Sitting behind an AeroVee

[marktbaldridge]

Hello All!

I am 22 years old, married, studying Electrical Engineering, and would LOVE to build a plane after I graduate, and get a job that can support it. ;)

I have jumped back and forth between a Van's RV-7, and a Sonex. Both are very cute airframes, and I must say the Sonex has a bit more personality.

The cost difference is huge though:
- RV-7 Quick build kit + mid-time Lycoming + avionics, paint, etc, is ~$92k according to Van's calculator.
- Sonex Quick build kit + AeroVee + avionics + paint, etc, is ~$40-45k.

My main concern with the Sonex & Aerovee however is reliability!

And is Jabbaru much better? From what I've read, they have heat/cooling issues. But I wasn't able to find much about reliability.

This article discusses auto-conversion engines from a statistical perspective, and VW engines have a large slice of the pie.
http://www.kitplanes.com/issues/28_2/ex ... 459-1.html

Here is a list of documented Sonex accidents:
https://aviation-safety.net/wikibase/db ... cType=SONX

If there have been something like 600 Sonex planes built, compared to those 25 accidents, that's a disturbing 4.1%!
Not all, but many of those are merely attributed to a "sudden loss of power". Such ambiguity disturbs me.

Questions:

1. How do I know that my AeroVee won't experience a "sudden loss of power"? Is it REALLY true that if I follow the instructions, maintain it correctly, and fly with common sense that I'll be "just fine"? How do I know I have built the engine right?

2. From what I've read, Sonex/AeroConversions have responded to engine failure by merely stating, "Well, they must have not built it right." How do you all feel about this?

3. How does the cost savings justify my perceived risk, not only to my own life (and my wife!), but also to the time and money I have in my plane?

A sudden loss of power over Nebraska might be just fine, but over hills, woods, or city, it could be disastrous!

The story of Sonex #602 still haunts me. A beautiful build, but he always had a finicky engine. And then one day, sudden loss of power, forced landing, pilot survives, but 1,000 hrs, and $40k did not.
http://www.sonex604.com/crash.html

I am happy the pilot survived, but seeing the ripped wing nearly makes me cry!

So help me though this, guys. I don't want to be a downer, and I love the Sonex air frame.

[hickej]

I cannot speak for all the AeroVee owners but I know quite a few who are very happy with their choice. I can state that I've had a great experience with the Jabiru 3300. The Sonex baffle kit for the Jabiru has worked very well for me and I run cool CHTs. The internet is a wonderful thing and it is a terrible thing. Bad information can circulate for a long time or a small number of bad experiences can multiply in the blogosphere. I have close to 500 trouble free hours on a late model hydraulic 3300 and our USA dealer, Pete Krotje, is quite knowledgeable and helpful. Jabirus are used in flight schools in Australia and Pete can give you the story on the CASA saga.

At the end of the day, you are flying a single engine aircraft and no engine is 100% reliable. The accident reports are full of engine failures with many varied causes on certificated aircraft and experimental aircraft. Your flying skills and judgement are the redundancy in a single engine aircraft. You must fly with the mindset that the engine could fail at any time. The question "Where would I land now?" must be constantly going through your mind. Whenever you are in a situation where an engine failure would put you in dangerous territory, you have removed the redundancy of your engine-off training. I highly recommend learning to fly gliders and practicing short approaches to learn energy management. Become so familiar with the flying qualities of your aircraft that you are confident you could put it down in that field. Know the signs of flying too slowly and train your mind to "fly into the crash" - instead of stalling 100 feet over the ground. Ask yourself if you should really be doing low passes or circling your friend's house. "Where would you land now?". Whether you're flying certified or experimental, you have to be prepared for the engine out scenario at all times. (Wow, I think I'm passionate about this!).

So, yes, you want the most reliable power plant possible moving your aircraft through the air, but you must realize that all single-engine aircraft have a weakness that can only be overcome by training and a proper mindset.

I'd love to hear some flight instructor perspectives on this topic.

-Jim
Waiex 3300 TD 492 hours

[marktbaldridge]

That's sound advice.

I'll also add I live about 3 hrs from Oshkosh. So visiting Sonex and attending Airventure are on my list next summer. :)

[Bryan Cotton]

Mark,
I was once a 22 year old EE student who wanted to build a plane after I graduated. First thing I did was to get my rating. Have you checked that box yet? You should, in my opinion. Also I find it curious you would go right to quick build. A new grad engineer generally has more time than money. Why shy away from building? If it is not your thing that is ok. There are plenty of engineers of all disciplines who don't change their own oil. That still gives you plenty of options. You can buy a flying Sonex, or RV6 for cheaper than you can build one. Back when I worked at Sikorsky there were a couple young guys who went in as partners on a solid C150 that needed a paint job. If it ever gets sold I bet they don't lose a dime.
Regarding the Aerovee, you have to make up your own mind. My wife will never get in the airplane with me but my boys will- and my oldest should solo in our Aerovee Waiex.

Sonex now supports a few more engine options, all of which I think are cool. I like the Aerovee.

Good luck! Have you done any co-ops during school?

[dbdevkc]

2. From what I've read, Sonex/AeroConversions have responded to engine failure by merely stating, "Well, they must have not built it right." How do you all feel about this?

Others struggle with the same questions. I Don't necessarily agree with question #2, and now especially in light of recent events that cannot be the standard response.

I highly recommend learning to fly gliders and practicing short approaches to learn energy management. Become so familiar with the flying qualities of your aircraft that you are confident you could put it down in that field. Know the signs of flying too slowly and train your mind to "fly into the crash" - instead of stalling 100 feet over the ground.

