RV-9A flip overs

I just saw on the So. CA group a link that Dan C. has set up for accidents and another RV-9A has flipped over onto its back. Also there was an 8A out of Calistoga, CA that flipped over. This is really starting to concern me for several reasons, one of which is whether or not the airplane has a dangerous tendency. Another is insurance, or lack of it. I just got my renewel notice from Nation Air and notice that the underwriter will no longer write policies for RV's. Nation Air will still apparently be able to get insurance for me but the cost seems to be going up for all of us so rapidly.

I'm not trying to start an argument among us, but I am really curious how so many 9A's are ending up on their backs. Out of what, 165 or so flying now there are about 5 that have ended up with the wheels up and the canopy down. I don't know about the 6A's, 7A's, and 8A's but this seems like a very high number of accidents of this type for the amount of airplanes actually flying. This latest one had a first flight in Sept. of '03 according to a photo on Clay's RV-9A site which makes the pilot experienced in type with two years under his belt now. What is going on?

I now have 180 hours on my RV-9A and just had something happen for the first time Saturday that I'm wondering if anybody else flying an "A" configuration has had happen. I landed at Gustine, CA for fuel at around 1opm which is located in the Central Valley and it was around 90+ degrees outside. The elevation is close to sea level and there was a limp windsock during the landing. I held 75mph on final with full flaps and greased the mains on, and they literally chirped but there was no feeling of them touching down. My wife said good one and for the first time when I set the nosewheel down very soft there was this vibration/rubbing sound. I immediately pulled the nose back up and it quit. I set it back down and it did it again. Up one more time and held it until it wouldn't stay up any longer. This time it was okay when setting it down. At the fuel Island I checked tire pressure, looked for rubbing of the tire in the wheel pant, etc., no evidence of anything. I was all over this thing before leaving and could find no reason for the noise. Usually I fly this thing exactly like Mike Seager taught me to, which is to hold the nose up until elevator authority is almost gone and then to slowly set it down. This is the first time that I can remember setting it down so soon and am wondering if the the nosewheel started to shimmy like the Cessnas tend to do. I have landed at Tahoe and Reno which require a higher groundspeed to maintain the airspeed for final and the nosewheel never did this. Have any of you experienced anything like this? The plane taxied great after this, and I put several more take offs and landings this weekend without anymore issues. (Note: my wheelpants are cut out at least 3/8 to 1/2" wider than the tires to prevent any chance of rubbing) Anyway, I felt something new this weekend and it wasn't neat!

Anyway, I would like to learn from your experiences if you folks would be good enough to share them. This is just happening to often to be overlooked. Even if it is a mistake that is being made by the pilots it is happening often enough that the rest of us need to be extra careful. If you happen to have experience with a flip over and would share the details of how it came to pass I would be very grateful. Please help the rest of us to prevent this scenario.


Many thanks in advance,
Bryan 9A "Flyin' The Flag"

Not sure if this was the 9A to which you were referring, but one apparently just recently flipped in Alaska, on a gravel runway. Apparently the gravel started and/or exacerbated a shimmy to the point that the plane flipped. With a lower landing speed than all the other nosewheel RVs, the 9A should be flipping less, but who knows...

Kinda hesitate to jump into this, but here goes anyway. I built and flew a 6A for 5 years before building and flying a 7A now for 3 more years. The nose wheel and bearing arrangement is different between the two planes. The 6A nosewheel configuration allowed the nose wheel to rotate quite freely, with little friction.

The 7A configuration, when installed has quite a bit of rolling friction in the system. The construction manual recognizes this and says that it is friction encountered with the bearing seal and will work it's way out after a period of time. I now have about 100 hours on the 7A and the level of friction has not diminished. I do occasionally experience nose wheel shimmy, but it is not of the back and forth type, but is of the up and down type. Other planes landing in formation with me have told me so. Sometimes, when touching the nose wheel to the pavement, the nose will actually bounce back into the air a few inches, and sometimes more than once.

