[macrafic]

I have been reading the posts about this topic for several weeks. There seems to be a general sense that steam guages (airspeed, AI and altimeter) are required as a backup to an EFIS for IFR. I'm not sure I'm understanding this. Could I get some comments on this?

In particular, could I get some comments on how the following configuration meets, or doesn't meet, your idea of an IFR platform? Dynon FlightDEK-D180 on the main buss, Dynon EFIS-D10A on the essential buss, Bob Nuckolls dual alternator and single batter "all electric on a budget", at least one E-mag and one P-mag (if not two P-mags), True-Trak Digiflight II (2-axis auto pilot), and 2 independent AOAs (Dynon and ACS).

The weakest point in this configuration seems to be a single point of failure for EMS information. While the D180 can feed its display to the D10A, should the D180 display fail, I suppose it is possible for the D180 to fail in such a way as to be unable to feed the D10A anything. In that case, I would have an EFIS (D10A), but no engine instruments (since these units can not share probes).

If the D180 fails. leaving me with the D10A, I still have all the instrumentation (and much more) that I would have if I had backup steam guages instead.

 

[DGlaeser]

IFR Panel

I believe many of us are using steam guages to back up a single EFIS unit. If you are going to have dual independent EFISs, that provides redundancy. Some may argue that if a software problem causes a failure, it might affect both units if they are running the same s/w. You get to decide if this is a real risk Your autopilot is actually a third way to keep the sunny side up.

If you follow Bob N's philosophy, power everything essential from the Ebus. Why lose your primary EFIS when you go to the Ebus? Switch off the other one to save battery if that is an issue. Same for Nav radios.

In an emergency, engine info is not essential IMHO - no backup required.

 

[frankh]

suddy (cloudy) side up

Here's mine

AI and alt steam guage
Dynon EFIS (battery backed up)
Pictorial pilot (also gives visual representaion of the horizon)
GNS 430
ICOM A200
GTX 327

Two electric fuel pumps (no mechanical pump)
SD10 backup alt (just runs fuel pumps, ICOM and Transponder, if the main alt dies)
Emag/Pmag

Frank

 

[Pirkka]

In an emergency, engine info is not essential IMHO - no backup required.

I would say same thing. It's unlikely that all problems will come at once. If you lose your Dynon, the propability of engine failure is smaller but exists. I think that it's better stay in ground rather than trying to backup everything.

And the another way: how much you really use engine meters? You just check quickly that engines are on green but how much closer you keep track on velocity, altitude or heading. If you would have no gauges at all what would be first meters that you would select? So they should work whatever happens also when something fails.


How ofter the pitot is blocked by bee or something? Just wondering is there reasong to have discrete pitot for electric/stream systems?

 

[N395V]

I have a friend with 2 Dynons who was VFR on top when lightning struck"nearby" both units went black.

I have 1 pitot and 2 BMA Efis's and a mud dauber disabled both my systems (shame on me for an inadequate preflight)

IMHO if you go IFR you need 1 steam guage gyro and a separate pitot /pitot static system as backup.

Also if your nav system is integral to the EFIi then a backup portable GPS.

 

[Captain_John]

Something to think about:

Everyone nowadays (including you, myself and certified builders) are installing backup instrumentation to any electric system. It is just the generally accepted "thing" to do.

I think this has something to do with the traditionally unreliable nature and pessimistic view of everything electrical/avaition.

Rapco has made a MINT on replacing pumps for years and we all know the unrelaible nature of the tradional AI, but we accept it because it is mechanical and we understand it's limitations.

Just a guess into the future here, but I say that when pilots treat their electrical systems with the knowledge and operate it with the same deftness that we do our steam system, we will see people dropping the steam backups and going totally with panel displays.

We, as a group are not ready to make that step now, being paranoid pilots... but there are a few bold souls out there and I am not going to chastise them for it!

CJ

P.S. Maca, I think you are on the right track!

