New (Second) Builder Questions - Inspection

[Badger830]

Good Evening Sonex Builders,

First of all, I want to thank everyone for your contributions to this site; it has been an invaluable resource over the last few weeks as I've been researching Sonex kits and the process of completing one.

I had an opportunity fall in my lap to purchase an abandoned kit that was originally owned by a local high school's aviation technologies class. The kit is an original Sonex design circa 2006. While the kit is missing some of the original components, it was priced accordingly and, to be honest, too good of a deal to pass up.

The students enrolled that were enrolled in the program managed to complete the ailerons, flaps, tail surfaces, and just started on some of the spar tasks. While I'm planning on pursuing a B model conversion kit, I'm considering drilling out the skins of the already completed components to inspect the internal structures.

On one hand, the completed components look to be in good shape. On the other hand, I was able to identify some mistakes on completed (but not yet installed) wing parts. Would the brain-trust recommend removing the skins from the completed components for inspection or leaving them as is (since they appear to have gone together fine). Thanks to all of you in advance for your advice and I look forward to continuing to learn from this great resource!

[Bryan Cotton]

Welcome to the forum, and congrats on your Sonex!

If it was me, I'd inspect as much as possible from the outside and through the rib tooling holes. If nothing scared me horribly I would leave it and keep going. There is a lot of margin in the airplane. But if it keeps you up at night, then go for it.

The challenge is drilling out all those rivets without causing more damage. Unlike solid rivets, some percentage of pops will spin. If you can get to the tails with vise grips, no problem.

Before you sell the classic A model short, sit in both. I don't have B model envy at all. The A model should be lighter.

Hopefully soon we will have ADSB out and will be going to KMSN for our passport stamps.

[Badger830]

Welcome to the forum, and congrats on your Sonex!

If it was me, I'd inspect as much as possible from the outside and through the rib tooling holes. If nothing scared me horribly I would leave it and keep going. There is a lot of margin in the airplane. But if it keeps you up at night, then go for it.

The challenge is drilling out all those rivets without causing more damage. Unlike solid rivets, some percentage of pops will spin. If you can get to the tails with vise grips, no problem.

Before you sell the classic A model short, sit in both. I don't have B model envy at all. The A model should be lighter.

Hopefully soon we will have ADSB out and will be going to KMSN for our passport stamps.

Thanks for the advice Bryan! Good point on drilling out the pulled rivets; I hadn't considered that. My wife and I (who is also a pilot) had the opportunity to tour the factory a couple of weeks ago and sit in both the A and B models; it was a great experience and helped us decide that the extra leg room and fuel made the B model worth it for us.

Enjoy flying to KMSN once you're ADS-B equipped; it's a great airport and breakfast at the Jet Room is hard to beat. With a healthy mix of military, commercial, and training traffic, it's a cool experience and no two flights there are the same. If you haven't been already, I also highly recommend flying to KJVL and visiting Bessie's Diner.

[Bryan Cotton]

If you haven't been already, I also highly recommend flying to KJVL and visiting Bessie's Diner.

I've been to Bessie's once, new year's day this year.

I flew the entire family in a rental C172 to the restaurant before Bessie's back in 2013, right after we moved here. Tim Stearns from Kenosha was also there that day in his Waiex, and that is really what inspired me to go the Waiex route. I had always liked the Sonex design and the philosophy behind the airplane, but on the ramp that day I realized that the Waiex really looks cool!

[Sonerai13]

Good Evening Sonex Builders,

First of all, I want to thank everyone for your contributions to this site; it has been an invaluable resource over the last few weeks as I've been researching Sonex kits and the process of completing one.

I had an opportunity fall in my lap to purchase an abandoned kit that was originally owned by a local high school's aviation technologies class. The kit is an original Sonex design circa 2006. While the kit is missing some of the original components, it was priced accordingly and, to be honest, too good of a deal to pass up.

The students enrolled that were enrolled in the program managed to complete the ailerons, flaps, tail surfaces, and just started on some of the spar tasks. While I'm planning on pursuing a B model conversion kit, I'm considering drilling out the skins of the already completed components to inspect the internal structures.

On one hand, the completed components look to be in good shape. On the other hand, I was able to identify some mistakes on completed (but not yet installed) wing parts. Would the brain-trust recommend removing the skins from the completed components for inspection or leaving them as is (since they appear to have gone together fine). Thanks to all of you in advance for your advice and I look forward to continuing to learn from this great resource!

Hello "Badger"!

Since you are in WI, I am not far away from you (once I get back north from Texas). If you can wait about a month before you get itchy to start drilling out rivets, I would be happy to stop over and take a look at what you have. Don't drill out those stainless steel rivets unless you absolutely have to. they are a gold-plated bi*ch to drill out! Not impossible, but it takes patience (and a lot of SHARP drill bits).

PM me and we can maybe set something up.

[Badger830]

I flew the entire family in a rental C172 to the restaurant before Bessie's back in 2013, right after we moved here. Tim Stearns from Kenosha was also there that day in his Waiex, and that is really what inspired me to go the Waiex route. I had always liked the Sonex design and the philosophy behind the airplane, but on the ramp that day I realized that the Waiex really looks cool!

What a cool origin story Bryan!

[Badger830]

Hello "Badger"!

Since you are in WI, I am not far away from you (once I get back north from Texas). If you can wait about a month before you get itchy to start drilling out rivets, I would be happy to stop over and take a look at what you have. Don't drill out those stainless steel rivets unless you absolutely have to. they are a gold-plated bi*ch to drill out! Not impossible, but it takes patience (and a lot of SHARP drill bits).

PM me and we can maybe set something up.

Thank you very much for the offer, Joe! I will send you a PM shortly and for sure hold off on taking skins off.

[Bryan Cotton]

they are a gold-plated bi*ch to drill out! Not impossible, but it takes patience (and a lot of SHARP drill bits).

Don't forget the chicken sacrifice at midnight, etc. I had to redo my left flap hinge for rigging early on. I have the short flaps. That was probably about 20 drill bits worth and I could get to the tails of the rivets. Once the bit is done, you need to just throw it away as it won't cut the stainless anymore but instead will harden the surface due to heat.

[Scott Todd]

I once bought a crashed Sonex. It wasn't bad as it was actually landed out in some scrub and not actually crashed. I needed to replace the entire Fuse bottom and the bottom on one stab needed repair. It was rough going. I probably used 30 drill bits to drill out the bottom. We were able to get to almost all the spinners from inside the fuse. It would be a nightmare if you couldn't reach them. From an Engineering point of view, its pretty hard to mess something up so bad its not airworthy. A good inspection should be fine. Jeremy and I actually talked about this before. We were both Mechanical Engineers and always had fun technical discussions. Boy I miss him....

[Badger830]

Wow you guys weren't kidding about drilling out the stainless rivets. Unfortunately, after I noticed the rudder rocking on the bench a little more than I liked, I set up a laser alignment jig to see if the rudder was straight. The picture shows how bad the bow is in the skin. I'll be ordering a new skin and ribs so I'm not messing around with out of spec holes.

Thanks for the tip about keeping the drill bits fresh. It makes a huge difference!