Know your avionics

[APACHE 56]

I experienced an alarming avionics display incident today and it was not the result of a failure of either of my GRT displays (HXr and miniAP). However, it points out a potential safety hazard that I bring to your attention. I may find after this post that there is already a solution that I am unaware of.

I experienced a dual screen total blackout and could not get the screens back on line: note that I said nothing failed.

My aircraft is a Vans RV8 which has a bubble canopy. Today in Florida was cloudless sky and very bright. I?m going to try to describe the button pushes that got me into this predicament. I departed Venice, Florida this AM about 0945. While on runway heading and scanning for traffic I wanted to turn the heading bug about 90 degrees North to get me on a gps intercept path. I?ve done it so many times that my left hand just knows about 90 degrees I then pushed the right button to call up the AP heading mode. Looking down to fine tune the setting I was shocked to see both screen blacked out. I went thru all kinds of trouble shooting steps, cb?s, avionics master, frantic pushing of soft keys all to no avail.

First my HXr is on the Master Switch with a TCW Smart Battery so when I start the screen does not reboot. If I had cut the MS that would have helped. Second, the left knob on the GRT HXr has two functions: heading AND Dim. If you are in Screen mode the Dim feature is activated. Two short spins to the left and you are in Blackout mode; but not exactly, more on that later. If you don?t notice that you are in Blackout mode and push any softkey or button the menus change and there is no way in heck you can find your way back. Once back in my hanger with only skylight as a source of illumination the min Dim setting had enough light to see the screen BUT NOT enough light to discern any of the softkey menus which change every time you select a different mode and there is a zillion of them. Once you lose track you are toast.

I am going to recommend that the two screen system (HXr and mini AP) Dim features be decoupled (I?ll get with my avionics installer to determine if that feature is already in place). Second there should be a ?panic? button that allows you to go to full bright and start over or a ?user selected min Dim? setting in the setup menu. If that is already there I could not find it.

All the avionics manufacturers make a plea with their customers to wring the system out in VFR and that is good advice. I can?t imagine how I?d feel had I been in the clouds.

As an aside when I fly beyond my zip code I always take my iPad and Stratus/Foreflight backup. That was good for an airspeed/altitude swag. Plus I am unable to completely wean myself from analog so I have one of those stackable JPI oil pressure displays and my Electronic Ignition Commander is set on RPM display when I fly. I was an easy flight back to the Space Coast.

[Steve Melton]

About a year and a half ago.... it was a good flight from El Paso until I decided to jump over a line of weather about 40 miles wide around Huntsville to avoid rain on January 25, 2015. After 20 miles over the top I had to climb higher than I originally thought. I climbed to over 20K ft and the temp was -27C. I was picking up ice as I flew across the tops and the prop had some vibration. The controller was giving me a hard time for unapproved flight into Class A airspace but eventually gave me a block altitude at fight level 200-210. Then I accidentally shutdown my avionics master (probably with my knuckle) and that shutdown my Dynon, radio, transponder, etc. The funny thing was I couldn’t figure out how to turn it back on. I remember looking at the Dynon backup power button and pressing it but later realized I was pushing the wrong button. I also checked my fuses, etc but somehow it didn’t compute. I remember putting my nose close the display and staring into the display thinking is this thing really dead when I need it. It took a lot of effort for me to check my fuses and I thought it was better to stop that and just fly. I was on O2 but I believe I set the level to 16K before the climb as I had been flying 9.5 to 13.5 K all day. After clearing the band of weather I found a hole and then spiraled down. After reaching 5K under the ceiling in the rain it was obvious to me the avionics master switch was off. I’m not sure if it was stress relief or more O2 that helped. I turned the avionics switch on and contacted center and they said they were declaring an emergency for me. The controller directed me to the nearest airport, DMQ. When I walked into the FBO the secretary said the FAA wanted to talk to me. The next several calls I made were to Memphis Center and then later the FAA office.

[Bavafa]

It is a good lesson to know about the dim function at least on GRT. Once after flying at night, I had forgotten to change the display to the brightest after arriving at the hanger. A few day later when I went for flying, I couldn't see the screen booting up and it took me a while to notice that it was on the lowest setting, one. Even after changing it to the brightest, you will need to wait a short while before shutting it down otherwise it will not be saved and on the next power up it will be on the pervious dim settings.

[rzbill]

Maybe GRT or a GRT user that installed the remote dimming function (I did not) could comment on whether the left knob menu selection for DIM is either gone or inactive in that configuration.

Its not clear from what I reviewed in the manuals whether that dim function disappears when external dimming is configured.

[BobTurner]

I have an HX/HS with external dimming.
The external voltage overrides the HX knob setting when present; no external voltage enables the knob setting.
The minimum brightness is software-configurable, but imho the minimum brightness desired for dark nights is so little that it will be hard to see in bright sunlight.

[rightrudder]

As a Sport SX owner, I appreciate you posting this, Don. I'm strictly VFR, but having the display go dark is, at the very least, unsettling. I do have some "steam" backups for peace of mind.

[n468ac]

Thats why we have a panel designed for backup ...

Two EFIS's Dynon and GRT HX
Two GPS's Bendix King and Garmin
stand alone autopilot
stand alone radio

The chances of running into a software or hardware error that will take down the complete panel is much lower. BUT YES ... you really need to know your hardware.

[RVbySDI]

Troubleshooting computer software and/or hardware (exactly the environment you found yourself in) should start with:

Step 1 - Whatever action(s) were taken immediately prior to the failure; reverse the action(s) in the opposite order they were enacted with the goal being to place the software back into the state in which it was prior to the failure.

[lrush8]

Having a failure of my I pad in IFR actual conditions and not flying as much as I would like has caused me to go back to Jeppesen paper . It works and doesn't fail at a critical time . Their is no room in real world IFR for confusion or failures than can take your life as well as others .

[Danny King]

Don,
Thanks for the great write up. You may have saved some RVer in the future.