Sonex-A purchase - What to look for

[daleandee]

The Jabiru 3300 sounds like an amazing match for the Sonex/Waiex. That extra 50% power must be amazing. The Corvair conversion sounds great, too.

120 HP makes a great plane become a fantastic plane! I did consider a Jabiru but I'm extremely thankful to have made the decision I did. The Corvair is very smooth and IMHO has the best sound of any engine you can choose to install:

https://www.youtube.com/watch?v=uYJm2H3pqXY

For what the "burps" sound like listen to the takeoff in this video (gets serious about a minute into it):

https://www.youtube.com/watch?v=PWIFGfGhjOM

FWIW ... I don't agree with Mike Farley that burping is just what engines do. My engine does not burp, stumble, or bumble. If it ever does it will go back to the hangar until I find the problem and fix it.

Years ago at Crossville there was a horrible accident after the fly-in was over and everyone was departing. The accident aircraft was departing when the engine stumbled/quit but it came back to life so instead of the pilot landing on the remainder of the >5400' runway he elected to continue on. At the end of the runway it quit again and he & his wife suffered severe injuries in the crash that followed.

The accident report revealed that on the way to the fly-in that the plane had stopped for fuel and when taxing out for take-off the engine quit. The pilot restarted it and went his way. Many wondered afterwards if the accident was caused in part because the pilot got used to the engine stumbling and quitting.

I believe that my plane should run at least as good as the truck I drove to the airport. Your milage may vary, but I doubt it ...

Dale
3.0 Corvair/Tailwheel

[MichaelFarley56]

FWIW ... I don't agree with Mike Farley that burping is just what engines do. My engine does not burp, stumble, or bumble. If it ever does it will go back to the hangar until I find the problem and fix it.

Don’t misread that statement as “you’re safe to fly an airplane even if the engine shuts down” or anything similar. I agree with you Dale that if an engine is not running correctly, the time to fix it is before a flight ever happens.

My statement should say…I spend a lot of time at airports and regularly see million dollar Bonanzas and Cirruses taxi by that aren’t idling perfectly smooth, quite possibly by not having their mixture set properly for taxi.

For what it’s worth….

[Bryan Cotton]

Anyone not too far from a course between KTHV and KGOO who would like to meet up first week in June, let me know!

KTHV to C77.png (506.63 KiB) Viewed 2791 times

It's about 600 nm to C77, so could be reached in 1-2 days depending upon your endurance. At least 6 hours of flight time. Not too far off the great circle route to KGOO. We have a guest bedroom. I'll PM you contact info.

Edit: I used KMPG, KGWB, and C09 as waypoints assuming you want to avoid class B and C. Not to mention Lake Michigan!

[Hambone]

As flying the Sonex home to California is imminent, I'm having some real concerns about the nationwide weather. My gut instinct is telling me this isn't a very good idea with forecast weather patterns what they are. Especially behind a low-hour AeroVee.

Then again, a 2600 mile UHaul drive isn't something to look forward to, either!

[Bryan Cotton]

My take is the weather game is the same no matter what engine/airplane you are flying behind/in. If it's not good, wait it out until it is. Broadly the weather moves west to east, so you can always wait for it to pass then continue west.

With a new to you airplane, your definition of good weather is likely to be more restrictive - so that means potentially more time to complete the trip.

I'd be gung ho to do it if I was retired and didn't have any time pressure.

[Hambone]

Well, I'm obligated now, so it's going to have to happen one way or another.

[bvolcko38]

The good the about the weather is, it's always changing. Bide your time wait for good wx

[builderflyer]

From the perspective of someone who has made dozens of flights back and forth across the country in light airplanes, (Aeronca 7AC thru Bellanca Super Viking) your greatest real life weather challenge in the Sonex will probably be wind. None of your T-38 or A-10 time will help you here. You'll likely find yourself taking on winds that if you were home, you'd just decide to wait to fly in another day or two but the temptation to push on when on a long cross country trip will be huge. Also, those of us who do most of our flying in California just don't get to fly with gusty crosswinds very much like they do regularly east of the Rockies.

Regarding the Aerovee engine........I don't know the builder of "your" Sonex but most Aerovee engines have likely been put together by someone who has never built an engine before. Given that scenario, if I was to buy an Aerovee powered Sonex product built by someone else, I think the first thing I would do is tear down the engine to its basic components and put it back together myself so that I could be sure of what I had.

I've had thoughts of selling my Sonex after playing with it for 25 years and one thing I've strongly considered is to include delivery to the buyers location as part of the selling price. Too many buyers have had issues getting their newly purchased Sonex home, worst case being they killed themselves in the process.

This reads like an awfully negative message. Sorry for that.

Art,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[Hambone]

Thanks for all of the advice! I'll certainly take my time, and am prepared to wait it out for decent weather before each leg. I aim to get a sunrise (or earlier) start each day, and be on the ground before the winds kick up. To mitigate the crosswind issue, I'm planning on using airports with crossing runways.

Of course, if it looks too bad at any point, I'll find a local A&P, take off the wings, and UHaul the rest of the way home.

Regarding the AeroVee and the Sonex, I'll fly it extensively for 2 days before departing on the cross-country. And if I don't feel up to it, or feel the airplane and/or engine aren't up for it, the seller will help me stuff it in a UHaul.

[Arjay]

Hambone wrote:
As I prepare to return to Pennsylvania to pick up the Sonex, I’m getting the jitters reading about all of the AeroVee vapor lock and overheating issues here in the forum. There seems to be an awful lot of after-build mods that are necessary to alleviate the overheating and vapor lock issues. Not being an engineer, or particularly mechanically-minded, it gives me cause for concern. I’m beginning to wonder if the AeroVee is the engine for me.

Hambone: My Story:
Like you, I purchased an Aerovee powered Sonex, with Aerocarb. That was back in 2014. With no prior checkout, training or even reading about the Sonex, (the guy I bought it from did not even know how to get it started). I got a ride to So. Carolina to see the airplane, and had to do some work to connect the throttle to get it running. After that, arranged an annual inspection and came back some time later to pick up the airplane and fly it home to Atlanta. Along the way, I stopped at Tocoa, GA where it experienced a flat tire, so had to leave it there for a few days to get a new tire. Then flew home. I had no problems with the engine during the trip until entering downwind at my home airport at KlZU the engine quit. So, there, my second landing in the airplane was dead stick. (That was interesting- probably my best landing ever in that airplane). Got the engine running on the ground, but it would die when pulled back to idle. That problem continued for several flights, afterwards, and we determined it was vapor locking. After trying several fixes, we finally solved the problem by insulating the exhaust pipes and fuel lines, and ducting outside air to blow directly onto the fuel line going into the Aerocarb. Later, we changed the Aerocarb to a Rotec TBI, which allowed us to do away with the gascolator and fresh air blowing onto the fuel line. Now it runs fine at all speeds, but is very sensitive to mixture---does not run well rich.

Hope this helps.

Ron