What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV-10 Landing Accident

There are 2 reports. Look at the first one

That link shows 2 reports. The top report is for the nose gear collapse on the RV10. The second report is for the right main collapse on a Lanceair
 
Not exactly a nose gear failure...
Got the following email from Russ Daves this afternoon:


From: Russell Daves
Sent: Wednesday, January 02, 2013 5:45 PM
Subject: RV-10 Elevator Control Column Failure


Talked to Bob Kaufman a few minutes ago. Failure was due to the elevator pushrod tube coming apart at the bolt on the WD1010 control column. Nut was missing but it could have fallen under the floor.

Bob and Sidney are fine, just a few bruises.

Bob lost complete elevator control on landing at Las Vegas.

Russ Daves

2ppgfpu.jpg


15qwvhu.jpg


The most important thing is that both occupants got out with just minor injuries...this could have been so much worse.
 
Glad to hear of the safe outcome.

And what is going on with the belly of that plane. That's a lot of oil or crapped themselves during the event.
 
..."From: Russell Daves
Sent: Wednesday, January 02, 2013 5:45 PM
Subject: RV-10 Elevator Control Column Failure
Talked to Bob Kaufman a few minutes ago. Failure was due to the elevator pushrod tube coming apart at the bolt on the WD1010 control column. Nut was missing but it could have fallen under the floor."

.......I am not familiar with the part referred to in the statement above. Is this part common to other models or just the ten. Is this a point that should be looked at or modified to prevent the possibility of this occurring again? Thanks, Allan...:confused:
 
PerfTech said:
.......I am not familiar with the part referred to in the statement above. Is this part common to other models or just the ten. Is this a point that should be looked at or modified to prevent the possibility of this occurring again? Thanks, Allan...:confused:
Click to expand...

Looks like it is the assembly in the top right drawing here:

http://www.myrv10.com/Plans/RV10_Plans_sec39-pg10.html

Pardon my ignorance (I'm not a builder yet), but are the primary control surface linkages on RVs really secured only with a nylock nut?

Seems to me that some secondary retention (drilled shank bolt and a castle nut with safety wire?) should be used to keep a critical nut from backing off, no?
 
Last edited:
apirkle said:
Looks like it is the assembly in the top right drawing here:

http://www.myrv10.com/Plans/RV10_Plans_sec39-pg10.html

Pardon my ignorance (I'm not a builder yet), but are the primary control surface linkages on RVs really secured only with a nylock nut?

Seems to me that some secondary retention (drilled shank bolt and a castle nut with safety wire?) should be used to keep a critical nut from backing off, no?
Click to expand...

A properly installed LOCK NUT is all that is needed on a bearing.

One must TIGHTEN the lock nut to the proper torque for it to work. It it is not tightened correctly, it will fall off over time and cause an accident.
 
Wow, I've never flown an RV10, but that looks like a best case scenario after losing complete elevator control.
 
Adam, the pushrod pivots on a ball and socket type joint. The bolt is not a hinge point or pivot. The ball is.

Only when the bolt itself is a pivot point, like the rudder cable ends, is a castellated nut and cotter key required, as is the case on most RV's.

Sounds like this particular case was a builder/inspector error.
 
WOW! Really lucky it failed close to the ground. God was with them, for sure!!

Roberta
 
Last edited:
Change Thread Title

Could someone change the thread title,
before this error goes down in history as a RV-10 Nose Gear failure.
Next thing people are going to ask Vans for a redesigned nose gear.

[Done; S. Buchanan]
 
Last edited by a moderator:
RV-10 accident

The push rods will also become disconnected if they are not deep enough into the rod ends.
 
I bought one of these http://tinyurl.com/adewcw2 to measure the running torques on nuts. It's a 1/4" beam torque wrench, 0 - 60 inch pound capacity. So far I haven't needed to use it on my slow-build RV-3B but it's here for when I do.

Click torque wrenches don't measure running torque, at least I don't know how to get them to do that. Running torque is added to the specified torque to get the torque that we actually use for installation.

There are self-locking castellated nuts available, that have the nylon insert as well as accepting a cotter pin. The ones I've seen are shear nuts. Sorry, I don't know their part number.

Dave
 
David - that is a great little tool. I ordered one.

Making no assumptions about this particular incident, even a severely under torqued nyloc nut is very unlikely to fall off of a bolt if the proper thread protrusion is there. I know this from my own personnal experience.

Be very careful using a torque wrench on the AN3 stuff, especially with the click type wrenches. There are many posts archived here where somebody broke the bolt, twisted it right off. Some of the nuts, expecially on control surfaces, are difficult to impossible to get a torque wrench on even with a crows foot or other extension and adding those devices makes operator error even more likely.
 
The entire site seems to be down right now as my normal Matronics bookmark isn't working either. In any event, the pics are the same as the ones Doug posted on the VAF frontpage.
 
I think the server is down, not that particular link..

