RV-12 Fatal Crash - Control Failure 6/6 Auburn, WA

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flyingron

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That sucks.
Any idea what kind of control failure in an RV-12 would give them enough time to make radio calls but still result in the complete loss of control like that? Flaps deploying asymmetrically?
 
AV8R_87 said:
That sucks.
Any idea what kind of control failure in an RV-12 would give them enough time to make radio calls but still result in the complete loss of control like that? Flaps deploying asymmetrically?
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The aileron system on an RV-12 is different from most GA aircraft. It's configured to allow the wings to be removed without having to disconnect aileron pushrods or cables. IIRC, the reconnect is simple and foolproof.

The 12 has considerable experience with this system, and similar setups have been used by sailplanes.

There is currently no evidence the system had ANYTHING to do with this accident. I only mention this in connection with AV8R's question.

I'm out of state right now, with no access to my Light Sport or EAB accident databases. But I don't recall seeing any similar accidents involving RV-12s.

Ron Wanttaja
 
Very sorry to read. I don't know anything about RVs, but I will say it could be anything. I had a winter glove fall and jam the rudder pedals on climb from takeoff once, that will wake you right up. From the sound of it, the pilot didn't have much time to diagnose and fix or workaround whatever it was.
 

Does it have the same AP?

www.vansaircraft.com

Jesse and Ken Norling's RV-12 - Van's Aircraft Total Performance RV Kit Planes

Congrats to Jesse and Ken on their new RV-12. Here’s their story: Nearly 10 years ago, I bought the RV-12 empennage kit after looking at several different airplane options. This started the best father-son project you could imagine. I started the build, and as I got further along it became a...
www.vansaircraft.com www.vansaircraft.com
 
wanttaja said:
The aileron system on an RV-12 is different from most GA aircraft. It's configured to allow the wings to be removed without having to disconnect aileron pushrods or cables. IIRC, the reconnect is simple and foolproof.

The 12 has considerable experience with this system, and similar setups have been used by sailplanes.

There is currently no evidence the system had ANYTHING to do with this accident. I only mention this in connection with AV8R's question.

I'm out of state right now, with no access to my Light Sport or EAB accident databases. But I don't recall seeing any similar accidents involving RV-12s.

Ron Wanttaja
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Plus the ailerons are flaperons, happened on base turn, just speculating but if flaps were added it might have made the ailerons totally unbalanced. rIp.
 
We’re all saddened to hear of this type of death.
Doubly so on hearing he was your friend, Ron.
 
There is a new SB from Van’s to inspect the control stick pushrod before further flight. The plans call for jam nuts on the rod ends that screw into the pushrod… if those aren’t there, or aren’t tight, bad things can happen.

I look at and check those every single time the floor pan is up for the condition inspection or anything else, but obviously I’ll do it again this week.
 
On Saturday, I was contacted by a local TV station, who interviewed me later that day.

Be advised that they undoubtedly found me via this thread on POA. Keep that in mind when you participate in threads here.

Ron Wanttaja
 
DaleB said:
There is a new SB from Van’s to inspect the control stick pushrod before further flight. The plans call for jam nuts on the rod ends that screw into the pushrod… if those aren’t there, or aren’t tight, bad things can happen.

I look at and check those every single time the floor pan is up for the condition inspection or anything else, but obviously I’ll do it again this week.
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Could you apply a paint dab or torque seal, and then drill the floor pan for inspection covers over both ends of the rod- about 1” diameter and a flashlight or borescope?
 
DaleB said:
There is a new SB from Van’s to inspect the control stick pushrod before further flight. The plans call for jam nuts on the rod ends that screw into the pushrod… if those aren’t there, or aren’t tight, bad things can happen.

I look at and check those every single time the floor pan is up for the condition inspection or anything else, but obviously I’ll do it again this week.
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Question for you, or anyone else familiar with the design: would this result in jammed controls, or just floating/unresponsive? Trying to understand if you could attempt to fly it using trim and rudder.
 
455 Bravo Uniform said:
Could you apply a paint dab or torque seal, and then drill the floor pan for inspection covers over both ends of the rod- about 1” diameter and a flashlight or borescope?
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Not sure; I'd have to look at the layout in person again and see. The floor pan comes up once a year minimum for every condition inspection, though. It's not like it needs to be a preflight inspection item -- once jam nuts are installed they shouldn't go anywhere. This is a pretty standard setup.
AV8R_87 said:
Question for you, or anyone else familiar with the design: would this result in jammed controls, or just floating/unresponsive? Trying to understand if you could attempt to fly it using trim and rudder.
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Each stick is connected to the flaperon controls by its own pushrod. If one were to come loose it would at least disconnect that stick from the flaperons. I don't know if it would be possible for it to jam the controls without looking at the setup in person (which I'll be doing this week). In any case you'd probably still have elevator and rudder, but if the flaperons were to become jammed in something other than a neutral position things would get very challenging.

