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RV-9A front gear folds

MrNomad

Well Known Member
And so my 64 hours of sheer pleasure came to an end this past Saturday. During a landing at MYF (San Diego) on runway 23 (very rough, seldom used paved runway), the front gear on my 9 folded under as I passed the bumpy edge of intersecting runway 28R.

Fortunately, the gear just folded under the airplane and the plane didn't flip. It skidded to a stop on the bent front and the two main gears. I experienced no damage other than a bent $2,000 cruise prop.

The wife refuses to fly ever again. Anyone interested in a 9A with 64 hours, lemme know. See the link below for the equipment list.

If you have to get stuck, MYF is the place to do it. Henry Sickels of Gibbs Aviation was an absolute prince providing a hangar, tools, and lots of quality advice as I disassembled the 9A and loaded it on my trailer with his forklift. Using a pipe wrench, Henry and I un-bent the front gear into a vertical position to better stabilize the airplane. Yes, you read that right. We un-bent the so-called new design gear with a pipe wrench.

I welcome all opinions concerning the remedy (assuming no one buys it).

For photos click on www.arizonaairparks.com/rv-nose-gear-incident.htm

Barry @ arizonaairparks.com
520-797-0265

FOLLOWUP as of 1/2009: After 60 days of non stop work & considerable exercise of the credit card, we fixed the 9A and added 40++ more wonderful hours since summer 08. In retrospect, several factors contributed to this mishap and I take responsibility for all of them. First, never land faster than you have to. Second, I avoid rough fields and, even on smooth runways, the front wheel never touches Mother Earth until gravity demands it. You can boast about all of the soft fields and rough places you've managed to land, but watching that front gear oscillate back and forth is not encouraging. Third, if there is any question what your breakout force is, don't fly. Fourth, if you don't know what your tire pressure is, don't fly. Fifth, if you haven't installed your front wheel pant and placed many layers of glass inside so the front pant can serve as a skid plate, don't fly. Sixth, install a spacer in the front wheel hub to preclude bearing compression and increased rolling resistance.

Yes, the wife agreed to fly again and one of the first trips was back to KMYF to say thanks to all of the folks who were so helpful.

rv9awheelpantsvr8.jpg
 
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Barry,
thats awful man. Glad you all were not hurt and i hope you had an uneventful trip home with it.
Did you by any chance take a pic of the sufrace that caused it to fold? I guess :confused:it was better to be on a hard surface to prevent it digging in and flipping. man i feel for ya buddy.
 
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Ouch

.......Using a pipe wrench, Henry and I un-bent the front gear into a vertical position to better stabilize the airplane. Yes, you read that right. We un-bent the so-called new design gear with a pipe wrench.....
Barry,

Your photos reveal a curious blend of the awful and the unusual. To what degree did the bumpy edge of the intersecting runway contribute to the damage and did the bump....and the force it was met with during roll-out....exceed the design limits of the nose gear leg? Combined with proper technique, one would naturally think the gear should be able to endure a reasonably rough surface. A bummer for sure but most importantly no one was hurt and at least the apparent and "seemingly" minor damage to the airplane can be repaired/replaced in a timely fashion not counting the potentially expensive engine teardown. Still, like they say "Once bitten, twice shy." :(

I am guessing the nose gear leg is a vendor supplied part. If so, does its post incident condition raise questions about the degree of quality control (or lack of) during its manufacture? For instance, was the correct steel used and heat-treated to required and specified hardness? Do multiple vendors supply the part?

Certainly Van's has an interest in safety. I suggest you contact Van's and discuss/negotiate shipping the leg to the factory for a closer examination and in-depth evaluation. That seems a prudent thing to do.

Good luck.
 
Curious on what the outcome on the nose gear will be.

I just ordered my finishing kit and it will have the new style nose gear in it. I have the old style gear already that I got when I bought my kit from another builder but haven't sent it off to Langair yet for the modification. Now I'm tore on which one I what on the plane. Which would be the best piece?

Maybe after talking with Van's you can shed some light on what you find out.
 
Wheel Pants

From the pictures you posted, showing the wheel pant bracket, I assume you had the wheel pants on at the time of the incident. Do you have any pictures of the nose gear wheel pants that would show where the impact occured? Best of luck with the decision on rebuilding or selling, hope you are able to get it in the air again.

