Cirrus SR22 Trim shoots to 100 nose up

[M3Stang 27]

Flying the Cirrus SR22 on a cross country flight, maybe 15 hours into the flight, the plane just starts stalling and I look at the trim and its pegged to 100. If I disable AP and correct it it seems mostly ok until I reenable AP. Never had this problem with over 100 hours into the game since launch, mostly using the SR22. Anyone else experiencing this?

[Crossover521 0]

I noticed the same issue and I was wondering whether I'm just not configuring the AP properly though in my case it seems to trim down and the aircraft dives. I adjust my selected attitude and then hit the ALT button and as soon as I engage AP it starts diving. It happened on every flight so I simply stopped using altitude hold. A basic bypass is to level the aircraft at your desired altitude and then engage the AP. It will maintain your attitude at the time of engagement so if  you're level it will remain there.

[FlyBaby 659]

It is an issue with more than just the SR22...

When engaging active pause while using the AutoPilot, the sim will spike the trim up or down.

I have seen this in the Virus and the VL3.

[robert young 2,897]

If you resync an aircraft using developer mode (after editing it) you need to move your ailerons fully in both directions otherwise pulling or pushing on your yoke/stick also operates the trim. I learned this after a couple of days after release when I was dumfounded by the most odd behaviour. I also move all my controls to their fullest extent when loading a flight, before moving as that seems to be necessary to get the control surfaces and trim to respond correctly.

[Nyxx 6,994]

SR 22 can fly for 15 hours across country wow!

100 hours, well done, that’s some flying.

Edited September 22, 2020 by Nyxx

[eslader 1,814]

AP definitely does something funky to the trim. I can trim it perfectly for straight and level, then engage AP with altitude hold (which should do nothing because I'm already holding altitude), then disengage AP and the plane will pitch up aggressively almost every time.

Definitely something to fix.

 

[sluihn 68]

Well even the modded cj4 did that to me last night 2am in morning trying to cross half of Atlantic ctty to birk. I had read myths that Iceland ctd'd most approaches and upon turning autopilot off plane shot straight up.  I was ready for it this time. Seems to be simulator problem.  I did notice on the fuel tab before disengaging ap that center of gravity was in red so was ready to handle disconnection

Planning the rest of flight to visit orbx Europe 

Steve

[Phantoms 800]

It's an AP problem with most planes, not a Cirrus problem. On sure way to get the AP to act up is using the regular "pause" key (active pause), but sometimes just switching from one mode to another on the AP or disengaging and trying to re-enagage will do it. Another issue is since the patch I occasionally have the AP just disengage on it's on. Happened last night during approach in the SR22, but other planes do it too.

[Captain Z 32]

I see it in the SR22 and TBM all the time.

[marsman2020 1,310]

It would be really nice if there were some kind of a 'black box button' that would save out a file with the flight parameters and all of the control/AP inputs for the last 5 minutes or something.

The information could be attached to Zendesk reports, we could use it to debug things on our side, etc.  Make some pretty graphs in MATLAB or Python.

[VFXSimmer 1,310]

3 minutes ago, marsman2020 said:

It would be really nice if there were some kind of a 'black box button' that would save out a file with the flight parameters and all of the control/AP inputs for the last 5 minutes or something.

The information could be attached to Zendesk reports, we could use it to debug things on our side, etc.  Make some pretty graphs in MATLAB or Python.

That would be quite useful.

[marsman2020 1,310]

11 minutes ago, VFXSimmer said:

That would be quite useful.

Upvote here - https://forums.flightsimulator.com/t/add-a-black-box-button-that-saves-telemetry-of-recent-events/283155

[Waldo Pepper 1,953]

If you engage autopilot and then apply any inputs to the stick,  the AP will respond by altering the trim.

[M3Stang 27]

I tried this again, this is what I have noticed. I have only been able to replicate this behavior on a VFR flight from KBLI to PKTN. At 12000 feet and NAV on set to GPS CDI on the PFD, everything is fine. I have icing set to visual only, (judge me if you want :P) but I notice that this issue occurs when the airframe/windows are COVERED in ice. It is almost like the ice itself is the problem, like it is using realistic icing settings. It might just be coincidence but I cannot replicate this behavior without ice. If I set pitot heat and airframe de ice the ice never goes away. OAT is like -3 - -6 C when this occurs. I cannot get the plane to un-ice itself without reloading the flight. Trim is at nose up 19.5 Degrees. If I disable AP then set it to like 3.5, and reengage AP it immediately shoots to 19.5 and stalls. Wonder if the issues only happen in ice for others.

[Stigi 0]

@M3Stang - Confirmed... same exact situation for me.  Always happens with icing.  Most recently...

Flight from KAUB to South Lake Tahoe; manually set weather to 'Snow' in Deluxe stock Cirrus SR-22.  There's a little frost on the window at flight load-in.  I immediately hit Pitot-Heat, Airframe De-Ice, and Max out the fan and cabin heat.  No matter how long I sit on the ramp, the frost never goes away.  I take off and 60 seconds into the flight I can barely see out of the window.  As I pass through 5500' ASL i get the stall warnings, switch to external view, and notice trim is 100% nose-up.  Nothing I do restores lift and appears as if the plan is just WAAAAAY overweight.

My guess is that the icing effect is dramatic.  What troubles me is that I got the 'Deluxe' edition because I like to fly the SR-22, JUST BECAUSE it has anti-ice!  But no matter what I try, it (cabin, windscreen, and airframe de-ice) simply doesn't seem to be working.  I'm assuming the massive nose-up trim is simply the autopilot trying to cope with minimized lift the wings are making and the extra weight of airframe icing... which makes sense assuming realistic accumulation (which is hard to determine, really).