Second thoughts

I was originally planning on putting a backup steam gauge airspeed indicator and altimeter in my panel along with my Garmin G3X system. Now I?m wondering if I really need the altimeter. VFR day and night. I know there are other electronic backup options, but I want good old fashioned mechanical backups.

Thoughts?

The Garmin G5 is better than any "old fashioned" mechanical backups. No moving parts, solid state, 4 hour battery, way more functionality.

You can pump static/pitot into it as well as have GPS backup information in case of a failure or clogged line.

Really, an amazing device for $1200.

... and if your G3X is available integrates quite nicely! (but doesn't depend on it)

If you have an issue, it will probably be with your Pitot or static system, which will impact your steam gauges.

Put a Dynon PocketPanel in, if you want a backup of some kind. Just keep in mind, it displays GS, not Indicated Airspeed.

I have 2 1/2" backups of both. I like having the ASI, the backup ALT is useless for the most part, but may be handy at night in the event of an EFIS issue.

I use the backup ASI during approach more than the EFIS, just since it is easy to see out of the corner of my eye vs the EFIS.

I may just be old, but my eyes always go to my steam gauge airspeed and altimeter during approach.
To me, it requires less mental processing. Is the pointer in the right spot? Check. Eyes back outside.

Also easier to see in some conditions.

I'm planning on putting both in my 8. But, if I had to pick one, it would be airspeed.

Psychologically, if something is amiss, I tend to dwell on the EFIS while my brain tries to understand what the number means. Whereas, if the steam gauge A/S needle is waaay down (or up) the dial, my reaction is immediate.

I was also on the fence when I converted my panel to glass and I ended up just having a G5 as a back-up. I'm very pleased with my decision.

D

Backups

-8A. I have backup steam gages - airspeed, VSI, altimeter below my AOA-equipped AFS 4500. I find I scan the steam gage VSI & altimeter for vertical speed and altitude and the AFS 4500 for airspeed.

Agree completely

I used a G5 at night, powered by its backup battery, to get home when the rest of my panel croaked -- and I can report very high satisfaction with the gadget.

I feel like a genius for having it installed (although to be fair I am very easily impressed with myself.)

If you already have a G3X I think installing one is a no-brainer.

bkervaski said:

The Garmin G5 is better than any "old fashioned" mechanical backups. No moving parts, solid state, 4 hour battery, way more functionality.

You can pump static/pitot into it as well as have GPS backup information in case of a failure or clogged line.

Really, an amazing device for $1200.

... and if your G3X is available integrates quite nicely! (but doesn't depend on it)

Click to expand...

The first dual SkyView panel I did (RV-10) I had both and analog altimeter and airspeed instrument. I found myself alway using the airspeed instrument for takeoff and landing, but not in flight. I also found I never used the altimeter. But - the two instrument fitted perfectly side by side above the GTN-650.

For the new RV-8 panel I again have two SkyView HDx displays (a 10? and a 7?). There is enough room for an analog altimeter and have added it.

When I build another RV-10 I?ll go with dual 10? HDX displays, the analog airspeed and a Dynon D10A next to it. I prefer the D10A over the G5 as it has real EFIS capability (as in CDI, GS, TAS, OAT, etc.) without the need for a second display, or dependence on the Garmin CAN buss and/or G3X feed.

But - I?m not a fan of Garmin so take this with a grain of salt.

Carl

I had backup airspeed and altimeters in my Dynon D100 equipped panel. In 10 years the only time I used them was when the D100 backlight failed (twice). I was happy they were there for those two occasions. I’m in the middle of a complete panel update with all Garmin glass. The new panel has a G5 with its own battery. I think it will do very well in place of the old stuff.

Carl Froehlich said:

I found myself alway using the airspeed instrument for takeoff and landing, but not in flight.

(as in CDI, GS, TAS, OAT, etc.) without the need for a second display, or dependence on the Garmin CAN buss and/or G3X feed.

Click to expand...

Agreed about round gauges for takeoff and landing. Here's my take on steam vs glass:
* If the parameters are changing slowly, and you know in advance what they should be (like when you're flying an approach, heads down), it's a wash;
* If you have no idea what the parameters are and you have to read them instantaneously because your attention is required outside the cockpit, steam wins big time;
* If the parameters are changing rapidly, steam wins.

I chose the G3X over the Dynon because at the time, G3X had decent steam gauges to display and the Dynon had an extremely clunky display. (Also, I'd talked to the chief engineer at Dynon at one of the shows and developed an extreme dislike for him. He's long gone, now. And there were other reasons.)