Mike S said:
Anyone else unable to access this link??
Click to expand...

I'll wait awhile and try the server again. I couldn't even get to matronics.com.
Matt's probably working on kit log pro updates and doesn't know his server is down:D
 
David Paule said:
I bought one of these http://tinyurl.com/adewcw2 to measure the running torques on nuts...
Click to expand...

FWIW, general practice in the military is running torque is only required on fasteners larger than 1/4 inch. Anything smaller uses the "hand tight" method - in other words, if you can turn the nut through the locking feature by hand, you discard the fastener.
 
Last edited:
De Ja Vu

This exact thing happened to me in my 6. I noticed on one flight when I was in Phase One (about 20 hours) my stick in pitch had another 1/8" play. I was very uncomfortable and got on the ground fast. I promised my self before I landed, that I would not fly again till I found the problem. The problem was very subtle. It was so subtle that had I not had so many hours in the plane, I would never have recognized it.

I started my investigation by tapeing the elevator to the horizontal stab. (my assumption was that a rod end bearing had failed WRONG) Everything checked out fine till I removed my floor and inspected the first rod end bearing to the push tube underneath my sticks. There was NO NUT or WASHER on the number 3 bolt that went through the rod end bearing. The bolt had partially slipped out and was wobbeling since I no longer had a double sheer attach any more.

So how did this happen and why didn't anyone catch it? I installed my wing leveler on top of the attach point and it was totally hidden from view. Even though I had no less than four inspections by highly qualified people, no one used a mirror and inspected that particular attachment. In fact I did such a thorough job of inspecting and correcting before before any one else inspected that there were only a few minor squaks.

If I had continued flying the plane and ignored a seeming minor problem, at some point I would have had A VERY BAD DAY.

Hopefully these 2 events will save someone else of the same event or worse.

Steve Barnes "The Builders Coach
 
Steve Barnes said:
There was NO NUT or WASHER on the number 3 bolt that went through the rod end bearing. The bolt had partially slipped out and was wobbeling since I no longer had a double sheer attach any more.
Click to expand...

Steve, do you think the nut and washer were never actually installed, or do you think they backed off somehow?

Bevan
"no one is smarter than all of us"
 
There are several "Jesus" bolts in the RV series and this is one of them.
In all my years of working with nylon and metal lock nuts, if it was servicable when it was installed and properly tightened it was not going to back off and I never saw one back off. In the RV-10 it is not difficult to inspect IF you have ALL the panels off for inspection.
 
Mike S said:
True, but if you look at the drawings, there is a jam nut, and it is safety wired.
Click to expand...

Is this only in the -10 plans? I don't recall ever seeing the bearings having safety wire. Thanks to Adam P. for posting the image of the plans. You can clearly see the safety wire around the bolt where it could pull out of the pushrod. I don't think that's in the -7 plans.
 
Safety wire

Safety wire is installed to keep the pushrod from rotating
For whatever reason on the RV10 only.
It has no bearing on the safety of the nut and bolt.
 
Is there any way the safety wire could be mis-installed, or move/slip, and alter the working of the joint such that the bolt did turn / rachet one way, and "wind off" the nut?

There's something about that drawing and the safety wire that just doesn't look ideal to me, when combined with the theory of a nyloc being safe due no possible rotation of the bolt...
 
N427EF said:
Safety wire is installed to keep the pushrod from rotating
For whatever reason on the RV10 only.
It has no bearing on the safety of the nut and bolt.
Click to expand...

Thanks, Ernst...I do believe there was an accident in the past few years where the end bearing pulled out of the pushrod. It was on an -8 doing acro, and the pilot had time to transmit that he lost elevator control.

My question was about the possibility of adding safety wire to the rod-ends so if they did detach, for whatever reason, that you would still have safety wire making the (albeit, loose) connection. That may still give you some control, I would think.

Is my thinking out of line on the need for this? I know it doesn't happen often, but I would think the loads pulling on the eye bolt would be pretty strong in many cases (high speed, large deflection, for example).
 
RV-10 accident

Sonny- the safety wire is not around the bolt, it is secured under the bolt to assure the pushrod does not twist from it's installed length.
There are over 400 flying RV-10s, no has ever had this problem with the properly torqued bolt.

Pascal
 
Do we know where (what altitude) the failure occurred? Was the aircraft flown for a period of time with trim only? Inquiring minds want to know.
 
Yes, I have seen this nut loose on a few inspections, including two very recent ones in the last month. I find it amazing that the final inspection ALL builders should perform is to go over the entire control system from beginning to end in all axis, insure each lock nut is tight, the jam nuts are tights, and the castle nuts have cotter pins in them and then MARK them with torque seal. It gives peace of mind to everyone. Once I find a loose jamnut or locknut on the airplanes I inspect, and there is no visible torque seal, I no longer trust the rest of the airplane.
It also pays many dividends for future inspections. One quick glance can confirm the security of the device.

