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-A Model tip overs

M

meloosifah

Well Known Member
Good morning all,

I am not trying to open a debate about tail vs nose wheel but have been keeping track of tip overs for nose draggers for the last two years. What I have found is that, to the best of my knowledge, there have been between 19-22 -A model tip overs in the past 24 months. Now the numbers are not precise because accident data is not available for most and so this is based on damaged planes for sale, posts on this and similar sites, discussions with various pilots, etc.

My questions to the group are:

1. Do you think this number is accurate?

2. If so (or even close) doesn't that seem ridiculously high? I have many hours in Tripacers and 172s and have never even heard of this happening, let alone with any level of frequency.

3. Why are owners not rushing out in droves to chop the deadly wheel off the chin, shrinking it down with a heat gun and putting it back on the tail where it belongs? JUST KIDDING!

Keep in mind, my informal "research" does not identify WHY the plane flipped, but it just seems really high, regardless.

Thoughts?
 
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Responsibility falls on pilot, not design

Having had both, and flown into short and rough fields on regular basis, if flown properly, the RV nose wheel design does fine. Its a small nose wheel so discretion is needed by pilot to make good decisions. I always treated the nose wheel as a tail wheel with the stick in the lap when taxing. Could the design be better? There is always an opportunity to improve a design. However, the pilot's failure to maintain an upright RV is not a design problem in my opinion.
Just FYI, my insurance for the nose wheel RV never went up and was very reasonable. I would assume, if the data indicates that the nose over numbers are approaching "high", the first to let us know is our insurance premiums. Ask the tail wheel Maule guys. :)

cj


meloosifah said:
Good morning all,

I am trying to open a debate about tail vs nose wheel but have been keeping track of tip overs for nose draggers for the last two years. What I have found is that, to the best of my knowledge, there have been between 19-22 -A model tip overs in the past 24 months. Now the numbers are not precise because accident data is not available for most and so this is based on damaged planes for sale, posts on this and similar sites, discussions with various pilots, etc.

My questions to the group are:

1. Do you think this number is accurate?

2. If so (or even close) doesn't that seem ridiculously high? I have many hours in Tripacers and 172s and have never even heard of this happening, let alone with any level of frequency.

3. Why are owners not rushing out in droves to chop the deadly wheel off the chin, shrinking it down with a heat gun and putting it back on the tail where it belongs? JUST KIDDING!

Keep in mind, my informal "research" does not identify WHY the plane flipped, but it just seems really high, regardless.

Thoughts?
Click to expand...
 
Sorry - edited to clarify - NOT trying to start a debate, rather just curious about this issue. I am building an -8 but agonized over the decision for months and was on the cusp of purchasing an -A project. I just wonder if this is as big of an issue as it looks to me after 2 years of looking at it.

People talk all the time about the risks associated with ground loop on a taildragger but I rarely hear the same level of concern over flipping these...but my informal research indicates that flipping is at least, if not more, prevalent than ground looping.

Again, just curious what the much more knowledgable group here has to say about this.

Thanks all!
 
I have to agree with grubbat on this. When I learned to fly back in the 60s, I was taught that the nose wheel is for taxiing only.

There is a lot of argument from -A drivers that..."I aways hold the nosewheel off".

Well many do, but I watch a lot of RV landings, and I just don't see it. Many let the nosewheel plop down early.

RV landing gear are not designed to be "idiot proof" like many Cessnas and Pipers are, but if flown properly, they are just fine.
 
I totally agree wth Grubbat's response. For enlightment you might want to follow the FAA's daily accident and incident report. http://www.asias.faa.gov/pls/apex/f?p=100:93:0::NO:::
You will see that nose gear collapse is one of the most common accidents reported with ALL TYPES OF AIRCRAFT! From C150's to King Airs, botched landings take out the nose wheel. Flippovers as a result are not uncommon. The two place RV's might be slightly more prone to flip once you take the gear out due to their tall stance and short wheel base.

Martin Sutter
Building and flying RV's since 1988
2500hrs in RV6, 1100hrs in RV7A
 
Nose overs

At my airport there a number of 6A's and like Mel said the owners seem to "plop" the nose down too early. Of these owners they also taxi fast especially around corners. If one is a bit aggressive with braking the potential to cause damage goes up. Just my observations.

Mark
 
I have always wondered how many A models did not suffer nose gear collapses and flips in the last year
 
Nose Gear Awareness

I built an -8A after long and thorough analysis of my particular situation. Your decision process will vary. As a Mike Seager-trained RV nosegear guy, I have developed great respect for my -8A nose gear procedures and limitations.

1. Stick full aft for taxi and holding short- all the time.
2. Constant attention during the flair - after touchdown slowly apply and hold full back stick.
3. Stick full aft on the takeoff roll and let it fly off.
4. Avoid pivot turns.
5. Stay on pavement if practical - one of the nosedragger compromises. The taildragger is much more dirt friendly. The -8A can certainly handle normal dirt, however, the risk of judging dirt runway condition wrong and the potential cost of a prop strike or flip in the -8A from a nosegear collapse warrants careful consideration.
6. If you get to a sweet spot regarding nosegear shimmy, don't mess with it. Carefully check the gear during the condition inspection, but don't readjust anything.
7. Accept the fact that Vans nosegear design is not as robust as you might like - caution is required. But unless you have a practical better idea, live with it, pay attention and be careful.

