From Sonex Technical Support, We are in contact with Justin on this issue. Before knee-jerk reactions and wholesale panic sets in among the Sonex community, please read this. The most likely reason for this failure is the NON-STANDARD, NON-SONEX tailwheel pushrod. The top-mounted pushrod on this aircraft was prying the the rudder drive rib down. The kit-provided pushrod and installation has the tailwheel pushrod mounted UNDER the drive horn. This was a builder modification that was not thought out. Many builder modifications and "improvements" lead to unintended consequences. We see it all the time The proper, Sonex-designed tailwheel push-rod has been [proven since it went in service in 1998 and no other aircraft has experienced this failure. There is no need to "beef up" the design. There is only a need to follow the plans provided with the parts provided. Buying a second-hand homebuilt is fraught with thousands of unknowns. Having one inspected by an A&P does not make an aircraft airworthy, it only makes it legal for the FAA. If you buy a used homebuilt, plan to go through every page of the plans to root out builder modifications or hire an inspector who is willing to do so. Kerry Fores Sonex Technical Support Manager
Thanks for the quick reply. This gives me even more confidence to go for a SubSonex JSX-2T knowing I can get this kind of customer support. See you in OSH '23
As I have gotten older, I wiil be 70 next month, I have realised the importance of "gut feeling". I realised probabably about 30 yearws ago that the number of times I had a "gut feeling" about something was often correct. I started paying attention to my "gut feelings". Many times I have been saved, whether it is a speed trap around the corner, a large truck appearing suddenly on a narrow road or a speeding car at an intersection, a wind shear on short final. Maybe it is just experience, knowing that these things can happen and have done so in the past. But I know to pay attention to them. I know it has saved me many times in the past. This fault was well spotted by you in this case and un-doubtedly saved you from catastropy. I appreciate the comment from Sonex. Small deviations from the design can have un-intended consequences, a valuable lesson to us all!
No matter how irrational and silly my gut feeling may be, I ground myself when I have one, and spend my flight time doing more viscous preflight inspections and maintenance.
I'm leaning on the side of divine intervention. The real lesson here is paying attention to those little feelings and intuitions. First you double checked the weather, then still felt something wasn't quit right. Good job listening to your own intuition or possibly a higher power trying to warn you. The way you discovered the problem is just incredible. I would add counting the total rivets on the plan to the annual inspection. Glad you're still with us.
Thank you. I’ll be going over every little detail as I disassemble the rudder And sharing the findings with Sonex tech-support who has been all over this. A few people have mentioned that they routinely pick up a tail in their preflight and certainly I could’ve caught the situation if I had done that… But honestly I just didn’t know to do that. Most tailwheel airplanes are not easily picked up from their tail And I had never considered that as being a requisite to a safe flight... Obviously going forward that will be a new box on my checklist.
Lucky we hobby pilots are not forced to fly. When you open the hangar, when you check the plane, the weather, the destination airfield - and when you regardless of all this feel bad . . . . don´t fly ! Listen to your soul ! It is always right.
@@LeanofPeakAviation I believe I understand why that happened. I have a design Idea of how to fix it. that plate at the bottom of the rudder is subjecting the rivets to torsion they weren't designed for. can we see pictures of the surface of the rivets at the point where they broke? does it look "stretched" at all or is it more "cracked?"
In almost 20 years of inspecting Sonex/Waiex/Onex aircraft as an EAA Technical Counselor and as a first flight test pilot of about 15 of these aircraft I have never seen this. However, as he noted, this would be a hard defect to detect from a typical preflight or even pre-buy inspection unless you knew to look for it. I recently sold my 2005 Sonex and forwarded this video to the new owner.
The manner in which you handle this experience shows a lot about your character, much Respect to you! Thank you for sharing this and allowing others to learn.
From an engineering perspective, that Tail Wheel Rudder connection design is very poor. Any stress from the wheel gets transferred to the row of rivets. The Plate should be redesigned to have a connection to the rudder hinge line. Therefore the massive stress between the plate and rudder would be transferred to the hinge not the pop rivets. In Air Liners they make use of epoxy adhesive in areas of extreme stress. This would be an area where an Engineering change should be authorised by the FAA to enhance the connection with Epoxy Adhesive like Araldite.
That feeling you had was divine intervention, and I thank GOD you had it, the spirit talks to us and thank you for listening to it. So glad you are alive. The world is better with you on it.
I wonder where divine intervention was during the holocaust or in Ukraine? It’s a pilots job to understand the weather and preflight everything, especially on a home built where non standard material and methods are used frequently by rogue builders. Lots of airplane crashes and zero divine intervention. Checklists and training saves lives.
god chose this guy to save while children with bone cancer live everyday in excruciating pain. Natural disasters, man made disasters, etc. leave horrible death and destruction in their wake, yet god chose to save this guy?
You know brother, I've been around the world and have an untold amount Of life experiences, I'm 68 years old, veteran of the United States Air Force, crewed F4E-phantoms, pretty much raised in a Christian valued family from a young age. It wasn't until I was around 28 years old I started listening to my inner voice (( the Holy Spirit )) that pretty much settled my mind's eye into starting to see different outcomes in what could have otherwise been very poor decisions. I had always noticed after a bad outcome our decision made that I remember getting a bad feeling are a different thought process before I made that bad decision. Once I stopped and started to seriously take into account any bad feelings or sideline thoughts inside myself And to give them serious relevance before I proceeded, I suddenly noticed terrible situations that were now being avoided. It can be hard sometimes because of our human nature to simply plow forward, but once you consciously quiet your mind And listen, you will be amazed at how that quiet whisper suddenly becomes more of a conversation. Stay blessed my friend, keep safe in these difficult times & be mindful of that quiet whisper. I've finally gotten to the point where I'm constantly giving thanks. I'm glad your family still has you around. Danny in Texas
My pre-buy and last annual inspection on my certified aircraft missed that it had a non-TSO ASI, VSI, and tach. Inspections may be expensive, but they’re not necessarily thorough. It was only discovered when I upgraded to IFR. Nothing life threatening, but bear in mind that many annuals involve people just going through the motions.
If it an amature built, Well enough said. A buddy built a Sonex 2 place with the 6 cylinder Jabaro Engine. He is a very Maticus builder. He must have done something drastically wrong. He said I got to get rid of this thing before it kills me. It's just way too much fun to keep upright for any length of time.
@@HoundDogMech My plane is a Cessna 150. It wasn’t the end of the world that it had non-TSO parts, but it was sold to me as a certified aircraft; so, it really shouldn’t have had required equipment on it that was non-TSO. The original IA who did the install and signed off on it paid for the replacement TSO parts, and I gave him back the experimental only parts to cut his out of pocket loses. I think it was just an honest oversight at the shop that originally rebuilt my plane.
So glad you listened and dodged a big one! It's taken me most of 74 years to learn to listen to "my gut". You can argue about the source of those feelings, but they do seem to be right a very high percentage of the time! Improper fit? Improper grip length? Or even wrong material / thickness / heat treat? It will be interesting to hear the result of your research! Stay safe!
Springs to move and steer your tail wheel: never use a solid link. Every time you bounce down a runway or land at any down-force you're going to induce that load repeatedly into the belt crank and rudder. Stupid design or bad installation of what should be.
Yeah you know Vans RV’s have been using that setup for years on lots of airframes and you don’t hear about this happening. I think it’s probably the implementation more than the theory. I hear your argument. It is probably safer with springs.
Great video-you did all the right things and gave an excellent, objective report. It is also great that Sonex came up with a quick, logical evaluation. It is stunningly WONDERFUL that this all was worked out without you getting injured or killed! Fly safe!
I will look out for this rivet problem on all the aircraft I fly. I would never have thought that this was an issue. The rudder issue is hard to spot without suspending that empennage. Good catch! I look forward to seeing follow-up videos. Thank you! 👍
I'll be looking at the rivets but I'm pretty convinced it was the control arm improperly rigged that ultimately cause the failure after hearing from Sonex.
