Steam vs Glass

[zav6a]

I think it would be an easy decision in a new build and as Paul and Alan imply, you need attitude which implies IMC.

I have come close to pulling the trigger on moving to glass in my 96 6A a few times. But, where I live and fly, clouds have ice and rocks in them so my mission is strictly VMC. And after flying around the West for ten years and getting familiar with its prominant landmarks, I find about all I use my moving map GPS for is ground speed and ETE to plan gas and potty stops. Still running a six pack with electric AI(bought it out of DR's old panel). It is switched and I have not turned it on other than to test since installed.

Glass sure appeals but i certainly can't justify taking out what works perfectly for the mission. I tell myself that I will make the change when something breaks, but it won't! The fact that they keep making it better and cheaper every year doesn't help.

The answer boils down to - mission.

[L.Adamson]

Originally Posted by zav6a

I think it would be an easy decision in a new build and as Paul and Alan imply, you need attitude which implies IMC.

I have come close to pulling the trigger on moving to glass in my 96 6A a few times. But, where I live and fly, clouds have ice and rocks in them so my mission is strictly VMC. And after flying around the West for ten years and getting familiar with its prominant landmarks, I find about all I use my moving map GPS for is ground speed and ETE to plan gas and potty stops. Still running a six pack with electric AI(bought it out of DR's old panel). It is switched and I have not turned it on other than to test since installed.

Glass sure appeals but i certainly can't justify taking out what works perfectly for the mission. I tell myself that I will make the change when something breaks, but it won't! The fact that they keep making it better and cheaper every year doesn't help.

The answer boils down to - mission.

My flying is also in the mountainous west. I've used my moving map GPSs (last is a Garmin 696) extensively.....with XM satellite weather. I found it extremely useful for long cross country flights, where weather wasn't all blue sky from departure to destination. Little additions such as real time TFRs are also a nice feature.

L.Adamson

[David Paule]

Just curious - how much does the wiring and connectors all weigh for a simple glass panel?

I'm thinking of one that has a single glass screen, the main sensor box, a GPS, EMS and autopilot. On the web sites, the system weights are given but that harness has got to be heavy - how heavy?

Thanks,
Dave

[aerhed]

The biggest part of your harness will be temperature probes, which you will have anyway.

[fmiddleton]

Originally Posted by David Paule

Just curious - how much does the wiring and connectors all weigh for a simple glass panel?

I'm thinking of one that has a single glass screen, the main sensor box, a GPS, EMS and autopilot. On the web sites, the system weights are given but that harness has got to be heavy - how heavy?

According to the Skyview installation guide (appendix B), using a 10" display and a 4-cyl EMS, you'd be looking at about 14lb including the AP servos (which are about 4lbs on their own). This does not include a couple of items (sv-net-servo and -hub) -- I can't find a weight for those. So, I'd guess about 15.5lbs all in.

[N355DW]

Originally Posted by RVNineA

I've read this claim many times, from many sources, but would like to review the data myself. Can anyone point me to the raw data or analysis that addresses the difference in reliability between steam and glass?

I also prefer the "look and feel" of six-pack steam flight instruments (not nav), but if I can get x2 or x3 reliability from glass, then I'll probably go glass in my -9A.

Thanks
John

I too would like to see some data on this.

My personal experience over thirty years of flying is glass is not as reliable as steam. I have far more time behind steam than glass, and the glass was professional grade stuff in a EMB-120 Brasilia. I had more failures in three years of flying glass than I have over thirty of steam use.

That was back in the nineties, so perhaps things are more reliable now. Having said that, I will say every computer, smartphone, tablet, GPS, satellite TV receiver, or almost anything with computer chips that runs software I have owned has failed, locked up, crashed, or just screwed up in one way or another.

It seems to me there are far more failure modes with glass than steam. Lots more ways things can go wrong. Especially if software is involved.

Anytime electrons are involved, there is potential for trouble. In all the airplanes I have owned, from a Citabria to a Baron, I have never had a steam failure, but I have spent a ton of money fixing electronic things like radios and autopilots.

A friend of mine that is a DAR has recertified several all glass cockpit Cirrus aircraft imported back into the country. His advice to the new owners after going through the logs is to budget $500/month for avionics bills.

All this is obviously anecdotal. I would also be interested in seeing any data/analysis on reliability.

Having said all of this, I do plan on using glass in my airplane, but it will be backed up with dual everything, back up batteries, and some steam gauges. If I end up spending a lot of money fixing problems, I can always take it out and put it up for sale!

[SteinAir]

Believe it or don't, the glass IS far more reliable than the steam stuff. The raw data analysis has been done many times over by air agencies, military, governments, and private enterprise. My background is also in the heavy iron, and specifically some time in the reliability department where we generated reams upon reams of data on every minute piece of an airliner. The Brasilia example is a terrible one, because it was certified with old Collins Proline II "glass" designed in the 70's (now almost 40 years old). I'd venture to say some of the sensors in even the lowest cost EFIS or an Ipad are equal to or superior to what was considered state of the art back then.

Personal anecdotal experiences aside, it's really a moot discussion because as I've said before, like or to not the steam stuff is going the way of the dinosaurs. Even the little peanut standby instrument in the heavy iron are all digital (no "steam" in new airliners) and fighters.