Vic
 
When I did the first flight for a 7A that I did not build, I took the time to examine every flight critical connection end to end. I looked to ensure that bolts and nuts were on, rivets installed to hold those VA-111 thingies, critical engine controls and hoses were on and secured, etc.

It took a while but it was my life on the line.
 
what safety wire on jam nuts?

Mike S said:
True, but if you look at the drawings, there is a jam nut, and it is safety wired.
Click to expand...
Hi Mike - I looked at my plans (-9A) and there is no safety wire on any of the jam nuts on any of the 7 pushrods that I can see. Also can't find it in the builders manual. Is it a -10 thing, did Vans add it after my kit, or did I just miss it and will someday have an interesting inspection?
 
only on the 10

I'm pretty certain only the 10 has the forward rod end saftied, as it is much longer than any of the others due to clearance in that area.

Vic
 
vic syracuse said:
I'm pretty certain only the 10 has the forward rod end saftied, as it is much longer than any of the others due to clearance in that area.

Vic
Click to expand...

Vic is correct.

Keep in mind, these are all different airplanes.
Even though they are all called RV's, it doesn't mean everything about them is the same. (in fact when comparing an RV-9 and RV-10 flight control systems, there is probably more things different than there is the same)
 
I haven't got to my final rigging of the control system yet but........

It occurs to me that during the process, nuts and bolts have to be removed and replaced to adjust the end bearings to get the correct deflections. It seems likely that with the rod lengths being made to the plan spec, it will be the end fittings that are chosen to make the adjustments. Could it be that if this is done enough times, the nut loses its lock properties?

After my aircraft is painted and I put it together for the final time, I intend to go through the entire control runs with my inspector, put on new nuts and re-torque.

On another point. If the disconnection should happen at a benign time and doesn't jam, it may be possible to control the pitch with trim and power.
 
I believe all the other tubes have rod ends where one side will tighten all the way before the opposite side runs out of threads and falls out.
 
vic syracuse said:
Once I find a loose jamnut or locknut on the airplanes I inspect, and there is no visible torque seal, I no longer trust the rest of the airplane.
It also pays many dividends for future inspections. One quick glance can confirm the security of the device.
Vic
Click to expand...

I've done over 600 airworthiness inspections on RVs. I've found loose jam nuts on almost every one. This is after several others have inspected them. You can't have too many eyes looking.
I don't mean to say that I'm a better inspector than others, but I'm typically the "final" inspector.
I shouldn't find anything!
 
RV-9 flap actuator pushrod requires safety wire

IowaRV9Dreamer said:
Hi Mike - I looked at my plans (-9A) and there is no safety wire on any of the jam nuts on any of the 7 pushrods that I can see. Also can't find it in the builders manual. Is it a -10 thing, did Vans add it after my kit, or did I just miss it and will someday have an interesting inspection?
Click to expand...

Dave:

If I understand your comment, you did not find a pushrod on the 9a that required safety wiring. Check drawing 33 (detail E if I recall); the flap actuator needs to be drilled and safety wire installed to prevent the locknut from rotating. Without the safety wire, or another positive safety, the rod end bearing can rotate. This can allow the flaps to deploy... dramatically. I failed to install the safety wire, and the bearing rotated free with another pilot aboard. Very sobering.

After the failure, I applied another builder's technique found on VAF: I drilled both the pushrod and the bearing, in order to safety the locknut, and prevent the bearing from rotating.

My two cents.
 
Thanks Esco - you caught me. I wasn't thinking of the flap pushrod... I have safetied that one per plans. Thanks for keeping me honest :)
 
paul330 said:
On another point. If the disconnection should happen at a benign time and doesn't jam, it may be possible to control the pitch with trim and power.
Click to expand...

Key point here is IF IT DOESN'T JAM. I have brought the Decathlon from downwind in the pattern to a good landing using only trim, power and rudder. A good thing to practice for one of those "it will never happen to me" events.
 
Maybe

Of all the RV's, the -10 needs an enormous amount of trim to relieve the elevator pressure and while it may be possible to bring one down with trim, IMO, the airplane probably would not be re-usable without some repair.

Best,
 
pierre smith said:
Of all the RV's, the -10 needs an enormous amount of trim to relieve the elevator pressure and while it may be possible to bring one down with trim, IMO, the airplane probably would not be re-usable without some repair.

Best,
Click to expand...

Absolutely!!!!!
 
Just a follow up on what Vic said. I highly suggest the use of torque seal once you have final installation of a nut like this. When you are several months/years into a build you will forget or believe that a nut has been torqued when it possibly has not. Torque seal is cheap, I have multiple tubes and colors in my box, Avery sells it. If I need to remove a previously torqued stripped nut the seal will chip right off. Also once I install a nylok nut and then remove it I throw it away and install new. Torque seal also makes your annual go much faster, if its still there and not cracked then the nut has not moved.

Pat
 
You must log in or register to reply here.
Back
Top