There are other pushrods connecting the flaperon mixer to the torque tubes that move the flaperons. Like pretty much any pushrod I've ever seen, there are jam nuts there as well. This is not specific to the RV-12; there's nothing unusual here. I don't care what the airplane is, if there's a control pushrod and an end comes loose, you've got a problem.
 
Now speaking of my RV-7A and not a 12 all pushrod rod ends are engaged by more than half the thread length so that if a jam nut comes loose and the tube happens to thread itself to an extend it still will not lose the other ends rod end. Maybe not the case for the -12 but I doubt it, that's a section 5 portion of the build manual. Dale, educate me if there is something unique here on the -12.
 
Yeah, both ends would have to have lost their jam nut tensions for the rod to come undone from one end.
 
Even then it should be impossible if there was the proper thread engagement.
 
Tragic building mistake that took 100 hours to manifest itself. Reminder to self: if controls don't work in some aircraft, go to the other stick and give it a try.


- NTSB issues the preliminary report into the fatal accident involving a Van's RV-12, N412JN, that occurred on June 6, 2024, in Auburn, Washington:
On June 6, 2024, about 1159 Pacific daylight time, an experimental amateur built Vans Aircraft Inc. RV-12, N412JN, was substantially damaged when it was involved in an accident near Auburn, Washington. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The airplane departed Auburn Municipal Airport (S50), Auburn, Washington, for what family members of the pilot reported as a routine pleasure flight. Preliminary Automatic Dependent Surveillance-Broadcast (ADS-B) data indicated that shortly after takeoff the airplane followed a southeast track, and after reaching the eastern foothills of Mt. Rainier, performed a 180° right turn, and followed a similar track back to Auburn. As the airplane approached the airport from the east, the pilot reported over the common traffic advisory frequency (CTAF) that he was just over midfield and intended to perform a full stop landing on runway 35. Correlation between recorded CTAF audio and ADS-B data indicated that over the next 60 seconds, the airplane overflew the runway, while descending from 1,500 to 1,250 ft. It then began a left turn, and as it rolled out onto the left downwind leg, the pilot transmitted, “Pan Pan RV412JN, I just had a control failure, I’m inbound for 35, without any controls”.
Over the next 45 seconds, the airplane began a descending left turn, that witnesses described as similar to a spin or spiral dive. A west-facing security camera, located on the exterior wall of a warehouse about ¾ miles southwest of the runway 35 threshold, captured the final 3 seconds of flight. It showed the airplane come into view at the top of the frame while in a 45° descending left turn. The airplanes roll rate rapidly increased, and the airplane struck the warehouse roof inverted in a 45° nose-down attitude.

The airplane came to rest inside the reception area of the warehouse. The forward cabin sustained crush damage through to the main wing spar. The complete right, and the inboard left section of the wings remained attached to the fuselage by the main spar, and the outboard fragments of the left wing were located on the building’s roof.
The airplanes roll control system consisted of full-length flaperons, connected to tandem control sticks through a series of pushrods, torque tubes, and a centrally mounted flaperon mixer bellcrank. Examination of the wreckage revealed that the left control stick pushrod (F1264-1) was not connected to the inboard eyebolt bearing (CM-4MS) at the flaperon mixer bellcrank (see figure 1).

When compared with the airplane’s plans, the inboard eyebolts were installed such that the eyebolt stud was connected to the pushrod, and its body to the mixing bellcrank, rather than the other way around (see figure 2). In this configuration, the stud end of the eyebolt was free to rotate within the threaded inboard section of pushrod.

Construction of the airplane was completed in May 2021, and by the time of the accident it had accrued about 100 hours of flight time. The pilot was flying the airplane from the left seat.
The wreckage has been recovered for further examination.
 
Ah. Looking at the picture in the prelim report, it's clear now what happened. Sad.
 
I'm surprised the airplane didn't have enough inherent stability to partially mitigate the issue to the point that trim, rudder, and power couldn't have gotten it down in a more controlled manner.
 
There seems no way (or I don't know how) to get a link to the report to open it in a web page.

