page was still set on "TAKE OFF" and never advanced to "CLIMB". Do you know if your PERF advanced to the next stage of flight? If not I belive this fix that is coming soon will fix your problem: https://github.com/flybywiresim/a32nx/pull/3924.

[Benjozork]

I have a promising fix for this. Will make a PR tomorrow.

[LordNecton]

Nice one..Looking forward to this :)

[clintonhankyau]

Same issue here, after inserting MCDU FPLN, plane just flies North once clicked on NAV

[clintonhankyau]

I have this problem but noticed the PERF page was still set on "TAKE OFF" and never advanced to "CLIMB". Do you know if your PERF advanced to the next stage of flight? If not I belive this fix that is coming soon will fix your problem: #3924.

Same issue here as well, PERF page stayed on "Take Off" and did not switch to "CLIMB"

[salzsalz]

I opened in issue and closed it. At takeoff, you need to use man flx / toga to takeoff, after takeoff lever back to clb and it switches to clb phase and follows the FP.

https://github.com/flybywiresim/a32nx/issues/3896

[LordNecton]

It must still be a bug tho right?? or does the real life version just turn and keep to a 360 heading unless you lever back to climb?

[clintonhankyau]

I opened in issue and closed it. At takeoff, you need to use man flx / toga to takeoff, after takeoff lever back to clb and it switches to clb phase and follows the FP.

3896

Thanks, just tried this workaround, worked flawlessly.

[kgaviation]

So I tested this issue again multiple times today and I noticed that the issue still persists. Yes, I even tried the workaround mentioned above, but is this issue still being fixed?

[Benjozork]

 but is this issue still being fixed?

Yes.

[Phantomflyer81]

I doubt this is a bug. The MCDU has to be out of take-off phase into climb. Set your flex temp (anywhere from 50 to 54) and use flex to climb. When you retract flaps and LG, pull the throttle back to CLB notch and use managed climb. Set your Managed heading (turns on NAV) but make sure you turn the plane to intercept the 1st waypoint at a decent angle (30 degrees max). It should navigate without input. Leave it and see. I just left RJAA for WSSS and the departure took me out 180 degrees from the 1st waypoint. I used flex 52 and flex throttle until I cleaned up (no AP yet) the flaps and LG, and throttling back to CLB meanwhile I was hand turning 180 degrees toward the 1st waypoint. Then I turned on the AP and used managed heading... worked a treat. Getting into Changi was perfect. Approach phase activated and confirmed - almost landed itself (not quite yet :) ).

[tomola2]

Click "LOC" - the plane will fly the normal path :)

[kgaviation]

I doubt this is a bug. The MCDU has to be out of take-off phase into climb. Set your flex temp (anywhere from 50 to 54) and use flex to climb. When you retract flaps and LG, pull the throttle back to CLB notch and use managed climb. Set your Managed heading (turns on NAV) but make sure you turn the plane to intercept the 1st waypoint at a decent angle (30 degrees max). It should navigate without input. Leave it and see. I just left RJAA for WSSS and the departure took me out 180 degrees from the 1st waypoint. I used flex 52 and flex throttle until I cleaned up (no AP yet) the flaps and LG, and throttling back to CLB meanwhile I was hand turning 180 degrees toward the 1st waypoint. Then I turned on the AP and used managed heading... worked a treat. Getting into Changi was perfect. Approach phase activated and confirmed - almost landed itself (not quite yet :) ).

Still, this was never an issue before the sim update. I’ve flown countless flights using the mod (dev version) and never once came across this issue ever. Something definitely changed or is different than it was before the sim update and others on the MFS forum have also noticed it.

[Benjozork]

Something being different does not mean it's a bug, just saying.

[kgaviation]

So I hear that "Yes" - it's still being fixed. Now its normal behavior and not a bug. Which one is it? Is it a bug that's being fixed or is that how it flies now? Maybe it wasn't right before the update, but ever since I've used the mod (several months), I've never experienced this issue. Why all of a sudden is it being "corrected" then?

[Phantomflyer81]

Have you got a screenshot of the panel and MCDU right after take off so I can see what phase of flight you are in?

[Phantomflyer81]

So I hear that "Yes" - it's still being fixed. Now its normal behavior and not a bug. Which one is it? Is it a bug that's being fixed or is that how it flies now? Maybe it wasn't right before the update, but ever since I've used the mod (several months), I've never experienced this issue. Why all of a sudden is it being "corrected" then?