Roger
 
Sorry to hear of your mishap, Barry. I read about it on the daily FAA report yesterday.

Any chance you could measure the intersection lip you hit?

It would be helpful to know what the mismatch limits are when it comes to going from one surface to another. I regularly jump up on a hard surface from turf and so far the only damage is a scratched nose gear fairing. You obviously hit something very hard and high enough to catch the nose gear above its center of lift.

From Rosie: Roee has a report on the runway here.
 
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It would also be helpful to know the air pressure in the tires... we are talking about fractions of an inch clearance here.
 
Btw: I too have had a positive interaction with Gibbs aviation.

When visiting San Diego I'll try to remember to thank them.
 
RV-9A nose gear collapse

Barry: I feel your pain. I did the same thing in my new RV-9a with 20 hours on it. This happened in 2005 on a wide paved runway. Our stories are very similar. A bunch of RV guys helped me remove the wings and I trailered it home. I ordered the "new" nose gear parts from Van's, a new prop and sent the engine back to Aero Sport Power for tear down. They found no problems with the engine. It took me about 50 hours for the repair over a period of six months. Mostly waiting for the prop to arrive. Since that time I have been very careful with the nose gear and will not take the plane on turf. As one person told me, "the nose gear is designed to hold the nose off the gound when it's parked!"

Ron Murray
N937RK
 
The wife refuses to fly ever again. Anyone interested in a 9A with 64 hours, lemme know. See the link below for the equipment list.

Barry, I am sorry to hear about your nose over. I am even more sorry to hear that your wife is now refusing to fly again. That is a real blow! I hope she has time to reflect upon that decision and perhaps re-evaluate it. I know my enjoyment of flying would not be near as great if my wife refused to share in it with me.

Good luck with your rebuild.

This airplane has an O-360 in it. How much heavier is that versus the O-320?
I am by no means an expert on this but I am building a 9A and have been talking long term with engine shops about my engine choice(s).

From my discussions with America's Aircraft Engines concerning ECI engines, the difference in weight between a 360 and a 320 is approximately 12-15 lbs (the 360 weighing that much more than the 320). For me, this was the deciding factor for why I am not going to be putting a 360 on my 9A.
 
Difference between RV7A and RV9A

:confused:
From my discussions with America's Aircraft Engines concerning ECI engines, the difference in weight between a 360 and a 320 is approximately 12-15 lbs (the 360 weighing that much more than the 320). For me, this was the deciding factor for why I am not going to be putting a 360 on my 9A.

I'm not trying to start another thread war - just trying to understand the differences. Isn't the fuslage and landing gear the same for a 7 as it is for the 9? And if an O-360 is OK for the 7's landing gear, shouldn't it be OK for the 9? I thought the reason Van's doesn't recommend larger engines in the 9 is due to different flying surfaces (wings and tail) not the undercarriage.
???
 
I don't understand it, but...

:confused:

I'm not trying to start another thread war - just trying to understand the differences. Isn't the fuslage and landing gear the same for a 7 as it is for the 9? And if an O-360 is OK for the 7's landing gear, shouldn't it be OK for the 9? I thought the reason Van's doesn't recommend larger engines in the 9 is due to different flying surfaces (wings and tail) not the undercarriage.
???

Vans information http://www.vansaircraft.com/pdf/Nose_gear_service_letter.pdf

Shows max front wheel weight of the 9A at 325 lbs and the 7A gets 369 lbs.


Kent
 
I Know the pain

Berry,
Glad you and your's are OK- that is most important.
I know the feeling first hand. Sent an Email...
 
Nose gear weight

Vans information http://www.vansaircraft.com/pdf/Nose_gear_service_letter.pdf

Shows max front wheel weight of the 9A at 325 lbs and the 7A gets 369 lbs.


Kent

Barry's landing nose gear weight was about 275#, assumming a combined pilot/passenger weight of 280# (how's that for being polite...:)...), 10 galls. of fuel and 40# of baggage.

If my combined people weight is low (likely), then the nose gear weight is less.

gil A

I did Barry's W&B charts...
 
A little speculation

Just from the photos, I wonder if the bend/distortion in the firewall and bottom skin is from the tire hitting the exhaust pipes, and forcing them up into the fuse, and not from energy transfered from/through the landing gear mount????

