mustang68w
Member
wow, that's a lot
Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
Year long discussion of "Another nosegear failure" -09/19/2010
- Thread starter rocketbob
- Start date
wow, that's a lot
6A Nose Gear
I have included a link to a video of a couple of takeoffs and landings with the Matco axle installed in my 6A. The video shows a mild fore and aft oscillation in the gear leg during the take off roll as weight is unloaded from the nose wheel and then a pronounced fore and aft oscillation during the landing as the nose gear comes back into contact with the ground. I don't know if the Matco axle is any better than Van's design, but it does make me feel a little better having it and the aircraft seem to roll better. I was told by Van's tech support that it wouldn't hurt anything, so I went ahead and installed it.
FYI, the runway in this video, although paved, is extremely rough. My normal practice is not to use this particular runway because of its condition, but did so for the video. A couple of other data points. I have not balanced the nose wheel as of yet, nor did I feel any oscillation inside the cockpit.
Should you feel compelled to critique my landing and/or aircraft, please be kind.....I am very fragile
John Crate
RV6A C-FNLY
http://www.youtube.com/watch?v=JGwfi0H1F1U
I have included a link to a video of a couple of takeoffs and landings with the Matco axle installed in my 6A. The video shows a mild fore and aft oscillation in the gear leg during the take off roll as weight is unloaded from the nose wheel and then a pronounced fore and aft oscillation during the landing as the nose gear comes back into contact with the ground. I don't know if the Matco axle is any better than Van's design, but it does make me feel a little better having it and the aircraft seem to roll better. I was told by Van's tech support that it wouldn't hurt anything, so I went ahead and installed it.
FYI, the runway in this video, although paved, is extremely rough. My normal practice is not to use this particular runway because of its condition, but did so for the video. A couple of other data points. I have not balanced the nose wheel as of yet, nor did I feel any oscillation inside the cockpit.
Should you feel compelled to critique my landing and/or aircraft, please be kind.....I am very fragile
John Crate
RV6A C-FNLY
http://www.youtube.com/watch?v=JGwfi0H1F1U
N941WR
Legacy Member
I have included a link to a video of a couple of takeoffs and landings with the Matco axle installed in my 6A. ...
Should you feel compelled to critique my landing and/or aircraft, please be kind.....I am very fragile
John Crate
RV6A C-FNLY
http://www.youtube.com/watch?v=JGwfi0H1F1U
John,
Those were good landings!
Question, since you have the time on the video, is it possible for you to take some more video and and download the data from your EFIS (if you have one) and correlate the airspeed and GPS speed with the time displayed on the flick? That will give us some idea how fast you are traveling.
BTW, very nicely done.
Nose Gear
The 6a gear is not as tall as the 9a/7a, It was always an after thought,add on.
On the 6 this gear was pushing the safety envelope and when one flipped it was always judged pilot error. The 9a /7a with longer legs stands taller and pushed the safety margin right to the edge and beyond . look at the dissension this has caused in the RV community 60% still scream Pilot error, don't fly from grass, don't taxi over bumps, heck years of my life,$60K+ invested and the best advice is don't leave the hanger. Van knows their is a problem. bad advice from inside the bubble ,litigation fears, the head aches of revising the mount, the leg, the fork, wheel, cowl changes ,he has already redesigned the gear,its called the RV-10 , BS you say! Well, why didn't he hang the old 7a spring on the front of the 10 ,they know it would flip over sitting in the hanger.
Our best shot at making change happen is to write Van a letter, ask him to
please revisit the 7a/9a nose gear issue, suggest a RV-10 gear system be retro fitted, state up front you would be willing to pay for a better gear.
Writing a letter to Van himself is the best action we all can take to move this ahead, the plane you save may be your own.
Bob
The 6a gear is not as tall as the 9a/7a, It was always an after thought,add on.
On the 6 this gear was pushing the safety envelope and when one flipped it was always judged pilot error. The 9a /7a with longer legs stands taller and pushed the safety margin right to the edge and beyond . look at the dissension this has caused in the RV community 60% still scream Pilot error, don't fly from grass, don't taxi over bumps, heck years of my life,$60K+ invested and the best advice is don't leave the hanger. Van knows their is a problem. bad advice from inside the bubble ,litigation fears, the head aches of revising the mount, the leg, the fork, wheel, cowl changes ,he has already redesigned the gear,its called the RV-10 , BS you say! Well, why didn't he hang the old 7a spring on the front of the 10 ,they know it would flip over sitting in the hanger.
Our best shot at making change happen is to write Van a letter, ask him to
please revisit the 7a/9a nose gear issue, suggest a RV-10 gear system be retro fitted, state up front you would be willing to pay for a better gear.
Writing a letter to Van himself is the best action we all can take to move this ahead, the plane you save may be your own.
Bob
Last edited:
PaigeHoffart
Well Known Member
RV-10 Video?
Has anyone made a video of the RV-10 nose gear? It would be interesting to see a side by side comparison of the two designs in operation (preferably on the same runway).
Paige
Has anyone made a video of the RV-10 nose gear? It would be interesting to see a side by side comparison of the two designs in operation (preferably on the same runway).
Paige
David-aviator
Well Known Member
Bob,
Your doom and gloom commentary is an exaggeration. What is the explanation of the success of many A model landings (some flown off of turf exclusively) with no failures? .
Truth is, there have been thousands, perhaps hundreds of thousands, of successful landings in all kinds of conditions with no failures. No one has posted a video of a successful landing to balance the impact of a couple failure videos - it would help alleviate the anxiety of the matter to see how it is done successfully on a very regular basis by many pilots.