I'm not a pilot but.. seeing that sent some chills down my spine. I am so thankful you noticed "something odd" and followed through with looking harder at it. Scary things can be a impactful teacher and this just made you an even better pilot.
That was a fantastically useful video. Thank you so much for sharing that with us. Your attention to detail saved you and taught the rest of us a valuable lesson.
Tail wheel push rod looks like it is bending where it comes out of rod end. In race cars suspensions, male rod ends are recommended as they are less likely to fail. Not to fly was great call.
I don’t like that solid pushrod from the rudder horn to the tail wheel, especially with that much caster angle. Any sudden side load on the tail wheel is going to beat the control horn to death..
Yep. I think we’ve pretty much narrowed it down to the control rod as being the primary factor. I’ll be posting a follow up once I have everything examined but so far what I’ve discovered is that control rod is causing a severe downward pressure on the horn whenever the wheel is turned away. This is not the standard control rod and the geometry and placement are wonky. It’s likely been subjected to repetitive detrimental stresses through normal operation.
So, So glad you listened to your gut!!! There is a lot to be said for listening when that feeling comes over you! I hope you have a chute on when doing any akro!
Thanks for this wake-up video. There is no end to the level of detail and due diligence a pilot must take to inspect his aircraft and ensure it is flight worthy. You avoided a potential tragedy, well done.
2:09 The control arm for tailwheel steering looks weird. Are the threads of the push rod loose? Why is that rod flopping like that? I am not familair with homebuilts but I've seen a lot of rod ends in my day but I've never seen one that has play in the threaded area the way this one does. Is this is normal? I suppose it could be a design I've never seen, but it doesn't seem right.
My eyes got big too when you dropped the control horn. I’m wondering if it’s been trailered in the past and someone strapped the tail wheel down rather than block up the tail and strap around the fuse. I had trailered a large r/c plane (10’ long) and strapped it just by the tail wheel bracket and had a similar failure. Now I block up the tail and strap around the fuse to avoid road bumps from ripping out the bracket. Glad you are ok and spotted it 👍 - Jacob
Now THAT is an interesting theory. Thanks for the comment. These foldable planes are meant to be trailered. I’ve not trailered the aircraft personally (it stays in a hangar) but again it’s a second hand plane.
Its surprising those rivets pulled out at all even if it was strapped. Each rivet can handle about 500 pnds of 'tensile strength', which I think is the term used for pull out strength. If the rivets were hand drilled the holes could have easily been widened too much, not providing the needed strength. Assuming the builder used the correct size drill bit. I would post this on the sonexbuilders forum. They would have a better idea of 'possible causes'.
In a trailering situation just like you described with a strap it is possible to overload it...I think. As an example when truck divers with flat deck secure cargo they regularly crush cargo with the winch/strap...huge forces there...
@@robertjensen2571 the rivets didn't fail. you can clearly see they are still there and intact. they pulled out of the metal. Tensile strength of a rivet is NOT pull out force from the sheet metal.
One way I can think of modifying the Rudder Controls would be to fabricate 2 angles to rivet the rudder to the control brackets, No loss of control, even if it did get loose on the bottom rudder cap
Always..... And I mean always... Go with with your gut feeling.... Flew thru very bad (unforcasted) weather wondering if this was my last flight... I had a gut feeling that day and I pushed thru it.... Go with your gut. Peace brother glad you made it. Yes this would not have been a good flight for you.
Glad you encountered the problem on the ground and that you are still with us sir! At the very least I would hope the manufacturer put out an AD on the aircraft. Hopefully the NTSB would ensure this info is forwarded to the proper governing body to help prevent an unnecessary tragedy.
I'm a new pilot, 15 hours of training under my belt in an archer iii. My cfi said you always want to check the butt hole of the plane and make sure the little nut and bolt for the elevator linkage are good, same concept. I like videos like this, something else to look for that everyone else could miss.
While trying to identify the mechanism of failure, I notice when the tailwheel is pushed one way, there is some downward force on the link. As a result, it is pulling downwards on that tab (with significant leverage, thanks to the tab design), exposing the rivets - you demonstrate that at 1:38 when you push the tailwheel to the right. So a violent tailwheel deviation to the right would apply at least some downward force in tension to those rivets. The remaining rivets fastened would help prevent failure in shear, so the only option left would be failure in tension for the rivets, which is what it looks like based on the shape of the rivets. So...I'm thinking this might have been the result of a violent tailwheel shimmy. Either that or a severe groundloop, but I think you would have other evidence of that somewhere else on the airframe, and a one-time excursion like that would likely have bent some of that link and tab mechanism. So I'd investigate it for shimmy, and perhaps think about a dampener of some sort.
That's pretty scary. after watching the video I went out to the garage to look at the tail of my Sonex project and looked at the plans for a while. Mine is a legacy Sonex, not a Onex, so it is not the same. The bellcrank and its attachment is a bit different on my Sonex. I would say double check that the tail assembly conforms to your plan drawings. I see you are in contact with Kerry Fores. He is the right guy to talk to about any Sonex technical issues. The rule of thumb in homebuilding is to build it exactly like the plans unless you have a very good reason and the skills to evaluate any changes. I'm glad you caught that before it let loose completely.
@@LeanofPeakAviation It is a design flaw and a major one...if you look at the possible pivot points in a pure static load situation or a bouncy touchdown those rivets will be pulled off from the front edge of the rudder rib no matter what...there should be a bulletin issued and redesign/rebuild all these I think! The issue is the tailwheel is too far back...it should be under the axis of the rudder...
I have been flying since 1986 and with in that time I have learned that if things do not feel right DO NOT FLY! Knocking on wood with just over 5754.2 hours total time nothing major has happened other than losing 2 cylinders out of 18 while ferrying a P-47 to it's new owner.
Glad you are still here. A&P comment: Have someone operate the rudder pedals to see how normal flight control inputs interact with the tail wheel " I’ve discovered is that control rod is causing a severe downward pressure on the horn whenever the wheel is turned away." rather than just pushing on the wheel. I would like to see that plate attached to the rudder end rib with solid rivets. Then slip it back in place and use pop rivets as it currently is installed. (make a new one!)
Thanks for your well-done video. You may have saved a life or two because this will inspire people to look deeper during pre-flights. It's a lesson that every pilot seeing it will take to heart. Having lost a rudder cable in flight in a factory-made and recently inspected Cessna 172, I know the shock of 'coming that close' to disaster. Aircraft that are homebuilt ( especially by others with unknown skill levels) compound the risks. As the homebuilt fleet ages, I wonder if the incidents will soar - given the inconsistent skill levels of various builders.
Excellent video. I (almost) had the same thing happen on a Fly Baby a few decades back. I'm Ron Wanttaja, I do a lot of homebuilt accident analyses. I looked at the Sonex accidents in my database (57 since the year 2000) and didn't see any reports of similar problems. Like yours, though, if they were caught on the ground they might be entered as Incidents, which I don't track.
Ron, thank you so much for publishing "Kitplane Construction". It has been and continues to be one of the most-used and important resources in my hangar bookshelf. I don't think I would have had the courage to enter the fascinating world of EAB if it wasn't for your book. Best regards from Brasilia, Brazil.
I am and was a mechanical engineer for over 35 years+. Rivets are a pain in the ass. They are susceptible to many types of material variations,residual stresses induced by heading process, equipment induced failures if critical operation parameters are not in control. If you have the time and patience, threaded fasteners always were the method of choice if fastening was required. When the concept of Design for Assembly started about 30 years ago the objective was to eliminate fasteners by using thing like toy tabs, redesign to incorporate 2 pieces into 1, simplification. There are a lot more but the brain goes fuzzy. Threaded fasteners require the correct torque to do the job. The torque puts tension into the threaded portion which hold the hinge together forever if done per manufacturers specifications. Thus ends todays lecture in Engineering Design 401. This will be on the mid term, I’m not kidding, it’s my job (Animal House).
