Third owner, first time owner
Posted: Wed Sep 14, 2022 1:12 pmI am buying a scratch-built legacy Sonex that was finished in 2014, sold to owner 2 earlier this year, then resold again. I'm not new to flying light airplanes, but new to the Sonex line. I logged some EAA chapter build time working on a Zenith, I'm a member of an RV-12 flying club, and have been involved in the maintenance and upkeep for several airplanes in the past. I cannot claim to be an experienced builder, but I am also not a total newb. I have lurked here for several months and spent more time than I'd care to admit reading back through this and other forums for several months to make sure I know what I'm getting into.
The plane I'm buying is definitely not a pristine show plane and the amateur nature of the build shows in several non-critical areas. Attention to detail and obsession about making parts look like factory CNC production was not the builder's goal. The pre-buy inspection revealed several areas that require attention before I'll be comfortable taking it for more than a test-flight around the pattern. This is not to say it's a bad build, but just being realistic about what it is. Perhaps more important is to be realistic about what it is NOT. The aircraft is airworthy and structurally sound. Edge distances for rivets are correct, the spar is properly constructed, and the AeroVee 80hp engine runs great. The 54/44 Sensenich prop looks brand new.
My concerns and plans to fix them are:
1) The brakes were unable to hold against even an 1800 RPM runup. I know the factory says you really don't need brakes, but I do need to do a proper runup and I prefer not to do it while accelerating down the taxiway. Stopping after landing used WAY more runway than I like. I could just barely feel any difference between no brakes and full effort braking. Since there was a lot of oil on the belly and gear legs, it's likely that the pads are well oiled. Once we get the plane home, I will dismantle and clean/adjust everything as much as possible. If that doesn't get significant improvement, I may drop an order for the hydraulic upgrade. I may also look into a proper caliper based disk brake system if that's not too much trouble. I welcome any advice on this subject.
2) As noted above, oil on the belly is coming from leaky pushrod tubes that the seller just replaced. His effort seems to have made a big difference, but there is still a little bit of oil weeping out of them. I'm probably just going to wipe off the drip, clean up the belly, and not worry too much about that for now.
3) Climb performance was underwhelming at best. I weigh 195 and the seller is about 170. With a 1/2 tank of gas we were pushing the upper end of the rated max. Our estimated T.O. weight = 1070 subject to a lot of assumptions and a little science. I need to do a new W/B measurement with calibrated scales because it was just freshly painted. We used well over 2k feet of runway and rotated at about 75 mph. The engine was turning between 3200 and 3300. Climb put us above the trees at about the 4000 foot mark and we were probably 100 feet above them as we left the airport property. We flew an abbreviated pattern much closer in than the standard Cessna training flight would do. I'm not sure we made it more than 400 feet high in our little trip around the patch, but I forgot to look at the altimeter while I was admiring the patchy fog spots glowing in the first light of dawn. Landing approach came down quickly as soon as power was reduced. It felt like he came in a little hot with quite a bit of throttle still applied, then pulled power and floated a long way before touching down. We used over 4000 feet of runway due to the previously mentioned lack of brakes. My conclusion from that flight is that this is a great single-seat airplane, but it really needs the turbo upgrade to be a usable 2-seat plane. Turbo kits are currently enjoying the same delays as everything else: 4 months. Not sure about the prop that needs to go with the turbo.
4) There is something wrong with the starter ring gear. He had to rotate the prop by hand to a place the starter would bite and spin the prop. I expect to replace the ring gear, but I'm not sure why it has this problem in the first place. The engine only has 65 hours on it so I suspect an alignment problem. This will be one of the first things that gets fixed once we have it home.
5) Age has done what it does to both fuel lines and the canopy. I will replace all the fuel lines while I have the engine off for the starter gear replacement. I might do the canopy too. There are several spiderweb cracks around bolt holes and some yellowing from age.
Overall, I am happy to get started with this project. I love tinkering and building stuff so buying a plane with known problems is not a scary thing to me. I'm sure I'll spend a lot of time with my friendly local EAA technical counselors. Due to the known issues, we are removing the wings and trailering it home.
The plane I'm buying is definitely not a pristine show plane and the amateur nature of the build shows in several non-critical areas. Attention to detail and obsession about making parts look like factory CNC production was not the builder's goal. The pre-buy inspection revealed several areas that require attention before I'll be comfortable taking it for more than a test-flight around the pattern. This is not to say it's a bad build, but just being realistic about what it is. Perhaps more important is to be realistic about what it is NOT. The aircraft is airworthy and structurally sound. Edge distances for rivets are correct, the spar is properly constructed, and the AeroVee 80hp engine runs great. The 54/44 Sensenich prop looks brand new.
My concerns and plans to fix them are:
1) The brakes were unable to hold against even an 1800 RPM runup. I know the factory says you really don't need brakes, but I do need to do a proper runup and I prefer not to do it while accelerating down the taxiway. Stopping after landing used WAY more runway than I like. I could just barely feel any difference between no brakes and full effort braking. Since there was a lot of oil on the belly and gear legs, it's likely that the pads are well oiled. Once we get the plane home, I will dismantle and clean/adjust everything as much as possible. If that doesn't get significant improvement, I may drop an order for the hydraulic upgrade. I may also look into a proper caliper based disk brake system if that's not too much trouble. I welcome any advice on this subject.
2) As noted above, oil on the belly is coming from leaky pushrod tubes that the seller just replaced. His effort seems to have made a big difference, but there is still a little bit of oil weeping out of them. I'm probably just going to wipe off the drip, clean up the belly, and not worry too much about that for now.
3) Climb performance was underwhelming at best. I weigh 195 and the seller is about 170. With a 1/2 tank of gas we were pushing the upper end of the rated max. Our estimated T.O. weight = 1070 subject to a lot of assumptions and a little science. I need to do a new W/B measurement with calibrated scales because it was just freshly painted. We used well over 2k feet of runway and rotated at about 75 mph. The engine was turning between 3200 and 3300. Climb put us above the trees at about the 4000 foot mark and we were probably 100 feet above them as we left the airport property. We flew an abbreviated pattern much closer in than the standard Cessna training flight would do. I'm not sure we made it more than 400 feet high in our little trip around the patch, but I forgot to look at the altimeter while I was admiring the patchy fog spots glowing in the first light of dawn. Landing approach came down quickly as soon as power was reduced. It felt like he came in a little hot with quite a bit of throttle still applied, then pulled power and floated a long way before touching down. We used over 4000 feet of runway due to the previously mentioned lack of brakes. My conclusion from that flight is that this is a great single-seat airplane, but it really needs the turbo upgrade to be a usable 2-seat plane. Turbo kits are currently enjoying the same delays as everything else: 4 months. Not sure about the prop that needs to go with the turbo.
4) There is something wrong with the starter ring gear. He had to rotate the prop by hand to a place the starter would bite and spin the prop. I expect to replace the ring gear, but I'm not sure why it has this problem in the first place. The engine only has 65 hours on it so I suspect an alignment problem. This will be one of the first things that gets fixed once we have it home.
5) Age has done what it does to both fuel lines and the canopy. I will replace all the fuel lines while I have the engine off for the starter gear replacement. I might do the canopy too. There are several spiderweb cracks around bolt holes and some yellowing from age.
Overall, I am happy to get started with this project. I love tinkering and building stuff so buying a plane with known problems is not a scary thing to me. I'm sure I'll spend a lot of time with my friendly local EAA technical counselors. Due to the known issues, we are removing the wings and trailering it home.