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Engine before avionics?

AeroDog

Well Known Member
Friend
I have bought and started installing the firewall-forward kit before purchasing the avionics kit. Right away I see that I'm supposed to connect wiring to parts from the avionics kit since the prescribed build order has avionics before engine. I've read that others have done this, but I'm wondering if building out of order will present much of a problem. Any opinions or advice will be welcomed.

Jerre
 
In my view it depends on your “build speed”, which will determine any “risk” that the avionics (if purchased and installed first) might advance/evolve/improve while you hang the engine.
 
When I bought my airframe kits at OSH in 2010 the lady in the booth said, “I don’t think I’ve ever sold all the kits at once.” At the time I realized continuing improvements would complicate my build trying to retrofit them.

My friend bought his empennage kit at the same time and is still building. He’s dealing with A LOT of changes!
 
Jerre,

I suggest purchasing the avionics last and try to time the purchase date with the expected lead time for the avionics so you won't find your project stalled.

New products/features are always coming down the pipe. Just since I've built my RV-12 Dynon introduced the HDX as an upgraded Skyview, introduced the AP and Knobs panels, came out with the ADSB-470 which was then upgraded to the ADSB-472 for dual-band, the GPS-250 antenna was upgraded to a GPS-2020 so ADSB would be 2020 compliant and Garmin introduced the GTR 200 which was later upgraded for Bluetooth support as the GTR 200B.

One thing to remember ... in the world of electronics, the technology advancement is at such an accelerated pace, the item is virtually obsolete the day you receive it ... just a fact. Wait as long as you can to potentially benefit from upgrades, new features or new products.
 
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Jerre
I was one of those builders between Dynon D180 and Skyview. I waited till the conversion work was completed and moved on with firewall forward. There were no downside to do this for me, but I do recall having to pay attention to those instructions involving what I would receive later in the avionics kit.
Sometimes it was wiring from the engine compartment to the avionics bay that had to be tagged for later, or wiring that should have been available from the avionics bay. I just put tags and notes to get caught up once the Skyview avionics package was available.
 
The engine technology isn't going to progress anywhere near as fast as the avionics are. Engine first, Avionics about a picosecond before you want to hit the starter for the first time if you want to have the latest hardware in your panel.
 
I have bought and started installing the firewall-forward kit before purchasing the avionics kit. Right away I see that I'm supposed to connect wiring to parts from the avionics kit since the prescribed build order has avionics before engine. I've read that others have done this, but I'm wondering if building out of order will present much of a problem. Any opinions or advice will be welcomed.

Jerre

No problem at all Jerre. There will be a few steps in either the avionics or powerplant build where you will need the other. Just tag those steps for later on.
 
Rob has a good point on evolution of avionics versus engine. Sometimes I wish I had waited for the Skyview, but on the other hand I had a mature design in the last of the D-180’s and my build was very straightforward without trying to figure out new mounting for the AHRS and how to interface the D-180 harness to the Skyview. All certainly possible, but it would have slowed me down. As an old guy running out the clock in retirement I’d rather fly than build!😝
 
Easier

I think it might even be easier to install avionics after the firewall forward kit. All the sensor positions and forward harnesses will be there and eliminate any confusion about best routing, etc. I have some experience with that as I completely changed avionics on a flying -12. That was a D180 to Skyview upgrade.
The search function is not finding my old thread on this so I'll include a link in case anyone is still contemplating such a change.
https://vansairforce.net/community/showthread.php?t=142898

My experience and comments relate to the legacy 12 and not the Super 12.
 
Engine Before Avionics

I had a very similar question with respect to installing the cowl prior to hanging the engine. I agree with all the advice given, delay the purchase of the avionics and complete the engine installation unless you can complete the project over the next couple of months.

If financing is an issue talk to your bank about the timing of the purchase and the issues. I have found that institutions such as Pilot Bank will work with the builder and the kit company to make things work out.
 
Struggling with the engine or avionics first question now. My thought is that the avionics would be much easier to install without the plane on the gear (taildragger).

Thoughts?
 
I had a very similar question with respect to installing the cowl prior to hanging the engine. I agree with all the advice given, delay the purchase of the avionics and complete the engine installation unless you can complete the project over the next couple of months.

If financing is an issue talk to your bank about the timing of the purchase and the issues. I have found that institutions such as Pilot Bank will work with the builder and the kit company to make things work out.

Donnie - I had send you a DM and an email about this. I was curious about your contact at Pilot Bank that was helpful. I ran into a brick wall there right from the start and would appreciate any info you might offer.
 
This thread seems to be attracting a lot of replies from people who aren't familiar with the RV-12is and kit packaging per E-LSA.

What I have heard from most people who have built a -12is is that the avionics first works best. You don't have the guess work on routing things because it's documented, you don't have wiggle room on avionics choices and chasing the hot new thing because it's bundled and documented as well. I suppose there is always an argument for the possibility of updates, but again as I understand things both FF and avionics kits go pretty fast on a 12is. I guess you could assume avionics will update and engine won't and roll the dice on deciding your order is better than what Van's suggests because something might change.

I don't know any of this from my own experience, I'm waiting on my finishing kit and have yet to order either one. I intend to order both at the same time if not within a few months of each other.
 
This thread seems to be attracting a lot of replies from people who aren't familiar with the RV-12is and kit packaging per E-LSA.

What I have heard from most people who have built a -12is is that the avionics first works best. You don't have the guess work on routing things because it's documented, you don't have wiggle room on avionics choices and chasing the hot new thing because it's bundled and documented as well. I suppose there is always an argument for the possibility of updates, but again as I understand things both FF and avionics kits go pretty fast on a 12is. I guess you could assume avionics will update and engine won't and roll the dice on deciding your order is better than what Van's suggests because something might change.

I don't know any of this from my own experience, I'm waiting on my finishing kit and have yet to order either one. I intend to order both at the same time if not within a few months of each other.
I ordered both at the same time and worked on what came first. Which was the avionics package. No issue at all doing that first
 
I put in MGL (Experimental) screens and radio's and stuff.
Therefore I had to wire myself. For that reason I put in the avionics first, needing the space in front of the avionics bay to walk and work.
Never considered wanting to have the latest version though: it's just like homecomputers, once you buy 'm there outdated -but hey, do they do what they're bought for? I hope my plane will last some years, and for sure the avionics WILL be outdated. No problem for me. Yet.
 
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