With regard to the old undocumented "fore and aft" motion videos posted recently, the strut is not supposed to be rigid. It should flex under load. The wheel assembly has to move fore and aft or it will break. The failures occur when the motion is so severe, it causes the nose of the fork to tuck under and catch the nut area. Everything about every airplane has limits including the NG assembly of our A models RV's.
(Have you observed the engines of a 747 in turbulence? They flex up and down, fore and aft a huge amount as if they were suspended by wire. While all this is going on the wing flexes up and down at the same time. It is an amazing thing to watch and it does not break. Rigid breaks, things that flex in a controlled manner do not. Same applies to our A model gear system)
Yes, there have been a some failures and it is apparent in most cases why they happened. I believe the impact of these events is grossly exaggerated and causing undo anxiety. I dare say if the records are carefully researched there are as many flipped tail draggers as flipped A models. In fact, 2 very popular pilots died in flipped tail draggers, Charlie Hilliard and Ken Brock. We hear no hysteria over flipped tail draggers, why all this ruckus over flipped A models? We know why they happen and can deal with it if we put our minds to it. Just like the tail dragger, sharpen your flying skills, avoid known rough runways, and the risk is greatly reduced.
Things need be kept in perspective on this matter. The situation is not nearly as sever as your message would lead the uninformed to believe.
az_gila
Well Known Member
And that is an effect....
...that has been somewhat ignored.
...the flexing going on that you mention is clearly in a fore-aft direction and is essentially undamped since the wood strips are not specified for the later gear legs.
This unconstrained oscillation can hit resonance under the right conditions of speed, surface roughness and distance between runway "bumps".
I think that some of these cases of the nut hitting the surface happen when all of the bad factors line up and resonance occurs. This will just amplify the range of motion.
A partial fix may just be some damping in the system...
I'm not certain, but weren't some of the -6A problems due to snapping because of fatigue at the top of the gear leg? This would have been not helped by the plans specified wood stiffener which was actually the original fairing.
...that has been somewhat ignored.
...the flexing going on that you mention is clearly in a fore-aft direction and is essentially undamped since the wood strips are not specified for the later gear legs.
This unconstrained oscillation can hit resonance under the right conditions of speed, surface roughness and distance between runway "bumps".
I think that some of these cases of the nut hitting the surface happen when all of the bad factors line up and resonance occurs. This will just amplify the range of motion.
A partial fix may just be some damping in the system...
I'm not certain, but weren't some of the -6A problems due to snapping because of fatigue at the top of the gear leg? This would have been not helped by the plans specified wood stiffener which was actually the original fairing.
Last edited:
I concur with Dave. Well stated.
Last edited:
flyboy1963
Well Known Member
are we experimental, or test pilots?
I am not comfortable with the nosegear.
The video of uncontrolled jitterbug motion can NOT be a good thing!
but look at it this way..... we are flying a 2nd version of a prototype gear.
I imagine certified aircraft went thru many gear types before hitting a sucessful one.
Do we want a better gear: Yes.
Do we want it tested like a certified plane? Yes.
Do we want to pay $432,000 for an RV that meets Part 23?. No.
the compromise?........
I'd pay $50 toward a better design.,
and perhaps $1000 for a better Nosegear/package.
Let's do something before the insurance companies force our hand.
I am not comfortable with the nosegear.
The video of uncontrolled jitterbug motion can NOT be a good thing!
but look at it this way..... we are flying a 2nd version of a prototype gear.
I imagine certified aircraft went thru many gear types before hitting a sucessful one.
Do we want a better gear: Yes.
Do we want it tested like a certified plane? Yes.
Do we want to pay $432,000 for an RV that meets Part 23?. No.
the compromise?........
I'd pay $50 toward a better design.,
and perhaps $1000 for a better Nosegear/package.
Let's do something before the insurance companies force our hand.
Ron Lee
Well Known Member
I don't have the exact number but probably have around 1500 hours in my 6A. Unknown number of landings.
I made one landing at a grass strip in Kansas before I knew of the tipover issue. Won't do that again.
One landing at Mulege Mexico this year after mucho research into the dirt strip condition. Did not, however, fly over to the San Ignacio strip due to perceived risk.
I must be a fluke case. No tipovers. I have modified the leg with new fork and beefed up the nose wheel pant forward section to act as a skid.
If a change is made that reduces the risk on rough/marginal runways, I may incorporate it...or just stay off of said marginal strips.
I made one landing at a grass strip in Kansas before I knew of the tipover issue. Won't do that again.
One landing at Mulege Mexico this year after mucho research into the dirt strip condition. Did not, however, fly over to the San Ignacio strip due to perceived risk.
I must be a fluke case. No tipovers. I have modified the leg with new fork and beefed up the nose wheel pant forward section to act as a skid.
If a change is made that reduces the risk on rough/marginal runways, I may incorporate it...or just stay off of said marginal strips.
Nose Gear
I am always sadden by the loss of a fellow pilot. Charlie Hillard died when his modified Bearcat flipped at an airshow, Ken if I remember was in a Thorp T-18 with his wife when a tail wheel chain broke, Very sad ,in Kens case maybe one of the fancy tail wheel links could have prevented that from happening ,their not part of the kit, nothing wrong with the old spring and chain,has worked hundreds of thousands of times with out a problem in all conditions,its just builders wanted a better, more accurate way to control the plane. Not that links don't have problems of there own, just a higher safety margin............
I apologize for the way this response comes across, much of what I have learned I have learned from you and this group as a whole over the years.My purpose is to get everyone who feels more needs to be done, to write Van and ask him to revisit the issue.