This is how the real world a32neo nav works. The MCDU HAS to be se up properly, otherwise you're not going to get transition into the next phase (take-off>climb>crz>desc>approach). I use flex temp of around 52 degrees at take off and use FLEX throttle position. As soon as I'm cleaned up, I pull the throttle back to CLB then I engage the AP, check my intercept angle to next waypoint and adjust to intercept manually, then when I see it's a going to be a good intercept, I engage Managed Heading (this is NAV) and the MCDU takes over beautifully. FYI, another change is max mach of .82. it's no longer .85. This is correct for the NEO. Also note that any Navigation freq other than Communications need to be inserted into the MCDU nav/rad button - I had to search for charts to find WSSS 02L ILS freq and Course. Put the course above the ILS freq, then just insert the ILS freq (no course before) and it will accept it. You can add NDB's and VOR's too without courses. Everyone is doing a great job on this bird - it's my favourite aircraft being so realistic. To get something similar, one would need to buy from noted developers.

[kgaviation]

I noticed today I was in TAKEOFF phase and then it switched to CLB and followed the FP. Also, sorry to sound dumb, but how do you know what FLX setting to use? Does it matter, like in terms of thrust? Lastly, a side topic, but I'm still having the bug where I can't disable the master caution warning light. Is that going to be fixed?

I guess my main concern is that for months the mod never had this issue. Why all of a sudden did this fix get implemented so many months down the road? See, now I've been used to flying the aircraft incorrectly for all these months and now have to learn a new way of flying it.

[Phantomflyer81]

I noticed today I was in TAKEOFF phase and then it switched to CLB and followed the FP. Also, sorry to sound dumb, but how do you know what FLX setting to use? Does it matter, like in terms of thrust? Lastly, a side topic, but I'm still having the bug where I can't disable the master caution warning light. Is that going to be fixed?

I guess my main concern is that for months the mod never had this issue. Why all of a sudden did this fix get implemented so many months down the road? See, now I've been used to flying the aircraft incorrectly for all these months and now have to learn a new way of flying it.

Set FLEX to 50 to 54 degrees - this is a setting that tells the engines how much heat is generated, thus more power they put out without causing damage. The setting depends on many factors - outside temp being the major factor. But, for sim use, just try 52 to 54 and you're good to go. Note - if it's hot outside, you may get an EGT overheat notice, so keep it under 54 in such cases. There's a lot of literature out there using Google that talks about FLEX temps. On a Boeing, these take-off temperatures are similar, but they don't use the term "FLEX". This is dependent upon the manufacturer of the FMC/MCDU and the programming input.

I understand that it can be frustrating when there's a sim update that breaks our mods. I, too, thought "now what??" but soon got the DEV model into my community folder. Yes. things changed, but I soon learned that they changed for the better. My 1st flight caused heading to North and I said "What now?" when the plane didn't navigate properly. After a little search in the sim forums and here, I realized that I was setting up the MCDU improperly. And, yes, whenever we anticipate problems after an upcoming update ("what are they going to break now?") we get a bit frustrated. We have to realize that the vanilla models are probably never going to follow real world practices. This is the prime reason for FBW - they are giving us the most realistic airplane, and it will continue to evolve as time passes.

[kgaviation]

So I was able to finally make it follow the FP. However, everytime I would engage the AP, the aircraft would bank hard right and then left and eventually follow the route. This is on the latest dev. version. Why is it so jerky and violent when the AP is engaged? Why does it always bank to the right first and then back to the left when it's engaged?

[Phantomflyer81]

OK - 1st of all, make sure that you set dead zones (my throttle has no dead zone but others may need one) on your input device to at least 10% (mine is 15% and my rudder is awful always pulling left - I have it at 20% dead zone. My Logitech extreme 3D pro needs a clean due to the lube they use).

Are you entering ZFW (Zero Fuel Weight) and CG? Look at your weight and balance. Add empty weight and passenger/baggage together (but NOT fuel!) and enter it as XXX/XX. The CG is listed in the new sim interface and can be adjusted (it's a great thing they did in the last update). I get rid of some passengers and luggage then add as much fuel as needed (long haul 100% for flights around 7 hours with tailwinds) then I set the CG using the scalar provided in the default weight and balance page until the weight and balance is deemed OK. I take note of both these figures.

Now for weather and winds - are you getting gusts that can cause the plane to crab or dip after lift-off? You can get rid of gusts by simply putting your cursor to the right and hitting backspace. Same is true if you want to adjust speed and direction and getting rid of gusts in your winds aloft. Voila - like magic, the gusts are gone. The weather and winds/gusts can be adjusted in flight and saved just like I stated before. Of course, this won't be true if you are using LIVE weather. I've saved many custom weather/winds/gusts and named them by date. Nice feature.