Thank you for posting this. I am finishing a Zenith Zodiac 601HDS that was started by someone else. I have been going through all the previous work carefully but this will have me redoubling all such inspection. Excellent advice to be aware of and respond to that feeling that something is not quite right. You and quite a few others have mentioned the possibility of divine intervention. I too subscribe to this idea and to listening to that "still small voice." And this reminds me of a quote from the Book of Proverbs that is super-applicable to aviation: "It's the little foxes that spoil the vines."
Scary. Agreed that a spin recovery can be problematic but not impossible. Look up neutral rudder spin recovery and try a few. Depending on the characteristics of the aircraft they are possible with enough altitude. Tail wheel landings without rudder would require a wheeled landing and ever so subtle differential brakes as required. Very problematic, but not impossible, especially if you find a runway in your area that is into the wind, divert there. One last thing for some of you newer pilots, I'm not addressing this channel, with any suspected flight control malfunction, declared an emergency. Don't try and tough it out. Other aircraft, controllers, and airport personnel should absolutely get a heads-up on your possible problems so they can give you priority and be there to help you.
Good for you, both for listening to the inner voice, (which must have noticed an anomaly), and for reporting it to the NTSB, (who probably don't really care about 1 homebuilt), and to Sonex, who probbly do care. Feelings that "something's not right" should be respected and acted upon.
Spin recovery is possible but you have to be pointing *straight* down and then use aileron to stop rotation (but only when airspeed has recovered) - rudder should at least be neutral if failed. Differential braking (if you have it) can save you on the landing but it will still be rough!
Do a inch -by-inch check on all the airframe. Something happened to me few years ago, did a throughout check on everything afterwards (took me 3 weeks) and end up finding two more structural issues that were eventually corrected. Peace of mind is gold!
Thank you! thank you! thank you! I am so glad you’re OK. This is A very important bit of reporting. Aviation is safe because of transparency, diligence and pocketing our pride.
Do you ever get severe tail wheel shimmy on landing? It's nice to have tailwheel steering like that but if it was me. I would lose that link rod, put a full swiveling tail wheel in place of the original and steer it with differential braking. It might be more prone to ground loops though unless you go to a dual spring system to help keep it centered. I would also advise you to get a very good look with a magnifying glass at both halves of the rudder to stabilizer piano hinge. I hope other owners of this model are notified of the problem you discovered so that they don't end up as a segment on Dan Grider's DTSB.
Good: you were wearing a parachute Good: you trusted your gut. Bad: you waaaaaaay overstated the danger of 'losing your rudder'. I had a rudder cable break, in flight, in a 150hp Super-Cub, ~35 years ago, and I am (mostly) alive. With no rudder control, if you land into the wind, on grass, on the mains: you might get a little bit of directional control using aileron deflection on roll out. At this point you have about a 50:50 chance of a ground-loop (unless you are in a Luscombe! Those things groundloop even when everything is working). Call the tower and say "Hey, I'm having some trouble with my flight controls, I need to land on the grass, roll the equipment.' Most modern aircraft need pro-spin control inputs to stay in a spin. That is to say that most aircraft will come out of a spin (and go into a spiral) if you just release the controls. Had the rudder control broken while in a spin, I (like to think that) would have given the aircraft at least one-turn before jumping, to see if it could sort itself out. When you get this thing put back together, do a one-turn spin then release the controls and see how many turns and how much altitude it takes to come out of the spin all on its own. It might not, but the odds are that the spin will turn into a spiral, given no input from the pilot. After you do that, if you are brave enough, try landing ON GRASS, with your feet 1/16th to 1/32nd of an inch off of the rudder pedals, into the wind, of course. You will be able to catch it , if a swerve starts. Then you will have more confidence in your aircraft and yourself: you know what it will do.
When I was young A&P, an old-timer taught me "Don't look at it, grab it. If it comes off in your hand, it's broke. If it ain't broke, don't fix it." Pretty sure I'd have caught this if it was me doing the inspection(s). I generally lift the airplane and grab stuff during 100 hour/Periodic inspections, especially if it's the first time I've looked at a particular airplane. And I find stuff that way, too. But I also have a bit of engineering background and I'm pretty sure I'd have flagged that tailwheel push-pull rod. When assembling mechanical stuff like this, I try to keep the pushies and pullems on the same axis whenever I can, and if they can't be on the same axis, then I try to get them as close together as possible. Somebody went to a fair bit of trouble to assemble this wrong. It's not a great linkage at best. I'm willing to give credit to the original builder of the part for using the right size drill for the pop rivets (#30). Using the correct size drill would certainly delay this failure. Using solid rivets would delay it further, but it's inevitable it would happen sooner or later. I find things like this from time to time on amateur-built airplanes.... and on certificated airplanes, maintained by professionals. Ya jus' can't let yer guard down and ya jus' can't stop looking.
As a fellow A&P you are spot on sir. I grab the shit out of flight controls, shake em, torque em. I have felt Cessna 172 elevator halves coming apart. I’ve found plenty of piper stabilators with excessive bearing wear etc etc.
Thanks for sharing bro. I hope other operators take this video seriously and conduct inspections on their own airplanes. You may have saved some lives with this one. WELL DONE!!!!
Justin, thank you so much for posting this, and going about it correctly!! This give EVERYBODY an opportunity to learn. It sounds like the Sonex folks have the issue with the pushrod figured out, which will bring others to not do that!
Holy shit dude, great video. I’m about to buy an ultralight, and as some of us pilots do we get lazy on our pre-fights. What an eye-opener and thank you for posting this.
The loss of the rudder is not automatically a death sentence as stated in this post. The correct procedure in the event of a spin in which you cannot determine the orientation, is to reduce the power and release all the controls. This is taught because if you become disoriented and apply the wrong inputs you can accelerate or flatten a spin, which may be unrecoverable with insufficient altitude above the ground. The design of the aircraft, assuming that it is within the CG envelope, will allow the aircraft to self recover from the spin. The rudderless landing is also not going to kill you, if you take the proper actions. Find a long and wide runway that is into the wind and has a rescue crew. Differential braking will keep you going strait just like landing a tail dragger in a crosswind. The rescue crew is there to get you out of the plane if it ends up inverted due to running off the runway. Your post was useful however to point out the importance of proper construction, inspection, and paying attention to the hairs on the back of your neck.
Great video. You did the right thing. Something didn't feel right and you didn't fly. Gut feeling and intuition often come from things you are picking up subconsciously and it makes sense to listen to what your body is trying to tell you. Thank you for sharing.
I had posted a “Trust your gut” comment and got thrashed by a bunch of pilots. So thank you, and holy crap that is an absolute design failure, I think the side load on that is all wrong. I would really like to see structure inside the rudder that is connected to the control arm. The inspectors, or being in the shop, getting moved around, side load on that wheel, in the wrong orientation could have done it.
Yeah if something feels off…go home and come back later for another look. Your “gut” is telling you something subtle isn’t right and you’ve sensed it but haven’t brought it to the front of your brain yet. Check out the next two videos to see the rudder structure.
Even without the unapproved modification, relying solely upon a riveted connection seems a bit dicey. Over time, vibration, hard landings, high loads during maneuvering, etc. can cause those rivets to loosen and pull through the bottom rib. Sonex should seriously consider adding a couple of bolts to prevent progressive failure.
I did ask my preflight, Wx, plan. Nothing out of the ordinary. I was all strapped in though has this very odd feeling. A feeling just something wasn't right. I closed up the airplane and didn't fly that day. Years later I still don't know why but I was taught to find a reason not to fly. If you can't then go up. Your lucky you found the reason why. Cheers.
I love airshows,, warbirds and aviation history. This is why if I ever get the chance I'm buying a boat 🛥. I think it's obvious that there is a special reason you got to make this video and not have one made about you on the other channels. Live long and prosper 😇
Never underestimate intuition. I'm sure this channel is viewed mostly by pilots - I have no idea why it came up for me. Oddly, I just spent over an hour talking with a couple of friends about things like intuition....some "foo foo" stuff", in the minds of most people. It was certainly foo foo to me for most of my life - have a bachelor of science in psychology and was deeply rooted in a Western, materialistic kinds of thinking. In 1994 I had my ass handed to me on a platter and the details would be more appropriate under some Sci-fi channel video. I'm so glad you listened to that inner voice, brother. It's a quantum thing, this life and this universe. You can chuckle, that's fine. But, again, listen to that inner voice. Peace and, again, so glad you're okay.....
