What am I missing?

[johnr9q@yahoo.com]

Cost of Airframe Kits (everything ready to fly except the engine and avionics/communication system)

RV-12 $23,785

CH-650 $19,500

Sonex $17,195

I tried to compare apples to apples but maybe someone can point out to me that I errored. In all my investigations I assumed that the Sonex was so much cheaper than the other 2 but there is only a $6600 difference between the most expensive (RV-12) and the cheapest (Sonex). Correct me if I'm wrong, but it seems to me that you get a lot more airplane with the RV-12 and CH-650 and they aren't that much more expensive.

[kmacht]

What you are missing is the cost of the engine. The RV-12 uses the Rotax 912 and costs $28,730. The Sonex uses an Aerovee and costs $7495.

RV-12 Kit (23,785) + Engine (28,730) = $52,515
Sonex Kit (17,195) + Engine (7,495) = $24,690

You can just about build two Sonex airplanes for the cost of one RV-12. Avionics also play a part in it. If you want to build the RV-12 as an E-LSA you have to buy and install the required $13,995 avionics package from Vans. Most people that build a Sonex end up using an MGL setup and have their panel complete for under $5000.

Yes, there are ways to build an RV-12 cheaper but there are also ways to build a Sonex cheaper. They both have their tradeoffs. You can build the RV-12 as an experimental-amateur built instead of an E-LSA and use a different engine and avionics. Doing so you have to be willing to do it without plans and fabricate things like your own motor mount, custom cowling, exhaust, intake, etc. On the flip side you can also build a Sonex completely from plans and only buy about $2500 worth of raw metal to get a pretty complete fuselage. I myself scratch built my Sonex and am flying (with an aerovee and a used EFIS, not counting paint)) for about $16,000.

Keith
#554

[johnr9q@yahoo.com]

Keith: Couldn't I put the Aerovee engine and the MGL set up in a RV-12? I didn't consider scratch build as this is not done often.

[JT1974]

Don't forget the strength of the airframe (i.e. aerobatic capability).

You won't find many YouTube videos of guys doing loops and rolls in their RV-12's or Zenith 650's with their smoke on.

[kmacht]

Anything is possible if you are capable of doing the engineering, design, and fabrication work. Some have put a Rotax 912 in a Sonex for that matter but there is alot more to it than just choosing a different engine. As I said before, custom cowl, engine mount, exhaust, intake, baffling, testing different propellers, weight and balance differences, etc. I was just answering you question as to why a stock RV-12 costs significantly more than a stock Sonex. I think you will find that most 2 place aluminum aircraft have about the same amount of aluminum in them. It is all the other stuff that goes into the airplane beyond the basic airframe that adds up quickly.

Keith
#554

[kmacht]

I didn't consider scratch build as this is not done often.

You would be surprised at how many Sonex were scratch built. When the company was just starting out they only offered plans and a few parts. Laser drilled matched hole kits are only a few years old in the Sonex fleet.

Keith

[johnr9q@yahoo.com]

Keith: Thanks for the good information. I guess I have been naive with things like "The Sport Aircraft Reality Check" implying the Sonex was much cheaper. I imagine we could argue forever the qualities/lack of qualities of each airplane. (compare the Aerovee to the Rotax or MGL avionics vs Dynon) But my original post was genuine effort to find out "what I was missing" not trying to argue. Maybe one airplane had a more expensive prop or the prop was extra or one included parts that were more complete in the package or one have better match holes. I really like the Sonex and everyone I talk to thinks it is a great plane but a VW conversion really worries me. (The biggest thing is available power in hot weather, high elevation and a full load. The 80hp is developed at 3500 rpm, but, because of limitations of the prop going supersonic, it can't ever develop that power. I know there is the Jabaru but that adds a lot more cost and, it has overheating problems. (whether this is real or not, it does make one concerned) I haven't heard any concerns regarding the Rotax. It seems to be a bombproof engine. I know a lot of the issues with engines are how they are perceived and maybe not based on realistic information but when you're at 10,000 feet with no place to land perception causes worries. I am not a pilot and just exploring kit building.

[Sonex1517]

John

I found your questions to be fair and accurate assessments of what most, if not all, of us went through. I obsessed for about 9 years with the same comparisons, although at the time Vans did not have the RV-12. (My choices came down to Zenith, RANS, and Sonex)

In the end, I really do believe Sonex offers the best airframe and engine for the money.

Their recent turbo kit for the AeroVee does increase available horsepower to 100HP or more....

Just my two cents. Welcome to the forum!


Robbie Culver
Sonex 1517
Chicagoland
Tails and Wings complete - finishing fuselage.
N1517S reserved

[NWade]

a VW conversion really worries me.

Just a note: You're painting with a VERY broad brush, by considering all VW Conversions to be equal. They are not, and since the engine has been around for a lot longer than the Rotax or the Jab, it has had a lot more time for people to do stupid stuff with it (both in building, and in flying).

I urge you to take a more-detailed look at the various conversions out there and understand the difference between the more-professional/complete conversions and some of the "shade-tree-mechanic" versions that have appeared over the decades.

--Noel

[seanmb]

(The biggest thing is available power in hot weather, high elevation and a full load. The 80hp is developed at 3500 rpm, but, because of limitations of the prop going supersonic, it can't ever develop that power.

You are working with some incorrect information here. The 3500RPM figure would be a concern for a 70"+ prop down at sea level, where speed of sound is 1126f/s. With a 54" prop, which is specified for the Sonex AeroVee combo, we will still be subsonic at 4400RPM all the way up to 15,000 feet, where speed of sound is 1036f/s.