Yesterday I was messing around with panel layout. The boss (wife) looked at it and told me I have to have some steam gauges for when the electrical system fails. I really don't think any redundancy is necessary for VFR flight but I better listen to her. I've been looking at designing redundancy into the electrical system but I haven't read about any methods that only require 1 alternator and are bulletproof. The closest I have found is having two independent buses and two batteries. The "essentials" bus runs off the normal battery until you switch to the backup battery. The backup battery is charged by the alternator but can only power the essentials bus. Problem I see here is if something fries the system everything could get fried because it is all tied together except the backup battery.

The other option is to install "needle ball airspeed" and run the needle off a venturi.

How would you add redundancy to a glass panel if you wanted only 1 alternator and no vacuum pump?

One tiny venturi running one small vacuum gauge is all you need.

Spruce has 4" venturis for $82. It'd be a pretty inexpensive back-up system.

Gump

GumpAir wrote:One tiny venturi running one small vacuum gauge is all you need.

Which vacuum instrument would you use?

Just a turn and bank if you want simple and minimal panel space.

A lot of us old farts have a bunch of IMC hours in our old Super Cubs and the like using nothing but needle-ball-airspeed. Once you learn it and get proficient, it's pretty much a non-event to bomb around in the muck. I still remember when flying IMC with a six-pack of gauges in the panel was a huge treat, and so easy it was like cheating.

Gump

Artificial horizon powered by a venturi.

Probably not powered by a venturi, but you'll notice one familiar gage in the panel of the 747-400

GumpAir wrote:Just a turn and bank if you want simple and minimal panel space.

A lot of us old farts have a bunch of IMC hours in our old Super Cubs and the like using nothing but needle-ball-airspeed. Once you learn it and get proficient, it's pretty much a non-event to bomb around in the muck. I still remember when flying IMC with a six-pack of gauges in the panel was a huge treat, and so easy it was like cheating.

Gump

You're an accident waiting to happen. Don't you know you'll DIE in a matter of seconds without multiple redundant instruments and four radios? Probably just the IFR flight plan that kept you alive. In fact, I think you probably did die in a crash and just won't admit it.

I was told that if I talked on the radio every 15 seconds, giving reports to the local airport that I was 10,000 feet above pattern altitude, that the airplane wouldn't death spiral and lawn dart me into the nearest daycare center. That's the ONLY thing kept me safe all these years.

Gump

The problem with a turn coordinator or turn and bank is they only give you a little bit of information.....not nearly enough to stay alive. Where are you going to get airspeed and altitude? Granted, you could get altitude (sorta) from GPS, but the GPS gets fried with the EFIS.

If you really do decide you want redundancy, I'd either install steam gauge airspeed and altimeter, OR a separate independent backup EFIS, like a Dynon D 10. Power that separately and if the EFIS dies, you've got everything you need.

Or, just install the primary EFIS and stay out of the goo. You can fly one of these planes with NO data after a little familiarity......as long as you're VFR.

MTV

Oh shit, I missed that part. Whee, you're gonna need a bigger panel.

Gump

mtv wrote:If you really do decide you want redundancy, I'd either install steam gauge airspeed and altimeter, OR a separate independent backup EFIS, like a Dynon D 10. Power that separately and if the EFIS dies, you've got everything you need.

Or, just install the primary EFIS and stay out of the goo. You can fly one of these planes with NO data after a little familiarity......as long as you're VFR.

How do you power it separately with one alternator? Install second battery and a diode so the battery gets charged and only runs the backup EFIS off the second battery?

I agree that no backup is necessary if you stay VFR...I guess my wife knows me too well.

GumpAir wrote:Oh shit, I missed that part. Whee, you're gonna need a bigger panel.

The Bearhawk is somewhat limited in panel space.

Here is my rough draft:


The 650 is a wish list item.

Very cool.

whee wrote:.... The boss (wife) looked at it and told me I have to have some steam gauges for when the electrical system fails. I really don't think any redundancy is necessary for VFR flight but I better listen to her.
....

For VFR flight, I'd add a steam-powered airspeed & altimeter, plus a ball. That should be plenty.
What's the odds of your glass panel gear failing at the same time as your accidental flight into IMC?

The dynon 180 has a internal back up battery good for at least 30 minutes, my back up is the Garmin 196 set to the panel page if needed, the 196 uses AA batteries, change them at the annual whether you use them or not, this system is dirt simple, light weight, and should get you out of the sop if need be and has served me well

With these new EarthX batteries, having 2 is not a big deal. Easiest way to have a redundant system with no steam is to have dual EFIS. If you are truly doing IFR with glass only, do invest in dual ADAHRS boxes or a backup electric attitude indicator. I've had one, a Dynon unit, fail. It was replaced immediately without any whining by the way.

We are putting MGL engine instruments in the S20 independent of the AFS engine monitor. If I were building another for myself, after a couple under our belt, I would still be VFR only, but basic engine gauges, Garmin 690-whatever portable, and an electric AI. All that EFIS is cool but in my opinion once the cool factor wears off you're left wondering why do I have this in my puddle jumper. [emoji1]

Or, if you're worried about panel space, stick a trutrak adi in place of the turn and slip. Comes with a ball and you get an electronic AI. dual earth-x to get a redundant power.

whee wrote:

mtv wrote:If you really do decide you want redundancy, I'd either install steam gauge airspeed and altimeter, OR a separate independent backup EFIS, like a Dynon D 10. Power that separately and if the EFIS dies, you've got everything you need.

Or, just install the primary EFIS and stay out of the goo. You can fly one of these planes with NO data after a little familiarity......as long as you're VFR.

How do you power it separately with one alternator? Install second battery and a diode so the battery gets charged and only runs the backup EFIS off the second battery? .

Yes. I believe that's the way they're set up "for real" in IFR airplanes.

An A/S and alt don't really do shit for you in inadvertent IMC......sorta. But a second independent EFIS would give you a lot of options. Or as others noted, install one of the Garmin GPS units with a "panel page". And call it good. Wife asks question, push appropriate button, demonstrate pertinent page.....jive on.

MTV

I am with the 747, Artificial Horizon is best:

whee wrote:..... I really don't think any redundancy is necessary for VFR flight but I better listen to her....

Are you looking for redundancy for when your electronics fail when you are accidently in IMC (small chance of failure during a small chance accidental IMC incursion), or redundancy so you can finish a VFR flight with the normal handle on your altitude & airspeed? Most of the glass panel personal aircraft I've seen have an airspeed, altimeter, & ball-- plus a compass (which you need anyway).

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This is a really interesting thread re panel design and redundancy.



I can't remember, but somewhere there was this website that allowed you to play around with a panel, and just brainstorm a layout.

I like what Whee has done re the mock up. I wish I could remember the freeware package & website that could complement these paper mock ups ?