Strange AP disconnection and speed issue [Answered- Turn on pitot heat]

[admin9]

I have the following issue recently were it will be following the flight plan fine then all of the sudden it will disconnect the AP and the speed will go into the red as pictured below. This has happened on two different flights in the last two days.
It was working well in previous flights and no changes to the system at all. Is there any reason for this and what is causing it, please?

The ap isn't flashing red in the picture however it does. When I take over it will reset after a short period of time and then I can hit ap again and it will continue the flight, it will sometimes then do it again.(sometimes this happens consecutively over a few minutes). Once it corrects itself it continues the.flight without any more issues. It appears it shakes before it does it but speed is okay so its not stalling. (Speed is lower in poc while trying to fix issue).

P3dv4.5/Active sky/rex sky force/rex environmental

issue ap.png (3.31 MiB) Viewed 530 times

[Taguilo]

Hi,

Don't forget to turn on Pitot Heat when OAT is below 5 C.


Tomas

[admin9]

Hi,

Don't forget to turn on Pitot Heat when OAT is below 5 C.


Tomas

Okay thankyou. Is that monitored by SAT on the main display unit? I note it states -5. Do you turn them on when it gets close to that temp in flight so you dont get that issue or on the ground in preparation that it may get below 5c

[Taguilo]

Okay thankyou. Is that monitored by SAT on the main display unit? I note it states -5. Do you turn them on when it gets close to that temp in flight so you dont get that issue or on the ground in preparation that it may get below 5c

Yes, and also by the OAT gauge on Pilot's side panel. On the ground, you can turn it on if temp is cold, and you should turn it on if temp is above 5 Celsius but will drop soon after take off. In summer days, where it is really hot even at high altitudes, you can leave it off in flight until you notice OAT below 0 Celsius or there is high moisture (clouds) with low temperature.

Tomas

[admin9]

Thank you great explanation. I will try and report if still issues. Appreciate the reply.

[admin9]

Hi,

Don't forget to turn on Pitot Heat when OAT is below 5 C.


Tomas

Okay just commenced a new flight and then I thought that the pitots are already on if the switches are up and not illuminated on the warnming panel? If so, they were already on in the previous flights and therefore not the issue (unfortunately pic doesn't show them but I always turn them on to remove the warning on the panel. Maybe I don't do that from now on unless required).

If they are already on could it be another de-icing switch that also needs to be on perhaps?

Just to add to the above. I just had a good flight until near TOD where it did it again for no apparent reason. Corrected it and then it was okay again. This is starting to get annoying. SAT was -6C RAT was 3C

[Taguilo]

Just to add to the above. I just had a good flight until near TOD where it did it again for no apparent reason. Corrected it and then it was okay again. This is starting to get annoying. SAT was -6C RAT was 3C

And what did you do to correct it?
Pitot Heat may fail if failure is selected in P3D failures, or in severe icing conditions.

Tomas

[admin9]

All failures turned off. Basically took over controls, put it back on course, speed reset itself and then hit ap again and it followed on its normal path. Im flying in the top of australia. Had engine anti ice on also and no ice on the windshield etc.

[Taguilo]

Were you flying with ActiveSky or any other wx addon? Could be the source of that issue.

Tomas

[admin9]

Yes active sky, rex sky force and rex environmental force. I use these apps on numerous other flights and has been okay but i dont think it may have reached the cold temps like recently.

[admin9]

Okay more testing today and appears it is Active Sky. It iced up really badly and went into the ap disconnect and red line on the speed.
Moved icing down to 0 in AS. Closed active sky and plane was now fine. Reloaded AS during the same flight, ensured icing was 0 still and icing came back straight away and caused the issue again. Unsure if the sim needs to be reset and new flight before the 0 icing takes affect? I wouldn't think so given it injects the settings into the sim. Therefore...

Is there a way that KA and AS can play nicely together and any setting recommended please? Does KA have any ice settings that can be modified and/or P3D also? I only have an unregistered version of FSUIPC so no settings there either.

[Taguilo]

KA and AS work fine together in most situations. The one you experienced seems to be an AS bug if you set icing at 0 and still get instant ice at one moment. Try flying in other regions with different weather situations and see what happens.

Tomas

[admin9]

Conducted another flight today and no icing at all when Active sky is set at 0% icing prior to loading the sim. For info of others if experiencing the issue. Make icing 0% in AS settings and it will then not have the issue. Will have to do further flights at different % of icing to see where the happy mix is. Thanks for the help.