Now - set your cost index from 1 to 100. I use around 80 to 90 (old habit). The higher, the more fuel burn, power and speed; to a point - the subject of cost index requires lengthy discussion. Enter cruise altitude either in thousands or flight levels. Both are accepted. Enter the wind and direction and speed (use the weather drop down). Not sure it needs the temp of your departure airport - I believe it doesn't accept ground temp so leave it if that be the case (this can change in future updates). On the take off page, double click your V speeds , V1 VR V2 one at a time. These are calculated by MCDU using the ZFW and CG you inputted earlier. They get inserted as you double click - no guesswork (this feature may change in future updates). You can step climb and the MCDU takes note of it. Hit enter when you see it. Enter the destination airport's winds and temperature, (approach phase) but DON'T activate and confirm the approach phase too early! Doing so will delete all waypoints before the STAR! You want to do that right after the last waypoint before the first waypoint of the STAR. All this works using the default flight planner if you use high altitude (IFR) planning.

Set the transition altitude (18000' for most countries - default Honeywell is 10000') both for cruise and descent. Here in Australia the transition altitude is 10000" but 18000' in the USA. This is the altitude where the STD (standard) barometer is set to 29.92 or 1013 in Mb.

One important point - choose your cruise altitude in thousands (odd heading east; even heading west) BEFORE you click "use high altitude airways" - that altitude then can't be injected by the Sim's choice (it's usually too high!) - it retains your choice. Then choose runways according to winds, then choose a SID and a STAR (the automatic modes are usually pretty decent in the default planner).

All that said, if you use SimBrief planning, things are different and I'm not going to get into that here because it requires much protraction.

If I missed something or I said something incorrectly, please (anyone) let me know. I won't be offended by remarks. This is a never ending learning curve for me on the Airbus (Honeywell) MCDU's. I am very proficient with Boeing FMC's, however.

I wanted to do a YouTube tutorial on setting up the MCDU but there are already plenty out there. I hope this is helpful to you. Let me know how you get on with all this. I'm happy to assist any time. Happy flying :)

EDIT - I just used the FBW installer and there's a new development update cd44024 today. I don't know exactly what this will affect but I will elaborate if things changed significantly. Just click the update in the sentence above to view the change-log. The most noticeable change is the automatic implementation of speed restrictions (250 knots max at altitudes at and below 10,000'). I was doing this manually before this update.

Thanks to all the developers for the work you do.

On Sun, Mar 14, 2021 at 10:13 PM kgaviation @.***> wrote:

So I was able to finally make it follow the FP. However, everytime I would engage the AP, the aircraft would bank hard right and then left and eventually follow the route. This is on the latest dev. version. Why is it so jerky and violent when the AP is engaged? Why does it always bank to the right first and then back to the left when it's engaged?

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[simoxmino]

It happened 3/4 times to me. In approach, entering in the star. flight plan disappeared from the mcdu (remain only the two ICAO) and a320 turn and go to north.

[Phantomflyer81]

I think that you may have activated AND CONFIRMED (This is last minute stuff per my comment above) your approach phase too early. You can activate it, but DO NOT CONFIRM it until you reach the end of way points BEFORE the first way point of the STAR. If you do that too early, you will lose all the way points of the flight plan before STAR. I learned that the hard way. But I saved the flight by manually inserting the missing ones (they will be listed in the plan drop down) by using "direct to" function. I know it's a hassle but it works. So, the next paragraph is now my M. O.

Another way of being sure you don't lose your plan is to insert a SECOND FLIGHT PLAN into the MCDU. All you need to do is activate it then continue to fly. It's a good habit/practice to get into. We all know that redundancies in aviation save lives (and a few red faces of embarrassment) 😉

IMPORTANT:: In real world (not necessarily long haul) flights, the weather can change significantly at the destination, hence the flight crew don't even enter the STAR until they've received a METAR from the FSS and clearances from ATC of the destination.

I just took from EDDK (Cologne Bonn) Germany for a long haul to CYYZ (Toronto) using an Air Canada livery - it's working with the newest Dev Mod. All perfect here. I will comment later if I can duplicate any bugs. I just reached 17000 feet and this plane is super nice to fly.

One more thing came to mind., failing my suggestions above - please try reducing your glass display refresh rate to low or medium. See if that helps you.

I will check in later. Can you tell me your PC specs please.