More thoughts:
* On tapes, having the current value overlay the tape is stupid. What this means is that you can't use the tape per se for fine adjustment because the value you want is under the digital readout, and you have to read the digits for fine resolution. Maybe this was a requirement when screens were narrow and there wasn't room, but these days, there's room to move the digital readout off the tape;
* Altimeter tapes are usually +/- 225 feet, but when a "thousand feet to go" chime goes off, that means "sometime in the future, but not now, start looking for the altitude bug." It would be so much smarter to have full scale +/- 100 feet, and reduced scale outside of that so that you can see the altitude bug appear when the chime goes off;
* RockwellCollins had a truly brain dead display in which the vertical speed was a short white needle on light blue tick marks. This was extraordinarily hard to read because there was so little contrast, but the human factors books say don't use blue anyway. (There was so much more to distrust about RC when I was there...);

Second point: the G3X now has a direct OAT input, so it can do all the air data stuff. And the instrument can be toggled between HSI and attitude indicator. Also, if it is hooked up to the CANbus, it serves as a backup ADHRS in case the ADHRS goes poop. In my system, if the ADHRS goes poop, I lose OAT (hence, TAS and wind, no big loss as the system reverts to groundspeed, which is what you really care about), AOA (no big loss there! only the aural stall warning is of interest) and magnetic heading (no loss there as I still have ground track from the GPS. And 99% of the reason for having heading is so that you can iteratively get the ground track you want, but GPS gives that to you directly.)

I've never seen a refereed article comparing readability of tapes to glass... but lots of opinions!

Last point. You know when the first vertical tapes flew? On the Boeing 757/767? C141? Nope, a little bit earlier, like 1925. Sperry made them, but I've not found any pictures on the web.

My main concern with proprietary black boxes is obsolescence and loss of support. Seen this happen too many times with industrial controls over the course of my engineering career. My UBG-16, FP-5, TruTrak AP, and Garmin Aera 660 are as much as I need in that department. The plane came with steam gauges which get the rest of the job done.

Tom @ N269CP said:

My main concern with proprietary black boxes is obsolescence and loss of support.

Click to expand...

Obsolescence and lack of support isn't limited to proprietary black boxes.

A Garmin G5 or Dynon D3 will continue to perform the same until they fail regardless of whether Garmin or Dynon are still around, same as steam gauges, except perhaps with the added benefit of no moving parts to break.

THANKS!!!

For all the input, I really appreciate it.

I decided to use both steam gauges but to locate the altimeter under the ASI on the left side of the EFIS.

+1 on steam gauges.

There's a reason you don't see too many digital watches anymore. Telling time is an analog function; the pattern the hands make is assimilated by the brain much more rapidly than reading a sequence of numbers and then interpreting them.

I like my EFIS for the wealth of detailed data it provides about almost everything but hardly ever look at the speed and altitude tapes.

And, don't forget about being able to bug out when the EMP hits...

(donning tin foil hat)

==dave==
N102FM

There's a reason you don't see too many digital watches anymore.

Click to expand...

.. yea .. they were replaced by phones .. the #1 referenced time piece is a phone (not a watch)

the pattern the hands make is assimilated by the brain much more rapidly than reading a sequence of numbers and then interpreting them.

Click to expand...

.. only if your brain is trained so .. pattern recognition is repetition .. if you grew up referencing digital time then the hands on a clock would take longer to recognize.

but hardly ever look at the speed and altitude tapes.

Click to expand...

I think it just comes down to what we're used to. As a fairly new pilot with the vast majority of my time with glass panels .. I have a harder time getting a good scan on steam gauges than ribbons .. it's just what I'm used to .. so I suspect that's the trick here.

...and

"...There's a reason you don't see too many digital watches anymore. Telling time is an analog function; the pattern the hands make is assimilated by the brain much more rapidly than reading a sequence of numbers and then interpreting them..."

I disagree. I think the main reason that you "don't see too many digital watches anymore" has more to do with the cellphone that is grafted to everyone's hand than how the information is "assimilated by the brain".

I spent close to three decades looking at steam gauges, and still do while instructing. We now have G5's in the training aircraft (as the attitude indicator) but the rest of the analog gauges remain. I also use digital format at work. There may be a brief learning curve on the digital format but I prefer it over analog now.

It basically comes down to individual preference. If you have conclusive data that the brain assimilates the analog presentation better than the digital, I would be interested in reading it...

rocketman1988 said:

It basically comes down to individual preference. If you have conclusive data that the brain assimilates the analog presentation better than the digital, I would be interested in reading it...

Click to expand...

That would be an interesting study.

I view flying and navigating an airplane in three dimensional space as a fundamentally analog experience. Artificial horizons are always an analog representation, as are GPS moving maps. Judging landing patterns, final approach glideslope, runway alignment during landing are all processed by the brain as analog problems..it's how the human brain is wired...I couldn't imagine doing this with digital representations. I find steam gauges, though perhaps less accurate for instantaneous values, are good at reflecting relative values and rate of change in those values where the instantaneous digital values are of lesser importance and would require "mental D/A conversion".