This may well download preliminary report.

Accident Number: WPR24FA182
Registration: N412JN

Here is one of the pictures so that along with the already posted text you may not need to bother.

I guess there was a missing locknut at the control stick end of the tube too? A locknut on the threaded portion of the rod-end cinched up against the (control stick side) end of the tube?

1719351714653.png


1719352244971.png
 
Damn. Rod end was supposed to go on the rod. Even without a jam nut on one end, if assembled correctly that end would have stayed assembled. Without a jam nut AND assembled that way, it unthreaded itself 100 hours later.

That sucks. Humbles one to consider that what they thought they did right turned around to grief 100 hours later.
 
It’s always tempting to think, “Oh, I’d never make that mistake”, or, “Of course I’d think to try the other stick”.

Maybe. Maybe not. And as humbling and occasionally humiliating as it can be, it’s a good idea to have someone else who knows more or is more detail oriented check your work. I know a guy who has an uncanny ability to walk in, glance at the airplane with the cowl off, and point out any little imperfection. The first few times I found it irritating as hell. Now I welcome it, and it’s made me a lot more attentive and focused on finding those things before he or someone else does. Or before one of those little imperfections kills me.
 
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If you realized the problem, you’d probably think to use the other stick.

In reality, it might not be so obvious at that moment what the problem is.

Also, it might not be as easy as you think to fly with the other stick. Perhaps he did attempt it. It might be difficult to see outside while stretched across to move the other stick. Checking airspeed? Not gonna happen.
 
Salty said:
Also, it might not be as easy as you think to fly with the other stick. Perhaps he did attempt it. It might be difficult to see outside while stretched across to move the other stick. Checking airspeed? Not gonna happen.
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Pretty easy, actually. I’ve tried it. No stretching required, the right stick is within reach.
 
Wow looking at the diagram, just a simple 180 deg swap and he's till be alive. Really eye opening that something like this can lead to devastating consequences.
 
Salty said:
If you realized the problem, you’d probably think to use the other stick.

In reality, it might not be so obvious at that moment what the problem is.
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You're moving the stick left - right. The aircraft is not responding. The other stick is NOT moving left - right. Maybe not obvious, but not exactly obscure either.

I can only speak for my personal experience with control system issues. When I experienced a jammed stick years ago, within 5 seconds I was applying every ounce of knowledge of the aircraft that I had to deduce the problem and devise a solution. I'm still here.

This accident was survivable.

I realize I'm being a heartless *******. But these discussions are not for the pilot, his family, or his friends. They are for the rest of us, to maybe avoid a similar fate.

Right now I assume every RV-12 owner on the planet is triple checking their rod ends.

For the rest of us, Aviate Navigate Communicate. If you have a control system issue, stay aloft, troubleshoot, and attempt to maneuver with other controls. The aircraft might have been controllable with roll-yaw coupling. The added time aloft might have been enough to notice the difference in stick movement and deduce the issue.

Maybe it's because I'm an acro guy. Control system issues are a known hazard in that world. But the playbook is well defined. Stay aloft. Troubleshoot. Attempt to use other controls to maneuver. Practice simulated landing profiles at altitude before you attempt to land.

Above all, do not panic, and do not give up.
 
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Ed Haywood said:
You're moving the stick left - right. The aircraft is not responding. The other stick is NOT moving left - right. Maybe not obvious, but not exactly obscure either.

I can only speak for my personal experience with control system issues. When I experienced a jammed stick years ago, within 5 seconds I was applying every ounce of knowledge of the aircraft that I had to deduce the problem and devise a solution. I'm still here.

This accident was survivable.

I realize I'm being a heartless *******. But these discussions are not for the pilot, his family, or his friends. They are for the rest of us, to maybe avoid a similar fate.

Right now I assume every RV-12 owner on the planet is triple checking their rod ends.

For the rest of us, Aviate Navigate Communicate. If you have a control system issue, stay aloft, troubleshoot, and practice maneuvering with other controls. The aircraft might have been controllable with roll-yaw coupling. The added time aloft might have been enough to notice the difference in stick movement and deduce the issue.

Maybe it's because I'm an acro guy. Control system issues are a known hazard in that world. But the playbook is well defined. Stay aloft. Troubleshoot. Attempt to use other controls to maneuver. Practice simulated landing profiles at altitude before you attempt to land.

Above all, do not panic, and do not give up.
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I'm in total agreement. I just also can see how the accident can happen.
 
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