Ouch, that looked scary! A good thing you listened to your intuition/sixth sense/guardian angel/whatever you want to call it. I've had a couple of times something similar happen to me, not aviation related though, but driving a car. For example, some sort of internal voice once said to slow down a bit and drive on the right curb when approaching a bend in the road, and what do you know, a few seconds later a speeding car came out of the bend toward me partly on my lane! Decided after that to always listen to that kind of internal voice/intuition/whatever.
Its always sobering to check something you'd never normally check and find it hanging by a thread. If each decision really does spawn a new universe then there are many universes that you're no longer in. Glad you're still in ours!
Man! You got soooo lucky on that one. Glad you are safe. Now I hope you don't have that Aerovee engine that has also killed quite a few people, and caused many others to set their Sonex down in alternate places other than intended.
The rigid linkage on the tailwheel seems like the main culprit inducing unneeded stress on the rudder…. There’s a reason most tailwheel aircraft have springs to absorb shock and allow some give as to not transfer stress to the control surface…lucky lucky lucky!!!
GOOD CATCH. completely replace the maim rudder rib. the factory may have already sent you a new one. if you can get hold of a grip gauge.. measure the gap the new holes. if you are using blind rivets... use cherrymax types. They are a bit expensive... SOME aIR fORCE SHEETmetal experiment here.
You had some serious divine intervention. Thank God you listened. My first thought was: You have a home build so therefore if you are not the original owner you are trusting that: A. The A/C was constructed exactly according to the specs provided by the manufacturer. B: There are no A/D's posted about this type which may cause concern. C: The A/C has been previously operated completety within the parameteres outlined for this type. IE. as a aerobat it has not exceeded its maximimum specified load rating either postive or negative . Too many factors yet something told you to as your wife clearly indicated. Live to fly another day! Thank God you listened!
Those of us pilot-builders arriving at this channel by accident for the first time… what’s the story with the thumbnail he used for the video; not related to the video content?
Just conversation. NOT saying you were wrong in ANY way. 1. Good catch. 2. And this is why I pick up the tail of my Sonex during the walk around. It's only about 25lb on the tailwheel - and picking up the tail allows for a thorough inspection of everything back there. 3. This particular rudder failure is somewhat unique to the design which is not common. Not unknown - just not as common as here. More planes have some kind of rudder horns which are easier to push and pull on to inspect. 4. Spin recovery - There is a non-PARE method that MIGHT work where you don't have a rudder. It works on a Cessna 150/2 and 172 that I am aware of as I have practiced it (with the CFI who showed me it). I do NOT advocate it as routine. It needs about 3,000ft of altitude and you have to finesse the end of the recovery to be sure you don't secondary stall or end up spinning the other way. I haven't actually tried it on my Sonex as even with pro-spin controls and IN the correct CG range - I find it hard enough to spin the plane normally! 5. Good catch.
Catching that in an annual would be unlikely as you wouldn’t unweight the tail of the aircraft. You definitely got away with one! I wonder how long it’s been like that.
Buddy, I don't fly but I'm 70 years old and still ride my motorcycles and that's exciting enough for me. I have had that nawing feeling that something wasn't quite right. I've learned to pay attention to it. It's saved my arse on more than one occasion.
You bring up a great point in that A&P’s are not type trained by a factory supporting a particular kit aircraft. Yes, the more experienced have a better tuned eye and feel to actually use the force to detect design and wear and tear issues. I flew a lot of rental aircraft, and it seemed like there were more often than not little things that caused some pre flight distress, but never legally enough to cross the MEL standards. I helped build 3 Vans Kits. Every one of them had an issues with someone thinking they were smarter than the original kit designers, and in searching for that extra mile an hour, made mods that should have been left to test pilots. So glad your judgement was God and higher self directed that day. I recommend after buying a kit that you don’t make with your own hands, go over ABSOLUTELY EVERYTHING in the original plans and note all discrepancies and changes. Then consult a DAR and the kit manufacturers builder technical rep to get best solution. Thanks for sharing you might just have saved someone’s life🙏
thats interesting...we all have days when there feels something wrong... my rule is ...check my headspace... and when 3 minor things go wrong...take a hint and stay on the ground.
I would have someone design some redundancy into that rudder pull. Pop rivets are not a good choice for that pull. Maybe add another pull in parallel with the bottom mounted a few inches higher and braced inside the tail. That is scary.
From my couch those rivets look too short. The rivets selected there for attaching the bottom plate seem a poor choice. A Cherry or Huck structural fastener would add significantly greater clamping forces. Please update when you have structural repair instructions from Sonex.
I'm an aerospace engineer and this video illustrates my reluctance to buy a homebuilt aircraft. Playing with avionics is one thing but there's a reason people get aerospace engineering degrees. Control systems and primary flight structures need to be left to people who know about them. And yeah, I wouldn't expect that rudder to have stayed on in a spin and the aircraft wouldn't have recovered without it. I would guess the guy's chances would have been 50/50 with a chute, 0 without one. He got lucky.
From Sonex Technical Support,
We are in contact with Justin on this issue. Before knee-jerk reactions and wholesale panic sets in among the Sonex community, please read this.
The most likely reason for this failure is the NON-STANDARD, NON-SONEX tailwheel pushrod. The top-mounted pushrod on this aircraft was prying the the rudder drive rib down. The kit-provided pushrod and installation has the tailwheel pushrod mounted UNDER the drive horn. This was a builder modification that was not thought out. Many builder modifications and "improvements" lead to unintended consequences. We see it all the time
The proper, Sonex-designed tailwheel push-rod has been [proven since it went in service in 1998 and no other aircraft has experienced this failure. There is no need to "beef up" the design. There is only a need to follow the plans provided with the parts provided. Buying a second-hand homebuilt is fraught with thousands of unknowns. Having one inspected by an A&P does not make an aircraft airworthy, it only makes it legal for the FAA. If you buy a used homebuilt, plan to go through every page of the plans to root out builder modifications or hire an inspector who is willing to do so.
Kerry Fores
Sonex Technical Support Manager
Thanks Kerry, your input here is valuable.
I don't know anything about this aircraft, but, that tail wheel pushrod just looked wrong to me. Nice quick reply from Sonex!
@@Rich-ey7jv I wouldn’t have caught that just looking at it. Will make a follow up video probably next weekend going over it.
@@LeanofPeakAviation No way to catch that modification. I would have assumed that's the way the tail pushrod is supposed to be.🤔
Thanks for the quick reply. This gives me even more confidence to go for a SubSonex JSX-2T knowing I can get this kind of customer support. See you in OSH '23
As I have gotten older, I wiil be 70 next month, I have realised the importance of "gut feeling".
I realised probabably about 30 yearws ago that the number of times I had a "gut feeling" about something was often correct.
I started paying attention to my "gut feelings".
Many times I have been saved, whether it is a speed trap around the corner, a large truck appearing suddenly on a narrow road or a speeding car at an intersection, a wind shear on short final.
Maybe it is just experience, knowing that these things can happen and have done so in the past.
But I know to pay attention to them.
I know it has saved me many times in the past.
This fault was well spotted by you in this case and un-doubtedly saved you from catastropy.
I appreciate the comment from Sonex.
Small deviations from the design can have un-intended consequences, a valuable lesson to us all!
No matter how irrational and silly my gut feeling may be, I ground myself when I have one, and spend my flight time doing more viscous preflight inspections and maintenance.
I'm leaning on the side of divine intervention. The real lesson here is paying attention to those little feelings and intuitions. First you double checked the weather, then still felt something wasn't quit right. Good job listening to your own intuition or possibly a higher power trying to warn you. The way you discovered the problem is just incredible. I would add counting the total rivets on the plan to the annual inspection. Glad you're still with us.
