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Secondator

Managed speed issues

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Finished a couple of flights on version 1.2.3.2 and everything is working great.  I hope everyone can have the same resolve. Cheers.

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 I notice this issue happen to me every time I changed the arrival on the MCDU right before starting descent . Also when I try to change the manage speed on the flight plan I get an error saying that I cant change it. When I try to change the speed on another waypoint it does the change but seconds after will reverse the change.

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@fedenav I am  following this topic for a couple of days. I've experienced the same bug with my A319, flying from Hamburg to Stockholm. I remember that I've also changed my arriving runway. This was the only flight with this issue and also the only flight, I was changing the runway during cruise/descent. All my other flights (could be about 10-15 flights) since the update were normal, but I didn't changed the runway there. I use Active Sky for P3D V4 and usually the wind-prediction seems to be correct. So changing the runway during flight was not necessary for the other flights, because I set the correct arrival-runway before departure.

This could be indeed a hot tip.

 

Best regards

Felix

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10 minutes ago, Felix.k said:

@fedenav I am  following this topic for a couple of days. I've experienced the same bug with my A319, flying from Hamburg to Stockholm. I remember that I've also changed my arriving runway. This was the only flight with this issue and also the only flight, I was changing the runway during cruise/descent. All my other flights (could be about 10-15 flights) since the update were normal, but I didn't changed the runway there. I use Active Sky for P3D V4 and usually the wind-prediction seems to be correct. So changing the runway during flight was not necessary for the other flights, because I set the correct arrival-runway before departure.

This could be indeed a hot tip.

 

Best regards

Felix

 

Your idea makes sense, but I experienced the issue on 1.2.3.0 even when flying the route as initially loaded without any modifications.  I have also changed the landing runway or the approach or the entire STAR + runway with no issue.

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OK, it's happened again.

A319 CFM on 1.2.3.2.  Windows 7 Pro.  i7-4790K @ 4.5 ghz.  GTX1080ti.  32GB DDR3.  ChasePlane, ActiveSky ASP4 with REX SkyForce (injecting clouds only), running in the background as usual. 

 

Flight plan:  KLAS BOACH8.RIKII SHTNR.ANJLL4 KLAX FL280

 

Loaded the flight, set cold/dark state as usual.  Used the fuel planner and the INIT LOADSHEET feature on the 3rd FMS, which I don't normally.  Flew the whole flight in managed mode without any modifications to the route (until the end anyway...decided to change the approach after speed went haywire).  Made a manual descent with V/S from FL280-260, and then again to 240.  Engaged managed DES prior to GLESN (has a window constraint FL240-300).  Managed speed worked fine until GLESN at which point it dropped to around green dot speed.  I also noticed something else strange...overhead GLESN and next two (I think) waypoints, the footrests on both sides of the cockpit extended and then retracted spontaneously.  I realize that those animate on their own when the aircraft enters the CRZ phase, so I thought it was worth noting.  They just extended and retracted on their own at the instant I passed GLESN, ANJLL, and CAANN.

 

I can test again, perhaps tomorrow night...but the last time I ran into this bug (see my post from a few days ago) was also in the A319 after passing a waypoint that had one of these window constraints (i.e. as above, cross GLESN between FL240-300 and 280KIAS).  I don't know if that is a common feature of procedures in Europe, but they are quite common on RNAV STARs in the U.S.

 

Logs attached.

 

 

managed_spd_2.zip

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A319 CFM on 1.2.3.2

 

LEMH MAME1D MAMEB DCT PTC UN851 VJF UL82 IBALU UN857 TERTO TERT6V GCLA (simbrief)

FL 370

 

Speed drop occurred on the climb out at around FL340. Magenta text was 102 but the green dot was around 200.

 

 

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Is this still being examined...? It's still not working.

Immediately upon selecting managed descent the speed drops back to something like 180... consistently. This is on 1.2.3.2. A320, 321, and 319, so far just been flying CFM but I can check IAE too.

 

Also, consistently chasing the descent green dot... I will be above by 20 feet then above by 949 feet, plane catches the profile then it happens again. Variations of a couple thousand  feet per minute. It has virtually no chance of hitting the most basic of descent profiles, as well. A couple of above restrictions and it shows a remarkably aggressive descent profile that it totally blows around 14,000 feet. Still needs a good deal of work... but I do not understand, because VNAV worked almost flawlessly before an update a few months ago.

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1 hour ago, mspencer said:

Is this still being examined...? It's still not working.

Immediately upon selecting managed descent the speed drops back to something like 180... consistently. This is on 1.2.3.2. A320, 321, and 319, so far just been flying CFM but I can check IAE too.

 

Also, consistently chasing the descent green dot... I will be above by 20 feet then above by 949 feet, plane catches the profile then it happens again. Variations of a couple thousand  feet per minute. It has virtually no chance of hitting the most basic of descent profiles, as well. A couple of above restrictions and it shows a remarkably aggressive descent profile that it totally blows around 14,000 feet. Still needs a good deal of work... but I do not understand, because VNAV worked almost flawlessly before an update a few months ago.

