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Backup gauges with glass panel: Yes or No ?

Buggsy2

Buggsy2

Well Known Member
I'm building a day/night VFR RV-9A. Planning on a glass panel: 10" Dynon Skyview, VP-200 electrical, iPad for basic backup.

At the moment I've allowed room for 3 gages on the panel: Magnetic Compass (vertical card), Airspeed, Altimeter. But I got to wondering if those will really be needed for the aircraft mission.

Thus I have a question for two groups of builders:

  • If you didn't include round gages in your glass panel, do you wish you had now?
  • If you did include gages, do you still think they're needed, or not?
 
For day/night VFR you don't need any. If you have a standalone autopilot you surely don't need any.

For IFR I would put airspeed, altimeter and T&B of some kind.
 
Midway through my first flight my Dynon went black. Dynon knew exactly what the problem was and promptly shipped me out a replacement unit with next day service at no charge. I have a backup ASI and ALT in the panel. Definitely glad I had the former. Losing my engine instrumentation was not that big of a deal (though a bit unnerving on a first flight), but losing airspeed is a big deal. I would not want to have to rely on my GPS for a "guesstimate" of my airspeed.

I don't have a (backup) whiskey compass, however. My GPS has batteries and I have a handheld NAV/COM for any needed directional backup.

Just one experience.
 
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I too built a VFR glass panel. My AFS 4500 is primary and my G3X is backup for airspeed and altitude - of course the G3X data is all GPS. If that fails I will use my iPad. If that fails I will use the old stick and rudder skills.

I don't miss adding steam gauges.

If you need another backup, buy the new Dynon portable attitude, airspeed and altitude unit. Looks like a nice device for what you want.
 
Buggsy2 said:
I'm building a day/night VFR RV-9A. Planning on a glass panel: 10" Dynon Skyview, VP-200 electrical, iPad for basic backup.

At the moment I've allowed room for 3 gages on the panel: Magnetic Compass (vertical card), Airspeed, Altimeter. But I got to wondering if those will really be needed for the aircraft mission.

Thus I have a question for two groups of builders:
  • If you didn't include round gages in your glass panel, do you wish you had now?
  • If you did include gages, do you still think they're needed, or not?
Click to expand...

What about an attitude indicator? That would be more for IFR.

Do you have a pair of AHARS and Magnetomers for your Skyview, or just a single screen with a single set of ahars/magnetometers?

Having back ups from a different manufacturer and technology type is a good thing. But if you have just one primary and one secondary, how will you determine which one is bad? If you are VFR, you can look out the window, but it your in IMC, that may not be an option. For fail safe operations, you need a third tie breaker. But that is for IFR operations. For VFR, you are just fine.

In my RV-10, I have three EFIS screens from two different vendors. I'll trust the data from the two that match. I decided to keep the technology similiar to minimize the looking at both new style tapes versus the older round gages. That was simply my preference.
 
Same idea here

I am building a -7A day/night VFR and have essentially the same thoughts as you. I have the Dynon D10A with back-up airspeed and altimeter and compass. I know that several people will say (probably rightfully) to leave out the compass, since the Dynon will fulfill the legal requirement and if you get lost at night you still have the iPad or other GPS for guidance. Some will also say that the airspeed is unnecessary as you will develop the ability to fly and land the plane by "the seat of your pants". For me, I would probably have left out the compass, but I still like the idea of back-ups for the AS and alt.
As others have said, build the plane that you want to build, not one that others think you should build.
 
Day VFR? No sweat from a flying standpoint without backups - assuming that you have practiced flying the airplane without ASI.....

The thing that many don't take into consideration is what their personal minimums are for engine gauges. Imagine you have landed at some little unattended self-serve strip in the middle of nowhere, and as you get ready to leave, the EFIS won't boot. The weather is fine, and you know that flying is not a problem. Are you comfortable with no engine info to get home?

Personally, I am good with just an oil pressure light for a Lycoming, but each pilot should decide for themselves.

Paul
 
For the first 300 hours I had a backup airspeed and altimeter in my -9. I didn’t bother with the compass because I had compass in my D100 and in my 496.

When I replaced the D100 this spring with a SkyView, I didn’t bother putting those backup instruments back in the panel. However, I did keep the 496, more for the weather than anything else.

If you are really worried about it, buy a Dynon D1 Pocket Panel. Then you will have a good backup, if you ever want to equip the plane for IFR flight.
 
I have them

I have backup gauges, and am very happy with the decision to put them in.

Last week one of my EFIS screens decided to take a nap just after prior to engine start, but because of the backups, I was able to make the flight to the Homecoming without any problem.

Here is a shot of the panel, (all normal in this shot) and as can be seen, the loss of an EFIS is not a big deal-----------other than the mode C was disabled, and the autopilot defaulted to heading mode.