Works-for-me info only - not trying to restart a debate.
 
N395V said:
I have always wondered how many A models did not suffer nose gear collapses and flips in the last year
Click to expand...

... I watch these numbers very carefully, as I am a little more involved than most and can possibly add some clarification. I am aware of only one flip over that occurred on an improved surface (concrete). The problem comes into play mostly when grass, dirt, golfers, or mud is introduced into the landing equation. These factors, and landing technique become extremely important when combined, and most flip over incidents involve more than one of these. Tail wheel airplanes (RVs) have there share of prop strikes as well, and these issues are not confined to the RV-A models. Imagine If other high performance 200 mph aircraft, Cirrus, Glassair, or worst yet Lancairs were operated off grass or unimproved runways with the frequency of the RVs. The daily statistics would be higher than the murder rate in Detroit. Overall, the RV accident rate is lower than the averages for certified aircraft as I see it. Not to say that we shouldn't be making efforts to improve the numbers. Thanks, Allan...:D
 
PerfTech said:
The problem comes into play mostly when grass, dirt, golfers, or mud is introduced into the landing equation.
Click to expand...

I don't think it's fair to blame golfers. They mean well, and I'd be surprised if there is any data to support them being worse (or better) with regards to flip-overs.
 
I calculated the widest/deepest rut I can taxi over using this formula





but I forgot to include the nose wheel fairing in my calculation. Duct tape fixed it in 5 minutes and I was airborne again :D


 
ChiefPilot said:
I don't think it's fair to blame golfers. They mean well, and I'd be surprised if there is any data to support them being worse (or better) with regards to flip-overs.
Click to expand...

I am sorry but I must disagree, hitting a golfer may result in a tip-over just like a hole or mud.
 
ChiefPilot said:
I don't think it's fair to blame golfers. They mean well, and I'd be surprised if there is any data to support them being worse (or better) with regards to flip-overs.
Click to expand...

...OK! I'm sorry. Ground squirrels. Two and four legged versions....:D
 
PerfTech;964842. Overall said:
Are we sure about this? Perhaps something has changed since this report was published. I don't think RV's are any better than the general E-AB fleet in this regard, but I could be wrong.
This was the most recent report that I am aware of. It is quite dated. If we have improved to the degree that our averages are better now than the certified fleet, I would be very impressed, and very surprised....
http://www.ntsb.gov/safety/safety-studies/Documents/SS1201.pdf
Click to expand...
 
Flip overs

The Tri Pacers were very prone to flips. Many occurred while taxiing downwind and then attempting to turn into the wind at too high a speed. Relative high CG, poor gear geometry. The Tri Pacer nose gear is very sturdy, most of these flips occurred with no gear damage.
The early 172's not so frequently. Lots of broken nose gears on 182's, very nose heavy aircraft and fragile nose wheel.
I worked for a Piper distributor when the Cherokee 140 first came out. The instructors let the students land on the nose gear all the time. The first week I worked there we drove several hours to rescue an airplane with a broken nose gear. The airplane flew home that afternoon. I replaced nose gear on that airplane at least every three months for about 1 1/2 years. The airplane is still active and I can still find where I installed patches.
While its 90% plus about pilot technique, there are some RV's that are obviously very nose heavy.
For any one who doubts the RV nose gear look at some of the horrid places Vlad has landed and then look at his hour meter.
 
no debate allowed!

hey guys, the OP said not starting a debate!

hmmm, so what AM I commenting on then?

well, I'd like to see some kind of movement towards an improvement, or recognition of the true hazard.
In all the accidents, is it possible that even the ham-fisted like me, that may let the nose plop down on roll-out, may never have a flip-over?
In all the video I've seen, which I think is much more informative than all the theory in the world, the spring steel rod allows a LOT of movement, in many directions. This is partly desirable.
But when I hit a pebble the size of a dime, and it nearly stops the nosewheel, and causes a significant 'tuck' of the gear leg, then my piloting technique is really not a factor.
When crossing asphalt seams, transitioning from tarmac to grass, or the reverse, or heaven forbid, the gopher hole, the nosepant scrapes show how close we come to the 'bad' kind of contact.
Let's look at a Vari-eze. Tiny, crazy hard nosewheel...... couldn't roll over a pencil, right? Number of flips? about zero, totally due to the trailing design of the gear...it's just tries to kneel more, and springs back.
our combination of energy in motion, gear flex, small wheel & high rolling resistance appears to be like Vlad's formula, adding up to a frequent and undesirable result when all the wrong parameters are exceeded.
Alan's leg stiffener and skid, bearing mod etc. are all good attempts to change the formula parameters, and this should be applauded.
 