As I usually start the descent before the ToD, I didn't really encounter the "managed descent" problem.

 

So, the aircraft starts its descent gently at 1000ft/minute, however as soon as it reaches the descent profile, it is a real hunting festival at the descent green dot (up and down). Usually I go back to Open mode to finish the descent.

A320 Cfm, weather by AS for P3Dv4.4, any FP.

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It's still being examined, and I can assure that it's still high on our priority list to get understanding what is going on and get it possibly fixed. About the VNAV. Have you inserted any winds by any chance? Are you descending in tailwind. This is what could cause the aircraft trying to chace the green dot all the way down. If this happens, just use some speedbrakes to keep the aircraft on profile.

Richard, do you by any chance have have weird spaghettin on your route or discontinuity that could change the VNAV calculations. This is what can possibly cause the green dot to jump up and down. You can see it if you go on plan mode and check if near some waypoint the route in constantly changing making the overall distance shorter and longer.
 

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1 hour ago, Secondator said:

It's still being examined, and I can assure that it's still high on our priority list to get understanding what is going on and get it possibly fixed. About the VNAV. Have you inserted any winds by any chance? Are you descending in tailwind. This is what could cause the aircraft trying to chace the green dot all the way down. If this happens, just use some speedbrakes to keep the aircraft on profile.

Richard, do you by any chance have have weird spaghettin on your route or discontinuity that could change the VNAV calculations. This is what can possibly cause the green dot to jump up and down. You can see it if you go on plan mode and check if near some waypoint the route in constantly changing making the overall distance shorter and longer.
 

I'll keep an eye on it next time. I would add that the winds had been entered for the climb, cruise and descent. Attached is the FP (no Star on arrival).

EDDMEDDH.flp

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I've just had the issue again, after a few flights without any problems. While I leave the room, the airbus was flying on autopilot. Smartcars was running in background. When I came back, after 20 minutes, the airbus was in Alpha-Floor-Mode.

 

Crusing level was 260. I leaved the room with autopilot on in Managed-Mode during climb at about 23.000 feet. When I came back, alpha floor was activated and the aircraft flew at 16.000 feet. The Managed-Speed was reduced to 119 suddenly. A look into smartcars shows, that the aircrafts reached its cruising level a few minutes, after I left the room. After further 10 minutes, a stall was recorded. So the issue must have occured at that period of time. Of course I did not do any input, because I was not in the room. The flightplan seems to be complete, no gaps. I used the Checklist and CoPilot-feature, so there were no abnormalities, compared to my other flight with the airbus. I used the A319 IAE, Active Sky. Tailwind was about 40 knots at that time.

 

Best regards

Felix

 

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@Secondator

Just doing the same flight again right now EDDMEDDH (see my previous message). This time no problem from beginning to end.

 

Your comment about the wind made me notice that from start to finish there was a headwind (+-65). On my previous flight, I don't remember where the wind came from, so....

 

I don't know if it matters but just in case, this time the CI was 30. The previous one was CI=50.

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We are slowly getting closer to understanding why this happens.... 

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ISSUE : sudden speed drop

 

Operating System: Windows 10 Pro
Simulator version: P3D v4.4.16.27077
Airbus version: 1.2.3.2
Add-ons in use: FS2Crew, Active Sky for P3D v4, Rex Sky Force, Aerosoft EGLL and LXGB, ORBX LEBB + Global

System specs: i5-7600K, 16GBRAM, GTX1070, NVIDIA drivers version 419.65

 

Description of the issue: I was afk for 2 minutes, and when i went back to my computer the speed was dropping. I was cruising at FL340 between EGLL and LXGB. I diverted to LEBB. Location of the issue in the screenshot. Aribus A320 IAE British Airways G-EUUU

Are you able to reproduce the issue? If so, what are the exact steps you are taking for this issue to happen?
-> The same issue happened in the same flight few weeks ago, on the same plane, but not same place (I was climbing out of EGLL when it happened).

I didn't have logs activated. Flight plan and screenshots below.

 

 

27353586_asbug.thumb.PNG.6446c2b2902f5fa141021486e140f884.PNG328067795_asbug2.thumb.PNG.c180158513f2f3e7e0b3feb00ee41a4e.PNG

EGLLLXGB01.flp

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On 3/15/2019 at 2:13 AM, Mathijs Kok said:

We are slowly getting closer to understanding why this happens.... 