Bob
I am always sadden by the loss of a fellow pilot. Charlie Hillard died when his modified Bearcat flipped at an airshow, Ken if I remember was in a Thorp T-18 with his wife when a tail wheel chain broke, Very sad ,in Kens case maybe one of the fancy tail wheel links could have prevented that from happening ,their not part of the kit, nothing wrong with the old spring and chain,has worked hundreds of thousands of times with out a problem in all conditions,its just builders wanted a better, more accurate way to control the plane. Not that links don't have problems of there own, just a higher safety margin............
I apologize for the way this response comes across, much of what I have learned I have learned from you and this group as a whole over the years.My purpose is to get everyone who feels more needs to be done, to write Van and ask him to revisit the issue.
Bob
Last edited:
jmbrwn
Well Known Member
I believe Charlie Hilliard was in a Sea Fury. The cause of the accident was determined to be locked brakes, if I remember correctly.
Letter to Van's
I am compelled to state my feelings to Van's on the RVXA rollovers. Your comments are appreciated.
Starbird, [email protected]
Van's Aircraft, Inc.
14401 NE Keil Road
Aurora, OR 97002
att: Mr. Van Grunsven
Dear Mr. Van Grunsven:
Let me also begin this letter by commending you on some really great airplanes. I speak from experience as a few years ago I helped a good friend build a 9A. It was an interesting experience and he now enjoys a wonderful aircraft.
I will be 72 years old in a few months. I am now building a 6A and at completion will have invested over 2 years and $45k in the project. At my time in life I want to enjoy the aircraft with safety and reliability being very important to me.
Lets face the facts. The structural integrity of the nose gear leaves me and many others very concerned. There have been far too many nose gear failures with resultant rollovers. I speak from experience as my partner in his 9A had nose gear failure on an asphalt runway. There were no injuries however there was an $8,000 repair bill. This is a bill that should not have been incurred.
I've read the 2005 NTSB study and examined ideas submitted by others. I have reviewed many pictures from accidents and alternate designs. It is obvious that if the gear leg would not bend there would be no need to increase the front nut clearance or carefully adjust the rolling resistance of the front wheel. It is also interesting to note that you have not utilized the same nose gear leg design in either the RV10 or RV12. If the current design were sound why was it not utilized?
While no design can fully compensate for pilot error, ground conditions, or builder mistakes a design with greater operation tolerance should be considered. I urge you to look into this matter again. Design, build, and sell us replacement parts that will reduce rollovers and bend front gear. The RV community is ready to cooperate with a team effort should you choose to organize one. I am equally certain folks would submit their real world experiences for your review, and offer their design ideas for your consideration.
Please take this opportunity to work with us and make these great airplanes even better.
Chet Oldakowski 24875
I am compelled to state my feelings to Van's on the RVXA rollovers. Your comments are appreciated.
Starbird, [email protected]
Van's Aircraft, Inc.
14401 NE Keil Road
Aurora, OR 97002
att: Mr. Van Grunsven
Dear Mr. Van Grunsven:
Let me also begin this letter by commending you on some really great airplanes. I speak from experience as a few years ago I helped a good friend build a 9A. It was an interesting experience and he now enjoys a wonderful aircraft.
I will be 72 years old in a few months. I am now building a 6A and at completion will have invested over 2 years and $45k in the project. At my time in life I want to enjoy the aircraft with safety and reliability being very important to me.
Lets face the facts. The structural integrity of the nose gear leaves me and many others very concerned. There have been far too many nose gear failures with resultant rollovers. I speak from experience as my partner in his 9A had nose gear failure on an asphalt runway. There were no injuries however there was an $8,000 repair bill. This is a bill that should not have been incurred.
I've read the 2005 NTSB study and examined ideas submitted by others. I have reviewed many pictures from accidents and alternate designs. It is obvious that if the gear leg would not bend there would be no need to increase the front nut clearance or carefully adjust the rolling resistance of the front wheel. It is also interesting to note that you have not utilized the same nose gear leg design in either the RV10 or RV12. If the current design were sound why was it not utilized?
While no design can fully compensate for pilot error, ground conditions, or builder mistakes a design with greater operation tolerance should be considered. I urge you to look into this matter again. Design, build, and sell us replacement parts that will reduce rollovers and bend front gear. The RV community is ready to cooperate with a team effort should you choose to organize one. I am equally certain folks would submit their real world experiences for your review, and offer their design ideas for your consideration.
Please take this opportunity to work with us and make these great airplanes even better.
Chet Oldakowski 24875
When the SeaFury is modified to include a back seat, the roll-over structure is removed. Not enough room for both.
BTW, I was at Sun-N-Fun when Charlie had his fatal accident.
Letter to Van's
" Now almost 40 years at the helm, Van continues to lead the company he founded – now the most successful in the field. Almost every weekday, he commutes to his desk in the engineering office (no private cubicle, no executive washroom, no reserved parking spot) in his original RV-4 – or his RV-10 – or his new RV-12. Well, almost every day…in the summer, when the soaring conditions are good, he pulls out his all electric self-launching Antares sailplane, takes a few days off…
And goes flying. "
As per the web site.
Vans aircraft sold us our kits, Can and do SB parts and systems when needed. Who better to redesign this nose gear than Vans aircraft. This issue is a moral hazard ,second only to the RV-3 wing spar issue years ago. A half hour and 44 cents, Write the letter to Van at Vans aircraft co. Make it hart felt, mail it, be proud, you made a difference.
Bob
" Now almost 40 years at the helm, Van continues to lead the company he founded – now the most successful in the field. Almost every weekday, he commutes to his desk in the engineering office (no private cubicle, no executive washroom, no reserved parking spot) in his original RV-4 – or his RV-10 – or his new RV-12. Well, almost every day…in the summer, when the soaring conditions are good, he pulls out his all electric self-launching Antares sailplane, takes a few days off…
And goes flying. "
As per the web site.