Now, i can't tell you that this is what is causing nose overs. I suspect it has more to do with pilot technique than anything else. I have been intending to contact Van's regarding this. Just have not done so yet.

steve ciha

I have been thinking the same thing. There sure seems to be a lot of 7A and 9A landing mishaps. The gear geometry on the newer kits is much different with the longer main legs on the 7/9A compared to the 6A. Add to that the longer fuselage in front of the spar and I would think the nose wheel would be carrying more weight than a comparably equiped 6A. Just things to ponder.

As for your vibration on letting down the nosewheel I have had the same on my 6A. If I set the nose down to soon I get a high frequency vibration. This could be a shimmy like the Cessnas but I don't know. In a strong crosswind when I land and then plant the nose I can definatly get some chatter from up front it I set the nose down while there is still some sideways movement when the wheel touches.

Keep up the soft field landings Mike tought you and the gear should last a long time. When taxiing on rough surfaces keep the speed as slow as humanly possible and don't let the nose bob up and down

Gary who aggress there are to many RV accidents and who's insurance rates reflect this.

Bryan Wood said:

I just saw on the So. CA group a link that Dan C. has set up for accidents and another RV-9A has flipped over onto its back. Also there was an 8A out of Calistoga, CA that flipped over. This is really starting to concern me for several reasons, one of which is whether or not the airplane has a dangerous tendency. Another is insurance, or lack of it. I just got my renewel notice from Nation Air and notice that the underwriter will no longer write policies for RV's. Nation Air will still apparently be able to get insurance for me but the cost seems to be going up for all of us so rapidly.

I'm not trying to start an argument among us, but I am really curious how so many 9A's are ending up on their backs. Out of what, 165 or so flying now there are about 5 that have ended up with the wheels up and the canopy down. I don't know about the 6A's, 7A's, and 8A's but this seems like a very high number of accidents of this type for the amount of airplanes actually flying. This latest one had a first flight in Sept. of '03 according to a photo on Clay's RV-9A site which makes the pilot experienced in type with two years under his belt now. What is going on?

I now have 180 hours on my RV-9A and just had something happen for the first time Saturday that I'm wondering if anybody else flying an "A" configuration has had happen. I landed at Gustine, CA for fuel at around 1opm which is located in the Central Valley and it was around 90+ degrees outside. The elevation is close to sea level and there was a limp windsock during the landing. I held 75mph on final with full flaps and greased the mains on, and they literally chirped but there was no feeling of them touching down. My wife said good one and for the first time when I set the nosewheel down very soft there was this vibration/rubbing sound. I immediately pulled the nose back up and it quit. I set it back down and it did it again. Up one more time and held it until it wouldn't stay up any longer. This time it was okay when setting it down. At the fuel Island I checked tire pressure, looked for rubbing of the tire in the wheel pant, etc., no evidence of anything. I was all over this thing before leaving and could find no reason for the noise. Usually I fly this thing exactly like Mike Seager taught me to, which is to hold the nose up until elevator authority is almost gone and then to slowly set it down. This is the first time that I can remember setting it down so soon and am wondering if the the nosewheel started to shimmy like the Cessnas tend to do. I have landed at Tahoe and Reno which require a higher groundspeed to maintain the airspeed for final and the nosewheel never did this. Have any of you experienced anything like this? The plane taxied great after this, and I put several more take offs and landings this weekend without anymore issues. (Note: my wheelpants are cut out at least 3/8 to 1/2" wider than the tires to prevent any chance of rubbing) Anyway, I felt something new this weekend and it wasn't neat!

Anyway, I would like to learn from your experiences if you folks would be good enough to share them. This is just happening to often to be overlooked. Even if it is a mistake that is being made by the pilots it is happening often enough that the rest of us need to be extra careful. If you happen to have experience with a flip over and would share the details of how it came to pass I would be very grateful. Please help the rest of us to prevent this scenario.