The nose gear leg is the "spring" in the system, the bend shown is hard to imagine in a correctly tempered piece of spring steel. Coupled with the fact it was straightened with a pipe wrench, makes me wonder if the leg had been tempered correctly????

As Stein would say, "just my $.02"

Bottom line, the two of you are unhurt.
 
Just from the photos, I wonder if the bend/distortion in the firewall and bottom skin is from the tire hitting the exhaust pipes, and forcing them up into the fuse, and not from energy transfered from/through the landing gear mount????

The nose gear leg is the "spring" in the system, the bend shown is hard to imagine in a correctly tempered piece of spring steel. Coupled with the fact it was straightened with a pipe wrench, makes me wonder if the leg had been tempered correctly????

As Stein would say, "just my $.02"

Bottom line, the two of you are unhurt.

There has been talk of this before- incorrect heat treating of gear legs. Anyone able to do a test on a leg that seemed to fold up a bit too easily?
 
Looking at the pictures of the gear and the geometry, I can't picture how this would have occured, at least not in the same way it was determined other similar accidents occured (i.e. the large nut digging in, the spring gear flexing, etc.)

It makes me wonder if the dynamics of the accident are somehow different. Perhaps in this case the speed was sufficient that the rim itself caught on the pavement, or perhaps the wheelpant somehow came into play.

In any event I'm just glad everyone was physically OK. The damage is certainly repairable, but I can understand your decision to sell the airplane.
I just feel bad that this happened to you.

I certainly will wait to see if anything shakes out from this before changing out my gear.

John Allen
RV-6a
 
Sorry to hear about your incident Barry. Please keep after it and make the bird fly again! As someone else asked, what were the tire pressures, including the mains?
 
Inspected...

Just from the photos, I wonder if the bend/distortion
in the firewall and bottom skin is from the tire hitting the exhaust pipes, and
forcing them up into the fuse, and not from energy transfered from/through
the landing gear mount????
.....
Bottom line, the two of you are unhurt.

Mike... I had a chance to check out Barry's plane today.

The center two engine mount supports are deflected a small amount
rearward. The lower part of the mount is definitely distorted rearward, but
not by much. No signs of the pipes actually hitting the bottom skin.

Barry's next job is to remove the engine/mount and see how much the
distorted mount is pushing back on the bottom firewall angle. Then the
damage extent will be determined.

It seems like a repair can be performed without too much dissasembly at the
firewall.

I too was surprised at Barry's description of being able to bend the
gear back...

gil A
 
POST MORTEM on the 9A that bent the front gear in San Diego

Thanks for all of your emails and good wishes. I will attempt to answer all questions.

At 7am today, 8 friends converged at my home (one with a tractor) and within 10 minutes the wounded 9A was off my car trailer and back on the ground.

Gil Alexander lives nearby and we just completed an extensive "look see". A more meticulous and knowledgeable fellow does not exist on this planet than Gil. During the 18 month build, Gil served as our technical counselor and would leave us with a HONEY DOO list after each visit that went on for pages. And that was ok cause we wanted to build a first rate airplane. Little did I know that included a front gear that shudders fore and aft all too often.

FIREWALL: Bent stringers, should be able to fix pretty easily once the engine and mount are removed.

ENGINE: We will dial the 64 hour, $20k SUPERIOR O-360 with low compression pistons. If it dials ZERO, and the gears look good, I'll leave it alone. If not, we'll take it apart and replace/repair what's needed in addition to gaskets and rod bolts. Min is $1,000, max could be $8,000 assuming we disassemble and reassemble ourselves.

PROP: If it cannot be straightened, another $1,500 or $2k.

FRONT GEAR LEG & FORK: $400 (imagine how happy I will be to spend $400 on another, same "quality" gear leg).

ENGINE MOUNT: Yes, mine is bent, I refuse to un-bend, another $1,000.

WHY A 360 versus a 320? As Gil already pointed out, the 360 with fixed pitch prop is within weight limits. An O-320 with constant speed would weigh approx the same but more of the weight would be towards the front. With 7.2 pistons, I can run just about any octane auto gas in the O-360 and horsepower is 168 to 172.

WHEEL PANTS: No, they were not installed and according to other posts, that does not always save the day. But that begs the question, is a wheel pant supposed to be a SKID PLATE or a wheel pant?

BENDING THE GEAR BACK: Remember, we bent the front gear BACK into position (forward) using a pipe wrench and an extension. But that begs another question. How long would a pipe wrench have to be to bend the front gear of a Cessna 150 or a Grumman?