PS - Have you updated your development mod? It's been released as of today. I will post some screenshots later as well to show you the inputs to the MCDU. There are a few points that I may have missed now that the MCDU has been updated.

My flight has never been smoother and so realistic. I'm very impressed with the latest Developer mod!!
Huge thanks to those working on it. K9

[kgaviation]

I don't remember activating or confirming anything that you mentioned above. I never used to actually enter all of that info into the MCDU anyways. I've never really gotten to the point in the sim where I set up my MCDU and all that, I prefer to just hop in the plane and fly. I know that's not the correct way to fly in real life, but a lot of that I don't understand very well and I've never had any problems flying this way with the mod before.

And no, I haven't had a chance to update the mod yet, but I will when I get the chance. Hopefully it's better now.

[Benjozork]

@kgaviation this is probably not the answer you're looking for but you'll have to configure the plane properly for this add-on to work. The objective here isn't to make a plane which is easy to fly, it's to make a plane which is realistic to how the real one works.

We have a tutorial series in the making, as well as a simple guide coming up on our documentation website.

[kgaviation]

I understand it's supposed to be a more realistic aircraft. But this has never been an issue in the 3 months since I've used the mod. So after all of this time using the mod and having successful flights, now all of a sudden you're telling me that it's changed to where I have to configure everything properly and set up everything in order for it to fly correctly?

I really grew to hate the default A320 because it wasn't realistic and flew horribly. I finally gave the mod a try and it was so much more realistic and most importantly, it had correct flight physics which the default/vanilla didn't. So now, I guess I better give up on the mod and go back to flying the terrible default A320 even though the mod has worked all this time for me. Sorry if I sound like I'm ranting, but I'm just a bit frustrated now.

Look, I'm not a real pilot nor will I ever be. However, I do love flight sim and I love flying. I always have. There's a lot about flying that I don't understand (such as instrument flying and commercial). I didn't know I needed to know all of that just to be able to fly with this mod. Like I said, I never needed to know all that before since I've been using the mod. Well, guess I'll just have to suck it up and go back to flying the default A320 which is terrible and doesn't even fly correctly. So much for the mod then...

[Benjozork]

I don't understand your frustration to be completely honest.

There's a fix coming which makes this a bit less problematic for when the aircraft is improperly configured, but at the heart of the situation many users are not properly using the aircraft.

I don't see how it matters that it worked before. If the behaviour was incorrect before then it's gonna change. It's not because something worked before that it was necessarily correct.

I'm not that knowledgable about aviation but it took me a good 10 minutes to learn how to do the most basic MCDU programming necessary for the aircraft to fly properly. It's not a daunting task and watching YouTubers like 320 Sim Pilot will help you a lot.

The major issue with how people fly the plane which leads to this problem is improperly taking off. You're supposed to takeoff with your throttle in the TOGA or FLX detent, then pull back to CLB at your thrust reduction altitude. If you don't do that, then your aircraft never goes into CLIMB phase and won't give the AP any guidance.

[Phantomflyer81]

The reason FBW has undertaken this monumental task was to create an A320Neo that simulates the real world aircraft as closely as possible. Being a retired military Aviator and currently a part time commercial aerobatic instructor, I am enthralled by the amazing work being done here and look forward to it evolving into one that does the job as good as, or even better than an aircraft developed by PMDG

Learning how to set up almost real-world MCDU takes time, but once you get how to do it, you will thrive knowing you've accomplished the immersion this ever-evolving modification gives you. Once you have done this, then when acquiring, say, another Airbus from Aerosoft (coming soon) ; or a Boeing 787-800 or 747-400/800 from PMDG, you will not be displeased.

If you don't like this mod, get rid of the a32nx folder from your communities folder and fly it as a Microsoft/Asobo unrealistic aircraft, however, I believe you'd not be doing yourself a favour. My opinion here is based upon the decades of both real-world experience and flight simulator experience to the point where I very much disliked planes without FMC's/MCDU's - they simply sat there and were never used. I really, really really, looked forward to flying. I subscribed to paid monthly nav-data updates from Navigraph so my FS and FMC/MCDU were always updated to match real world nav aids. Trying to fly in the on-line VATSIM community without these updates would have been futile.