Many thanks in advance,
Bryan 9A "Flyin' The Flag"

Click to expand...

Re: Insurance

If you're looking for additional insurance quotes, I had great luck with Falcon Insurance/AIG. They insured me in my 6 with zero tailwheel hours. Their only requirement was 10 hours dual, and another 10 hours solo before carrying a passenger.

They sent my local agent to Oshkosh for 8 days, and he went from asking "what's an RV-6?" to knowing all about homebuilts and insuring them. This is just my theory, but it looks like Falcon/AIG see an opportunity in the homebuilt market and are gearing up for it.

One thing Ive been considering down the road is a larger diameter front tire/wheel- mostly for increasing safety on grass strips. I wonder if a larger wheel might help reduce the shimmy often mentioned with the "As", due to slower spin speeds?

What's the common thread?

I recently helped a friend disassemble his -9A after a landing incident. I wasn?t in the plane and the following is based on his description.

He touched down on the mains at his normal speed. The nose wheel was still in the air when he was hit by a gust of wind. The plain started flying again and gained maybe four feet of altitude when the gust died, slamming the plane back to the ground before he could react.

The nose wheel tucked under the plane and was perfectly vertical when it stopped bending. The prop struck the ground and that was about it.

(Total damage was one front strut, yoke, wheel pant, prop, and an engine needing an overhaul. The airplane & engine had less than 30 hours TT on them at the time.)

I was thinking that he got lucky in that he was on a hard runway and the airplane didn?t go over on its back.

His only comment was that the Trinidad he used own had been dropped in much harder than what he did with his -9A and he couldn?t understand how or why there was so much damage caused by this firm arrival.

It would be interesting if Doug could start a thread on nose gear failures to see if there is a common thread among them. (Hard/soft runway, Solo/gross weight, tire pressure, wheel pant on or off, large or small engine, etc.)

(BTW, It is never too late to convert to a tail wheel! Sorry, I just had to throw that in.)

check your nose gear tension

Check the "break out" tension on your nose gear. It will need to be tightened occasionally.

I try to always keep my nose gear off the ground on landing until a full-up elevator won't hold it anymore. With the huge elevators on the 9, this means it can be held up for quite a while.

-Clay

From the Eggenfellner list, posted Aug 3.

At Oshkosh we displayed our RV-7A in the Eggenfellner booth and had a
wonderful time. It was great to meet some of the faces that go with
names I see here on the Eggenfellner group.

We stopped at Beaumont Hotel, Kansas for lunch and while taxing out
for take off, the nose gear collapsed. We didn't strike a hole but
the ground was wash board.

My wife and I were in the aircraft with 80# of luggage and a total of
15 gallons of fuel in the tanks. I had just looked at my GPS to check
the taxi speed and it was 4 Knots. I truthfully don't know what went
wrong or how I could have done things differently.

There were no injuries, it was just one of life's little bumps which
keeps things interesting.

You can see photos here:

http://homepage.mac.com/mikec6/PhotoAlbum1.html

Notice that neither the cowling or spinner were struck.

Click to expand...

http://groups.yahoo.com/group/subaruaircraft/message/22027

Relayed without permission, hope it's ok.

Make sure that the wheel opening in the pant is truly large enough. I trimmed up the wheel pants to where I thought they were sufficiently large enough. I flew the plane for about 35 hours during Ph I and my trip out west with no problems. I took them off for painting and reinstalled them. The very first landing I had the nose wheel grab the pant and tear a chunk out creating a very scary moment. After that, I repaired the pant and added an extra 1/4' on the sides and front and an extra 1/2" in the back (where the tire hit). I gave all 3 pants this extra clearance. No problems since.

Another thing is make sure your tire pressure is always at least 30 psi.

Mike Seager told me that to insure you have enough clearance for your tires is to flatten the tire and make sure it does not touch the pant anywhere.