Get the point?

GIBBS AVIATION: If you gotta get stuck, I recommend San Diego and General Mgr Henry Sickels. He deserves a special place in heaven. Henry called ME the morning after we left SD to check on us. How many vendors do that? With his forklift and three of the teenagers who work for him, the 9 was on my car trailer in no time.

CAR TRAILER: Given the "quality" front gear leg, Vans ought to post directions how to convert a car trailer into a plane hauler. Using 2 pieces of 2" box steel laid across the car trailer, we created a cradle and set the 9main gear into the cradle. See my website for more pictures of the cradle and the damage to the firewall.

http://www.arizonaairparks.com/rv-nose-gear-incident.htm

FRIENDS: None better than Chet Oldakowski who helped me build the 9A over 18 months. While I ripped the plane apart in SD, he got keys to my house, hooked up my car trailer to my Dodge van, and 7 hours later arrived in San Diego from Tucson.

TIRE PRESSURE: Always between 25 & 30 lbs. According to my friend Roberta, she uses 35. I will too (from now on).

WHY DID IT OCCUR? Before the tow truck carted us off the runway, the NTSB had the driver measure the skid. It started at the intersection where runway 23 crosses 28R. 23 is known as the "old runway" to the locals because it is rarely used and very rough. Where the two runways meet there is a height difference. Given that 23 is 3500 feet long, I let the front wheel settle and applied brakes. All three wheels were on the ground and I was slowing (for what was supposed to be a pleasant weekend vacation).

The front wheel tucked under and suddenly we were looking at the ground as it slid to a stop approx 50 feet later. Using the right brake, I was able to keep it on the runway. To the best of my recollection, all three wheels remained on the ground at all times. I am amazed (and thankful) it did not roll over.

I have hundreds of landings in this airplane and can do touch and goes with the front wheel never touching the runway. I like to think of landing like a ballerina dancing on tip toes.

FORCED LANDING? Better to carry a parachute and jump because if the gear cannot handle rough runways and the occasional bump, what's it going to do off field?

BEACH AND GRASS FIELDS? Fuhgetaboutit.

WIFE: Update... she says OK for short trips, forget long trips.

PERSONAL OBSERVATIONS: This is a great airplane and I love it. No, it's not going to be sold. Yes, I will fix it and I removed the FOR SALE from my website. But if anyone can think of a way to apply pressure to Van to improve the front gear, lemme know.

VAN'S RESPONSE WHEN I CALLED: This is a quote: "We have 4000 hours on our planes and not one front gear has failed".

That's just ducky.
 
There should be someplace locally that can determine if the material properties meet spec. It would be nice to know...
 
Barry, so glad it didn't go over and that you are both ok physically.

I know you have a ton of stuff on your mind now as you begin the repair process.

However, in the interest of preventing these problems, it would really be helpful if you could provide a little more information when you are able. I've written a fair bit on this forum about possible explanations for these accidents that are outside of the explanations and analyses given in the NTSB work done to date.

You mentioned a skid was noted on the runway. It would be very, very helpful if you could be very detailed in the exact observations, specifically near the start of the event. Or photos if possible. Did there appear to be any tire skid marks at the immediate beginning of the event, prior to the bending under of the gear? Additionally, the measurement of the vertical mis-alignment of the pavement would be helpful.

Thanks, and best of luck with the return to flight!
 
Heat Treated

I am curious to see if you can take the nose gear leg to an expert to see how well it was heat treated and or hardened. This just not ought not to be happening..... Best of Luck!
Best
Brian Wallis
 
I'd love to see Cessna get away with that line!

VAN'S RESPONSE WHEN I CALLED: This is a quote: "We have 4000 hours on our planes and not one front gear has failed".

Granted Cessna is a certified mfg but I doubt Van's would get away with using that line as defense in a court case!

What about the 5500+ flying planes out there?

The fact that a A model nose gear failed like a wet noodle on a paved runway has me concerned.
 
The fact that a A model nose gear failed like a wet noodle on a paved runway has me concerned.

When it hit the edge of an intersecting runway...

L.Adamson --- RV6A

FWIW, there are two 6A's close to my hangar. One has slightly less than 1000 hrs, and the other has around 1100. Both are over 10 years old, and neither has had a nose gear failure.
 