Thank you. I’ll be going over every little detail as I disassemble the rudder And sharing the findings with Sonex tech-support who has been all over this. A few people have mentioned that they routinely pick up a tail in their preflight and certainly I could’ve caught the situation if I had done that… But honestly I just didn’t know to do that. Most tailwheel airplanes are not easily picked up from their tail And I had never considered that as being a requisite to a safe flight... Obviously going forward that will be a new box on my checklist.
Lucky we hobby pilots are not forced to fly. When you open the hangar, when you check the plane, the weather, the destination airfield - and when you regardless of all this feel bad . . . . don´t fly ! Listen to your soul ! It is always right.
devine intervention lol. why not just pray and skip the pre flight with that logic?
@@LeanofPeakAviation I believe I understand why that happened. I have a design Idea of how to fix it. that plate at the bottom of the rudder is subjecting the rivets to torsion they weren't designed for. can we see pictures of the surface of the rivets at the point where they broke? does it look "stretched" at all or is it more "cracked?"
@@holski77 HOLY WATER MAY BE EFFICACIOUS. NO CONTROLLED STUDIES HAVE BEEN DONE. WOULD YOU LIKE TO VOLUNTEER?
In almost 20 years of inspecting Sonex/Waiex/Onex aircraft as an EAA Technical Counselor and as a first flight test pilot of about 15 of these aircraft I have never seen this. However, as he noted, this would be a hard defect to detect from a typical preflight or even pre-buy inspection unless you knew to look for it. I recently sold my 2005 Sonex and forwarded this video to the new owner.
I strongly suspect this will continue to be a rare incident. Will be posting the findings in a f/u. This is going to be a builder error.
The manner in which you handle this experience shows a lot about your character, much Respect to you! Thank you for sharing this and allowing others to learn.
Thank you.
From an engineering perspective, that Tail Wheel Rudder connection design is very poor. Any stress from the wheel gets transferred to the row of rivets. The Plate should be redesigned to have a connection to the rudder hinge line. Therefore the massive stress between the plate and rudder would be transferred to the hinge not the pop rivets. In Air Liners they make use of epoxy adhesive in areas of extreme stress. This would be an area where an Engineering change should be authorised by the FAA to enhance the connection with Epoxy Adhesive like Araldite.
Very relieved you caught this, and glad you posted this video, a lot of great points!
That feeling you had was divine intervention, and I thank GOD you had it, the spirit talks to us and thank you for listening to it. So glad you are alive. The world is better with you on it.
I wonder where divine intervention was during the holocaust or in Ukraine? It’s a pilots job to understand the weather and preflight everything, especially on a home built where non standard material and methods are used frequently by rogue builders. Lots of airplane crashes and zero divine intervention. Checklists and training saves lives.
god chose this guy to save while children with bone cancer live everyday in excruciating pain. Natural disasters, man made disasters, etc. leave horrible death and destruction in their wake, yet god chose to save this guy?
You know brother, I've been around the world and have an untold amount Of life experiences, I'm 68 years old, veteran of the United States Air Force, crewed F4E-phantoms, pretty much raised in a Christian valued family from a young age. It wasn't until I was around 28 years old I started listening to my inner voice (( the Holy Spirit )) that pretty much settled my mind's eye into starting to see different outcomes in what could have otherwise been very poor decisions. I had always noticed after a bad outcome our decision made that I remember getting a bad feeling are a different thought process before I made that bad decision. Once I stopped and started to seriously take into account any bad feelings or sideline thoughts inside myself And to give them serious relevance before I proceeded, I suddenly noticed terrible situations that were now being avoided. It can be hard sometimes because of our human nature to simply plow forward, but once you consciously quiet your mind And listen, you will be amazed at how that quiet whisper suddenly becomes more of a conversation. Stay blessed my friend, keep safe in these difficult times & be mindful of that quiet whisper. I've finally gotten to the point where I'm constantly giving thanks. I'm glad your family still has you around. Danny in Texas
My pre-buy and last annual inspection on my certified aircraft missed that it had a non-TSO ASI, VSI, and tach. Inspections may be expensive, but they’re not necessarily thorough. It was only discovered when I upgraded to IFR. Nothing life threatening, but bear in mind that many annuals involve people just going through the motions.
If it an amature built, Well enough said. A buddy built a Sonex 2 place with the 6 cylinder Jabaro Engine. He is a very Maticus builder. He must have done something drastically wrong. He said I got to get rid of this thing before it kills me. It's just way too much fun to keep upright for any length of time.
@@HoundDogMech My plane is a Cessna 150. It wasn’t the end of the world that it had non-TSO parts, but it was sold to me as a certified aircraft; so, it really shouldn’t have had required equipment on it that was non-TSO. The original IA who did the install and signed off on it paid for the replacement TSO parts, and I gave him back the experimental only parts to cut his out of pocket loses. I think it was just an honest oversight at the shop that originally rebuilt my plane.
Instruments you listed are not required to be TSO’d.
@@mmayes9466 They are for a certified aircraft, especially if you want an IFR certification. Please don’t make up rules that IAs don’t recognize.
So glad you listened and dodged a big one! It's taken me most of 74 years to learn to listen to "my gut". You can argue about the source of those feelings, but they do seem to be right a very high percentage of the time! Improper fit? Improper grip length? Or even wrong material / thickness / heat treat? It will be interesting to hear the result of your research! Stay safe!
Springs to move and steer your tail wheel: never use a solid link. Every time you bounce down a runway or land at any down-force you're going to induce that load repeatedly into the belt crank and rudder. Stupid design or bad installation of what should be.
Exactly what I thought.
Yeah you know Vans RV’s have been using that setup for years on lots of airframes and you don’t hear about this happening. I think it’s probably the implementation more than the theory. I hear your argument. It is probably safer with springs.
Every certified taildragger uses springs & chains since the beginning with no problems & thousands of hours in all conditions.
The RV12 does not have solid link. It is a solid rod inside of a hollow rod with a spring inside the hollow rod.
@@TailwheelTimes You’re correct. I looked at them recently to see if they might fit my airframe.
That is phenomenal. Really glad that you've discovered this and it didn't end in a tragedy.....
Great video-you did all the right things and gave an excellent, objective report. It is also great that Sonex came up with a quick, logical evaluation. It is stunningly WONDERFUL that this all was worked out without you getting injured or killed! Fly safe!
Thanks for your comments!
I will look out for this rivet problem on all the aircraft I fly. I would never have thought that this was an issue. The rudder issue is hard to spot without suspending that empennage. Good catch!
I look forward to seeing follow-up videos. Thank you! 👍
I'll be looking at the rivets but I'm pretty convinced it was the control arm improperly rigged that ultimately cause the failure after hearing from Sonex.
I'm not a pilot but.. seeing that sent some chills down my spine. I am so thankful you noticed "something odd" and followed through with looking harder at it. Scary things can be a impactful teacher and this just made you an even better pilot.
That was a fantastically useful video. Thank you so much for sharing that with us. Your attention to detail saved you and taught the rest of us a valuable lesson.
Tail wheel push rod looks like it is bending where it comes out of rod end. In race cars suspensions, male rod ends are recommended as they are less likely to fail. Not to fly was great call.
Gotta listen to those promptings. Great work and glad to hear this story has a happy ending.
Great presentation. Glad you are alive and able to save more lives with this video.
I don’t like that solid pushrod from the rudder horn to the tail wheel, especially with that much caster angle. Any sudden side load on the tail wheel is going to beat the control horn to death..
Yep. I think we’ve pretty much narrowed it down to the control rod as being the primary factor. I’ll be posting a follow up once I have everything examined but so far what I’ve discovered is that control rod is causing a severe downward pressure on the horn whenever the wheel is turned away. This is not the standard control rod and the geometry and placement are wonky. It’s likely been subjected to repetitive detrimental stresses through normal operation.
So, So glad you listened to your gut!!! There is a lot to be said for listening when that feeling comes over you! I hope you have a chute on when doing any akro!
