Autopilot Rolls Into Turns Like A Fighter Pilot

[Solana]

You are correct that you cannot set the autopilot before takeoff for a flight. It will basically clear your commands at takeoff. Nonetheless, you can operate the autopilot, which you would want to do as a pre-flight check that it is functioning properly.

Also, the manual (at least the experimental manual) does not describe a pre-flight procedure for the autopilot. All certified aircraft I have flown have such a procedure, so you have to roll your own.

 

[Rhino]

Thanks.

 

[TrevorMills]

I have the exact same symptoms after updating. The roll is very aggressive and I get roll slip in turn. It was very smooth before the update. My cruise speed is around 110 Kts.
I’ll send the diagnostic files to you this week.

 

[Dynon101]

Hi Dynon Tech Support,

Any update on this issue? I am glad that it is not just me...

 

[AlanR]

I updated/installed V16.2.4 a few weeks ago and so far have not noticed any difference at all in the Autopilot operation in my Bristell NG5. To me, so far at least, it seems to do banks and turns etc just the same as always has done.

 

[TrevorMills]

I could use diagnostic files from you guys with this issue. Engineering wants to look into it.

Don - I've sent my files to support and they are available here.

Dynon Diagnostic Files - Google Drive

drive.google.com

Thanks
Trevor

 

[RV8JD]

Don (Dynon),

Any update in finding the cause of this issue in v16.2.4?

Thx!

 

[dbwindom]

My first A/P use after upgrading saw ROLL SLIP in light turbulence and an uncommanded “fighter pilot” roll to the right and nose drop, as if rolling in on a ground target! At 170 knots, it was a little disconcerting. Would NOT have wanted to see such action while in the soup on an approach.
It was when I was expecting a left turning intercept of my GPS course.
Also, my fuel flow/use is no longer “spot on” , as it was before upgrade.
I also am getting “Message” audio alerts, but NO new messages.
Lastly, I am not confident I am getting all the Traffic displays I should.

 

[lancair360]

Catching up on some reading for plane, been neck deep in the Boeing 737 for a while.

On my Lancair it would roll smartly into and out of turns, no roll slip, worked great. After 16.2.4 I get roll slip now. Will have to adjust sensitivity. This update the first big step backwards....roll slip, tach error (didn't affect me) and error adding fuel in the EMS. 1 star, would not recommend.

 

[dmanp]

I have the same issue, AP does very sharp turn initiation now after 16.2.4 upgrade. Was always smooth before. Cruise TAS of 110 in a Sport Cruiser. It’s a fairly disconcerting difference from before. Hope this gets worked out soon.

 

[TrevorMills]

I decided to play with the autopilot settings to see if I could correct the 'aggressive' roll during course changes. The first settings I noticed on the 'Roll Axis' screen are labeled "Low Speed Sensitivity' and 'High Speed Sensitivity'. Not sure if they were there before V16.2.4 ( I don't remember them ). Anyway I changed the 'High Speed' setting from 20 to 12 and it seems to have corrected the problem. Rolling into and out of turns is smooth with no 'aggressiveness'.

Not sure it's technically the correct solution but it has certainly helped to make flights on AP much more comfortable.

It would be interesting to see if others find this solves their issue too.

 

[lancair360]

I had to turn mine down from 20 to 12 as well. Fixed the problem rolling into a turn. If I'm rolling into a turn and then reverse the turn I still get roll slip, but that should happen in normal ops so no big deal.

 

[RV8JD]

Dynon (Don),

You've announced that v16.3.2 is out and fixes some bugs. But the release notes for v16.3.0 and v16.3.2 make no mention of a fix for this aggressive roll-in behavior many of us have seen.

Have your investigations found a cause? Is it an AP settings issue or a bug? If a bug, does v16.3.2 fix it? If a settings issue, what do you recommend?

Please help us out here.

Thanks.

 

[swatson999]

I don't use the A/P that much, so hadn't noticed, but yep...I see the same thing. When it initiates a turn, it's like BOOM, it snaps over right away, then slows to a normal roll-in to a turn. Roll-outs are normal. Adjusting the Heading bug or NAV courseline or what have you, and BOOM, does it every time. I messed with the sensitivity a bit, but only just to futz around and see if it affected it, not as part of any tuning procedure. Lowering it to 8 *seemed* to help, at first, but it was still there.

It's like it's got a step function in the entry to the PID loop, going from 0 to the desired angle as quickly as possible on entry into it.

 

[Rhino]

It's like it's got a step function in the entry to the PID loop, going from 0 to the desired angle as quickly as possible on entry into it.

Don't say loop. You might give it ideas.

 

[RV8JD]

Dynon (Don),

You've announced that v16.3.2 is out and fixes some bugs. But the release notes for v16.3.0 and v16.3.2 make no mention of a fix for this aggressive roll-in behavior many of us have seen.

Have your investigations found a cause? Is it an AP settings issue or a bug? If a bug, does v16.3.2 fix it? If a settings issue, what do you recommend?

Please help us out here.

Thanks.

Bump this request.

And to paraphrase Dr. Evil: Throw us a frickin' bone here! We're the customers ... need the info!

 

[jcarne]

Bump this request.

And to paraphrase Dr. Evil: Throw us a frickin' bone here! We're the customers ... need the info!

+1 on the bump.

Dynon I hate to be this guy but if I'm being honest some of these known issues that have not been dealt with make me feel like existing customers are not being valued. I know that supply chain issues have really put you guys in a crunch to find substitutes so I'm really trying to be patient but my patients is really starting to morph into other emotions. This autopilot issue is a big deal at times and probably a major deal for those that fly IMC. Really hoping it gets fixed sometime soon.

 

[swatson999]

I'm beginning to agree with jcarne about the lack of progress on a lot of known issues. And supply chains don't (or shouldn't) affect *software* development.

 

[Rhino]

It could affect it if hardware changes caused by supply chain problems are tying up developers trying to adapt software to the different hardware. I'm not saying that's the reason. I'm saying there are valid reasons that may not be obvious to us who are not involved in the operation. I spent many years in technology, and saw things like that happen all the time, so I'm most definitely giving them the benefit of the doubt. I have a hard time believing developers are just sitting around at Dynon staring at the ceiling. I think they just aren't communicating well with the customer base, which is hardly anything new for Dynon or any other technology company.

 

[AlanR]

I wonder if this problem of increased aggressive roll is just happening on Skyview HDX versions, because updating to 16.2.4 on Classic D1000's in my Bristell NG5 appears to have made no difference to roll at all!
The autopilot works perfectly as before without displaying any extreme or aggressive fighter roll type symptoms. I am using exactly the same settings as I did before updating the software.