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To VP-X or Not to VP-X?

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I have the VP-X sport in my RV-9A. I would install another because I like the utility it brings to the electronics. I have auto wig-wagging lights. Flap and trim control and the ability to see just how much current everything is pulling.
HOWEVER, if the VP-X goes on the fritz, you are stuck. Yes, this happened to me during my Phase 1 period and the unit came out and went back to Vertical Power for repair twice (their problem, not mine). After the second time, I ended up getting a replacement unit under warranty, and it has been rock solid for the last 4 years of flying.

If I were building something like a -12 or -14 where the electrical systems are all laid out and part of the built harnesses, I wouldn't change that and put in a VP-X. There are benefits to having it, but again, there are some downsides that would need to be considered. The fuse panels that Van's have in the -12 and -14 are just fine.
 
HOWEVER, if the VP-X goes on the fritz, you are stuck. Yes, this happened to me during my Phase 1 period and the unit came out and went back to Vertical Power for repair twice (their problem, not mine).

Your experience isn't unique. The two friends I have with VPX's in their airplanes have both had AOG instances caused by the VPX.
 
Just to add my $0.02 (inflation adjusted)

I was initially inclined to use a VP-X -- neat system! --- but, as I was designing my avionics stack, it became clear or me that when in flight, if some electronic subsystem went south, I wouldn't spend any time in the air to debug. I'd evaluate the situation, make a choice about continued flight, and then debug the issue on the ground. I went with fuses; breakers ... what makes you (me) think that I can reset a fault in the air and go on and fly forever into the future? Something's very wrong when a breaker blows.

I prefer a hard failure (fuse blow) and then go on to understand why back in the hangar. That's also why I also have a steam ASI and ALT next to all my Garmin glass. Call me nostalgic, but it's nice to have some analog backup to the highly capable digital screens.

YMMV.
 
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VPX?

One more free opinion from a guy who flys hi tech computerized planes at work and also has been a A&P-IA for a long time. I like the VPX and what it does, but it?s not for me. I agree with the ?all the eggs in one basket? statement and if the box has to come out for repair the plane is likely grounded. (Hopefully not away from home base). I?m going simpler.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
I?ve finally decided-

Although I started this thread, it has taken on a life of its own and is not just about me but, for what it is worth, I’ve arrived at a final decision NOT to include VP-X in my installation. That said, opinions expressed here have certainly made me appreciate the attraction of VP-X.

This has taken a lot of thought, mostly directed at the consequence of varios failure modes. Although I see workarounds for most of these, acommodating them would result in a heavier and more complicated system with VP-X than without. Three aspects are especially daunting.

1- The “eggs in one basket” scenario of losing everthing connected to the VP-X at the same time with no means of in-flight analysis possible.
2-The reiance upon software/firmware inherent in the design. This also obviates the “solution” of using two VP-X units, as they both would be vulnerable to any software glitch that might be inadvertantly embedded in a firmware update.
3- The weight and complexity of sufficient alternate power pathways to avert disaster are nearly the same as a standard switch and breaker system.

Good old switches and breakers can fail, of course, but such failures only affect one sub-system at a time, and they still constitute excellent problem isolators. Also, they are already installed in my airplane and can be re-purposed to support the panel upgrade with the addition of just a few more of each.

If I were planning to be fair-weather VFR only, I’d regard an iPad and one or two steam guages as as sufficient backup, but I’m aiming higher with my bird’s capabilities.- Otis
 
I commend you on your thoughtful consideration of the options, Otis. You are sure to have a plane in which you can have confidence and pride using this approach. Good on ya! :)
 
Are you implying...

Are you implying that those using the VPX should not have confidence or pride in their aircraft?

If not, disregard.

If so, the. That is a silly statement. There is no way to design or build a perfect mechanical system. That being said, every individual must complete his own risk assessment and decide what level of risk they will accept. No two builders will have identical risk tolerance, yet there are many here that think their conclusion is the only conclusion. There aren?t any absolute right or wrong conclusions.

Another example is the thread on weather minimums and approaches. There are people here that won?t fly an approach to less than 800?. That?s fine...for them. I have no qualms about flying to published minimums...that?s fine... for me. There are no absolute right or wrong answers.

It would be nice for people to remember this when having these discussions...
 
Are you implying that those using the VPX should not have confidence or pride in their aircraft?

Not at all, I'm a fan of the VPX and used it in my RV-10. I even posted my power distribution diagram in this thread.

I was simply supporting Otis for taking a thoughtful and measured approach to his decision. No right or wrong here, just a commendable effort to gather the available info by a builder.
 
I have a VPX Pro in my RV-9A.

Twin screen G3X Touch, dual ADAHRS, and a GTN 650. No steam, and no other backup.

I routinely fly it to minimums IFR.

The VPX has, and I have implemented a completely separate backup battery system with an IBBS Li-Poly battery. In the very unlikely event I lose either my entire electrical system, and/or the entire (dual bus) VPX system. I still have enough separate electrical power to run enough avionics to safely get me down.