I am always trying to acquire new data on this subject.
Can you you direct me to the video that shows a dime sized pebble causing the gear leg to tuck?

flyboy1963 said:
In all the video I've seen, which I think is much more informative than all the theory in the world, the spring steel rod allows a LOT of movement, in many directions. This is partly desirable.
But when I hit a pebble the size of a dime, and it nearly stops the nosewheel, and causes a significant 'tuck' of the gear leg, then my piloting technique is really not a factor.
Click to expand...
 
clarification

Scott, by tuck I mean move back, before springing up and over the obstruction. Perhaps nod would be a better word.
Alan's antisplat videos in slo mo show this to good effect.
 
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JonJay said:
Are we sure about this? Perhaps something has changed since this report was published. I don't think RV's are any better than the general E-AB fleet in this regard, but I could be wrong.
This was the most recent report that I am aware of. It is quite dated. If we have improved to the degree that our averages are better now than the certified fleet, I would be very impressed, and very surprised....
http://www.ntsb.gov/safety/safety-studies/Documents/SS1201.pdf
Click to expand...

...I guess I stated this wrong and meant to refer to the type of accident that was being discussed in this thread. You don't see that many of the other types of GA aircraft landing in fields or on grass so the numbers can't be accurately compared, I/E Golfers and Prairie Dogs have no effect on a King Air or a Lear 35. There are a very large number of other aircraft that would need to be removed from the equation to accurately compare this type of flip over accident rates. A more meaningful comparison perhaps, would be to only look at aircraft operated from unimproved strips. Would surly be interesting to see. Thanks Allan...:D
 
Bevan said:
I thought I was the only one who could make a divot large enough to flip an A model RV.

Bevan
Click to expand...

...A little humor keeps the thread going. Even at the expense of a few "Golfers". This proves conclusively you guys do read the thread. Thanks, Allan..:D
 
ChiefPilot said:
I don't think it's fair to blame golfers. They mean well, and I'd be surprised if there is any data to support them being worse (or better) with regards to flip-overs.
Click to expand...

this is why they charge higher-than-market rate at South St. Paul. Because Brad's on the field.

And it's pretty much worth it.
 
The noseover incident that I know of occurred on a fairly rough grass strip and involved a long fast landing and some hard if not panicked braking. It is entirely possible that a tailwheel airplane might have also flipped over under these circumstances. These airplanes need to be treated with respect irrespective of where the 3rd wheel is. Both configs have their pros and cons.

For me the TW is more fun and that is my only criteria. Others will have different goals and that's great too. Some of my best friends fly -As and I never snicker in front of them.:D
 
Landing gear

I know of a couple of T18's that have flipped, one was fatal. Both taildraggers although there were at least a couple of T18's with nosewheel.
 
Major thread drift, but Scott Risen, Van's President and former hangar mate, was a crop duster. He was pulling out of a pass directory into the path of a hawk carrying it's lunch, yes, a Gopher. The Hawk dropped the Gopher and it stuck in his flying wires. Back at the field, those present saw Scott roll in with the Gopher. He was young and new and they had a great time teasing him for flying low enough to pick up a Gopher.
Joe and Scott can correct my account of Scott's story.
 
I went with the wood gear stiffeners, an option that's spelled out in Van's instructions. I haven't flown my -9A yet, but this video is pretty convincing as to how they smooth out a lot of the oscillation:

https://www.youtube.com/watch?v=w86kIBn3TcE

I think that proper maintenance goes a long way toward safety, things like checking the nose wheel breakout force at every annual, maintaining correct tire pressure and balance, ensuring that there's no looseness in the nose gear socket, etc.
 
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rightrudder said:
I think that proper maintenance goes a long way toward safety, things like checking the nose wheel breakout force at every annual, maintaining correct tire pressure and balance, ensuring that there's no looseness in the nose gear socket, etc.
Click to expand...

Good advice, but when it comes to break-out force, once per year is not enough.
An owner needs to be vigilant of any sign of nose wheel shimmy and at the very first indication, it should be checked. Once someone gets to know their airplane, they can often tell when it is loosening up slightly by how it feels when they maneuver the airplane around on the ground by hand.
This is particularly important when it is first new. It is not uncommon to have to adjust it a couple times during the first 100 hrs or so while everything settles in. The same goes for after it is disassembled / reassembled for any reason.

Monitoring nose tire pressure is another item that gets let go far to often. Low nose tire pressure can have a serious impact on starting the chain reaction lead leads to a very bad day.
 
rvbuilder2002 said:
Monitoring nose tire pressure is another item that gets let go far to often. Low nose tire pressure can have a serious impact on starting the chain reaction lead leads to a very bad day.
Click to expand...

One of the things that's fascinating to me is the varied tire pressure that people use and the varied results. I'm often curious about why that is. I've tried the higher pressures people have recommended on VAF and found it to perform poorly. Currently I'm about 30 psi, I think, and everything seems fine.

Also, I've also started rolling out without braking and don't bother thinking that making that first turnoff (assuming nobody is behind me) is a test of my manhood.
 
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