P2030033.jpg


The above is my standard setup for cross country flight------one EFIS is dedicated to the map and AP, the other displays engine and fuel status, but there is still essentially a full "six pack" of gauges. The TruTrack ADI counts for 3 :D
 
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No steam guages

IFR - Dynon 7" skyview as primary, D10A as back-up, and most recently a D1 as well. Auto-pilot and zero steam gauges.

two alternators, main battery, internal batteries for both EFIS, plus 2 ADHARs.
 
I had the same concerns when I designed my panel, and opted for having some back-up steam gauges. Given the reliability of today's glass panels, I wouldn't hesitate to omit the steam gauge back-ups for VFR flight. I honestly never even look at the round gauges.

However, I also had aesthetic goals in my panel design, and form won out over function. Symmetry is big with me.
N8RV_Panel_1.jpg


Besides, I needed the other gauges to balance the TT autopilot. How goofy would that have looked as the only round gauge? :D
 
Back ups

I put an A/S and ALT in my panel for back up. Mostly because I'd never flown with glass and was a little intimidated by it. It was a mistake. I've looked at the back ups ONLY to confirm that they worked!!! Transitioning to the glass has been very easy. I would save the space for something useful at least in a VFR machine.
 
I think you are putting an awful lot of faith in uncertified electronics to not include a standby ASI, Alt and attitude (TT ADI or similar). Although the avionics on offer today are reliable, they are not infallible. In opting for un-certified equipment you are taking something of a risk as none of the manufacturers will tell you what hardware or software standards are used in the design and build of their systems. How good are your installation skills? The in-service experience is generally very good, but ...

Back-up instruments are an insurance policy, taking account of your own experience and the type of flying you will be doing you will have to weigh up whether you want to buy that insurance for your airplane.

Pete
 
penguin said:
I think you are putting an awful lot of faith in uncertified electronics to not include a standby ASI, Alt and attitude (TT ADI or similar). Although the avionics on offer today are reliable, they are not infallible. In opting for un-certified equipment you are taking something of a risk as none of the manufacturers will tell you what hardware or software standards are used in the design and build of their systems. How good are your installation skills? The in-service experience is generally very good, but ...

Back-up instruments are an insurance policy, taking account of your own experience and the type of flying you will be doing you will have to weigh up whether you want to buy that insurance for your airplane.

Pete
Click to expand...

Interesting perspective considering the ENTIRE aircraft is uncertified. How many guys are flying behind uncertified props and engines too? I find this funny.

Nothing in the certificaiton process guarantees reliability. It only shows the production conforming equipment demonstrated a certain reliability during the test period. I had the needle pop off my brand new certified airspeed indicator in my previous airplane within the first few hours of flight.
 
I have a Dynon D180 and steam VSI, altimeter, airspeed, and in panel compass. The compass is useless. It varies up to 30 degrees from the correct heading. I'll probably pull it.

I find myself using the steam AS, altimeter, and VSI as my primary references. I'm used to looking at those at a glance and they smooth the data. They aren't as jumpy as the digital displays.

So yes, I would recommend a spinkle of steam gauges as well as your Dynon.
 
N8RV said:
N8RV_Panel_1.jpg
Click to expand...
Hey Don, a little off topic but what is your source for the two curved mirrors on the sides of your canopy frame. I would like to find a mirror like that.

panel%2520pic%2520large.JPG

On topic, to answer the original poster's question about whether there were regrets about not putting steam gauges in, I did not put steam gauges in my all glass panel and have no regrets yet. I have dual AHRS, dual GRT HX EFIS, with triple power source feeds and a 1 hour backup batter. For backup I have a Garmin 695 with GPS derived 6 pack data, independent TT autopilot info and an iPad with GPS data as a third backup source. Then lastly, as a VFR pilot, I have the calibrated eyeball out the window and the seat of the pants stick and rudder skills I acquired through the years.

I might add, I have actually had to put those last two items to true tests early on in flight testing and shortly after completion of the testing phase when on more than one occasion I failed to remove the pitot cover and did not discover it until I became airborne. Nothing like getting the feel of your aircraft on final approach with no airspeed indicating at all. One of those times when even a steam gauge backup would not have worked either by the way. Something I have kicked myself over many times since those incidents was that I did have the GPS 6 pack to fall back on. At the time it never even dawned on me to use the GPS. I just came in using the seat of my pants and eyeballs as instruments. Even so, they still got the job done.
 
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Back to the original post:

I'd ask what you mean by "night vfr"? If you mean flying in the dark over well lighted cities I think you're all set. If you mean flying over the Atlantic on a hazy night, I'd personally want either a TC or AI in the back ups.
 
Don, you win the award for "Strangest Looking Dynon D100 and D120 Ever." Nicely done. Do I detect a hint of F-16 in that cockpit?

If those extra buttons work, I'd like to buy you a beer!