 

[MTBehnke]

Backups are great, but regardless of whether your talking redundant glass, glass with steam backup, or all steam, you also need a way to decide which one's telling the truth. I'd be careful to not assume an EFIS failure is going to be obvious by a blank or locked up screen. A software bug in your EFIS could be showing level flight while your backup is showing a steep bank turn. Which one you going to follow?

 

[aadamson]

I totally agree

There is no *requirement* for backup steam gauges in an IFR experimental panel. There is currently in the certified world however. So that has carried over to the airplanes that we build. I would suggest that some DAR's may be more comfortable with seeing a panel with those 3 mentioned gauges, but again, it isnt a requirement.

I also agree fully with the failure concepts listed above. I advocate greatly, training, including partial panel with a hybrid panel. There are ways that you can introduce mach failures into a hybrid system that you should really learn to recognize and adjust your scan and flying based upon.

You'll have to develop each of these flight environments once you have your panel and set behind it for awhile, but it should be included in your currency training.

IMHO that is

 

[prkaye]

IFR upgrade?

How big a deal is it to upgrade your panel to IFR later on? I was thinking of getting my plane done as a VFR machine, for cost and time (and because I'm not IFR certified). But if I think I may someday want to go IFR, should I make the panel that way right at the start, or is it not too big a deal to open it up and add the required instruments later?

 

[DGlaeser]

IFR Upgrade...

How big a deal is it to upgrade your panel to IFR later on? I was thinking of getting my plane done as a VFR machine, for cost and time (and because I'm not IFR certified). But if I think I may someday want to go IFR, should I make the panel that way right at the start, or is it not too big a deal to open it up and add the required instruments later?

The big problem is predicting exactly what you will want in your IFR panel. The electronic world changes quite rapidly, and by the time you're ready to upgrade you'll probably have choices that don't exist now. My suggestion (worth what you paid for it - when you're ready to upgrade, get a new IP and configure it with what you want - including re-use of stuff you already have.
The one thing I do suggest is to be sure your fuseblocks (primary and Ebus - assuming you're doing an AeroElectric inspired system) have some empty slots for future expansion.

 

[Dad's RV-10]

Here?s my 2 cents. My father has asked me to help him conceptualize the remainder of his RV-10 EFIS build. My philosophy is all about eliminating a single point of failure (SPOF). He?s already purchased a 2 screen Chelton system, but has yet to purchase an EIS. Plus, there is still the issue of backing up basic flight information (attitude, airspeed altitude and heading).

My understanding is that the 2 screen Chelton uses a single AHRS and a single ADC, which is combined into a single remote unit with GPS. You can add a second redundant GADAHRS, at additional cost.

I think however a better and more cost effective solution would be the addition of the Advanced Flight System AF-3500. Combined with a 2 screen Chelton, the AF-3500 solves a lot of the functionality and redundancy issues. It is a combination EFIS/EIS and has its own internal AHRS and ADC. This solves the issues of backup flight information plus provides a source of engine instrumentation (not to mention flap position, AOA, W&B, checklists, audio alerts and a few other things). I would however provide independent pitot and static sources for the AF-3500 to eliminate another potential SPOF.

Powering the AF-3500 via a separate bus provides power redundancy. Plus if I?m not mistaken, the AF-3500 can be ordered with an internal battery backup for additional power redundancy.

Also, the AF-3500 will interface with the Chelton allowing for the display of engine parameters should the AF3500 display fail.

Based on the reading I?ve done thus far, this is the configuration I?m recommending to my father. I think it will provide a VERY redundant, functional platform. Obviously this is not the cheapest setup, but it is more efficient than adding a separate EIS and purchasing a second GADAHRS for the Chelton. More bang-for-the-buck. Throw in a second GPS and a good AP and this should be a very reliable system (if wired smartly).

My basic philosophy for redundancy is to start at the panel and work backwards. If I come to a point where losing one source (whether it?s power, pitot/static, attitude, air-data, symbology, etc) would cause a complete loss of the respective information, I look for an alternative.

Brad

 

[aadamson]

Brad, I suppose you know that the Cheltons are "dual redundant" between themselves. Put one on one buss, and the other on another, and if either screen fails, the other picks up. or if either buss fails. You still have flight instruments.