Off topic, but as a glider pilot myself I strongly agree with this. It is concerning that even high-time pilots have had stall/spin into terrain accidents. And it is not just a Sonex phenomenon, it is a problem across the board in GA. Glider training teaches not just "short approaches", but steep approaches. And that with no motor you only have two forms of energy - speed and height (kinetic and potential). You can trade one for another, but if you have no height and no speed you are SOL. I know no one wants to put the plane down in an off-airport field, but better that then attempting a turn or some other maneuver with way too little height or speed, skidding the turn because you are under stress and want to get it turned around, then spinning it into the ground. As another side note, I personally have an issue with a lot of the big, long legged patterns I see at my local airport. Some of the finals look like if the engine even just sputtered along the way, they would not make the runway.

[radfordc]

Have you also examined RV accidents to see if engine problems are a factor?

I agree that flying behind a VW engine may be less reliable than a factory installed Lycoming. But, I think it is fair to say that most VW problems are related to builder errors and maintenance issues. In my experience the Sonex factory is always concerned when a problem is presented to them and will do their best to help you solve the problem....even if you did cause it.

Finally...if you believe that you will always be "worried" when flying behind a VW , you will probably never enjoy having one.

[vwglenn]

Welcome.

Let me start by saying that Sonex is probably the right plane for you to start with. Despite my board name, I purchased (didn't build) a 3300 powered Sonex.

That being said, up until about 2 years ago, I drove aircooled VWs exclusively for close to twenty years. I drove my cars everywhere. The grocery store, work, school, across the country and even delivered Pizzas in a '68 Beetle for two years to help make ends meet. In all that time and for hundreds of thousands of miles I never had an engine grenade on me. Did I have mechanical problems? Yep. Did they require some TLC? Yep. Did they quit on me? Yep...but never without warning and never because of the engine itself. It was usually something like a cheap fuel pump or one of the other peripheries. I'm a firm believer that a well maintained VW built with decent parts will run much like the energizer bunny. I was attracted to Sonex in the 90s because of the VW option. Would I fly behind a VW? You bet your butt I would...and have. I've often considered selling #600 and building a VW Onex. I still might do that one day.

The Jabiru's reliability has been called into question just as often as the VW in my opinion. So much so that the Australian aviation authority banned them from night operations and over populated areas for a time. I've run into some problems with mine that have had me really scratching my head. Has that stopped me from flying across the country in my Jab powered Sonex? Nope.

I agree that the "sudden loss of power" problems are cause for concern. The FAA and NTSB, however, don't really put the effort into digging deep into the problem because the aircraft are experimental. Their opinions of experimental aircraft are pretty biased and there may be a culture where they feel they can't figure out any issues because there is too much variation between one aircraft and the next. Half of the synopsis you'll read fail to even mention which engine the plane was equipped with. I'd personally like to see more attention paid to the fuel and ignition systems installed in the aircraft.

The good news is the airframe is a work of art. It's simple and robust. We're trained from day one to expect engine failure when flying any airplane. Even if the fan stops spinning, it still flies. Almost every fatal Sonex accident I've looked at can be attributed to the pilot failing to fly the plane (spinning it in) or attempting the impossible turn (spinning it in). If you fly the plane to the point of contact, you're more likely to survive and walk away. The two things that scare me the most while flying are fire and structural failure. There is no evidence of either being a problem with the Sonex. I don't think you have any more to fear in a Sonex than a 20-40+ year old certified airframe.

As far as Jeff (Sonex 604), you'll note that he built...another Sonex...which speaks volumes in my opinion.

[radfordc]

The cost difference is huge though:
- RV-7 Quick build kit + mid-time Lycoming + avionics, paint, etc, is ~$92k according to Van's calculator.
- Sonex Quick build kit + AeroVee + avionics + paint, etc, is ~$40-45k.

You can buy a flying Aerovee Sonex for around $30K.

[kmacht]

I used to think it was always builder error or maintenance issues that caused aerovee engine issues. That changed when the factory had not one but two aerovee planes crash on takeoff. Those engines we we supposed to be built and maintained by the authority on the aerovee. I don't know how you convince yourself that it is a reliable power plant at this point. I fly behind an aerovee because I bought and built before these accidents happened. I am ready on every takeoff for it to quit. You can say that you should be ready for that with any airplane but I just don't get the same pucker factor taking off in a Cessna than I do in my sonex. Keep in mind when reading posts on here that it is a sonex oriented forum. You are more likely to hear positive than negative opinions about the airplane and the engine. I suggest you take everyone's opinion as a whole, look at the facts and then make a decision.

Keith
#554

[vwglenn]

I used to think it was always builder error or maintenance issues that caused aerovee engine issues. That changed when the factory had not one but two aerovee planes crash on takeoff. Those engines we we supposed to be built and maintained by the authority on the aerovee. I don't know how you convince yourself that it is a reliable power plant at this point. I fly behind an aerovee because I bought and built before these accidents happened. I am ready on every takeoff for it to quit. You can say that you should be ready for that with any airplane but I just don't get the same pucker factor taking off in a Cessna than I do in my sonex. Keep in mind when reading posts on here that it is a sonex oriented forum. You are more likely to hear positive than negative opinions about the airplane and the engine. I suggest you take everyone's opinion as a whole, look at the facts and then make a decision.

Keith
#554

So you know for a fact that both crashes were caused by engine failure and said engine failure was caused by and internal defect of the Aerovee? Because I'm not aware of any evidence to support that. We don't even know that engine failure was what caused Jeremy's accident. It could be engine failure but speculation without evidence is just that...speculation.