Easy Bending

Based on your description of bending the gear back with a pipe wrench and a long extension, I would most definitely have a metallurgy lab test the leg for proper hardness, etc. I would do it locally, before you send it back to Van.

Then I'd strongly consider buying an engine mount that was set up for taildragger gear, and make the conversion during the repair.
 
That gear leg was hard

If that gear leg was not heat treated, it would have bent just from the weight of the plane sitting on it when sitting still. I would be EXTREMELY surprised if it was a heat treatment issue. I do encourage you to get it tested somewhere locally though just so you know.

I am sorry to hear of your unfortunate day though. I hope the repairs go well and you and your wife are able to enjoy the plane again, hopefully sometime soon.
 
gear leg

The gear leg should be checked for rockwell hardness as the gear can be treated but not to the right hardness.If it is to soft it would hold up until something like this happens. Maybe we should all chip in to have it tested as this is starting to worry me. It looks like to me it might have bent a little on the runway then the cross runway finnished it off.
Sorry about the accident.
 
The straw that broke the camels back

Well your post just just convinced me to finish my 9A as a 9. I haven't ordered the finish kit yet so I will order it as a tail dragger. I have been concerned for the last two years of this ongoing project about the nose gear. One of my favorite places to visit is Gaston's Resort on Saturday morning with friends for breakfast. I am only 15 minutes away in the RV and in the summer it is a frequent adventure. I refuse to stay home because I am afraid of ending up upside down in the middle of a grass runway.
I can't imagine how frustrating it must be for you to have to rebuild your beautiful plane and my heart goes out to you. If I wasn't 1000 miles away I would be there to help in any way I could.
 
so, the runway was rough but no ledge at the intersection? if a ledge how high was it? i am having a hard time visualizing this. all the temeper testing and vans bashing is a waste of time.(the part is just too weak) what made it roll under? it had to catch on something? brakes (hard) on would increase the nose wheel load. were you trying to get off onto a taxi way in a hurry?they give me that all the time at KMYR. just trying to better understand the sequence of events that led to this, as i am soon to fly mine (7A) :eek: and this is a mild concern. i tend to be a little claustrophobic (ya know, trapped in an upside down airplane and all.) well i wouldnt be trapped for long, as i would cut out the side to exit.:eek:
 
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Nose Gear Design

Maybe someone should consider stealing what seems like a better idea from the Glastar nose dragger. It appears similar from the stance of the plane, but the shock absorption is taken up with rubber donuts in compression in the motor mount and the gear leg itself deflects very little since there is a pivot point at the firewall.

I took a demo ride in a nose dragger Glastar some time back and the demo pilot said just land it beside the runway! It was very rough, bounced a lot, but nothing bent or broke...very impressive.

Mitch Garner
RV-4 flying
 
.......all the temeper testing......is a waste of time.(the part is just too weak) what made it roll under?.......
Granted, bashing Van's is ill-advised and I'm quite certain Van's does the very best it can to produce a quality product. What bears further examination in this case in particular, is the quality of the vendor part it may have received from a supplier. Aviation is chock full of uncounted cases of vendors cutting corners to increase the profit margin and then go on to certify the parts shipped out as meeting spec. The big airframe manufacturers catch such things all the time through in-house quality control departments. Now I'm not saying that a dishonest vendor is at work here, but I am saying when a crucial part fails under dubious circumstances, any meaningful investigation would include thorough testing of the part to insure it is within compliance. There can be any number of reasons to cause failure and testing is one way to rule out the part as being defective. On occasion problems in quality can be traced back to the guy on the (vendor) shop floor not doing the job correctly but thinking he is. Dishonesty is not necessarily at work here... but something is.
 
Tire Pressure

I noticed Barry's tire pressure will now be 35 psi after running at 25-30. I think that is too low. I run with 45 psi in all of the tires. It makes a difference on the plus side.

I can not condemn the NG system outright. Along with other guys, I've been flying off a sod strip for 3 years with many landings and no incident. Yes, I did go through a flip in a farmers field in 2003 but that was river bottom sand.

I just do not understand how the nose gear can get bent back on a hard surface runway the way Barry's did. Maybe the runway ought to be condemned, not the airplane.
 
