GRT and BMA lockup in the same flight. ARGH!

[Kahuna]

In 250 hours I have had 4 BMA G3 Lite lockups and 1 GRT lockup in flight. You would think that the chances of this happening in the same flight are near zero. Well near zero is not zero and it happened to me yesterday while on a return trip from Cozumel with our group on my last leg.

Whiz banging along smooth air, my BMA went TU with the following screen. Sorry for the crappy screen, but you get the jist.


I reset it and everything was fine.
About 60 miles later I was set up for a GPS approach into LZU. Weather was deteriorating with rain and low vis so I selected the GPSA approach into LZU. I had never done this approach in my RV8 into my home airport, but I thought it was worth trying based on my inbound direction it was easier to set up. So I requested it and punched everything in. As I got close to the airport, wx was getting worse, I decided I wanted the ILS 25 into LZU instead to get the lower minumums. I went to change runways on the GRT an wammo, locked up tight. Could do nothing on the screen. Froozen solid and I snapped this crappy picture.


I changed over my scan to the BMA G3 and was able to finish the landing uneventful.
Moral of the story is.
1. If you think these things are ready for prime time, think again.
2. Be ready for issues with all these gee whiz features
3. If you think having 2 differnt EFIS helps lower the risk, your probably right. But lower is not zero.
4. I highly recommend a power switch to reboot these things in flight. When they lockup, you dont want to have to kill your entire panel with an avionics sw or master sw. while working an approach or in the system.
Have a seperate sw on the EFIS for the ability to cycle the power in flight.

Be careful out there.
Best,

[n468ac]

First ... I agree you must have a way to reboot your EFIS's inflight without effecting other systems (we have seperate CB's with Sporty's Yellow CB cabs on them for the EFIS's, the red ones are for trim and flaps.)

Two ... Looking at the screen shots and hearing your writen issues, are you are seeing a low or over voltage problem? Could they both be overheating?

Three ... no matter what system or systems we used they can fail and will fail at the wrong time. If you were using an vac system and the pump when out, there would have been no way to 'reboot' it. If you were using an VOR/ILS and the head or radio quit, then what? I have had both of the previous have happened to me ... the first one in a 421 and then the second in a King Air F90.

[Sam Buchanan]

Moral of the story is.
1. If you think these things are ready for prime time, think again.
2. Be ready for issues with all these gee whiz features
3. If you think having 2 differnt EFIS helps lower the risk, your probably right. But lower is not zero.
4. I highly recommend a power switch to reboot these things in flight. When they lockup, you dont want to have to kill your entire panel with an avionics sw or master sw. while working an approach or in the system.
Have a seperate sw on the EFIS for the ability to cycle the power in flight.

Mike, sorry to hear of the stressful approach after what was no doubt a great trip! I have to wonder if two glitches within 60 miles is more than a coincidence. Might be time to take a hard look at the power feeds to your EFII to make sure nothing weird is going on.

Observations concerning the points you made above:
1) The digital flight instruments are probably as reliable as a vacuum system. Pumps and gyros have been failing for decades but have still been used in prime time.
2) We should be ready for issues with all the equipment in our panels, regardless of whether electronic or mechanical.
3) True.
4) I agree. Sometimes the best recourse is reboot, and we need to have an easy way to accomplish it.

Thanks for the report and reminder that anything in our panels can fail, and will probably do it at a time when least convenient.

[Kahuna]

Originally Posted by n468ac

Two ... Looking at the screen shots and hearing your writen issues, are you are seeing a low or over voltage problem? Could they both be overheating?

Overheating? ....I dont think so. But I have no way of knowing. These both happen in ~70F OAT cloudy skies and not hot. They have been in hot hot hot temps and I have not seen this. DOnt think it is heat related.

These are on 2 different busses. I have under and over audible voltage alarms with tight tolerances on the voltage for a quick alert(ACS2002 eng monitor). The system voltage was stable when this occurred. Alarms are trapped and must be acked to proceed and there were no alarms.

On the GRT, she locked up while pushing buttons to change runways so Im pretty confident its a software issue there.

On the BMA, I really dont know. It locks up like that when just flying along. I can make it lock up like that if I jump in, fire up, and taxi too quickly before the ahrs has a chance to stablize. But the fourish times it has done this in flight, I was not doing anything strange. Just cruising along.

And Sam, all good points.
Best,

[Jamie]

Kahuna:

Sorry about your problems. That really sucks.

But on to more important issues: Where are your trip pictures for all of us wannabe's?