Vans aircraft sold us our kits, Can and do SB parts and systems when needed. Who better to redesign this nose gear than Vans aircraft. This issue is a moral hazard ,second only to the RV-3 wing spar issue years ago. A half hour and 44 cents, Write the letter to Van at Vans aircraft co. Make it hart felt, mail it, be proud, you made a difference.
Bob
Last edited:
Hilliard
The cause of the Hilliard accident was pilot error. The brakes were not locked but he got on the brakes enough that the tail came up and he went off the pavement and flipped on the soft ground. It is unlikely the turnover structure would have helped on the soft ground.The airplane had relatively minor damage and has been flying again for many years.
The cause of the Hilliard accident was pilot error. The brakes were not locked but he got on the brakes enough that the tail came up and he went off the pavement and flipped on the soft ground. It is unlikely the turnover structure would have helped on the soft ground.The airplane had relatively minor damage and has been flying again for many years.
Sam Buchanan
been here awhile
I saw the accident, too. It was a freak deal.....when the plane flipped the tip of the rudder/stab buried in the sand, and compressed Mr. Hilliard into a position which tragically resulted in suffocation. If the accident had occurred on hard pavement, the vertical stab would have most likely protected the pilot.
My apologies for the thread creep, now back to the subject at hand.
Last edited:
comparing taildragger flips to RV6A flips
Several posts have compared taildraggers flips to Van's nose gear equipped a/c flips. IMHO that is like comparing apples to oranges. The cause/mechanism of taildragger flips is completely different from the known or suspected cause of Van's flips. To wonder where all the outrage is over taildragger flips compared to Van's a/c flips is not a fair analogy.
I just don't believe my 6A even when expertly flown is a good fit for rough, soft, uneven runways. I don't land my plane on these types of runways but it has not diminished my enjoyment of flying such an agile plane.
Several posts have compared taildraggers flips to Van's nose gear equipped a/c flips. IMHO that is like comparing apples to oranges. The cause/mechanism of taildragger flips is completely different from the known or suspected cause of Van's flips. To wonder where all the outrage is over taildragger flips compared to Van's a/c flips is not a fair analogy.
I just don't believe my 6A even when expertly flown is a good fit for rough, soft, uneven runways. I don't land my plane on these types of runways but it has not diminished my enjoyment of flying such an agile plane.
The thread moved off course,when I incorrectly identified a Seafurry as a Bearcat, My response was a "off the cuff defense" to the accusation I was
over dramatizing the problem,if one even exists by someone who has flipped a nose gear, many more hours in type than myself and I might add,I respect.
We are all bright people here,no need to cross swords. What I am advocating as a first step. WRITE A LETTER, PUT A STAMP ON IT, MAIL IT TO VANS, Take some pride in the fact you stood up for what you believe!
Bob Hill
over dramatizing the problem,if one even exists by someone who has flipped a nose gear, many more hours in type than myself and I might add,I respect.
We are all bright people here,no need to cross swords. What I am advocating as a first step. WRITE A LETTER, PUT A STAMP ON IT, MAIL IT TO VANS, Take some pride in the fact you stood up for what you believe!
Bob Hill
MrNomad
Well Known Member
Progress is the very essence of aviation
Perry, You hit the nail squarely on the head. Insurance rates for RVs are significantly higher and every incident of failed nose gear will only raise rates further. The value of these planes will improve if we can reduce failures, plus our ability to travel to more places would be great. It's impossible to know if the local gophers dug a new hole since last week but the results can be catastrophic just like they were in Ohio 3 weeks ago to that very accomplished pilot and passenger.
No one expects the nose gear to survive any and every situation but if we can improve it relatively inexpensively, reduce the number of incidents, and save a few broken bones, what's wrong with that goal? Some of the suggested improvements I've seen can be performed for a few hundred dollars. That's a lot less than the 3 months and thousands of $$ I spent when my nose gear bent under.
Fortunately, all of this dialogue seems to be motivating people. Another builder I heard from contacted the U of A. His goal is to get the U of A interested in an ME program for their senior design class. Unfortunately, they're booked for the next year. Undaunted, this same fellow plans to meet with Vans next week (in person) and measure their interest. Perhaps a univ in Oregon is interested.
Just like every classic Chevy I have built over the last 30 years, I try to improve the quality of whatever comes out of my workshop. I sanded and painted the hood of my first 57 Chevy 11 times until I achieved the quality I desired. The 6A we're building now contains improvements over the 9A we built 3 years ago. Virtually every page on this website contains tips and ideas how to improve these airplanes. Progress is the very essence of aviation and that's no different from medicine, science, and every other endeavor mankind has embarked on.
100 years ago, bleeding was the method used to cure disease.
I see no reason not to make these fantastic airplanes better if we can. I see no reason not to offer the RVXA owner more places to fly to, lower insurance rates, fewer injuries, and fewer repairs. If we can accomplish all of this by implementing simple changes we gotta be nuts not to.
My .02 cents.
Perry, You hit the nail squarely on the head. Insurance rates for RVs are significantly higher and every incident of failed nose gear will only raise rates further. The value of these planes will improve if we can reduce failures, plus our ability to travel to more places would be great. It's impossible to know if the local gophers dug a new hole since last week but the results can be catastrophic just like they were in Ohio 3 weeks ago to that very accomplished pilot and passenger.
No one expects the nose gear to survive any and every situation but if we can improve it relatively inexpensively, reduce the number of incidents, and save a few broken bones, what's wrong with that goal? Some of the suggested improvements I've seen can be performed for a few hundred dollars. That's a lot less than the 3 months and thousands of $$ I spent when my nose gear bent under.