Folks - I'm not an RV'er but rather a person who owns a Davis DA-2A and benefits greatly from the information shared here. Why am I posting here? Well, it's because Harmon Lange built the second DA-2A to fly (back in '69 if I recall correctly). Harmon made the gear for his airplane and has been making them ever since. Same goes for Whittman's designs - Harmon is the "vendor of choice". Harmon also flies a very slick RV. He's also the guy who makes the RV landing gear legs. With nearly 40 years of experience under his belt he knows quality and won't do business like a mega-corporation, cutting cost to put a few more pennies in his pocket. I've only spoken to the man twice but the advice I obtained from him was about as straight as it could get. He doesn't mess around with anything that's even the slightest bit questionable, and doesn't advise anybody else to do so either.

All of this is to say that if it is indeed Harmon who's supplying the nosegear legs then you're dealing with a quality supplier. Since he's modifying the "early model" nosegear legs to newer format I'd suggest that he's probably got some suggestions as to how to get around this particular "gear retraction" problem.

BTW, it just makes me sick at heart to see such beautiful airplanes as these RV's dumping over on their noses. You have my deepest sympathies and my fervent hopes for a quick and permanent solution to this problem.
 
Maybe someone should consider stealing what seems like a better idea from the Glastar nose dragger. It appears similar from the stance of the plane, but the shock absorption is taken up with rubber donuts in compression in the motor mount and the gear leg itself deflects very little since there is a pivot point at the firewall.
Several aircraft have the rubber roughnut suspension design for the nosewheel, Diamond DA20/40 for example. Works well, simple, no moving parts. It does add a consumable, as they have to be replaced every few years.

TODR
 
We are still missing a very valuable data point here: What was the height of the 'bump' at the intersecting runways?
 
I just do not understand how the nose gear can get bent back on a hard surface runway the way Barry's did. Maybe the runway ought to be condemned, not the airplane.

At Oshkosh, several years back, I saw one of the EAA Young Eagle RV-6As being towed back to the Pioneer Field hangar with a nose gear bent under just like this one. This was from a landing on Pioneer Field. If it can happen there it can happen anywhere.
 
More answers to your questions

so, the runway was rough but no ledge at the intersection? if a ledge how high was it? i am having a hard time visualizing this. all the temeper testing and vans bashing is a waste of time.(the part is just too weak) what made it roll under? it had to catch on something? brakes (hard) on would increase the nose wheel load. were you trying to get off onto a taxi way in a hurry?they give me that all the time at KMYR. just trying to better understand the sequence of events that led to this, as i am soon to fly mine (7A) :eek: and this is a mild concern. i tend to be a little claustrophobic (ya know, trapped in an upside down airplane and all.) well i wouldnt be trapped for long, as i would cut out the side to exit.:eek:

After a mishap like this, you can well imagine the sense of concern for my wife of 39 years followed by the rage I felt seeing 18 months of work turned to trash. I was on the ground with all three wheels. I decided that given the remainder of the 23 runway, it was time to apply gentle braking. I did not slam on the brakes, I never slam on the brakes, & I did not seek to exit sooner than required. I treat this airplane with loving care and typically float the front wheel off the ground as long as possible.

In the past, friends watching me land have told me the front gear moves fore and aft after setting on the runway. We call it shudder and so the right procedure is to keep the nose gear aloft as long as possible. I determined it was time to start gradual braking "so the nose didn't dive". Obviously, something caught the nose and I determined that the height difference between 28R which is in good condition and 23 which is rough (known as the old runway by the locals) provided an edge for the front gear.

LEDGE SIZE? It's also not like you can walk around a runway after an incident like this. It was my first incident and hopefully my last. But looking back where the tow truck operator walked under orders from the NTSB people who were on the phone almost immediately, my skid mark started at the junction of 23 and 28R. The plane slid for another 50 feet (approx), veered slightly to the left and so I used rite brake to remain in the center of the runway.

I can tell you this. It is a terrible feeling to be looking down at the runway, basically out of control. I'm glad I had enough brains during the build to "round" all internal cabin surfaces in the event of something like this. Removal of sharp edges cannot be overstated when building any vehicle which will house my wonderful wife.

I am also thankful to the great female controller who was so understanding. As soon as this happened, I must have apologized to her 50 times for screwing up her airport. After all, no operations were possible till they carted me away.