Thanks for this wake-up video. There is no end to the level of detail and due diligence a pilot must take to inspect his aircraft and ensure it is flight worthy. You avoided a potential tragedy, well done.
2:09 The control arm for tailwheel steering looks weird. Are the threads of the push rod loose? Why is that rod flopping like that? I am not familair with homebuilts but I've seen a lot of rod ends in my day but I've never seen one that has play in the threaded area the way this one does.
Is this is normal? I suppose it could be a design I've never seen, but it doesn't seem right.
I noticed that too. Looks like the pushrod is cracked in the threaded area. Should not flop around like that!
My eyes got big too when you dropped the control horn. I’m wondering if it’s been trailered in the past and someone strapped the tail wheel down rather than block up the tail and strap around the fuse. I had trailered a large r/c plane (10’ long) and strapped it just by the tail wheel bracket and had a similar failure. Now I block up the tail and strap around the fuse to avoid road bumps from ripping out the bracket. Glad you are ok and spotted it 👍 - Jacob
Now THAT is an interesting theory. Thanks for the comment. These foldable planes are meant to be trailered. I’ve not trailered the aircraft personally (it stays in a hangar) but again it’s a second hand plane.
Its surprising those rivets pulled out at all even if it was strapped. Each rivet can handle about 500 pnds of 'tensile strength', which I think is the term used for pull out strength.
If the rivets were hand drilled the holes could have easily been widened too much, not providing the needed strength. Assuming the builder used the correct size drill bit.
I would post this on the sonexbuilders forum. They would have a better idea of 'possible causes'.
Will do.
In a trailering situation just like you described with a strap it is possible to overload it...I think.
As an example when truck divers with flat deck secure cargo they regularly crush cargo with the winch/strap...huge forces there...
@@robertjensen2571 the rivets didn't fail. you can clearly see they are still there and intact. they pulled out of the metal.
Tensile strength of a rivet is NOT pull out force from the sheet metal.
Wow! Glad you’re safe. Sometimes it’s hard to know when those feelings are something worth acting upon or not.
One way I can think of modifying the Rudder Controls would be to fabricate 2 angles to rivet the rudder to the control brackets, No loss of control, even if it did get loose on the bottom rudder cap
Always..... And I mean always... Go with with your gut feeling.... Flew thru very bad (unforcasted) weather wondering if this was my last flight... I had a gut feeling that day and I pushed thru it.... Go with your gut. Peace brother glad you made it. Yes this would not have been a good flight for you.
Wow, I'm glad you followed your gut instinct. Will be interested to hear what you learn. Scary !
Thank you for posting this very critical inspection analysis! It has been most enlightening!
Someone was telling you not to fly that day. Glad your all right! God bless.
Glad you encountered the problem on the ground and that you are still with us sir! At the very least I would hope the manufacturer put out an AD on the aircraft. Hopefully the NTSB would ensure this info is forwarded to the proper governing body to help prevent an unnecessary tragedy.
The problem is in putting out an "AD" to cover a construction deviation. I'm not against it, but that would be new regulatory territory.
I'm a new pilot, 15 hours of training under my belt in an archer iii. My cfi said you always want to check the butt hole of the plane and make sure the little nut and bolt for the elevator linkage are good, same concept. I like videos like this, something else to look for that everyone else could miss.
While trying to identify the mechanism of failure, I notice when the tailwheel is pushed one way, there is some downward force on the link. As a result, it is pulling downwards on that tab (with significant leverage, thanks to the tab design), exposing the rivets - you demonstrate that at 1:38 when you push the tailwheel to the right. So a violent tailwheel deviation to the right would apply at least some downward force in tension to those rivets. The remaining rivets fastened would help prevent failure in shear, so the only option left would be failure in tension for the rivets, which is what it looks like based on the shape of the rivets.
So...I'm thinking this might have been the result of a violent tailwheel shimmy. Either that or a severe groundloop, but I think you would have other evidence of that somewhere else on the airframe, and a one-time excursion like that would likely have bent some of that link and tab mechanism. So I'd investigate it for shimmy, and perhaps think about a dampener of some sort.
Thanks for the comment!
Words to literally live by...glad you listened to the man upstairs
Me too! I don’t think I’ve ever been so sure something was wrong without having any idea what it was. You have to listen to that.
That's pretty scary. after watching the video I went out to the garage to look at the tail of my Sonex project and looked at the plans for a while. Mine is a legacy Sonex, not a Onex, so it is not the same. The bellcrank and its attachment is a bit different on my Sonex. I would say double check that the tail assembly conforms to your plan drawings. I see you are in contact with Kerry Fores. He is the right guy to talk to about any Sonex technical issues. The rule of thumb in homebuilding is to build it exactly like the plans unless you have a very good reason and the skills to evaluate any changes.
I'm glad you caught that before it let loose completely.
Thanks. I’m actually going over the plans and ordering parts right now. Will get it straightened out and airworthy again.
Share - Share - Share this video with every Sonex pilot! Thanks and stoked that you're still alive! Blue Skies!
Thank you. Close calls are something for all of us to learn from!
@@LeanofPeakAviation It is a design flaw and a major one...if you look at the possible pivot points in a pure static load situation or a bouncy touchdown those rivets will be pulled off from the front edge of the rudder rib no matter what...there should be a bulletin issued and redesign/rebuild all these I think!
The issue is the tailwheel is too far back...it should be under the axis of the rudder...
I have been flying since 1986 and with in that time I have learned that if things do not feel right DO NOT FLY! Knocking on wood with just over 5754.2 hours total time nothing major has happened other than losing 2 cylinders out of 18 while ferrying a P-47 to it's new owner.
Glad you are still here. A&P comment: Have someone operate the rudder pedals to see how normal flight control inputs interact with the tail wheel " I’ve discovered is that control rod is causing a severe downward pressure on the horn whenever the wheel is turned away." rather than just pushing on the wheel. I would like to see that plate attached to the rudder end rib with solid rivets. Then slip it back in place and use pop rivets as it currently is installed. (make a new one!)
Good comment. I do intend to do further testing with the old and new rudder (I’ve decided to build a whole new one)
@@LeanofPeakAviation excellent!
Thanks for your well-done video. You may have saved a life or two because this will inspire people to look deeper during pre-flights. It's a lesson that every pilot seeing it will take to heart. Having lost a rudder cable in flight in a factory-made and recently inspected Cessna 172, I know the shock of 'coming that close' to disaster. Aircraft that are homebuilt ( especially by others with unknown skill levels) compound the risks. As the homebuilt fleet ages, I wonder if the incidents will soar - given the inconsistent skill levels of various builders.
Thanks for your comments!
Definitely someone is watching for you 🙏🏻✈️
The question is : does the builder follow the plans 🧐
Excellent video. I (almost) had the same thing happen on a Fly Baby a few decades back. I'm Ron Wanttaja, I do a lot of homebuilt accident analyses. I looked at the Sonex accidents in my database (57 since the year 2000) and didn't see any reports of similar problems. Like yours, though, if they were caught on the ground they might be entered as Incidents, which I don't track.
Ron, thank you so much for publishing "Kitplane Construction". It has been and continues to be one of the most-used and important resources in my hangar bookshelf. I don't think I would have had the courage to enter the fascinating world of EAB if it wasn't for your book. Best regards from Brasilia, Brazil.
I am and was a mechanical engineer for over 35 years+. Rivets are a pain in the ass. They are susceptible to many types of material variations,residual stresses induced by heading process, equipment induced failures if critical operation parameters are not in control. If you have the time and patience, threaded fasteners always were the method of choice if fastening was required. When the concept of Design for Assembly started about 30 years ago the objective was to eliminate fasteners by using thing like toy tabs, redesign to incorporate 2 pieces into 1, simplification. There are a lot more but the brain goes fuzzy. Threaded fasteners require the correct torque to do the job. The torque puts tension into the threaded portion which hold the hinge together forever if done per manufacturers specifications. Thus ends todays lecture in Engineering Design 401. This will be on the mid term, I’m not kidding, it’s my job (Animal House).
Thanks for your comments!