--Ian
Dynon Avionics
 
BobTurner said:
Back to the original post:

I'd ask what you mean by "night vfr"? If you mean flying in the dark over well lighted cities I think you're all set. If you mean flying over the Atlantic on a hazy night, I'd personally want either a TC or AI in the back ups.
Click to expand...

Fair enough. Probably no Atlantic flying :rolleyes: and really not even remote over-land flying...most remote (light-less) land here in NorCal is mountains and no way would I do that at night regardless of my instruments.
 
penguin said:
I think you are putting an awful lot of faith in uncertified electronics to not include a standby ASI, Alt and attitude (TT ADI or similar). Although the avionics on offer today are reliable, they are not infallible. In opting for un-certified equipment you are taking something of a risk as none of the manufacturers will tell you what hardware or software standards are used in the design and build of their systems. How good are your installation skills? The in-service experience is generally very good, but ...

Back-up instruments are an insurance policy, taking account of your own experience and the type of flying you will be doing you will have to weigh up whether you want to buy that insurance for your airplane.

Pete
Click to expand...

If you only fly Day VFR like a lot of pilots (I know it doesn't happen in the UK very often...:)...), then the only question is "what do you need to fly the plane to land safely if all of the electronics go POOF?"

Probably just an ASI would do, an ALT and non-electronic slip indicator would also probably be nice but not essential.
 
I have D100 and D120 plus Garmin 495, radio & transponder. I originally put in small airspeed, altimeter, and compass. I never use any of those gauges, and like others, the compass is probably off by 30 degrees most of the time (seems to change rapidly even after swinging it). I did this originally because I had never flown glass and was just unsure. If I find something more useful to put in those holes, I'd pull them in a minute. I fly pretty much day VFR only. If you have qualms, then put them in and pull them back out later. Or go the Dynon backup gauge route. If/when I build another airplane, I won't bother with the round gauges.

my two cents,
Greg
 
RV8R999 said:
Interesting perspective considering the ENTIRE aircraft is uncertified. How many guys are flying behind uncertified props and engines too? I find this funny.

Nothing in the certificaiton process guarantees reliability. It only shows the production conforming equipment demonstrated a certain reliability during the test period. I had the needle pop off my brand new certified airspeed indicator in my previous airplane within the first few hours of flight.
Click to expand...

Yeah, but most builders realise that the airframe and (maybe) the engine prop are uncertified. I find that many don't realise what that means for avionics, especially as radios are all TSOd, there is an assumption that because EFIS look smart they also meet a similar standard.

I would disagree about what the certification process gives you. It shows that the product was designed and built to certain standards that at least one airworthiness authority has deemed to be sufficient (don't let's get into whether the FARs or TSO are fit for purpose). Could I suggest that your experience shows the manufacturer's QC processes are poor, or his workforce does not care?

Pete
 
az_gila said:
If you only fly Day VFR like a lot of pilots (I know it doesn't happen in the UK very often...:)...), then the only question is "what do you need to fly the plane to land safely if all of the electronics go POOF?"

Probably just an ASI would do, an ALT and non-electronic slip indicator would also probably be nice but not essential.
Click to expand...

At the moment we're only allowed to fly Day VFR! Agree that nothing electric is needed, I like the TT ADI as it says what your track is.
 
Wow, thanks for the great replies.

Based on these I think I'll go for no mechanical gages for now...but with space to add them later. I've already routed the air lines needed so will just cap them off.

Here's an XPanel image. Not final layout by any means.

Panel2VP200mglnogages2_Full-001.jpg
 
I assume you've read all the posts about how poor the iPad visibility is in direct sunlight.

Note to Pete: Here in the US the statement that "all radios are TSO'd" is not true for operations under part 91.
 
I've got a lot more time behind glass than steam gages. I've also had many more steam gage failures than glass failures.
 
I know a couple have argued that one can learn to fly the plane by feel even absent an airspeed indicator. Aside from my experience, when I lost my EFIS on my first flight before having the chance to get to know my plane (and its airspeed) by feel, how many of us have really been trained to truly fly a plane entirely by feel? I know it was never part of my initial PPL, nor part of any binannual, nor part of my tailwheel training, nor part of my transition training. Granted, I think some are probably very good at it, and granted, it's a skill I'd like to (and plan to) acquire someday, but I don't think we should encourage other pilots to leave out a backup airspeed indicator on the basis of "good" pilots being able to fly entirely by feel.

Just my further $.02.
 
I often cover up numerous gages during the course of giving flight reviews. ASI, VSI, DG, Turn Coordinator, and Main attitude gyro all get covered up. And the ball, always cover the ball.

FORCES the victim, ......... er, I mean, the evaluee, to actually look out the window at the biggest natural gyro in the world: the Horizon. Forces them to listen to the airflow noise to "feel" the airspeed". Smoothes out all stick inputs like magic! Airspeed fluctuations are much smaller.