Fortunately, all of this dialogue seems to be motivating people. Another builder I heard from contacted the U of A. His goal is to get the U of A interested in an ME program for their senior design class. Unfortunately, they're booked for the next year. Undaunted, this same fellow plans to meet with Vans next week (in person) and measure their interest. Perhaps a univ in Oregon is interested.
Just like every classic Chevy I have built over the last 30 years, I try to improve the quality of whatever comes out of my workshop. I sanded and painted the hood of my first 57 Chevy 11 times until I achieved the quality I desired. The 6A we're building now contains improvements over the 9A we built 3 years ago. Virtually every page on this website contains tips and ideas how to improve these airplanes. Progress is the very essence of aviation and that's no different from medicine, science, and every other endeavor mankind has embarked on.
100 years ago, bleeding was the method used to cure disease.
I see no reason not to make these fantastic airplanes better if we can. I see no reason not to offer the RVXA owner more places to fly to, lower insurance rates, fewer injuries, and fewer repairs. If we can accomplish all of this by implementing simple changes we gotta be nuts not to.
My .02 cents.
These are Experimental Aircraft - Not Certified; I am responsible
I believe I built an experimental - ametuer built aircraft and take full responsibility (and credit) for what I built. Van provided me parts. My RV is not like any other plane. It has lots of attributes that exceed other homebuilt and certified aircraft and with that came some compromises to do that. We know one short coming is the nose gear. I will use all the information from this great forum to decide what I will do to mitigate risk of my nose gear. I do not expect, or require, Van to do anything. This is my responsibility and I am glad to have it as the alternative would be no freedom from the FAA for us to build our own aircraft. That freedom allows us to learn and build planes of our own creation. We love that freedom when all is well. We try to shun that responsibilty when things go bad. I see this no different then us (the RV builders) designing and building better/different cowls, wing tip, gear leg fairings, and engine installations.
I believe the nose gear design from Van is adaquate as long as you know the limitations. If I do not want those limitations I will build something different. If I want an airplane with certified perfromance and safety then I will send a letter and check to Mr Cessna.
I do not know what you expect Van to do.
I believe I built an experimental - ametuer built aircraft and take full responsibility (and credit) for what I built. Van provided me parts. My RV is not like any other plane. It has lots of attributes that exceed other homebuilt and certified aircraft and with that came some compromises to do that. We know one short coming is the nose gear. I will use all the information from this great forum to decide what I will do to mitigate risk of my nose gear. I do not expect, or require, Van to do anything. This is my responsibility and I am glad to have it as the alternative would be no freedom from the FAA for us to build our own aircraft. That freedom allows us to learn and build planes of our own creation. We love that freedom when all is well. We try to shun that responsibilty when things go bad. I see this no different then us (the RV builders) designing and building better/different cowls, wing tip, gear leg fairings, and engine installations.
I believe the nose gear design from Van is adaquate as long as you know the limitations. If I do not want those limitations I will build something different. If I want an airplane with certified perfromance and safety then I will send a letter and check to Mr Cessna.
islandmonkey
Well Known Member
To be honest, I cannot see any point or merit to this post. What is wrong with trying to get a better safer design for a flawed component from the person who created the design in the first place. Nobody knows it seems what Vans will do but it is worth nudging them to see if they will do something. If a new safer more robust design is made available from Vans then there will a lot of demand for the product (and profit) from people just like the above poster. A safer stronger noseleg will increase peoples freedom to visit strips and areas that probably would not have been contemplated with the original design.
I believe the nose gear design from Van is adaquate as long as you know the limitations. If I do not want those limitations I will build something different. If I want an airplane with certified perfromance and safety then I will send a letter and check to Mr Cessna.[/QUOTE]
SO................... Does that mean you won't be writing the letter?
SO................... Does that mean you won't be writing the letter?
SO................... Does that mean you won't be writing the letter?
I may send the letter as no better person to ask then Van. I just do not know what we expect and ought to try and come up with a solution on our own. I think this group can do just that.
I think shifting the reponsibility to Van starts down the slippery slope of part makers for the experimental community being liable. This will kill experimental aviation and maybe even drive a company like Van's out of the market.
Last edited:
There is my basic difference. I do not think the gear is flawed. It is adaquate for the limitations I put on the gear and my flying technique. Can the gear be improved? Yes. Will I improve mine? Yes, if it meets my requirements. If Van comes up with a better design will I upgrade? Probably.
David-aviator
Well Known Member
SO................... Does that mean you won't be writing the letter?
[/QUOTE]Bob,
I hear your message and have all along. There is a valid concern about the limitations of the NG assembly and in keeping with that concern, I will write to Van's and ask them to consider changing what we have to something a bit more robust and forgiving.
It would not surprise me one bit to find out later they are studying the matter already and may have been doing so for some time. If there is a fix that makes sense operationally and economically, we will hear from them.
In the mean time, I believe the operational limitations of the system have been identified and we need to adjust our daily flying envelop to cut down on the events we so much wish did not happen.
For all I know a cantilever shock set up attached to the leg and covered by a fairing along with a low resistance wheel bearing ,slightly bigger tire would increase the safety margin 10 to 20%, or a clean paper design, its beyond my skill set and not for me to say. In January 2005 ,Van beefed up the roll bar in the tip-ups, provided the parts free of charge,there was no pressure, no one ever complained, Why? In 2009 they out sourced the investigation, made one change the fork, that one change required other changes but returned the biggest bang for the buck. The aftermarket has resolved the bearing issue.
We all said OK lets see what happens now. I don't know why some legs bend like wet noodles when resonant and others don't but they do.