If you flew a little Cessna, you wouldn't exactly need a rudder...
You can steer by opening and closing the doors for direction.
Bahahaha. Maybe I need a tricycle Sonex 😉
Thank you for posting this. I am finishing a Zenith Zodiac 601HDS that was started by someone else. I have been going through all the previous work carefully but this will have me redoubling all such inspection. Excellent advice to be aware of and respond to that feeling that something is not quite right. You and quite a few others have mentioned the possibility of divine intervention. I too subscribe to this idea and to listening to that "still small voice." And this reminds me of a quote from the Book of Proverbs that is super-applicable to aviation: "It's the little foxes that spoil the vines."
Thank you for the comments! Be safe!
Scary.
Agreed that a spin recovery can be problematic but not impossible. Look up neutral rudder spin recovery and try a few. Depending on the characteristics of the aircraft they are possible with enough altitude.
Tail wheel landings without rudder would require a wheeled landing and ever so subtle differential brakes as required. Very problematic, but not impossible, especially if you find a runway in your area that is into the wind, divert there.
One last thing for some of you newer pilots, I'm not addressing this channel, with any suspected flight control malfunction, declared an emergency. Don't try and tough it out. Other aircraft, controllers, and airport personnel should absolutely get a heads-up on your possible problems so they can give you priority and be there to help you.
The title of this video is super-click-baitey
Good for you, both for listening to the inner voice, (which must have noticed an anomaly), and for reporting it to the NTSB, (who probably don't really care about 1 homebuilt), and to Sonex, who probbly do care. Feelings that "something's not right" should be respected and acted upon.
Spin recovery is possible but you have to be pointing *straight* down and then use aileron to stop rotation (but only when airspeed has recovered) - rudder should at least be neutral if failed. Differential braking (if you have it) can save you on the landing but it will still be rough!
No differential brakes!!! Don’t worry the ground would certainly stop me. 😉
@@LeanofPeakAviation Yikes... well, I'm very glad you never had to find out!
Valuable video for everyone; not only Sonex owners. Well done, and it's nice to keep you in the land of the living ! Good comments from Sonex.
Thanks for your advice, never enough.
Good catch. You went with safety first. Hopefully you will find out more about it and the inspection you had.
Do a inch -by-inch check on all the airframe. Something happened to me few years ago, did a throughout check on everything afterwards (took me 3 weeks) and end up finding two more structural issues that were eventually corrected. Peace of mind is gold!
I think that is very good advice.
Thank you! thank you! thank you! I am so glad you’re OK. This is A very important bit of reporting. Aviation is safe because of transparency, diligence and pocketing our pride.
Do you ever get severe tail wheel shimmy on landing? It's nice to have tailwheel steering like that but if it was me. I would lose that link rod, put a full swiveling tail wheel in place of the original and steer it with differential braking. It might be more prone to ground loops though unless you go to a dual spring system to help keep it centered. I would also advise you to get a very good look with a magnifying glass at both halves of the rudder to stabilizer piano hinge. I hope other owners of this model are notified of the problem you discovered so that they don't end up as a segment on Dan Grider's DTSB.
Divine intervention. Your angel whispered in your ear. It happens.
Good: you were wearing a parachute
Good: you trusted your gut.
Bad: you waaaaaaay overstated the danger of 'losing your rudder'.
I had a rudder cable break, in flight, in a 150hp Super-Cub, ~35 years ago, and I am (mostly) alive.
With no rudder control, if you land into the wind, on grass, on the mains: you might get a little bit of directional control using aileron deflection on roll out. At this point you have about a 50:50 chance of a ground-loop (unless you are in a Luscombe! Those things groundloop even when everything is working). Call the tower and say "Hey, I'm having some trouble with my flight controls, I need to land on the grass, roll the equipment.'
Most modern aircraft need pro-spin control inputs to stay in a spin. That is to say that most aircraft will come out of a spin (and go into a spiral) if you just release the controls. Had the rudder control broken while in a spin, I (like to think that) would have given the aircraft at least one-turn before jumping, to see if it could sort itself out.
When you get this thing put back together, do a one-turn spin then release the controls and see how many turns and how much altitude it takes to come out of the spin all on its own. It might not, but the odds are that the spin will turn into a spiral, given no input from the pilot.
After you do that, if you are brave enough, try landing ON GRASS, with your feet 1/16th to 1/32nd of an inch off of the rudder pedals, into the wind, of course. You will be able to catch it , if a swerve starts. Then you will have more confidence in your aircraft and yourself: you know what it will do.
Great catch! Glad you're here!
When I was young A&P, an old-timer taught me "Don't look at it, grab it. If it comes off in your hand, it's broke. If it ain't broke, don't fix it." Pretty sure I'd have caught this if it was me doing the inspection(s). I generally lift the airplane and grab stuff during 100 hour/Periodic inspections, especially if it's the first time I've looked at a particular airplane. And I find stuff that way, too. But I also have a bit of engineering background and I'm pretty sure I'd have flagged that tailwheel push-pull rod. When assembling mechanical stuff like this, I try to keep the pushies and pullems on the same axis whenever I can, and if they can't be on the same axis, then I try to get them as close together as possible. Somebody went to a fair bit of trouble to assemble this wrong. It's not a great linkage at best. I'm willing to give credit to the original builder of the part for using the right size drill for the pop rivets (#30). Using the correct size drill would certainly delay this failure. Using solid rivets would delay it further, but it's inevitable it would happen sooner or later. I find things like this from time to time on amateur-built airplanes.... and on certificated airplanes, maintained by professionals. Ya jus' can't let yer guard down and ya jus' can't stop looking.
As a fellow A&P you are spot on sir. I grab the shit out of flight controls, shake em, torque em. I have felt Cessna 172 elevator halves coming apart. I’ve found plenty of piper stabilators with excessive bearing wear etc etc.
Thanks for sharing bro. I hope other operators take this video seriously and conduct inspections on their own airplanes. You may have saved some lives with this one. WELL DONE!!!!
That’s my hope here. Fly safe!
The gut feeling is a real think. Always listen too it. Be safe up there.
Thank you for taking the time to report. 🙏🏻
Justin, thank you so much for posting this, and going about it correctly!! This give EVERYBODY an opportunity to learn. It sounds like the Sonex folks have the issue with the pushrod figured out, which will bring others to not do that!
Holy shit dude, great video. I’m about to buy an ultralight, and as some of us pilots do we get lazy on our pre-fights. What an eye-opener and thank you for posting this.
Great you are alive!! Great Advice!!
The loss of the rudder is not automatically a death sentence as stated in this post. The correct procedure in the event of a spin in which you cannot determine the orientation, is to reduce the power and release all the controls. This is taught because if you become disoriented and apply the wrong inputs you can accelerate or flatten a spin, which may be unrecoverable with insufficient altitude above the ground. The design of the aircraft, assuming that it is within the CG envelope, will allow the aircraft to self recover from the spin.
The rudderless landing is also not going to kill you, if you take the proper actions.
Find a long and wide runway that is into the wind and has a rescue crew. Differential braking will keep you going strait just like landing a tail dragger in a crosswind. The rescue crew is there to get you out of the plane if it ends up inverted due to running off the runway.
Your post was useful however to point out the importance of proper construction, inspection, and paying attention to the hairs on the back of your neck.
Great video. You did the right thing. Something didn't feel right and you didn't fly. Gut feeling and intuition often come from things you are picking up subconsciously and it makes sense to listen to what your body is trying to tell you. Thank you for sharing.
Glad your ok. Good job preflighting.
I had posted a “Trust your gut” comment and got thrashed by a bunch of pilots. So thank you, and holy crap that is an absolute design failure, I think the side load on that is all wrong. I would really like to see structure inside the rudder that is connected to the control arm. The inspectors, or being in the shop, getting moved around, side load on that wheel, in the wrong orientation could have done it.
Yeah if something feels off…go home and come back later for another look. Your “gut” is telling you something subtle isn’t right and you’ve sensed it but haven’t brought it to the front of your brain yet. Check out the next two videos to see the rudder structure.
