Replies to This Discussion

Permalink Reply by Ralph Powell on February 4, 2019 at 2:15am

If you are looking for a conservative, non factory, opinion contact Gary Motley. Gary has learned a lot about engine reliability the hard way and I respect his opinions. Not being as conservative as Gary I do things differently, but he has experience.   

You might consider sending him a friend request and go from there. He has gone the xtra mile to insure that his 350 will not let him down.

Ralph

N750RP

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Permalink Reply by Robert Riat on February 5, 2019 at 7:26pm

First, I will tell you that I really like my 350is, but I went with one ECU for the same reasons you mention and sometimes I question how smart that was. Just because they haven’t had a failure, doesn’t mean it can’t happen, or won’t.  From what I have read, there has been some issues with the alternator and/or wiring and I only have one and one battery so I plan to, at least, add another battery when Spring comes.  I have an Earth X battery (pricey of course) but not heavy.  I have 1/2 interest in an old Piper Warrior that has had two inflight mag failures in the last few years and it  wouldn’t be here if not for 2 mags!   Thanks for your message - I hope more people will respond.

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Permalink Reply by Mark MacAulay on February 7, 2019 at 12:09am

Thank you Ralph and Robert for your inputs.  My price quote for the 2nd ECU is $4,370 which an awful lot of money  for something that doesn't contribute other than perhaps some peace of mind.  Not clear if that includes as second set of sensors, which adds wiring complexity.  From what I've read about engine failures, they are generally fuel related, or loss of electrical power.  If nothing else, a 2nd battery seems very worthwhile, and doesn't incur the extreme expense.

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Permalink Reply by Jan Eggenfellner on February 11, 2019 at 8:03pm

https://www.vikingaircraftengines.com/electrical-wiring.html

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Permalink Reply by David J. Beaulieu on February 7, 2019 at 9:29am

Mark,  the second ECU setup will add another set of ECU sensors and an additional wiring loom to pass thru the firewall to the ECU.  I'm running a 2011 UL350iS with a dual ECU setup, dual EarthX battery, single 30A alternator setup.  My "mission-style" flying is year round VFR, low-level, remote over less than hospitable terrain with off airport overnight stops.  I too, was looking to achieve reliability through redundancy (besides proactive maintenance.) Two batteries in good condition should give me at least 45 minutes of flying time if the alternator or R/R goes kaput, in cold weather environment here in Maine, I can use both batteries for engine start, and if a battery goes bad, I can start/fly on one.  So, IMHO, for my particular situation, the benefits of two batteries outweighs the additional cost, weight, complexity, etc.  If I had intended to do IFR flying, then I would certainly have added the dual alternator setup...

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Permalink Reply by Jerold Ebke on February 7, 2019 at 9:00pm

There have been more elegant and informative answers already given, but:

I did.

Looked at price and decided I would buy into "never had a failure".

323 hours on 350i  at this point and never a hiccup from ECU.

I have great trust in my UL, but I also do fastidious maintenance and have never run straight 100LL. My travels have been planned around unleaded availability, but now with retirement, I hope to expand beyond Mexico, Missouri and Oshkosh, Wisconsin from southeast Nebraska. I hope the FAA unleaded fuel comes soon to allow the UL flying community easier fuel availability.

 I try not to think about failure when I am in the air beyond following my training to be prepared for the unexpected.

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Permalink Reply by Jan Eggenfellner on February 11, 2019 at 8:06pm

The single ECU is fine.  Work on perfect wiring, etc.  the ECU will not quit mid flight

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Permalink Reply by Oliver Reik on March 11, 2019 at 10:56pm

I understand that the ULPower engine can run on the alternator alone. With a properly sized battery and a solid electrical system, you'd therefore automatically get electrical redundancy, since the engine could run either on the battery or the alternator alone.

Keep in mind, that the more complex the system becomes, the higher the risk of misuse or the failure of a component, associated with the redundant system, will be.

With the ECU I am a bit on the fence - to make any sense at all, also all the sensors and the fuel injectors would have to be redundant. Then again, modern electronic ignition and fuel injection systems are so incredibly reliable that the added complexity and potential risks that come with a redundant system, just don't seem to be worth it. Just ask around an airport how many people had problems with their magnetos - you'll soon find out why two are needed to make a reliable system. ;-)

Also, if reliability is your primary concern, I'm not sure I'd go with a relatively new engine of which few have accumulated a significant amount of hours. There is also so much other non-redundant stuff on your engine (throttle and throttle cable, pressure regulator, crankshaft, camshaft, prop, etc) and the airframe that a failing ECU wouldn't be of particular concern to me.

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