Also, the cost of the AI, AS, and ALT (and I'm going to use an all electric AI - the Sportys certified one with TB Level), is still cheaper than the 3500. I'd have to do the math, but if you went with an ADI or something similar for and AI, and an EIS 6000, I'd bet that price would still be cheaper than the 3500. so then you'd have to figure out how much the GLASS concept is worth for redundancy. Might be that the cost difference would fund that second GADAHRS

Isn't the ability to do what you *want* a wonderful thing? Good luck, I'm in the process of putting my Dual Chelton system in, but went down the path of the 3 steam gauges, with a twist. I could swap out the AI for a BMA G4/Lite - if they every get all the bugs out of it that is ...

 

[Dad's RV-10]

Brad, I suppose you know that the Cheltons are "dual redundant" between themselves. Put one on one buss, and the other on another, and if either screen fails, the other picks up. or if either buss fails. You still have flight instruments.

Yes Alan, you are correct. That gives you redundancy for an individual screen failure and/or a bus failure. Obviously the single GADAHRS is the SPOF for the dual screen Chelton.

Also, the cost of the AI, AS, and ALT (and I'm going to use an all electric AI - the Sportys certified one with TB Level), is still cheaper than the 3500. I'd have to do the math, but if you went with an ADI or something similar for and AI, and an EIS 6000, I'd bet that price would still be cheaper than the 3500. so then you'd have to figure out how much the GLASS concept is worth for redundancy. Might be that the cost difference would fund that second GADAHRS

I haven't done the math recently, but the AF-3500 offers a lot of functionality for the price. I don't think (though I could be wrong) that the EIS 6000 has audible alerts. Also, the integration of the flap position, fuel level and checklist features combine for a very clean panel layout. The EFIS functions would normally be relegated to back-up roles, leaving the engine parameters displayed full screen.

Isn't the ability to do what you *want* a wonderful thing? Good luck, I'm in the process of putting my Dual Chelton system in, but went down the path of the 3 steam gauges, with a twist. I could swap out the AI for a BMA G4/Lite - if they every get all the bugs out of it that is ...

Yeah...there are tons of options. One of the things I tried to consider was scan proficiency. Flying with a PFD destroys your six pack scan. You get very used to having all necessary information presented in a very centralized location.

I considered a steam gauge trio as a back-up option for my dad. But if things were to get bad enough that the Chelton were not usable (GADAHRS failure, pitot/staic failure, dual screen failure) combined with an AP failure (the AP should be the REAL crutch here), you're going to have to get hand flying in a big hurry, and you're also going to be flustered trying to figure out what the heck is happening.

If this were the scenario, as unlikely as it is, being able to revert to a single screen EFIS display (the AF-3500) would be a much easier transition under pressure than trying to pick through three or four steam gauges (likely not arranged in a six pack) that you haven't been looking at for the past 500 hours.

Good luck to you too Alan. It's even more wonderful for me because it's not my money

Brad

 

[aadamson]

I can't remember on the EIS either... I went to the MVP-50 on mine, which has a bunch of alarms with voice if you like. The Chelton tho, does have alarms, it's part of it's cautionary warning system. Those include some of the information from the mvp50 (which btw, Chelton calls the EAU-2, not to be confused with the EAU-1 which was the EIS from GRT that was used by Chelton and probably still is)...

Don't get me wrong, the 3400 is a pretty cool box... But its got lots of technology that isn't proven yet. I wanted my "backup" to be as reliable or better than my primary .... And flying behind a G1000 for the last 2 years, which also includes the 3 steam gauges makes it, for me, and easy transition.

In the certified world an EFIS *can't* be the primary nav source, the 3 steam gauges are ... Go figure.... FAA at it's finest.

 

[JonathanCook]

EFIS backup and Grand Rapids Sport EFIS

Brad,

My plan for EFIS backup is three steam gages and a compass. The main reason for this is that you need something to break tie when one instrument fails.

