Sonex First Flight
by Bill Brown
from On Final November 2004
Members have seen Bill’s white-on-aluminum Sonex in the northeast corner of the chapter hangar for a couple months now. What you may not know is that Bill took his Sonex up for a successful first flight on Tuesday, October 12th.
What got you interested in flying?
When I went to work for IBM back in 1963, one of my coworkers got me started. I got my private license in 1969 at Benson airport in White Bear Lake, and I’ve been flying ever since. I now have something over 1200 hours in everything from Champs to a King Air. Most of my time is in taildraggers.
How did your family and friends react when you decided to build your own airplane?
Most were very supportive. My dad had a private license, and my wife Sue has soloed.
How did you happen to choose the Sonex?
This is actually my 3rd homebuilt  I have built a Sonerai and also an RV-4. I knew John Monnet, who designed both the Sonerai and the Sonex. I had also met both Jeff Coffey and John Koser of Chapter 25, who completed their Sonex’s over a year ago. Both have been very cooperative in demonstrating their aircraft and answering questions. I also got a chance to fly the Sonex before building my own. My first flight was with Dave Koelzer from Marion, Iowa in his 3300 Sonex. I was sold!
How did you get started with building the Sonex?
I didn’t want this project to drag on, so once the decision was made I dove in. I bought a complete Sonex kit and started building on December 12, 2003. It was cheaper to buy the whole kit at once, and I didn’t want any delays.
Did you make any design changes?
I like the basic Sonex as designed, and the only change I made was to flush rivet the whole airplane. This was not a huge extra effort.
Did you get help with the project?
I did most of the work myself, but I did get help from several friends, especially Kevin Kavaney and Jim Wallace. Jim is a college buddy who lives in Dallas now and flew here to help me wire the panel and other things. I also had Peter Denny, a technical counselor with Chapter 25, inspect the project on three different occasions. Peter was most helpful.
How did the FAA inspection go?
The FAA approval involved a lot of paperwork. But the inspection itself was brief and easy. The inspector s are friendly but overworked, and things move slowly.
How did you prepare for the first flight?
I did a lot of planning, including flying several airplanes to get current. I flew three times with Jeff Coffey in his Sonex. I did not want an audience for my first flight, so my wife Sue was the only one who knew in advance.
How did the first flight go for you?
First of all, my plan for privacy was blown when Sue and I got to the chapter hangar that Tuesday morning. The hangar construction crew was busy applying insulation to the hangar door when I arrived. But it turned out just fine. The crew that day consisted of Steve Adkins, Lee Hurry, and Harvey Havir, and they gave me the space I needed yet were also very supportive  in fact, they took the only pictures I have from that day. I was confident that I had done everything necessary to prepare for the flight, but still, you can’t help feeling nervous beforehand because of the cons equences if something goes wrong. The flight itself went well, the Sonex performed beautifully, and when I landed I was elated, pleased, and relieved!
What did you learn on that first flight?
Mainly, what a great design the Sonex is. It performs close to my RV-4. I have added a trim tab to the rudder, and I am still doing some fine-tuning with that.
What are your plans for the test flight period?
I’ll be flying off the 40 test hours from Airlake. The test area is an odd-shaped area to the south. So far I’ve flown about 5 hours. I’ve been dealing with what appeared to be an overheating problem. It turns out that I had programmed the wrong cylinder head temperature probes in the software so was getting erroneous readouts. Once I straightened out the software the problem disappeared. So now I can get back to flying!
Any advice for others contemplating homebuilding, or building a Sonex?
Do it! You can spend your time in front of the boob tube or spend it building an airplane. Same amount of time goes by – different results! The Sonex won’t fit the needs of everybody. For those who like this type, the Sonex is well designed, the kit well done, with super blueprints and factory support. Obviously, I am very pleased with the Sonex. I built mine, flush riveted, in 8 months. Love retirement!