Roberta

robertahegy said:

After that, I repaired the pant and added an extra 1/4' on the sides and front and an extra 1/2" in the back (where the tire hit). I gave all 3 pants this extra clearance. No problems since.

Click to expand...

Hi Roberta,

After this change what would you estimate is the current size of the gap between the tire and the pant?

Kevin

I must correct my last post (getting old and memory failing) I believe I cut 1/8" extra off the sides and front and 1/4" off the back. It looks like I have about 1/2" along the sides and front and about 5/8" clearance in the back.

Sorry,

Roberta

9A Rollovers

I am concerned about the rollovers, in your post you refer to a website listing RV accidents, I would be interested in reading about these accidents, could you provide the website address.
Thanks
Jim

rv accidents

check out Dans Site, awesome site that is. if your building anything it will save you worlds of time and its great reading also..

http://www.rvproject.com for the main site

and accidents

http://www.rvproject.com/ntsb.html

Out of curiosity, I did a quick count of the RV accidents recorded. Only 28% of the accidents reported involved "a" models (86 of 216) , and only 25% of those involved fatalities (22 of 86). The fatality rate of the draggers was abt 38% (13% with RV-6's, most fatalities involved R-4's (38 of 60)). The RV-6As had the worst 28% fatality rate (19 of 68) of the "a" models.

Because the 7/8/9/10's are so new and fewer flying, it doesn't make sense to compare them with the older models as a group, however, the relative numbers seemed quite low over the last several years.

Assuming that the more experienced pilots gravitate to the taildraggers , the numbers are quite convincing in favor of having a front wheel.

Apples and Oranges

The location of the little wheel has very little to do with fatal accidents as I don?t think a nose wheel will save your life if you stall and spin it in on short final, thus those numbers really don?t signify anything. I am assuming that 99% of the flip over accidents are nonfatal but I could be wrong here.

What would be interesting is the percentage of -6A?s built vs. the number of -6A?s that have flipped. Then look at the percentage of -6?s built vs. the number of -6?s flipped. (You can add ground looped as well but that is a different issue than the one being discussed.)

Then do the same calculations on the -7A to -7, -8A to 8, and -9A to 9.

Just my $.02

Any idea how many of each model have been built and flying?

I don't have a clue where to find those stats; a comparison would be interesting.

Noise coming from nose wheel

Bryan:
One other item to check is the spacers used between the front fork and the wheel. These are not intended to rotate and are expected to be held in place by the torque on the axle nut. During my first condition inspection (some 4 months ago), I noticed some scoring on these spacers. After reassembly and retorque, I painted some index lines across the hub and spacer(s) O.D. If I see any more rotation, I might consider drilling and adding a pin on each side to stop rotation.
Terry Kohler

Another nose over

This is interesting:

On September 18, 2005, approximately 1230 mountain daylight time, a Vans Aircraft RV6A, N985JS, piloted by a private pilot, was substantially damaged when it impacted terrain at the Thomas Memorial Airport (76V), Glendo, Wyoming. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 CFR Part 91, without a flight plan. The pilot sustained serious injuries. The local flight originated at Glendo, Wyoming, at an unknown time.

According to the pilot, he was attempting a spot landing during the air show. He said the airplane nosed in and flipped over. According to an FAA inspector, the left and right wingtips were damaged, the propeller was damaged, there were wrinkles on the left side of the fuselage behind the wing, and the horizontal stabilizer was wrinkled.

According to USWX.com, the weather at Sibley Peak, Wyoming (SIB), located 4 miles south of 76V, at the time of the accident was; winds 140 at 7 knots with gusts of 12 knots, temperature 19 degrees Celsius, dew point 6 degrees Celsius, and visibility and ceiling were not reported

Tobin

what do you expect?

If you try to put your plane down before it is done flying, bad things happen.

I'd be willing to bet the pilot pushed the stick forward to "hit the spot" rather than pulling back until the plane stalled for a squeaker on the mains.