 

Excellent news;  now are you getting closer to saying  it is definitely a local PC issue and therefore we can’t fix the problem, or are you getting closer to saying it is in fact caused by our code, it’s a bug, and therefore we can fix it.  Either way this issue is driving us all nuts!  I’ve stopped using it the whole saga reminds me of the Flight 1 ATR LNAV, issue!  I don’t think that ever got fixed I don’t know for sure, because I stopped using it, and just absorbed the cost.  Deja vu

 

All the best

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Hello, I meet the same problem. Sudden speed drop.
I did some tests, putting the SID and STAR in the FMS before takeoff, modifying in flight, etc ...
When I got the SID and STAR before take off, I made two flights without any worries. 
I thought everything was ok.
But today, in the same configuration, the problem arises again! And what's more, it ends with a crash of P3D!
I hope you find a solution quickly, for the moment, I think, regretfully, resume my 737 PMDG.
Good luck.

 

 

Operating System: Windows 10
Simulator version: P3D V4.3
Airbus version: 1.2.3.2
Add-ons in use: AS, ORBX

System specs: Gyagabyt Z170, GTX1080, I7-6700K


 

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I just had the same problem, but this time with the A319 CFM. Screenshots below, logs in attached .zip. This time I also activated the pause at TOD, but it didn't worked. I was also AFK, and found my plane hitting the water (crash disabled in game).

bug1.thumb.PNG.dd999c610c14fe577f054a687e15c24e.PNGbug2.thumb.PNG.ccbdb8d58add5f71694309951a0ce41e.PNG

A319CFM_LIML_LICJ_crash_logs.rar LIMLLICJ01.flp

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On 3/16/2019 at 5:27 PM, sprowse said:

 

Excellent news;  now are you getting closer to saying  it is definitely a local PC issue and therefore we can’t fix the problem, or are you getting closer to saying it is in fact caused by our code, it’s a bug, and therefore we can fix it.  Either way this issue is driving us all nuts!  I’ve stopped using it the whole saga reminds me of the Flight 1 ATR LNAV, issue!  I don’t think that ever got fixed I don’t know for sure, because I stopped using it, and just absorbed the cost.  Deja vu

 

All the best


Right now we have no reason to believe it's a local PC issue. I have been able to recreate the issue as well and have it well documented and we are working now to understand what is causing it. We'll keep you updated once we know more. Thanks for the help so far with the reports and logs!

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Gents;

 

Sorry I don't have the required info for a formal report (so disregard if not useful)...my managed speed issue yesterday was having the FMC directly set VAPP immediately upon the automatic transition to approach mode...with my flaps UP 😕

 

I just managed the speed myself for the approach, but figured it was worth mentioning.

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21 minutes ago, Matt S said:

Gents;

 

Sorry I don't have the required info for a formal report (so disregard if not useful)...my managed speed issue yesterday was having the FMC directly set VAPP immediately upon the automatic transition to approach mode...with my flaps UP 😕

 

I just managed the speed myself for the approach, but figured it was worth mentioning.


Hello Matt,

If I understood correctly. When APPR phase activated on the FMGS, the managed speed commanded Vapp which was shown below the speed tape on the PFD. If so, this is completely normal, and is not related to this issue at all. With APPR mode active the aircraft will command Vapp but will respect the flap limits still normally. In other words it will not reduce below the green flap speed bugs until respective flaps are selected.

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18 minutes ago, Secondator said:


Hello Matt,

If I understood correctly. When APPR phase activated on the FMGS, the managed speed commanded Vapp which was shown below the speed tape on the PFD. If so, this is completely normal, and is not related to this issue at all. With APPR mode active the aircraft will command Vapp but will respect the flap limits still normally. In other words it will not reduce below the green flap speed bugs until respective flaps are selected.

 

Yes, that is the situation I was referring to - thanks for setting me straight. I've been bouncing back and forth between Boeing and Airbus aircraft models and for some reason I thought the actual speed bug on the display went to S and then F as flaps were added. Sorry to muddy the waters...seems that as I get older I remember everything, whether it happened or not :)

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Hi All,

 

I was flying earlier today, and I noticed that my climb speed was sat at 180knts after 10000ft - I thought nothing of it and let the aircraft climb to cruise - where it was still sat at 180knts - if I took manual control of the speed and set it to 0.78mach, the aircraft met that speed with no problem, but as soon as I set managed mode on the speed selector - it wanted to drop back to 180knts again, even at cruise. The FMC is showing that it is expecting 0.78knts - however, managed mode doesn't seem to want to follow this.


Haven't seen this before on any other flights

 

Thanks

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Just reading though this topic - I wonder how many people experiencing the 'bug' are using AlviaSoft's Electronic Flight Bag? - This is my first flight with it on trial and I'm seeing the issue, I will try it again without and report back

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42 minutes ago, Leacho said:

Just reading though this topic - I wonder how many people experiencing the 'bug' are using AlviaSoft's Electronic Flight Bag? - This is my first flight with it on trial and I'm seeing the issue, I will try it again without and report back

 

I have never experienced this issue, and I use the Avilasoft EFB on each flight.

 

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