Instead of AFS you may want to look at Grand Rapis Sport EFIS. It is virtually the same as their top of the line product, the horizon Series. The sport does not have HSI, but it does have CDI and glide slope. (I do not represent Gand rapids, but I spoke with them and other vendors at length last week.) Sport EFIS is $2800 plus $1400 for engine monitor (four cylinder with probes). GRT also has a no cost upgrade path, so you can start with a sport and later get the horizon.

Jonathan

 

[Dad's RV-10]

Hey John...we looked at them all at OSH and felt the AFS had a better display and function set.

Who knows...wait another week and there will be another option

Brad

 

[az_gila]

A question on EFIS and gauges

For those of you flying with back up steam gauges, I have a question..

As an example (fairly typical, I think)
A panel set up with an EFIS (say a Dynon) with a 3 1/8 Airspeed and Altimeter on either side of it....

Do you really look at the EFIS for your data, or is it easier for your eye to see the traditional Airspeed and Altimeter (in a familiar analog format)?

Do you really use the EFIS airspeed and altitude, or are you still subconciously using the old gauges?

gil in Tucson ..... wondering what a transition to an EFIS would be like

 

[osxuser]

I can't remember on the EIS either... I went to the MVP-50 on mine, which has a bunch of alarms with voice if you like. The Chelton tho, does have alarms, it's part of it's cautionary warning system. Those include some of the information from the mvp50 (which btw, Chelton calls the EAU-2, not to be confused with the EAU-1 which was the EIS from GRT that was used by Chelton and probably still is)...

Don't get me wrong, the 3400 is a pretty cool box... But its got lots of technology that isn't proven yet. I wanted my "backup" to be as reliable or better than my primary .... And flying behind a G1000 for the last 2 years, which also includes the 3 steam gauges makes it, for me, and easy transition.

In the certified world an EFIS *can't* be the primary nav source, the 3 steam gauges are ... Go figure.... FAA at it's finest.

The G-1000 doesn't have an external Nav head does it? I've never seen one. I don't think thats quite correct because even the new G550's and stuff have glass backup instruments, no real steam gauges.

 

[JonathanCook]

what functions did you like?

Brad,


I know that people like the AFS engine display commenting that it well laid out and easy to follow. What functions does AFS have that you liked better than GRT?
Jonathan

 

[Ironflight]

Good Question!

For those of you flying with back up steam gauges, I have a question..

As an example (fairly typical, I think)
A panel set up with an EFIS (say a Dynon) with a 3 1/8 Airspeed and Altimeter on either side of it....

Do you really look at the EFIS for your data, or is it easier for your eye to see the traditional Airspeed and Altimeter (in a familiar analog format)?

Do you really use the EFIS airspeed and altitude, or are you still subconciously using the old gauges?

gil in Tucson ..... wondering what a transition to an EFIS would be like

Gil,

I have to be honest Gil - I still catch myself flying with the analog instruments (especially VFR), since they are in my field of view! I have spent plenty of time flying with EFIS displays, and I have no trouble with them when there aren't any analog instruments in sight...biut it is hard to ignore them when they are there! And quite frankly, I don't think there is a need to ignore them- use whatever tools get you to where you want to be!

When I am "on the gauges" IFR, it's different - all my attention is on the EFIS, and I do tend to use the EFIS tapes for AS and Altitude (I guess maybe that is a sign of tunnel vision? ), since I am watching the PFD more closely.

I keep thinking I should take some instrument covers along some day, and cover up the backups for a few hours, just to see if I Can force myself to use the tapes more....

I'd be interested to see what others think about this!

Paul

 

[aadamson]

The G-1000 doesn't have an external Nav head does it? I've never seen one. I don't think thats quite correct because even the new G550's and stuff have glass backup instruments, no real steam gauges.

The G1000 doesn not have an external nav head. I suppose I should rephrase that.... Of those that are using the G1000 in GA aircraft, I know of no one that has certifed the G1000 as primary for flight instruments, the 3 steam gauges are all the primary instruments. This goes for Mooney, Cessna, Columbia, Diamond, Beechcraft, etc.

