D100 Display: Right Turn Drift

[bule]

Intermittent Problem. After engine start, aircraft on level ground, display will initiate a right turn (up to 30 degrees). Occasionally will persist into the flight regime after taxi. Generally, it corrects itself and stabilizes after 5-10 minutes following start.
I only noticed this begin to occur following bright screen upgrade last year (not suggesting that it's related). Is there any history of this intermittent condition and if so, what is the corrective action? Trouble shooting tips are welcome. HS34 and AP74 are installed (FYI).
Thanks!

 

[jaroberts2pe]

My D180 also shows intermittent 5 degree turn to left after start, sometimes lasting 5-10 minutes into flight. Always corrects in time. Did not correct with installation of 5.1. Don't like it but am getting used to it.

 

[bule]

Thanks. Any insight from Dynon or anyone else experiencing the same condition?

 

[dynonsupport]

When you guys say turn, do you mean in heading only, or bank angle, the turn rate indicator, or some combination of the above? Heading issues are often explained by a non-optimal EDC installation location, but erroneous bank indications usually warrant a trip back here.

 

[bule]

It is erroneous bank indication.

 

[dynonsupport]

Is it only after engine start, ie, when things are vibrating, or is it anytime after the unit is first powered on? We don't have any widespread vibration-related issues, though once or twice in history we've managed to narrow down odd attitude behavior to a particularly shaky panel. It probably wouldn't hurt to have your unit back here for a look, especially if it's not correlated to the engine being on.

 

[bule]

I will have to start checking the unit prior to engine start and let you know. Engine operation is smooth (0-360). The failure mode is intermittent, and recovers with time (regardless of power setting/flight regime). It behaves like the older Gyro's that were "slow to spool".
Will advise.
Thanks.

 

[DBRV10]

like this?

 

[bule]

Yes. I checked it today prior to engine start (to address the engine/panel vibration concern) and took similar pictures with iPhone, which I will load later. The bank angle varied between 5-10 degrees (on ground and in flight). Nose up pitch indication is roughly 3-5 degrees. System stabilized 15-20 minutes after engine start. Aircraft had not been flow in 3 weeks (not sure if that matters). It may be a good idea to have the unit bench tested if there is no widespread instance of this failure mode. The unit was installed back in 2001 and was sent to Dynon for bright screen upgrade last year. This condition has only occurred (intermittently) at initial power-up.

 

[dynonsupport]

If you power up in gusty wind conditions, the airspeed aiding might be causing some momentary erroneous attitude depictions. If that's not the case, then we should probably take a look at your unit.