I'm no going to try to twist your arm here - I'm only trying to assist you. I'm certain that, if you stick with me in this regard, I will help you get through what you call changes that never were there before. To quote you "But this has never been an issue in the 3 months since I've used the mod. So after all of this time using the mod and having successful flights, now all of a sudden you're telling me that it's changed to where I have to configure everything properly and set up everything in order for it to fly correctly?" - the definitive answer is Yes you do have to configure the MCDU properly. After all, that's exactly what the FBW team are diligently working on and not asking for a cent to do so. PMDG/QW/Aerosoft/Wilco and others charge premium fees for aircraft that requires such configuration. I am extremely thankful for the FBW folks, for they have given me an aircraft that- does what it's supposed to do without asking me for any payment whatsoever. Can you think of any other value for money than that? I certainly can't. If you want to stick with this, I will, as I said earlier, stick with you (or any other readers following this thread). I can assure you that, once you grasp everything that- I will walk you through, you will not want to go back to the Sim's default method. This takes both trust and patience.

Think about it and feel free to ask me more questions. Send me a PM ( I've not been a member here for long. If you know how to send me a PM, please do so and I'll happily provide you with my email address.

**Look at that!! I DON'T know how to PM someone here!** You can assist me and vice versa....LOL

[kgaviation]

That’s what I’m saying. After using the FBW mod for three months now, no part of me wants to go back to the default/vanilla version. I’ve gone back to it a couple times and I can’t believe I used to fly that. It’s definitely not as realistic and it flies terribly.

I really want to keep using the mod. I love how realistic it flies and all the realistic sounds and way it looks. I never used to use any mods or add ons and this was the first I ever used. I guess it’s just frustrating when the sim updates break the mod, but I guess I should know that’s expected to happen. I love the way the mod flies because the physics feel much more authentic and realistic. I guess what I’m trying to say here is that I’m just not wanting to put a lot of time and effort trying to learn an aircraft system and how to fly an aircraft when I’m not a pilot nor ever will be. I’ve gotten by all this time with not having to do that, but I suppose now I’ll have to try and learn how to fly this aircraft properly or else it’s back to the awful, default version.

Sorry for ranting, I don’t want to. Again, I like the mod mod I have no intention of going back to the default version, because it’s a mess still. The mod is definitely the way to go, I’ll just have to adapt and learn new techniques of flying it more realistically.

P.S. by no means do I fly crazy or like a stunt pilot. I don’t mean that. I treat my flights as they were real and I fly smoothly as in real life. I’m just saying, I was never to the whole immersion aspect of using the MCDU and all the other functions of the aircraft, just the basics I guess.

[iFred320]

I don´t want to rain in anyones parade but that this plane has problems following the flightpath is nothing new, it happens from time to time, mainly in approach phase, sometimes in the middle of the flight. So that´s why I think that the most ppl are waiting for the custom AP and the workingtitle-integration is finished. So yes, the problems are still there, but your specific problem (going north after takeoff) has something to do with the mode the plane is actually in. But yes, other problems are still there.

[Phantomflyer81]

I'm still waiting to hear about your PC specs. This is not a plane one just hops in and flies like a default msfs2020 plane. I keep seeing "but I used to be able to". That mindset will get you nowhere with the FBW mod. What "used to be" is ever evolving.

I don't understand what "I don't want to rain on anyone's parade" implies. The plane, using the mod, does exactly what it's supposed to do for me and most others. We certainly don't profess to be having any parades - either in the rhetorical regard or in the literal regard. We're constantly upgrading to make this aircraft as close as possible to the real A320NEO. At some point in the future, a limit will present itself. We haven't reached that point yet - in fact there's much more work to do. But, at this juncture, the mod works. Please read my instructions above. Set up the MCDU as stated. As I said more than once, if you don't understand anything or can't find where to input data, let me know exactly where. Use a screenshot to assist me. It's important that you state your pc specs as well. Without that, I can't give you the best answer. Look at the sticky notes with regard to minimum pc specs. Your Windows version is important too.

[Phantomflyer81]

""I understand it's supposed to be a more realistic aircraft. But this has never been an issue in the 3 months since I've used the mod. So after all of this time using the mod and having successful flights, now all of a sudden you're telling me that it's changed to where I have to configure everything properly and set up everything in order for it to fly correctly?""

I'm sorry to s say this but the short answer is yes. You need to configure the MCDU properly. After a few times, it becomes 2nd nature.

Please don't forget to let me know your PC specs and your Windows version. I have no intention on abandoning anyone who needs help setting up the MCDU for flights that you will really enjoy because they act as they are supposed to. In fact, I just started writing a tutorial using screenshots of the MCDU and other systems integral to every phase of a flight. I need some time to do this, so all I ask is for some patience.

I think this thread would benefit many other pilots if it's taken to a point where issues are considered solved and methodology in setting up the MCDU is understood. Doing so will benefit so many other simmers out there and is something I am happy to do for the benefit of those having issues.