Further on the nav head, the G1000 has 3 nav heads actually... 1 - HSI, and 2 RMI's that can be overlayed on the HSI. Makes doing an ILS with cross radial waypoints very easy...

 

[Dad's RV-10]

Brad,


I know that people like the AFS engine display commenting that it well laid out and easy to follow. What functions does AFS have that you liked better than GRT?
Jonathan

Honestly John, I've experienced quite a bit of data-dump since OSH, but I was primarily swayed by the display brightness and clarity as well as the flap position indication, AOA information, W&B feature and checklist functions.

We were also discussing with Stein whether the two GPS output signals (the Chelton's and the GNS430's) could be selectable via an A/B switch into the Chelton. According to Stein, it could be done but he said if be very expensive to do so. I think the number was something like $3000 in additional wiring alone.

With the AF-3500's HSI representation, we can link one of the GPS sources directly to that EFIS and minimize wiring expense while still maintaining a redundant NAV source should the Chelton become completely inop.

Also, with the GRT, you still have to mount the EIS LCD control head (for lack of a better term) someplace. It doesn't have to be on the panel, but it has to go somewhere. All of the EIS componentry is internal to the AF-3500 as I understand it. Not a big deal, but just another reason I liked the AFS.

There are lots of options, but this is the system I like best as of today. I've never been a big fan of the screen quality and symbology of GRT. I think the AFS will integrate best with the Chelton and provide the most comprehensive feature set. Your mileage may vary.

Brad

 

[aadamson]

We were also discussing with Stein whether the two GPS output signals (the Chelton's and the GNS430's) could be selectable via an A/B switch into the Chelton. According to Stein, it could be done but he said if be very expensive to do so. I think the number was something like $3000 in additional wiring alone.

Brad,

Ah, I think what you are talking about with dual "nav inputs", isn't the GPS signal, it's the ARINC429 signals. The RS-232 Serial could be switched just fine with a simple toggle switch.

Perhaps a quick description of what it is that I think you are doing.

If you want the ability for the Chelton to display your "nav" info from the NAV reciever on the 430, then you need a 429 to 232 convertor, those are expensive. If you want the Chelton to use the GPS data from the 430, just use a toggle switch. I don't think there is much benefit in the later tho.

Now to the Autopilot, yes, both should be fed to it and just use a switch to select it's source. (if it's a TruTrak that is).

One note, I don't have a 430, so for the expert opinion, talk to Tim Olson who does, and also who has a tripple screen chelton ...

 

[Dad's RV-10]

I think you're right Alan...it was the NAV signal, not the GPS (like I said, data-dump .

Actually, the question came up after looking at Tim's panel. Tim (and a few others using "all" glass) had included a steam-gauge OBS in his panel. After asking "why?" (everyone had a different reason) we came upon the fact that you can't easily switch the 2 NAV signals for display on the Chelton.

Rather than include an additional OBS, this was another compelling reason to go with the AFS. One less instrument to have to buy and mount. Problem solved.

Brad

 

[aadamson]

I think you're right Alan...it was the NAV signal, not the GPS (like I said, data-dump .

Actually, the question came up after looking at Tim's panel. Tim (and a few others using "all" glass) had included a steam-gauge OBS in his panel. After asking "why?" (everyone had a different reason) we came upon the fact that you can't easily switch the 2 NAV signals for display on the Chelton.

Rather than include an additional OBS, this was another compelling reason to go with the AFS. One less instrument to have to buy and mount. Problem solved.

Brad

yep... Most include the CDI for backup... If you loose an EFIS, you still have the radio and CDI to get you somewhere... in my panel. I elected to not include it for two reasons. I'll have a 496 in the panel and if all goes to crude, I can fly the six pack on it. I also spaced my 3" gauges such that I could fit in a BMA G4/Lite, it can take external nav signals and act as a dedicated HSI if it's really needed. Sort of an upgrade strategy to my panel.

Just for kicks I looked at my panel, and I couldn't fit a 3400 anyway. No room without some major moving of stuff.