IMHO, I believe Van wants to fix this ,other dark forces are at play here.
Bob
We all said OK lets see what happens now. I don't know why some legs bend like wet noodles when resonant and others don't but they do.
IMHO, I believe Van wants to fix this ,other dark forces are at play here.
Bob
MrNomad
Well Known Member
An earlier post asks what Vans could do......
What could Van do? Amongst other ideas.......
Post pictures & facts of those mods & replacements done to the front wheel that contribute to the reduction of bent NG. Include tire pressure studies, replacement parts, and the results of those changes. My free spinning front wheel mod cost less than $2 to implement.
Contact tire suppliers such as Desser and Spruce and ask them to work with tire manufacturers to sell us oversize tires and possibly run flat tires. My old 150 had Desser monster tires that fit the same rim but had a larger outside diameter (raise the nut off the ground). Desser and Spruce are more likely to respond to the largest RV kit supplier than you or me.
Organize a series of controlled tests using in-house personnel or volunteers amongst the many builders who visit this site. Work with local universities and those vendors who supply parts. Identify those conditions that contribute to bent NG and the cumulative propensity of multiple factors.
Validate thru testing whether the NTSB statement about the contribution of the horizontal stab is valid or not.
Our freedom to innovate is served by increased testing and cooperation with customers & vendors. Dynon, amongst other vendors, expended lots of effort organizing and testing their glass panels. Problems were assigned case numbers and followed to their logical conclusion. The military improved the barrel of the M16 till it could take down a fly at 1000 yards. Those of us whose life depended on their rifle appreciate those efforts.
I don't need nor want big government telling me what to do like the NTSB did with Zodiac. Rather, I'd like to tell government what we've done so that they leave exp aviation alone to innovate. I like my freedom, but I understand that my freedom comes with a price.
FYI, I wrote my letter to Vans and look forward to a reply.
What could Van do? Amongst other ideas.......
Post pictures & facts of those mods & replacements done to the front wheel that contribute to the reduction of bent NG. Include tire pressure studies, replacement parts, and the results of those changes. My free spinning front wheel mod cost less than $2 to implement.
Contact tire suppliers such as Desser and Spruce and ask them to work with tire manufacturers to sell us oversize tires and possibly run flat tires. My old 150 had Desser monster tires that fit the same rim but had a larger outside diameter (raise the nut off the ground). Desser and Spruce are more likely to respond to the largest RV kit supplier than you or me.
Organize a series of controlled tests using in-house personnel or volunteers amongst the many builders who visit this site. Work with local universities and those vendors who supply parts. Identify those conditions that contribute to bent NG and the cumulative propensity of multiple factors.
Validate thru testing whether the NTSB statement about the contribution of the horizontal stab is valid or not.
Our freedom to innovate is served by increased testing and cooperation with customers & vendors. Dynon, amongst other vendors, expended lots of effort organizing and testing their glass panels. Problems were assigned case numbers and followed to their logical conclusion. The military improved the barrel of the M16 till it could take down a fly at 1000 yards. Those of us whose life depended on their rifle appreciate those efforts.
I don't need nor want big government telling me what to do like the NTSB did with Zodiac. Rather, I'd like to tell government what we've done so that they leave exp aviation alone to innovate. I like my freedom, but I understand that my freedom comes with a price.
FYI, I wrote my letter to Vans and look forward to a reply.
Ron Lee
Well Known Member
Reducing these incidents is certainly desirable. There is one way that can be accomplished TODAY at zero cost.
Stay off of rough/marginal strips.
The incident that precipitated this current round of posts was a pilot who had left the field in question because it was too rough for him. Yet he came back. And it bit him.
Work on an improved gear system that makes using rough/marginal strips safer.
Stay off of rough/marginal strips.
The incident that precipitated this current round of posts was a pilot who had left the field in question because it was too rough for him. Yet he came back. And it bit him.
Work on an improved gear system that makes using rough/marginal strips safer.
MauiLvrs
Well Known Member
Fixing this would be heavy
This cant be good...
A design to protect against this would likely be very heavy...http://www.youtube.com/watch?v=0ahvvBM5qAU
A design to protect against this would likely be very heavy...http://www.youtube.com/watch?v=0ahvvBM5qAU
Hey Bob - do you know how many FAA guys read these forums? There are more than you think - do you really want to report on an unreported mishap near you with the world watching?
Kyle Boatright
Well Known Member
That's not uncommon. I know of a couple of local ones that weren't reported.
rustyscrew
I'm New Here
RV 6A nose gear
I can say that the Van's nose gear with the modified fork is adaquate as configured. This is based on first hand experience in landing a 6A in a hay
field after engine failure due to camshaft fractlure. I would like to add that the strut was modified with a concave half round oak moulding 2' long attached to the strut with the red-green method of 4 wraps of approved duct tape at the center and each end. The landing was made without flaps and toutchdown at about 80ias with the nose held high and the stick in my gut. After crossing a ditch which caused the nose pant to disintergrate into pieces
which inclueded a built in skid plate in the nose, the nut did not dig in nor was any tendency to nose over. No brakeing was used as the hay was long and matted which helped to brake the rollout. I can only say that the added
oak snubber on the strut and the taildragger experience of keeping the stick
in your gut led to a safe landing with minimum damage and no injuries.