Really don't understand the reluctance to use a VPX based on the reliability/safety decision. If you implement the system as they recommend you still have a very flyable/safe setup for 45-60 minutes.

-Dan
 
Not at all, I'm a fan of the VPX and used it in my RV-10. I even posted my power distribution diagram in this thread.

I was simply supporting Otis for taking a thoughtful and measured approach to his decision. No right or wrong here, just a commendable effort to gather the available info by a builder.

I agree. It's the thought process, not the choice. There is no right or wrong.
Otherwise..... Follow Dan H.'s human nature decision and self justification tree....
 
I commend you on your thoughtful consideration of the options, Otis. You are sure to have a plane in which you can have confidence and pride using this approach. Good on ya! :)

Thanks for the kind words, Paddy! This was not an easy decision and I?m certainly making no ?right way, wrong way? claims here. It just makes sense for me to go with the simpler and lighter choice here, partly due to the fact that my Garmin suite already incorporates many of the features the VP-X would provide.

I do appreciate everybody?s input to this thread.- Otis
 
For most of the airframe build everything is laid out for your Van's. Once you are on to the wiring its up to the builder to design the system he wants. Many find the VPX fills in a gap here, but it does come with some (in my view) serious limitations. There is a huge amount of really useful information on the Vertical Power web site, but some claims are a little disingenuous (for example c/bs are unreliable ...).

Many of the benefits are really only true in marketing land. The purpose of an electrical system is to reliably distribute electrical energy to the services in the aircraft. Complex electronic hardware and many lines of code are not required. Some switches and fuses are all it takes. If circuit breakers are your thing, that's fine, they are almost as reliable as fuses. I don't want anything else messing with my trim or flaps, particularly software that has been designed and tested to unknown standards. I want to be able to expand my electrical system as I want, not to be constrained by the number of channels in box. I only really care what my system volts, and occasionally how much current I am pulling, more information will only keep your head stuck inside too long. If a fuse or c/b blows I will go without the service until I am safely on the ground.

Learning to wire an airplane is about a difficult as learning to rivet. We've all learnt how to rivet, and most enjoy riveting. Look on wiring as just another skill to learn and task to enjoy. Install the electrical system that meets the needs of you and your airplane, rather than make your system comply with the constraints imposed by an equipment supplier.

Here's some thoughts, the time to set fuse or cb ratings is at design time - changing the rating on the fly is not really a benefit, wig-wag comes for free with most LED landing lights, the best flap positioning system is counting how long to hold the switch, circuit breakers are reliable, Garmin now provide many useful features in the G3X almost for nothing. All equipment should earn its way onto the aircraft. 'Because I want one' is a good reason for buying something (even a VPX), but understand the constraints imposed by your purchase.

Pete
 
I like Dan?s ?typical human behavior? tree. It now sits in the back of my mind as I try to justify my own decisions or thoughts, and as I read others. It is spot on in how we act as a human animal, albeit a little ?snarky?, perhaps ;)
It could be applied to several current threads.
I will use it, if nothing more than to ?check? myself.
 
I don't think Dan is a "self proclaimed expert". Smart, truly knowledgeable and talented based on real world experience, yes.

I consider everything Dan has to say on VAF. It's usually well based in fact and worth pondering.

I kinda like his blunt sense of humor and how he drills down to the basics and the facts, separating out the fluff and BS along the way.
 
I think this one has been thrashed enough. People have listed the pros and cons of a VPX installation for others to ponder. Install it or don't. Simple as that. Same applies to engines, avionics, fuel and ignition systems, paint, primer etc.

Lots of choices in this game. Not everyone will agree with your reasons or choices nor you with theirs.

Doug's posting rules are here: http://www.vansairforce.net/rules.htm Please respect rules 4 and 7.
 
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Just a minute..... While I get the popcorn...

LMAO, so true. :D:D:D:D

I have a VPX Pro in my RV-9A.

Twin screen G3X Touch, dual ADAHRS, and a GTN 650. No steam, and no other backup.

I routinely fly it to minimums IFR.

The VPX has, and I have implemented a completely separate backup battery system with an IBBS Li-Poly battery. In the very unlikely event I lose either my entire electrical system, and/or the entire (dual bus) VPX system. I still have enough separate electrical power to run enough avionics to safely get me down.


Really don't understand the reluctance to use a VPX based on the reliability/safety decision. If you implement the system as they recommend you still have a very flyable/safe setup for 45-60 minutes.

-Dan
So what happens when one of the internal circuits stops working during an approach ? I'm not asking to be a smartA, I'm really curious.
A friend of mine chased what he thought was an Alternator problem that ended up being his VPX but he only found out because he lost power to his flaps and intermittently his trim. After spending hours chasing it down to the VPX and spending valuable time on the phone with them, he ended up taking it out, sending it back to them only to be charged several hundred dollars for another board. My question is if VPX circuits can fail that way, what happens when the circuit to the EFIS or GPS fails during an approach? You mentioned redundancy, how does that work? Are you only referring to the battery/power? Or is there built in back-up circuits in the VPX?
 
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