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Over-speeding at cruise altitude


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Hi,

I was trying to discuss this subject in other topics, but unfortunately without result. I do admit that so called "hijacking" of others posts is no good and that's why I am following the advice to open a separate post for the same issue, no matter that obviously many others are having the same issue.

Anyhow, let me start with a bit of a background first:

- platform - FSX:SE;

- Aerosoft Airbus 320 / 321, software version AS_AIRBUS-A320-A321_FSX-P3DV2-P3DV3-FSXSTEAM_V131;

- weather engine - FSX Active Sky Next;

- setting add on - FSUIPC4;

- current rout - LFBO - LFML, cruising altitude F240;

- CI - normally between 15 and 30;

Prior to continuing the subject, I would like to mention that such situation happens almost frequently in all my routes and on any cruise altitude. I am recently flying between European airports, trying to have short trips basically for training landings considering them as my weak point before joining any group societies.

The plane follows the climb profile normally. Thrust is decreased to climb at calculated altitude and it reaches the cruise altitude almost at calculated place. Unfortunately and instead of following the cruise speed and having no vertical speed, both start to increase uncontrolled without any valid reasons. I am attaching below some pictures, which talk much better than any explanations. Hope same can be seen in heraldic order in order to get proper impression how it develops.

I am trying all necessary ways to stop the process, but unfortunately no stable method can be found since now. The thing, which sometimes works is switching off the ATH and switching it on after some time, but this cannot be considered as a stable solution. Emi mentioned on other place that this cannot be the solution, but no matter of his statement, it works sometime. I am unable to include the FPS in the pictures simply because I have no idea how to do it. The key combination Ctrl-Z pressed 2 times, unfortunately doesn't work for me. Would appreciate instructions on this also.

I cannot see any sudden changes of the side winds passing through different blocks, which another confusing situation.

Reviewing all the above, I would appreciate any opinions and suggestions how to avoid such situations. The problem is that it applies almost to all my flights recently and I hope all will agree that such is highly annoying.

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Hi Goshob

 

Is your Pitot-Heating set to on when flying in high altitudes.
When the hearting is not on - the correct speeds are not taken as the measuring equipment is full of ice, and the airbus "thinks" he is too slow and tries to accelerate

 

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Hi @Goshob,

 

please look at your first picture: There you can see, that you are experiencing a Master Warning! Why? Because you are overspeeding and the aircraft pitches up in order to get the speed down... You can see that, when you look at the upper left corner of the PFD. There you have "SPEED" with an orange box around it. Orange always means, that something is going wrong ^_^ ! Also the speed indicator is getting into the area where those red bars are, the overspeeding area.

But I don't understand why the aircraft isn't keeping its speed :blink: ?! Please make sure, that you have both levers in the CLB position and A/THR active and it is really indicated on the upper ECAM!

And: If you want, you can try what @christian1974 said. But for me it works without setting it to on, because it normally is on AUTO and the Airbus turns it on when needed...

EDIT: I had this problem on my old laptop as well, but only with very, very bad frames... There the Fly-By-Wire respectively FADEC didn't work correctly

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Hi,

Thank you for the advises! Let me make some comments on them:

Unfortunately the pictures could not be uploaded in chronological order, how I made them. I purposely left the speed / altitude to increase till I got warning signal. This was done just to show what happens. I am also wondering too much why the plane doesn't want to keep the speed and altitude later?! My levers are in climb position with no doubt. Checked several times already. I had also noticed that the indication on PFD remains on SPEED instead of changing to MACH. This is the real problem, which I thing is the base of all the troubles. Telling that because after several attempts to switch off and on A/THR it turns to MACH and everything returns to normal. Means the plane decreases the speed and goes down to cruise altitude.

I had tried the advice of Christian1974 with no success. Situation is same with or without anti ice switched on. I also feel that this is an automatic function.

I am also curious to know what the FPS at that time, but unfortunately I do not know how?

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@Goshob Ah, okay, I see! But I would say, that MACH or SPEED is irrelevant! It normally changes at a higher Flight Level and basically it is the same: It's just the unit in which the speed is! 

To the FPS thing: I didn't find the command in the settings, but you can somehow change it in the FSX.cfg! But for this you need to ask others or do a google research! Something like "FSX Shift+Z" or so...

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The key to your issue is in the 3rd picture

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Check your FMA: TOGA LK.
Please check the Step By Step guide on the meaning of TOGA LK and how to turn it off again.
When TOGA LK is not turned off by the pilot your engines are stuck in TOGA thrust. In the climb that is not an issue since the airplane holds the speed with the pitch, once you level off however you will accelerate until you overspeed which then triggers the overspeed protection which in return causes the Airbus to climb again to reduce speed.

 

12 hours ago, christian1974 said:

Hi Goshob

 

Is your Pitot-Heating set to on when flying in high altitudes.
When the hearting is not on - the correct speeds are not taken as the measuring equipment is full of ice, and the airbus "thinks" he is too slow and tries to accelerate

 

 

The Airbus turns on the probe heat automatically once the engines are started, thus it is not needed to turn on the switch manually.

Always keep the dark cockpit philosophy in mind: When there are no lights on everything is fine.

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Hi Emi,

What you are mentioning above sounds quite logical. Unfortunately the main question how the Alpha Floor protection was activated without noticing it, remains. It is clear that the AC switching in TOGA LK mode automatically if the nose was lifted up too much during take of, for example, and the pilot has to switch it off later. At the same time I strongly feel that corresponding information / warning message should be given by the flight instruments.

I normally follow the take of procedure recommended by real world pilots. Pull up the side stick achieving no more than 3 degrees when VR is reached in order to avoid hitting the tail into the ground. The angle can be increased to app. 15 degrees when the AC is airborne.

Can you please comment a bit more about Alpha floor protection and its indication, if possible? I will try several departures also from the same runway in order to clarify if I was doing something wrong.

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Hi,

It seems the subject is not interesting for the audience anymore and I may suggest to be closed. Just before that and in order to support the users who are too "busy" to read the manuals, I will describe the switching off procedure for TOGA LK status. The manual states as follows:

QUOTE
a. Set the thrust levers into the TOGA position;
b. Switch off auto thrust using the FCU button;
c. Now bring back the thrust lever to the CL position;
d. Activate auto thrust again using the FCU button;
e. If already activated the Autopilot has to be switched to ON again;

UNQUOTE

For me personally it works also with switching off and on the A/THR button several times even when the thrust levers are in CLM position, but it is much better and strongly recommended to follow the rules instead of using some weak points of a software.

Thanks to all who supported in the subject!

 

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  • 2 weeks later...
  • Deputy Sheriffs

Because we believe this topic has been answered we have closed it. If you have any more questions feel free to open a new topic.

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