Walt RV-6A
IO-320 cs
I can say that the Van's nose gear with the modified fork is adaquate as configured. This is based on first hand experience in landing a 6A in a hay
field after engine failure due to camshaft fractlure. I would like to add that the strut was modified with a concave half round oak moulding 2' long attached to the strut with the red-green method of 4 wraps of approved duct tape at the center and each end. The landing was made without flaps and toutchdown at about 80ias with the nose held high and the stick in my gut. After crossing a ditch which caused the nose pant to disintergrate into pieces
which inclueded a built in skid plate in the nose, the nut did not dig in nor was any tendency to nose over. No brakeing was used as the hay was long and matted which helped to brake the rollout. I can only say that the added
oak snubber on the strut and the taildragger experience of keeping the stick
in your gut led to a safe landing with minimum damage and no injuries.
Walt RV-6A
IO-320 cs
Let me guess......... landed 5mph over stall on smooth blacktop, touched down on the mains and the held the nose off till it touched down at about 20 mph. With the stick still full aft, the nose wheel caught on something and the aircraft flipped over.
The rest of the story.......... later.
The more that get reported, the quicker this will get resolved.
Kyle Boatright
Well Known Member
No doubt you're correct.
However, if the pilot/owner is self-insured, reporting the accident/incident/whatever will only have negative ramifications for the owner. First, he'll have to deal with the Fed's, and second, the airplane will have an accident history, making it harder to sell when/if that day comes.
That being the case, there is a segment of the population that doesn't report incidents like these.
Reporting or not reporting the accident will not change the accident history of the aircraft. The only thing that will change the accident history is if the seller makes a choice to be deceitful and lie to a purchaser. I am looking for a RV as we speak. So far I can say thats it seems to be a wonderful community of pilots who go out of there way to help others. I had a wonderful experience today looking at a RV6 with my son and can't say enough good about the people I met today and the community as a whole. I hope your friend does not give me reason to change my mind.
George
George
Experimental - "NO", Amateur-Built - YES.
I have always had a problem with the term "Experimental" as it applies to homebuilts. Homebuilts such as the RV are "amateur-built" aircraft for "recreational or learning purposes". Very, very few would consider modifying even this "non-certified" design. I didn't buy a RV to become one of Van's test pilots. I'm doing my best to build the 7A to Van's instructions and have no plans to modify anything that may affect the flight worthiness of the aircraft.
Van's, along with other kit manufacturers, charge a price for their kits. I, and the aviation community, should expect no less engineering effort, testing and responsibility for the basic design than with a "certified" aircraft. With respect to the NLG, I consider myself an excellent pilot who still will flub a few landings such as in cross-wind landings where the angle-of-attack is minimal, thus increasing the weight on the nose wheel, until lift-off or immediately on touch-down. To have a nose gear that is unforgiving, whether grass or asphalt, is unacceptable regardless if it be amateur-built or certified.
[ed. A sentence here about lawsuits and stuff removed by dr. I'm not too cool with people using my site to talk about sueing people. I would ask the other moderators to delete similar text. dr]
Paul
N277PM
LAF
I have always had a problem with the term "Experimental" as it applies to homebuilts. Homebuilts such as the RV are "amateur-built" aircraft for "recreational or learning purposes". Very, very few would consider modifying even this "non-certified" design. I didn't buy a RV to become one of Van's test pilots. I'm doing my best to build the 7A to Van's instructions and have no plans to modify anything that may affect the flight worthiness of the aircraft.
Van's, along with other kit manufacturers, charge a price for their kits. I, and the aviation community, should expect no less engineering effort, testing and responsibility for the basic design than with a "certified" aircraft. With respect to the NLG, I consider myself an excellent pilot who still will flub a few landings such as in cross-wind landings where the angle-of-attack is minimal, thus increasing the weight on the nose wheel, until lift-off or immediately on touch-down. To have a nose gear that is unforgiving, whether grass or asphalt, is unacceptable regardless if it be amateur-built or certified.
[ed. A sentence here about lawsuits and stuff removed by dr. I'm not too cool with people using my site to talk about sueing people. I would ask the other moderators to delete similar text. dr]
Paul
N277PM
LAF
Last edited by a moderator:
Personally I know of three on pavement. Of those, two were by the same pilot, same airplane.
Bob, you seem to be in the nexus of RV flipping. I think I will keep my 6A away from your part of the country.
David-aviator
Well Known Member
Three cheers on the red ink.
The subject of this thread has about been beaten to death and I wish someone would lock it down.
L.Adamson
Well Known Member
I think it's getting a bit over done around here. I've been around RV's for 16 years, and the nose gear IS forgiving. I've seen RV's drop through the flare rather harshly. I've dropped through the flare. It's not as if a nosewheel RV is going to go splat and flip over as a normal coarse of action. Two friends of mine have over 1200 hours on their 6A's over the last 10 years with no harm. They don't read the forums, and don't worry about it. With the paranoia that sometimes develops within these forums, I'm surprised we fly these things at all...
L.Adamson ---- RV6A
Mike S
Senior Curmudgeon
Thanks, I will be glad to.
Clue in post #11
I have no horse in this race but the clue to this flip over is in
Rocket Bob's explanation of the action that was taken by the pilot in the course of this flip over.
Quote"He first heard a bang and felt the nose drop, as soon as that happened he pulled all the way back on the stick and heard another bang, then flipped."
I know it could happen to anyone but the stick is supposed to be back in your lap at the mechanical stop before you start bouncing. In fact it should be there for a soft or rough field landing and stay there until you are parked.
Blaming nose wheel design to cover for poor pilot technique and follow up with legal action hurts all of us.
I have no horse in this race but the clue to this flip over is in
Rocket Bob's explanation of the action that was taken by the pilot in the course of this flip over.
Quote"He first heard a bang and felt the nose drop, as soon as that happened he pulled all the way back on the stick and heard another bang, then flipped."
I know it could happen to anyone but the stick is supposed to be back in your lap at the mechanical stop before you start bouncing. In fact it should be there for a soft or rough field landing and stay there until you are parked.
