Steam Gauges - Economical and Reliable

[Kyle Boatright]

Originally Posted by rfinch

I own an Aircoupe and am building an RV-9A. There will be no steam gages in my RV, or at most altimeter and airspeed gages for IFR backup. And absolutely no vacuum pumps, ever.

Reliable?? The altimeter in my Coupe, of unknown vintage, died a few years ago and I got a refurbished United altimeter. Now it too has died and TGH wants nearly $600 to fix it. For about $700 I can get a new one...these are TSO'd of course. Non-TSO altimeters are available for less than $250 but my mech doesn't think the FAA will do a field approval.

The DG went out in my Coupe a year or two ago. Refurbed that too, it precesses more than the old one but it's legal.

Economical?? Many hundreds of dollars for refurbed TSO'd steam gages. Put steam gages in your shiny new RV and watch its resale value plummet.

Steam gages suck. We're in a new century.

The problems you've described are more related to the age of your gauges and the fact that they are TSO'd than anything else.

How reliable will your Dynon, Blue Mountain, or Chelton EFIS be in 50 years and what do you think it'll cost to fix it? ;-)

[rfinch]

Originally Posted by Kyle Boatright

The problems you've described are more related to the age of your gauges and the fact that they are TSO'd than anything else.

How reliable will your Dynon, Blue Mountain, or Chelton EFIS be in 50 years and what do you think it'll cost to fix it? ;-)

The costs I described are due to TSO, but not the problems. The problems are due to mechanical stuff worked on by techs in a dead-end job.

The electronic stuff doesn't get fixed. Throw it out and buy another, which by that time (5-10 years) will be way cheaper and better. But you already knew that.

[AlexPeterson]

Like Kyle, I finished my plane before this revolution in EFIS's.

Lots have mentioned reliability of steam gauges. My experience in 950 hours is:

HSI rebuilt after some part inside of it came loose, seemingly only due to being poorly manufactured.
HSI glideslope flag needed replacing around 100 hours.
HSI sent back after rebuild because the belt was slipping.

Electric (RC Allen) T/C is starting to whine (too many rolls I suppose...)

Altimeter, A/S, VSI, A/H all doing fine.

I have no idea how I would configure the panel if I were building today - seems like too many choices. The target is moving too quickly. Good luck to those doing so! I would definitely put some sort of glass in though.

I plan to replace the T/C when it croaks with a small Dynon, but otherwise I'll just keep things as they are.

[Kyle Boatright]

Originally Posted by rfinch

The costs I described are due to TSO, but not the problems. The problems are due to mechanical stuff worked on by techs in a dead-end job.

The electronic stuff doesn't get fixed. Throw it out and buy another, which by that time (5-10 years) will be way cheaper and better. But you already knew that.

If the plan is to throw your glass panel out every 5-10 years, why wouldn't that work with mechanical stuff?

Shoot, for $50 to $400/item, you can even replace the mechanical gauges and instruments one by one when they eventually go south. Might even save a few bucks over time that way... I've got 7 years on my airplane and have spent under $200 on instrument repairs in that time. Considering that I only have about $2k invested in gauges in the first place, I figure I'm coming out ahead of the game.

Don't get me wrong, glass panels are nice, but there are less expensive ways to build a basic panel. Beyond that, there are plenty of manufacturers of steam gauges, so if the manufacturer of my CHT gauge goes out of business, there is another product that'll drop right in the hole if mine ever fails. That probably won't be true when EFIS manufacturers start falling by the wayside.

[MacNab]

I've been round and round about making the decision of a glass panel upgrade. Last month I was ready to pull the trigger, but every time I look at the classic sports car appearance of my analog gauge cockpit, I balk.

Now I think I'll wait until somebody comes up with a HUD...

[Rivethead]

I had a straight steam gauge panel planed and even had all the gauges except for the attitude indictor and gyroscopic compass. The least expensive way to go that I could find was using a vacuum pump driven set of instruments for these last few items. Once I crunched the numbers for fairly good quality pump and instrument package I came to the conclusion that I would be way ahead money wise and better equip if I went with a Dynon EFIS and EMS combo. So I sold everything I had except for a set of three shown in the picture below that are used for redundancy.




There is method to my madness, the Airspeed, Altitude and VSI indicators are where they are for the second seat to fly by. Since the Dynons swap pages the Attitude indicator page, or for that matter any other page, can be displayed on the EMS giving the second seat a pretty good set of instruments.

[the_other_dougreeves]

Originally Posted by jmartinez443

If you're building a new panel, glass can actually be cheaper. Here are the other pluses I see to flying with glass:

- there are no mechanical gyros to bang around during abrupt maneuvers

I agree - if you want gyros, go glass. But if you're strictly VFR, do you need gyros? Hence my idea of steam gauges for VFR airplanes.

TODR

[Rainier Lamers]

Originally Posted by Yukon

I'm starting this thread so that newcomers to the forum can learn about alternatives to glass panels.

As a manufacturer of Glass panels you might think I'd advertise the one over the other. But I will not do that.
I think both have almost equal merits and the final decision is based on what the builder wants. A well equiped mechanical panel using quality instruments can be very functional and very pleasing to the eye as well.
There is absolutely nothing wrong with a VFR panel using steam. I would advocate going for an electronic AI of good quality though - vaccum stuff I think is definitely out.
When it comes to IFR and NAV glass is probably in the lead - I think few will argue that. Yes, they can fail and they do fail. But they aren't as bad as some may make out - modern glass tends to be quite tough and reliable.

It all gets down to a couple of things: What do you like ? What are you comfortable with ? What is your budget ? What do you want to do with your aircraft ?

Simply specifying the most sophisticated glass panel because everybody else is doing it may not be the right choice for your circumstances.

But if you go mechanical - yes it will cost more than many current EFIS's - buy good quality, it will reward you with a long life. Cheap gauges may only give you useless readings (Engine gauges come to mind), become inaccurate and wear out rapidly with vibration.

Rainier
CEO MGL Avionics

[Rainier Lamers]

Originally Posted by Kyle Boatright

How reliable will your Dynon, Blue Mountain, or Chelton EFIS be in 50 years and what do you think it'll cost to fix it? ;-)

An excellent question.
Here is my answer:
In 50 years none of the parts made for any of the above instruments (and all of the ones not quoted) will be long out of manufacture. This goes for displays, processors, memories and just about anything else.
Will any of these panels last 50 years ?
Probably not.
However - things are not quite that bad - prices are tumbling so fast, an EFIS is becomming a comodity. One thing I can say for sure - in 50 years time you would not want any of the above EFIS systems and you will be more than happy to replace your U/S unit with the latest 3D virtual reality heads up display...

Rainier
CEO MGL Avionics

[Robski]

G'day all,

Interesting to read that so many people are building with just glass, no 'steam' backups at all!

Here in the UK (where we regularly get accused of being behind the times) it is a legal requirement both for homebuilds and the likes of Cirruses that there is a minimal traditional panel (ASI, Altimeter etc) in addition to the acres of glass, in case of electrical failure.

It would certainly concern me to fly a purely glass cockpit aircraft, having experienced power failure in the past.

Rob