No to be sarcastic and I'm probably gonna raise some hackles with this (no flames intended), but again it's a relative waste of time to even discuss it because it doesn't matter what anyones personal experience behind old stuff in old airliners is (and even that is dubious because an individual exposure to the life & abuse of a system in an airliner flying 10+hrs per day 7 days per week is not a good data point), the world is going glass - period. Glass of old does not equal glass of new.

Regarding costs, the Chinese Steam stuff is cheap but terrible in the reliability department. That leaves you with certified stuff, and set of gyros (plus an HSI) will run you MUCH higher than the cost of a simple EFIS. Here's some quick math:

Gyros: - about $6K for certified ones.
Simple CDI - $1800 (no HSI)
ASI+ALT+VSI: $1K for decent ones.
HSI - No way anyone would even consider an analog HSi at $7-10K so we'll leave that out.

That's almost $9K right there and you still don't have an HSI, Autopilot, OAT, AOA, no compass, no fuel computer, no trim indicators, no flap indicators, no warning systems, no annunciator, no moving map, no weather, no terrain, no traffic, no charts, no plates, no sectionals, no Ammeter, no voltmeter, no tachometer, no egt, no cht, no fuel pressure, no oil pressure, no oil temp, no manifold pressure, no W&B, no checklists, no hobbs meter, no G meter, no flight planning, etc.. All of the above which can be had in everything from a Dynon, AFS, GRT and Garmin for about the same price.

Engine instruments are also far superior digitally than analog and have been for some time. Boeing/Airbus/Douglas/Lockheed quit using analog engine instrumentation sometime in the previous century. Again somewhat dubious to debate because that's where the world is going. Even for simple VFR, you're way farther ahead to just go buy a good EFIS and be done with it.

That being said, if you're really stuck on old stuff - I have a box of old steam guages that are for sale cheap! However, if you put it in the plane it'll be worth a whole lot less money and a whole lot less functional than if you'd spent the exact same amount on glass - that's a fact. I won't get into the Space Shuttle metrics but Paul can probably fill us in on that history/progression!

Cheers,
Stein

[RV7ator]

Having both steam and glass is very good. EFIS' don't have bearings that wear, vacuum systems to fail, they don't tumble, they put up useful information...it's a computer. Make it as fancy as your wallet allows.

BUT...

They're horrible human interfaces. I retain a big 3 1/8" four-pack surrounding the EFIS because they're so easy to use. Glance, and you know. An EFIS you have to focus on, read, and interpret. Especially AS. I'm shopping EFIS' right now for the next project, and the universal characteristic is clutter. Oh, you'd get used to a particular unit, but they are not easy to use. You could drop me into a six-pack airplane without any briefing and I could fly an approach.

I've built several panels for various -7s. The absolute happiest is a four-pack surrounding a D6 in the AH position, and a D10A in the DG position for an HSI. Dual EFIS redundancy, round dials for legibility for the 98% of my flying that isn't instruments.

John Siebold

[N355DW]

Originally Posted by SteinAir

The Brasilia example is a terrible one, because it was certified with old Collins Proline II "glass" designed in the 70's (now almost 40 years old).

Interesting. No wonder I wasn't impressed with the reliability.

Originally Posted by SteinAir

Personal anecdotal experiences aside, it's really a moot discussion because as I've said before, like or to not the steam stuff is going the way of the dinosaurs.

I don't doubt it.

Originally Posted by SteinAir

No to be sarcastic and I'm probably gonna raise some hackles with this (no flames intended), but again it's a relative waste of time to even discuss it because it doesn't matter what anyones personal experience behind old stuff in old airliners is (and even that is dubious because an individual exposure to the life & abuse of a system in an airliner flying 10+hrs per day 7 days per week is not a good data point), the world is going glass - period. Glass of old does not equal glass of new.

It does indeed matter what someone's personal experience is. Good or bad, that's how most of us make decisions about almost everything in life. By this I guess you are saying the new glass stuff is even more reliable than every computer, smartphone, tablet, satellite TV receiver, aircraft GPS, car GPS on the market now? They will never crash, lock up, lose data, get a virus, need to be rebooted? My repair bills will not someday go through the roof like they have on the simple nav/comm radios and autopilots I have owned previously?

I have never had a totally reliable computer, or computer driven device in the thirty or so years I've used them. I am skeptical this new glass will prove to be any better than all these other devices I use all the time, but as I said I do plan on buying them. I also plan on having a lot of back up. From airliners to the Space Shuttle, I'll bet the redundancy of the systems is more than double in most. Triple or better in most airliners I flew, and I'd wager the Shuttle had more redundancy than most airliners.

I'm going to use glass, I like it for a lot of reasons, but I am not dazzled by it like so many people seem to be. I am old enough to look at a car with all those fancy gadgets and toys on them and think to myself "that's all going to break someday and I will have to pay to fix it". I have never had a totally reliable computer or computerized device in my life, and I don't believe these devices are any better. So I will look forward to my nice glass cockpit, but I will have plenty of redundancy.

[jthomas]

Thanks for the info, It is amazing how much info you can get on this board, hard to imagine building an RV without it.
I have flown glass for the past 13 years in Citation Ultra, X and now in the Sovereign and have only had 1 tube failure and that was on the ground at a service center so I think the reliabilty is good, I think I will just stick with glass. Now I guess I just have to make up my mind on which one.
Thanks
James