How much work to replace steam with glass?
 

Hi all!

I'm in the market for a pre-built RV-4 or RV-8. I have certain irreducible minimums (180hp, C/S prop, day/night VFR). I'm looking for an airplane with good structural and engine bones, but my thinking is that the instrumentation can be minimal and steam because before too long I'd want to re-do the cockpit and go glass. I'd rather save money on the instrumentation when I buy and then upgrade with the newest systems later. Also, a steam gauge system is better because I'd rather not have a middle age glass system.

But I wonder how sensible these ideas are and I have a few basic questions. So I came to the best RV web page I know::

Is there a book that discusses this transition, that is good?

Do you end up saving weight over a vaccuum pump driven, steam gauge system?

Do you end up saving complexity over a vaccuum pump driven, steam gauge system?

Aside from money, is there substantial differences in the amount of work if I go IFR glass vs VFR glass?

Can you build and do substantial testing of the new panel outside of the a/c? I'd like to be able to fly it as much as possible before grounding the plane for the final installation and test.

How much work is it, really?

I once considered buying a plane with an O-320 F/P prop and then upgrade later but it turns out that you often have to do substantially more work than I imagined - such as possible substantial cowl work. That's in addition to the other things like installing a MAP gauge and running the prop control back to the cockpit etc. So I gave up on that idea.

I'm wondering if this instrumentation idea of mine is reasonable.

Any insight into this would be welcome and appreciated.


thanks!

I recendly upgraded all avionics to new/ glass, specifically Skyview on a RV6A. I removed the vac system. End weight was a wash, but I added 2 axis AP and ADS-B. I did a dual redundant system i.e. 2 ADAHRS and 2 displays, 2 backup batteries. Access behind the panel was the biggest PIA, including removing and replacing the panel and sub panel. I think the -8 might be easier in this respect.

My take...
 

Went through this with my 6 a couple years ago. Weight depends on what you're starting with and what you add. I had a very basic steam panel with no vacuum. I put in a dual screen, back up battery system with servos. I gained weight (though to be fair, I also added leather interior at the same time).

In terms of work, like all things, double your estimated time and you'll be close. Crimping pins and fiddling takes time.

In the end, was it worth it? Yes. But when the fancy touch screens came out I didn't think more than two seconds about another upgrade before discarding the idea!

YMMV.

It's a good transition to do, but it will take time. You can get the new panel ready before you pull the other panel out, which will save down time as you suggest.

As for IFR vs VFR glass, that's not really a choice unless you go certified. The question is whether you use an IFR GPS and/or Nav/Com tied to your glass. IFR will likely require an ARINC adapter, which will add wiring, and the IFR GPS will add additional wiring. The decision to keep existing radios and intercom vs replacing will change the amount of wiring needed a great deal.

Weight will likely be a wash within a couple of pounds.

The complication depends on what wiring is already in and what system you are using. Some are easier to wire because of network bus systems among modules.

Complexity is a hard thing to answer. Your glass system will be much more complex in some ways, and much more simple in others. It's nice to eliminate vacuum and go all electric, which removes complexity, but with glass you have many more things intercommunicating, which adds complexity. You also have much more complex information with moving map, synthetic vision, altitude and density altitude, IAS/TAS/GS, digital engine info with lots of complex details, etc. the glass is much better for engine monitoring and for situational awareness. In-flight weather is great for safety in some ways, and less safe as you may push the envelope (getting closer to or trying to thread your way through storms).

You will definitely know more about your new system if you wire it yourself, which will be a big plus.

It's a big job if you haven't done it before, but not too big if you have. The biggest time savings will be determining what existing wiring you can utilize.

At my last annual, I pulled out the vacuum instruments and replaced everything with a D10A. It was more work than I expected, but it was actually very easy. My panel is far from glass now, but it is more capable and lighter. Someday, I will pull he panel for a complete overhaul, but am not willing to sacrifice the flying time now. From your post, I see you are in Massachusetts. My -4 is at Fitchburg. You are welcome anytime to see the aircraft. In November, it will be down for annual in case you want to see the "guts".

Good luck with your purchase.

I did my complete "steam to glass" conversion in 2013 and don't regret a thing. The interconnectivity design isn't that hard to do but the actual wiring is a huge PITA especially in an already existing panel when you are not a skinny young guy which I certainly am not. It took me almost 6 months to get the panel completely converted. It is a big job but most people here can pull it off without a lot of aggravations.

Weight differences will depend on what you have and what you are going to have, but for the most part will be a wash.

There isn't a whole lot of difference in wiring a VFR or IFR panel but once again it depends on the equipment you will install. Cost will be different due to extra modules and certified equipment needed for IFR that are not required for VFR operations.

Here is a link to the pictures I took during the entire process. It will give you an idea of what I went through.

N819PR new glass instrument panel

:cool:

I built an RV-8, my wife has an RV-4.
The RV-4 has a tilt over canopy, and the fuselage cover over the instrument panel comes off with the removal of 20 some odd screws.
Working on this panel is a breeze, also working in the foot well etc. you just stand in front of the wing and reach in.
The RV-8 is much taller on the gear, the fuselage is deeper, and the windshield is fixed to the skin which is riveted to the fuselage. The back of the panel is accessed by diving under while your back is bent over the spar and around the control stick.
To make matters worse, you have to squeeze in between the gear towers, so the work area is narrow.
I have removed the control stick and made a back board to gain access, but still it's harder because you can't bring everything into this work area, so you are constantly climbing in and out to get tools and supplies etc.
My RV-8 panel is removable, and has an engine sub panel I can reach thru. Also I can remove the Dynon D-10a and reach a hand in there. To make this work, everything is wired with at least 8" service loop of extra wire so the panels can be removed with the instruments & avionics in them.
So for panel work, the RV-4 is a dream compared to the RV-8, although it does have less panel space.

PM sent
 

Hi Dean,

PM sent regarding making a visit to see your -4. I'd love that. Is it based at KFIT?

The D10A sounds like a major step up in capability in upgrading an old panel. Many a/c for sale don't have a DG or an AI. While I'm a VFR pilot (working on IFR) I feel a little uncomfy without an AI and I like having a DG. A D10A upgrade sounds like the simplest way to get an AI and DG.
And you get a Turn rate/ball with it as well.

From reading the Dynon description I get the impression that all you need to connect it is to route power and connect the pitot static system. Is this correct?

What about VOR?
 

Sticking with the VFR realm for now.....

I also want to have a VOR capability and many pre-built a/c/ do not have it. So this requires replacing the radio, mounting VOR antennae, and .......

...then you need a display. Looks like the D10A has an HSI capability. So if I select the right radio, I get that with a D10A.

But then the question comes up - for VFR flight, is a good GPS a replacement for a VOR capability?

If one is completely redoing an instrument panel, today, should one expect VOR to die off in the next few years?

Galen,

Thanks for the pointer to the pictures...a great help in understanding.