But yes, personal preference and experience undoubtedly play a significant role.

I?m thinking steam airspeed+altimeter AND G5. Overkill?

question

"...I couldn't imagine doing this with digital representations..."

So what if you had a digital representation of the analog gauge? The needle on the gauge indicates value and the rate of change is indicated by the speed that the needle is moving, right?

The tapes are the SAME information, presented in a linear arrangement versus radial...the tape pointer indicates present value and the speed at which the tape moves represents the rate of change.

Same information presented in two different formats.

Yes, it is definitely personal preference over one being "better" than the other...

My original statement was flawed; I should have said "There's a reason most wristwatches today are analog, not digital....."

Didn't mean to start a new 'primer wars' topic, and I agree that people will prefer what they're used to or learned on. Both systems work well.

Lotsa stuff online about analog vs. digital human factors. you see quotes like:

"A digital clock will tell you that it's 8:50, while an analog clock will show you it'll be 9:00 in 10 minutes. For most people, it's easier to look at the relative position of the hands than it is to do the math"

and even:

"In aircraft accident investigation it has been mentioned that pilots failing to notice that their speed was dropping over time was due to digital meters. If an analog meter changes there is a change to the 'gestalt' of the image,...."

(whatever "gestalt" is supposed to mean here but I guess it's like reading that you're going 58.6 mph on a digital speedometer vs. just noting that you're almost at the 60 mph speed limit (or 60 kt stall speed in an airplane) on an analog gauge.

Digital is more precise for sure, but analog is nice in some situations as well..(I don't think I'd like a digital attitude indicator, although it would still provide the same info

Analog vs Digital

How many times have you looked at your analog watch, gotten the information you needed, then someone asked you what time it was, and you had to look at your watch again to answer them. That?s because analog instruments provide information that digital instruments usually can?t. We can look at the hands on a clock and know, for example, how much time we have left to do something or see that we?re late without actually observing the time of day. Same with most other instruments. As simple, and as second nature as it may be, you have to do the mental math to know that 18gallons means half your fuel is gone, whereas a needle in the middle between E and F on an analog gauge needs no calculation/interpretation. Finally, analog displays don?t have to be mechanical. So called ani-digi displays qualify as analog.

Well...

Well, I guess there will be a market for those used analog steam gauges!

Av8torTom said:

I was originally planning on putting a backup steam gauge airspeed indicator and altimeter in my panel along with my Garmin G3X system. Now I?m wondering if I really need the altimeter....

Click to expand...

I fly day VFR and am adding the analog ASI but am not adding an analog altimeter. I figure that I can estimate my altitude well enough to get home. Night would be a different story, and for that I'd add an altimeter.

Dave

Yep

rocketman1988 said:

Well, I guess there will be a market for those used analog steam gauges!

Click to expand...

I bought mine used.

rocketman1988 said:

Well, I guess there will be a market for those used analog steam gauges!

Click to expand...

I have a surplus of analog gauges! the box-o-gauges is filling up! Need to start selling.

D

Av8torTom said:

How many times have you looked at your analog watch, gotten the information you needed, then someone asked you what time it was, and you had to look at your watch again to answer them. That?s because analog instruments provide information that digital instruments usually can?t. We can look at the hands on a clock and know, for example, how much time we have left to do something or see that we?re late without actually observing the time of day.

Click to expand...

True for those that grew up with analog clocks .. not so much for those that grew up with digital clocks.

It's the same with steam vs efis .. my scan gets me faster info from my efis, because that's where most of my flying experience has been, with glass. No problem flying steam, my scan is just slower.

It's all relative to what you're used to.

I'm very happy with my decision to go with steam airspeed & altimeter to complement my GRT Sport SX EFIS. Part of it is that a grid of multiple rectangular panels is ultra BORING! I wanted a bit of the old school, so two round dials and a whiskey compass were part of the original plan.

Oddly, I tend to use the airspeed tape of the EFIS, yet rely more on the steam gauge altimeter.

Nice to know that you have a couple of functional gauges even with a complete electrical system failure.

I believe the key to quickly interpreting digital tapes is to always set the bugs as this gives an immediate visual reference if you have strayed above or below the desired value.

Having said that I do have a steam gauge ASI and I find it quicker and easier to interpret which is an advantage for instance during a short field approach when you need most of you attention fixed on the landing strip.

The only time I use digital airspeed is when flying on instruments as it is easier to scan all the digital data (with the bugs set) on the one instrument.

Fin 9A

For those of you flying behind a SkyView (I don't know about the other brands), you can change the screen to analog instruments in flight. Heck, you can even turn off the synthetic vision.

Give it a try, go back and forth and report back.