Finally, Rick Galati claims that Vans builds a quality product. For the most part I would agree. They are helpful and seem fair, however, know that in our effort to stabilize the RV after the incident we BENT THE NOSE GEAR INTO A MORE UPRIGHT POSITION. Admittedly, we used a pipe wrench and a bar at the end, but I am not Rocky Balboa. I was still able to bend the gear the other direction with a helper.

I am diligently disassembling the airplane. If anyone would like to test my gear to see if it is as hard/stiff as they'd expect, I am happy to cooperate. I have access to one of the brightest technical advisors on the planet (Gil Alexander) who also cares about safety. WE would like to help others avoid this kind of mishap.

HOW LARGE WAS THE BUMP? If anyone lives near MYF, please take a walk and photo the intersection where 23 crosses over 28R after class D shuts down. That's where this mess started. Had I floated over the intersection (of course, this was my first landing at MYF) we probably would not be having this conversation, my wife would still be willing to fly, I would NOT be out (between) $3k to $12,000 nor would I be facing 2-3 months of work. Given the smooth Tucson air outside today, I know where I'd be had this not happened.

SUMMATION: Ask whatever you'd like. This should not have happened nor should it happen to anyone else. If I can facilitate the safety of others, I am willing to assist.

Barry
Tucson
 
Finally, Rick Galati claims that Vans builds a quality product. For the most part I would agree. They are helpful and seem fair, however, know that in our effort to stabilize the RV after the incident we BENT THE NOSE GEAR INTO A MORE UPRIGHT POSITION. Admittedly, we used a pipe wrench and a bar at the end, but I am not Rocky Balboa. I was still able to bend the gear the other direction with a helper.

I hope nobody takes this as me bashing Van's, since I think they're terrific. However, I'm sure that much of what they include in our kits is produced elsewhere and without the paper trail that parts for a certified aircraft would have. I am by no means an expert in metalurgy, but will bet the farm that the part involved was never heat treated properly. Consider trying to bend an automotive leaf spring or Volks torsion bar with a pipe wrench! I can tell that some folks are already suggesting that it was pilot error, but this can't explain that gear being so soft. Let's face it, we are putting a lot of faith in Van's exercising the proper diligence when sourcing parts like bolts, rivets, tube, etc. All of these parts are supposed to be of aircraft grade, but we get no documentation to prove it. I sincerely hope you'll go to the trouble of getting this part tested so we can have a clear answer.
 
Sorry to say, there is no way you should be able to straighten out the leg with a pipe wrench. You can send the part to a lab for a hardness test or do a quick and dirty hacksaw test to start with.

There have been a few other fold incidents in years past which might indicate improper heat treatment. It would be good to know if this is the case or other factors caused these. Stuff like this does happen in many industries where there has been a lapse in quality control.
 
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I don't know metals

I would be interested if there is someone on this site that is an expert and not just like me in thinking "things should just work the way I think".

Questions for an expert in metals:

1. Can Harry's bent leg be tested for proper treating? (If so then I would be willing to chip in for the test, although I think that Vans should pay for it).

2. Is there a treatment specification for the gear leg (or an assumed standard)?

3. How can I test my gear leg to make sure that it isn't bad, weak, soft?

Kent
 
I would be interested if there is someone on this site that is an expert and not just like me in thinking "things should just work the way I think".

Questions for an expert in metals:

1. Can Harry's bent leg be tested for proper treating? (If so then I would be willing to chip in for the test, although I think that Vans should pay for it).

2. Is there a treatment specification for the gear leg (or an assumed standard)?

3. How can I test my gear leg to make sure that it isn't bad, weak, soft?

Kent

Kent poses excellent questions. I'm very interested in the answers, but I don't have a clue where to start. I do know there are several engineers that frequent this site. Maybe one of them would be able to point us in the right direction. Perhaps a few people with lipstick cameras could make some videos of the gear while landing. It might give us another few data points.

The variation in circumstances leads me to suspect there is a quality control problem. I have heard of people having the gear fold while taxiing at around 5MPH. Then there are people who are based on sod fields that have never had a problem. Pilot technique may explain some of the incidents, but it doesn't explain all of them (at least to my satisfaction).
 
More data needed

Barry's landing nose gear weight was about 275#, assumming a combined pilot/passenger weight of 280# (how's that for being polite...:)...), 10 galls. of fuel and 40# of baggage.

If my combined people weight is low (likely), then the nose gear weight is less.

gil A

I did Barry's W&B charts...