Even without the unapproved modification, relying solely upon a riveted connection seems a bit dicey. Over time, vibration, hard landings, high loads during maneuvering, etc. can cause those rivets to loosen and pull through the bottom rib. Sonex should seriously consider adding a couple of bolts to prevent progressive failure.
I did ask my preflight, Wx, plan. Nothing out of the ordinary. I was all strapped in though has this very odd feeling. A feeling just something wasn't right. I closed up the airplane and didn't fly that day. Years later I still don't know why but I was taught to find a reason not to fly. If you can't then go up. Your lucky you found the reason why. Cheers.
I love airshows,, warbirds and aviation history. This is why if I ever get the chance I'm buying a boat 🛥. I think it's obvious that there is a special reason you got to make this video and not have one made about you on the other channels. Live long and prosper 😇
Lol thanks for the comment! You’d rather be on the ground wishing you were in the air than the other way around for sure!
Never underestimate intuition. I'm sure this channel is viewed mostly by pilots - I have no idea why it came up for me. Oddly, I just spent over an hour talking with a couple of friends about things like intuition....some "foo foo" stuff", in the minds of most people. It was certainly foo foo to me for most of my life - have a bachelor of science in psychology and was deeply rooted in a Western, materialistic kinds of thinking. In 1994 I had my ass handed to me on a platter and the details would be more appropriate under some Sci-fi channel video. I'm so glad you listened to that inner voice, brother. It's a quantum thing, this life and this universe. You can chuckle, that's fine. But, again, listen to that inner voice. Peace and, again, so glad you're okay.....
Thanks so much for your comments. These sorts of things certainly don’t apply strictly to pilots!
Ouch, that looked scary! A good thing you listened to your intuition/sixth sense/guardian angel/whatever you want to call it. I've had a couple of times something similar happen to me, not aviation related though, but driving a car. For example, some sort of internal voice once said to slow down a bit and drive on the right curb when approaching a bend in the road, and what do you know, a few seconds later a speeding car came out of the bend toward me partly on my lane! Decided after that to always listen to that kind of internal voice/intuition/whatever.
Its always sobering to check something you'd never normally check and find it hanging by a thread. If each decision really does spawn a new universe then there are many universes that you're no longer in. Glad you're still in ours!
Trust that Gut Instinct, Had a simular feeling one day. A flight in a Jet ended with a Brake failure with an over run. You listend and saved yourself.
did you check the type of ribits used. I would recommend to replace all the ribits to specs or better specs to be sure.
Man! You got soooo lucky on that one. Glad you are safe. Now I hope you don't have that Aerovee engine that has also killed quite a few people, and caused many others to set their Sonex down in alternate places other than intended.
If you look at the seam it has a greater gap at the front than the rear. Something is out of alignment that is causing stress.
God has your back Buddy! I thank him and surely you did too! 🤗
The rigid linkage on the tailwheel seems like the main culprit inducing unneeded stress on the rudder…. There’s a reason most tailwheel aircraft have springs to absorb shock and allow some give as to not transfer stress to the control surface…lucky lucky lucky!!!
GOOD CATCH.
completely replace the maim rudder rib.
the factory may have already sent you a new one.
if you can get hold of a grip gauge.. measure the gap the new holes.
if you are using blind rivets... use cherrymax types.
They are a bit expensive...
SOME aIR fORCE SHEETmetal experiment here.
SOB!......Good catch. I always use my "GUT" feeling too when I flew. Enjoy!
You had some serious divine intervention. Thank God you listened. My first thought was: You have a home build so therefore if you are not the original owner you are trusting that: A. The A/C was constructed exactly according to the specs provided by the manufacturer. B: There are no A/D's posted about this type which may cause concern. C: The A/C has been previously operated completety within the parameteres outlined for this type. IE. as a aerobat it has not exceeded its maximimum specified load rating either postive or negative . Too many factors yet something told you to as your wife clearly indicated. Live to fly another day! Thank God you listened!
Those of us pilot-builders arriving at this channel by accident for the first time… what’s the story with the thumbnail he used for the video; not related to the video content?
Just conversation. NOT saying you were wrong in ANY way.
1. Good catch.
2. And this is why I pick up the tail of my Sonex during the walk around. It's only about 25lb on the tailwheel - and picking up the tail allows for a thorough inspection of everything back there.
3. This particular rudder failure is somewhat unique to the design which is not common. Not unknown - just not as common as here. More planes have some kind of rudder horns which are easier to push and pull on to inspect.
4. Spin recovery - There is a non-PARE method that MIGHT work where you don't have a rudder. It works on a Cessna 150/2 and 172 that I am aware of as I have practiced it (with the CFI who showed me it). I do NOT advocate it as routine. It needs about 3,000ft of altitude and you have to finesse the end of the recovery to be sure you don't secondary stall or end up spinning the other way.
I haven't actually tried it on my Sonex as even with pro-spin controls and IN the correct CG range - I find it hard enough to spin the plane normally!
5. Good catch.
Thank you for the comments. Lifting the tail would have found this problem sooner and will certainly be part of my preflight going forward!
You need a spring loaded pushed on your tailwheel. To absorb the shocks while taxiing.
Catching that in an annual would be unlikely as you wouldn’t unweight the tail of the aircraft. You definitely got away with one! I wonder how long it’s been like that.
Buddy, I don't fly but I'm 70 years old and still ride my motorcycles and that's exciting enough for me. I have had that nawing feeling that something wasn't quite right. I've learned to pay attention to it. It's saved my arse on more than one occasion.
That feeling in your gut, was the Hevenly Father speaking to you. You were blessed
Not sure if it's a good design to have the tailwheel riveted to the rudder. See how other taildraggers use linkage and compare
I guess an inspection lift of tail to check rudder & wheel should be added to preflight....
When you wiggled the tailwheel control rod and said not much going on here. But I saw the front rod end wiggling in the threads and sloppy!!
You said it, pal:”Thank God”. When putting yourself into a more risky situation for fun…..pray regularly.(Assuming you are Born Again)
You bring up a great point in that A&P’s are not type trained by a factory supporting a particular kit aircraft. Yes, the more experienced have a better tuned eye and feel to actually use the force to detect design and wear and tear issues. I flew a lot of rental aircraft, and it seemed like there were more often than not little things that caused some pre flight distress, but never legally enough to cross the MEL standards. I helped build 3 Vans Kits. Every one of them had an issues with someone thinking they were smarter than the original kit designers, and in searching for that extra mile an hour, made mods that should have been left to test pilots. So glad your judgement was God and higher self directed that day. I recommend after buying a kit that you don’t make with your own hands, go over ABSOLUTELY EVERYTHING in the original plans and note all discrepancies and changes. Then consult a DAR and the kit manufacturers builder technical rep to get best solution. Thanks for sharing you might just have saved someone’s life🙏
I smell a Sonex AD coming soon. Glad you’re safe.
thats interesting...we all have days when there feels something wrong... my rule is ...check my headspace... and when 3 minor things go wrong...take a hint and stay on the ground.
I would have someone design some redundancy into that rudder pull. Pop rivets are not a good choice for that pull. Maybe add another pull in parallel with the bottom mounted a few inches higher and braced inside the tail. That is scary.
Did the controls feel different before and after repair?
Still waiting on the control rod from Sonex. Will post an update when it’s all done!
From my couch those rivets look too short. The rivets selected there for attaching the bottom plate seem a poor choice. A Cherry or Huck structural fastener would add significantly greater clamping forces. Please update when you have structural repair instructions from Sonex.
Sonex told me to build it back according to the specs. All the parts have been ordered.
I'm an aerospace engineer and this video illustrates my reluctance to buy a homebuilt aircraft. Playing with avionics is one thing but there's a reason people get aerospace engineering degrees. Control systems and primary flight structures need to be left to people who know about them. And yeah, I wouldn't expect that rudder to have stayed on in a spin and the aircraft wouldn't have recovered without it. I would guess the guy's chances would have been 50/50 with a chute, 0 without one. He got lucky.