I very HIGHLY recommend you go flying and cover up the instruments for a few hours. Don't go fly straight and level, but do stalls, slow flight, steep turns, and if you do aerobatics already, do them sans instruments.

I guarantee it will make a better pilot out of you.:cool:
 
Would still install...

We included:
2" airspeed
2" vertical card compass
4 warning lights
starter
ems
alt
oil
Everything else is backed up by the view outside and the 696.

Without the airspeed you can't tell your airspeed.
Without the compass you may not be able to tell where you're headed.
 
BobTurner said:
Note to Pete: Here in the US the statement that "all radios are TSO'd" is not true for operations under part 91.
Click to expand...

Yeah, I should have said any radio that is worth installing is TSOd. I'm a firm believer in having a good radio. I have found it really comforting to be able to talk to a calm voice when caught out by weather and low. Several friends have reported transmit and receive problems at longer ranges from cheaper radios. There are areas to save money, but a good radio isn't one of them. I have an SL-30 and King GPS/Comm in my aircraft.

Pete
 
penguin said:
I would disagree about what the certification process gives you. It shows that the product was designed and built to certain standards that at least one airworthiness authority has deemed to be sufficient (don't let's get into whether the FARs or TSO are fit for purpose). Could I suggest that your experience shows the manufacturer's QC processes are poor, or his workforce does not care?

Pete
Click to expand...

Nope..my experience shows just the opposite. Reliability testing is conducted by "binning" data points on a particular test article over a specified period of time. A statistical analysis is conducted from the data in all the "bins" and repair/damage/wear history during the test period to come up with projected reliability. A an example of a "bin" might be - time at X g's, or X temperature and vibration level, etc.. however, the data does not GUARENTEE reliability only a likelyhood to achieve it. As in most things in life there exits a distribution of actual reliability vs predicted. If the test period was sufficiently long and the bins sufficient in depth and range the distribution will show most test articles reaching predicted reliability (measured as Mean Time Between Failure - MTBF) within one standard deviation of the MTBF. If not, more articles will fail earlier and/or later.

So again, certification does not guarentee anything other than it was certified to have passed the test prescribed by regulation - how your particular piece of equipment performs will fall somewhere on the distribution described previously.

If this were not the case then the entire FAA AD process would not be necessary - search AD related to Garmin avionics for instance.

anyway... my .02

OUT
 
Not done building yet, but I've installed a 10" Skyview as primary, a Dynon D6 as backup. No steam gauges. The two EFISes are on different busses, both have battery backups. Did an FTA to identify the various failure modes and ensure that absent some seriously catastrophic event like a lightning strike frying everything, I'll have sufficient flight instrumentation to land safely.

I may not have full *engine* instrumentation (that's only on the SV), but I can manage that if the SV goes down. That is to say, I'm single-fault tolerant (the primary EFIS fails AND an engine problem simultaneously is not within scope of the fault tree).

Additionally, the SV GPS can act as a backup to the 430W GPS in an emergency, should my primary *nav* source (430W) go down (and I have a second comm, an SL-40...primary and seconday comms are on different busses).

As far as I could determine, there is only one single-point failure which I have not mitigated...pitot/static (well, and AOA, but if that quits, c'est la vie). The pitot and static lines are each from a single source, Tee'd to the SV ADAHRS and the D6. So a blocked pitot or static would affect both systems. I accept this as a SPF exception, given the GPS data available.
 
Van's fuel level sending units and Dynon

Can anyone tell me if the standard fuel level sending units will work with the Dynon EMS10 fuel inputs? I believe they will as they are resistive. I'd like to scrap the analog gauges to make room for a second radio. Only other concern is how much they'll clutter the EMS screeen.
 
Yes, you can use the standard Van's resistive senders with all of our EMS products.
 
It is surprising to me that people want a backup ASI but no AI

If you get in IMC the last thing you want to loose is your attitude instrument. Airspeed is trivial compared to attitude. Maybe you have to have experienced unexpected IMC at night and the loss of airspeed indication due to ice in IMC to appreciate the relative importance.

Bob Axsom
 
Bob Axsom said:
If you get in IMC the last thing you want to loose is your attitude instrument.
Click to expand...

Norman CYYJ said:
Basic instruments required if you lose your EFIS.

Airspeed
Compass
Turn and bank
Altimeter
Click to expand...

All true for IMC, but my mission is not IFR. And, I plan on an entirely separate electronic backup, an iPad or portable GPS, which should be enough for the unlikely combination of (accidental IMC OR night VFR and no ground lights) AND primary EFIS failure.
 
Panel location for Fuel Gauges

Does anyone know why Van's offers the side panel for the fuel gauges for the 8A, but not the 8?

Also, thanks for the answer on the Dynon EMS10
 
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