Blaming nose wheel design to cover for poor pilot technique and follow up with legal action hurts all of us.
rocketbob
Well Known Member
I have been a lurker for years and some of the comments in this and related threads were enough to push me to make my first post. Whereas I am an ATP by profession, I fly a homebuilt single engine when I want to fly for the pleasure of flying. The reason I have been lurking is that my homebuilt is not an RV. However, I have been thinking about building an RV as my next project.
Some posters have been loud about repeatedly declaring that the flip overs are simply because them pilots don?t know how to fly/taxi. There are Thousands of small planes flying with tricycle gear. They are flown by pilots just like RV pilots. They don?t all have the same nose gear issues as the RVs. I have difficulty with the notion that somehow RV pilots are worse than other pilots.
There have been pilots advising others to simply not fly into unknown turf strips, or to avoid unpaved strips altogether. I want to inject a parameter into this flip over equation that I believe is critical for all pilots ? and that is in-flight emergencies and emergency landings. When I am flying at FL290 with a crew and lots of redundancy, I have many choices. On the other hand, flying a single engine plane solo at 6000 feet is a whole different ballgame. There was an excellent post on these forums earlier, from a fellow pilot who had an engine failure and the only choice he had was to land at a Private Grass Strip. He only had a few seconds to commit to that strip. As any pilot who has had to make an emergency landing will tell you ?it all happens so fast??. The point being that a few seconds of hesitation because this happens to be a grass strip, can mean the difference between the hangar or the grave. Whether you are flying a certificated plane or a homebuilt makes no difference, please do not forget the dictum well prepared pilots live by ? it can happen to you?. In other words, it is not someone else?s problem. It is in everyone?s best interest, including Van?s, to resolve the nose gear issue before the regulating agencies feel the need to step in. That would be a bad thing.
Jim
Some posters have been loud about repeatedly declaring that the flip overs are simply because them pilots don?t know how to fly/taxi. There are Thousands of small planes flying with tricycle gear. They are flown by pilots just like RV pilots. They don?t all have the same nose gear issues as the RVs. I have difficulty with the notion that somehow RV pilots are worse than other pilots.
There have been pilots advising others to simply not fly into unknown turf strips, or to avoid unpaved strips altogether. I want to inject a parameter into this flip over equation that I believe is critical for all pilots ? and that is in-flight emergencies and emergency landings. When I am flying at FL290 with a crew and lots of redundancy, I have many choices. On the other hand, flying a single engine plane solo at 6000 feet is a whole different ballgame. There was an excellent post on these forums earlier, from a fellow pilot who had an engine failure and the only choice he had was to land at a Private Grass Strip. He only had a few seconds to commit to that strip. As any pilot who has had to make an emergency landing will tell you ?it all happens so fast??. The point being that a few seconds of hesitation because this happens to be a grass strip, can mean the difference between the hangar or the grave. Whether you are flying a certificated plane or a homebuilt makes no difference, please do not forget the dictum well prepared pilots live by ? it can happen to you?. In other words, it is not someone else?s problem. It is in everyone?s best interest, including Van?s, to resolve the nose gear issue before the regulating agencies feel the need to step in. That would be a bad thing.
Jim
Mike S
Senior Curmudgeon
Welcome to VAF!!!!
Hey Jim, welcome to VAF.
Dont have to be building or flying an RV to be welcome here, everybody is welcome.
Good to have you aboard.
Hey Jim, welcome to VAF.
Dont have to be building or flying an RV to be welcome here, everybody is welcome.
Good to have you aboard.
eric_marsh
Well Known Member
From what I've seen of the video and read of this discussion my impression is that the root of the problem is that the front gear permits too much forward/aft motion. All of the absorbed energy should be directed up and down, not forward and aft. As the leg flexes the nut and other non-moving components get nearer to the ground and at some point something digs in and disaster follows.
I think that it would even be better to have the leg designed so that in the event of failure it would fail completely, i.e. fold under the airplane and thus prevent pivoting on it. Perhaps if the leg had a section of tube designed to collapse at certain energy levels. The obvious risk is that it might collapse at the wrong time. But if that concern could be eliminated then it would still be better to land with the nose dragging on the ground than the canopy dragging.
What I like about the 10 system is that it appears to be designed with rigid tubing that won't go flexing for and aft and with a pivoting system where all movement is up and down. It's not fail safe but I'd bet that if all of Van's models had such a system we would not be having this conversation today.
As for pilot error and especially rough strips, perhaps I missed it but I don't recall anything in Van's literature regarding landing strip requirements. My impression, partly given by Van's video, is that grass strips are perfectly OK. I've been kicking around the idea of building my own strip at some point but after reading this and other related threads I'm a bit wary of the idea of landing anywhere but on pavement.
I think that it would even be better to have the leg designed so that in the event of failure it would fail completely, i.e. fold under the airplane and thus prevent pivoting on it. Perhaps if the leg had a section of tube designed to collapse at certain energy levels. The obvious risk is that it might collapse at the wrong time. But if that concern could be eliminated then it would still be better to land with the nose dragging on the ground than the canopy dragging.
What I like about the 10 system is that it appears to be designed with rigid tubing that won't go flexing for and aft and with a pivoting system where all movement is up and down. It's not fail safe but I'd bet that if all of Van's models had such a system we would not be having this conversation today.
As for pilot error and especially rough strips, perhaps I missed it but I don't recall anything in Van's literature regarding landing strip requirements. My impression, partly given by Van's video, is that grass strips are perfectly OK. I've been kicking around the idea of building my own strip at some point but after reading this and other related threads I'm a bit wary of the idea of landing anywhere but on pavement.