[MrNomad]

According to G3, their program relies upon DOS. According to GRT, their product relies upons Windows.

As we've all learned to appreciate (tolerate), Windows is the target of every hacker on the planet. Having built & repaired Windows pcs and pc networks for the better part of the last 20++ years, it would NEVER be my first choice to run my panel.

In this instance, a responsible software vendor would place this matter on the top of his priority list and potentially dispatch an engineer to your hangar so he can research the issue when the equipment craps out. That's what I did when I served as CEO of a national software development firm and my product was NOT being used at 10k AGL.

Assuming the vendor forces his (creative) programmers to produce code that never exceeds arrays causing aberrant conditions, and selects electronic components that can handle sags, surges, and transient spikes, it's possible to produce a reliable product on either operating system.

In both cases, another program may be dispatching a signal that the G3 and GRT were not programmed to handle. The common bus can also contribute "information" neither was programmed to handle. The G3 displayed EXCEPTIONS that are useless to the end user, and the other does what Windows typically does, FREEZE.

For the sake of all of, please contact the vendor(s) and let both know that you'll be producing a running dialogue on this forum and other forums to keep fellow pilots apprised on the problem resolution.

Feel free to contact me offline. Before I retired, I did a lot of disaster recovery work concerning other people's software.

No charge.

[Ironflight]

Kahuna -

Great report on a bad day! I agree with you and Sam's posts - and add that the name of the game is backups, backups, backups! I spend a huge part of my life in simulators and simulations with sophisticated flying machines having their systems failed on me non-stop. I ALWAYS expect to be flying with nothing left but two half-dead AA batteries and a couple of pieces of re-used safety wire keeping me functioning. Do that four thousands of hours, and you are amazed when the real flight goes so well - and you become very paranoid, wondering what has failed that you haven't caught yet!

It's good to hear of other people's "incidents", as it reminds us to always be ready. I haven't had a lockup in my GRT systems yet, but I have the TruTrak as my prime backup, and good old partial panel as a backup to that (and I practice it!). Not going to try and troubleshoot your problem by remote control - it is clear that you have a well-practice backup plan yourself. I agree with those posts that point out that the old stuff can fail as well....

The best protection is a well-thought out operational redundancy scheme, practice, and currency!

Paul

[Yukon]

Originally Posted by n468ac

First ... I agree you must have a way to reboot your EFIS's inflight without effecting other systems (we have seperate CB's with Sporty's Yellow CB cabs on them for the EFIS's, the red ones are for trim and flaps.)

Two ... Looking at the screen shots and hearing your writen issues, are you are seeing a low or over voltage problem? Could they both be overheating?

Three ... no matter what system or systems we used they can fail and will fail at the wrong time. If you were using an vac system and the pump when out, there would have been no way to 'reboot' it. If you were using an VOR/ILS and the head or radio quit, then what? I have had both of the previous have happened to me ... the first one in a 421 and then the second in a King Air F90.

If vacuum pumps are replaced every 500 hrs, they are as reliable as any electrical component. A vacuum system is a mechanical system totally separate from the electrical system, and when combined with an engine vacuum source backup, are nearly 100% reliable.

[n468ac]

Originally Posted by Kahuna

Overheating? ....I dont think so. But I have no way of knowing. These both happen in ~70F OAT cloudy skies and not hot. They have been in hot hot hot temps and I have not seen this. DOnt think it is heat related.

These are on 2 different busses. I have under and over audible voltage alarms with tight tolerances on the voltage for a quick alert(ACS2002 eng monitor). The system voltage was stable when this occurred. Alarms are trapped and must be acked to proceed and there were no alarms.

Just thinking out loud ... Are they on the same ground bus?

I would also like to hear what support for both these products have to say.

[todds]

I happened to see a post about this lockup and forwarded it to Jeff in our software department. He was able to determine the problem and we will have a new release to this afternoon.

A few notes:
1) We address all software issues, and they are of the highest priority.
2) We have found Windows CE to be highly stable.
3) The software has been so reliable that most users are unaware that the display can be rebooted by holding down the left and right outer softkeys for 5 seconds.
4) For IFR our system is designed as a dual screen system with a seperate AHRS to allow a single display to be rebooted while the second display is still operational as another level of backup.
5) We can only address software or hardware issues that we are informed of, had I not seen this posting we would not have been able to make a fix.
6) The AHRS (Attitude) is independent of the display unit and is never effected by the display lockup, and a 10 second reboot would restore the display.


Todd Stehouwer
Design Engineer
Grand Rapids Technologies, Inc.
todds@grtavionics.com
616 245-7700