Barry, I hate that this happened and can't even begin to imagine how you and your wife must feel. I lost a cylinder on a 172 and made a "precautionary" landing at Birmingham many years ago, and I can still remember the emotions I felt after getting out of that airplane. Sounds like your mental state is starting to mend. Glad to hear you're not going to sell after all.

Not sure if this is to Barry or to Gil, but based on the previous post by Gil, I'm interested in what your "Weight on Nose Wheel vs. Gross Weight and CG location" were at the time of the incident. In other words, can you reconstruct these data and place them on Van's chart for the 9A? I understand you might have to estimate, but it would be helpful to know where your data point falls on the chart provided by Van. This goes a little farther than what Gil posted previously.

Nose_gear_service_letter_Page_6.jpg


Hope you get it back in the air soon,

Don
 
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Steel testing service

Testing steel for hardness is routine stuff. There are two primary tests: the Rockwell test is used for a quick and dirty figure of merit, the Brinell test is better but a bit more involved. Both are affordable as far as I know. The test would want to be done to several sections of the gear leg to check for non-uniform heat treatment. To the degree possible, unbent sections should be selected to avoid the strain hardening that occurred. Important: tests should be performed on the center of the leg as well as the surface to determine what degree they are surface hardened vs. through hardened.

There may be testing services closer to AZ than So Cal, but I didn't find it.
http://www.thermal-vac.com/services/index.html

There is perhaps a better way to skin this cat, however. I seem to remember direct testing of shaft strength by suspending each end of the leg on vee blocks, and then applying calibrated force via hydraulic ram to the center of the shaft. Both spring rate and ultimate yield could be determined directly. Those are the numbers you really want. Of course, the leg would have to be straightened first.

I would be surprised if certified aircraft vendors don't do something like this.

Best,
T.J.
 
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I watched Kent's first two videos and this one in particular
http://www.youtube.com/watch?v=VdOL44YGMX0
seemed interesting. The gear seemed twitchy at about 3:15 into the video, and again at about 3:20. Again, I'm not an engineer, but I can think of a few questions.

As the gear flexes aft, doesn't it get closer to the CG? And if that's true, doesn't the weight on it increase? How much does it need to flex before that weight exceeds the Van's limit?

If you were unlucky enough to hit a bump while it was flexed aft, would that be worse than if you hit it when it wasn't flexed aft?

Is there some set of variables that could conspire to set the gear into some harmonic oscillation that would go unnoticed by the pilot?

Don't know if these questions make any difference, or even if they make any sense, but whenever I see the pics of these accidents, the gear legs all look the same.
 
Need for Data

Here is the data I'd like to see collected for each one of these incidents. I think the NTSB/FAA study contained some of this data for some of the incidents; but not all. If a large enough sample could be collected then some common threads might become visible:

GENERAL:
Model: 6A,7A,8A,9A
Engine:
Prop:

WEIGHT & BALANCE (at time of incident):
Nose:
Left:
Right:
Location on the Van's W&B charts:

NOSE GEAR:
Leg: (believe there have been 3 versions)
Yoke: (believe there have been 2 versions)
Bearings: (believe there have been 2 versions)
Biscuits staked:
Tire pressures:
Bearing Preload:
Pull out:
Pants Installed:
If installed, ground clearance, tire clearance:

GROUND SURFACE:
Operational Phase: landing, taxi, etc
Ground Speed:
Density Altitude:
Wind Conditions:
Material: sod, gravel, dirt, asphault, etc
Hardness:
Smoothness:
Topology at start of or just before the catch or skid: Dead rabbit, pot hole, ledge, etc.
 
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Don't remember it all...

As the gear flexes aft, doesn't it get closer to the CG? And if that's true, doesn't the weight on it increase? How much does it need to flex before that weight exceeds the Van's limit?

When I did these videos it was just me in the plane (235 lbs). I was most likely with full fuel and maybe 10 lbs of stuff in the baggage.

I held full aft on the stick throughout the video and don't use any braking until speed drops below 20 knots and then not very often.

Although the gear move quite a bit at the time you pointed out I don't think that the total distance to CG would have changed much, maybe 1 to 2 inches. I think that the stress on the leg when it moved back would be much greater at that point because it would be trying to left the plane up then.

I assume that that force would be accounted for with the Vans specification about weight.

Kent
 
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