Uncommanded roll with D10A/AP74

[Sandyt]

I have logged one previous post on this subject. That was to explain a very critical upset I suffered in a military jet I use for business travel on Nov 11 2011. The first high altitude test flight resulted for an uncommanded roll by the EFIS-D10A in IMC conditions. The event ocurred passing through 15000 ft in a climb.
The unit was returned to Dynon and a refurbished unit sent back. My Avionics shop installed this one and in a test flight passing 5000 ft in a climb, the horizon shifted about 30 degrees from horizontal with the aircraft level. The unit was diagnosed with a fault on the ground which would have required re-programming  by the local shop. A different problem.
A third EFIS unit (refurbished) was then sent and installed. This unit was unusable because the display was so dim it could not be viewed even with the highest brightess set.

Finally, a fourth EFIS has been sent to us by Dynon. This time it is a new one.
Through all of this my aircraft has been out of service since November, my shop has spent considerable time on the R&R, I have spent several thousands of dollars on jet fuel for testing, and I came as close to having a fatal accident as I have in my flying career.   
I am hopeful that Dynon will in the end stand behind their equipment and appreciate my inconvenience.

 

[dynonsupport]

Hi Sandy,

I'm not one of the people that you've been working with at Dynon, though I have heard about your case since it involved such exceptional circumstances. I've just looked a bit closer at your RMA history, and I can see that we've been through a couple of iterations (and units), and we're not happy that you're continuing to have problems with our products so far. I hope we're about to end them with the new unit that we recently shipped.

We do try our best to ensure that every customer is delighted with our products, and when they don't, we try to get things fixed in a hurry. To that end, we'll continue to work with you to get you the performance that you're after (if it can be attained in your aircraft), or, if it can't, or if you just decide that you want to go in another direction, we'll take your products back for refund at any time while we're trying to work through this issue with you. I'm hoping you won't decide that, but I just wanted to put the offer out there.

For everyone else following along - the original problem that Sandy experienced wasn't directly reproducible at Dynon or evidenced by a clear failure, and the ideal datalogs that might have helped figure out exactly what was going on weren't available. To be clear, the problems with the units he's had since his original unit weren't related to the original issue. His string of problematic units is rare and embarrassing, frankly.

Sandy - please continue to work with the engineers and support team within Dynon (using the email case thread you have going with them) as you install and check out your new EFIS. Some specific things that come to mind:

- Please make sure the datalog is set to 1/sec updates (I think you've already done this) so that we can catch any anomalies that might shed some light on a root cause if you should continue to experience any issues.
- Before using the autopilot at all, make sure the EFIS's instruments - particularly the attitude indicator - work properly in flight.
- Before using either the autopilot or attitude indicator in IMC, make sure that they're fully tested and working reliably in VMC conditions.

Thanks for your continued patience.

Michael Schofield
Product Manager
Dynon Avionics