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Matt Ronics

Joined: 30 Apr 2007
Posts: 22

Posted: Wed Dec 19, 2007 10:48 pm Post subject: Re: 601 and wing failiers

I'll flog the dead horse with my take.  I chose to build a 701 instead of 601XL over this issue.  I considered  a 601HD but found that the 701 was close enough to 601HD speeds to suit my needs.  I've previously built a canard composite.



The issue I have with the 601XL failures is simply that they are not adequately defined.  My talk with Sebastian didn't help this concern.



My totally unsubstantiated theory is that the design, as it currently exists, is intolerant of some combination of builder error.  A failure to design in enough "builder error tolerances" may explain why most 601XLs will fly forever (and test well with sandbags) and a few will catastrophically fail.  Who knows if you might make just the right combination of fatal flaws when building your 601XL.



Even in the event of pilot error, when reviewing other fleet aircraft, wings just don't seem to come off as often as with the 601XL.  I am not arguing that the Rutan canard is a superior aircraft, but there has simply not been an airframe failure in the canard  fleet, even though 2000+ airframes have been built by amateur builders.  So long as builders have *attempted* to place all the layers of fiberglass on, and balanced the surfaces, none have failed the structure in flight (even well past VNE).  There is a tremendous amount of "margins for error" designed into the Rutan canard.  I don't think such a margin exists in the 601XL spar/wing design.



My opinions only.

Martin Pohl

Joined: 30 Jan 2006
Posts: 118
Location: CH-8645 Jona SG, Switzerland

Posted: Thu Dec 20, 2007 1:16 am Post subject: Re: 601 and wing failiers

Hello everybody!



I personally like the wing locker option: I'd rather have my 70 lbs baggage in the wings (wing lockers) and stress the wing spar at the wing/fuselage connection to a much lesser extent than when having all this stuff in my aft baggage compartment.



Nevertheless it is true of course that the wing structure itself is weakened by the lockers.



So lets go and start an effective diet and loose some pounds: that most probably is the best way to increase safety (keeping the weight of the loaded fuselage low and therefore the wing loading low ... and besides keeping your heart running for much longer)       .



Cheers Martin

_________________
Martin Pohl
Zodiac XL QBK
8645 Jona, Switzerland
http://www.pohltec.ch/ZodiacXL/Main.html

jetboy

Joined: 22 Jul 2006
Posts: 233

Posted: Thu Dec 20, 2007 1:29 am Post subject: Re: 601 and wing failiers

I'm concerned about the XL wing as to whether it may be susceptible to flutter, induced by improper handling or loading. At least one pilot report of  "washboarding" on this list remains unexplained. Its only the XL wing that seems to be affected, although I would be confident to fly in one that was built standard, and flown appropriately, but would be reassured if some flight test data was tabled showing how the prototypes handled these conditions - by what margin they were tested to - and whether the CZAW mods were ever put thru the same testing? Not advocating for any retest of this - just confirmation of what tolerance for loading / CG and Vne / Vd exists? 



When choosing the 701, I could have fitted an 0-200 as I already had one in a C150 that I was parting with, but chose to not use it because of the extra vibration - especially if running rough or 1 cyl. out, could be a bit much for the airframe, and besides, the weight puts it outside the design envelope. The fatal crash in Canada and the cracking of Horiz. stab attach brackets when used with the 912S are examples taken into account.



Ralph

_________________
Ralph - CH701 / 2200a

tjs22t(at)verizon.net
Guest

Posted: Thu Dec 20, 2007 2:34 am Post subject: 601 and wing failiers

Martin,



I respectfully disagree with your statement below and would like you to back 

it up with some factual , empirical evidence.  As Larry stated yesterday the 

D-tube structure of the wing gives it the strength.



tj   do not archive

 	  Quote: 	
		  

 Nevertheless it is true of course that the wing structure itself is 

 weakened by the lockers.

psm(at)ATT.NET
Guest

Posted: Thu Dec 20, 2007 3:12 am Post subject: 601 and wing failiers

I can't say you are wrong about the "Builder margin" issue, but I can 

say I disagree with you (whoever you are).  There is a basic 

difference between conventional airplane design and canard 

architecture that might explain this little mystery.  Canards cannot 

be allowed to stall, because if they do the result is always 

unrecoverable and fatal.



If the main wing in a canard airplane stalls before the front wing, 

the plane will fall tail first through the air.  That is a certain 

death for the plane and all the folks in it.  To prevent this 

catastrophic flight condition, canard designers must limit the 

elevator authority so that stalls of the main wing are impossible.



The Zodiac XL is designed with extremely effective control surfaces 

in all three axes.  That means the pilot has great control of the 

plane even at very low airspeeds.  The down side of this choice is 

the pilot can assert such great forces on the airframe when the plane 

is going fast and he applies high control force inputs that he can 

literally pull the wings off.  Chris Heintz seems to always refer to 

this design choice when he writes about the structural failure 

issue.  It is a potential problem for pilots who are prone to panic 

or otherwise tend to use ridiculously high forces on the controls.



We will never know exactly why there are alarmingly high failures on 

Zodiac XLs.  They might just go away, or some day there might be a 

little "Beef up" fix like there was on the V-Tail Bonanzas after 

decades of in-flight structural failures.  Still, most of the XL 

drivers and builders must be doing something right because the number 

of failures still represents only a very small percentage of the flying XLs.



Paul

XL fuselage



At 10:48 PM 12/19/2007, you wrote:

 	  Quote: 	
		  



I'll flog the dead horse with my take.  I chose to build a 701 

instead of 601XL over this issue.  I considered  a 601HD but found 

that the 701 was close enough to 601HD speeds to suit my 

needs.  I've previously built a canard composite.



The issue I have with the 601XL failures is simply that they are not 

adequately defined.  My talk with Sebastian didn't help this concern.



My totally unsubstantiated theory is that the design, as it 

currently exists, is intolerant of some combination of builder 

error.  A failure to design in enough "builder error tolerances" may 

explain why most 601XLs will fly forever (and test well with 

sandbags) and a few will catastrophically fail.  Who knows if you 

might make just the right combination of fatal flaws when building your 601XL.



Even in the event of pilot error, when reviewing other fleet 

aircraft, wings just don't seem to come off as often as with the 

601XL.  I am not arguing that the Rutan canard is a superior 

aircraft, but there has simply not been an airframe failure in the 

canard  fleet, even though 2000+ airframes have been built by 

amateur builders.  So long as builders have *attempted* to place all 

the layers of fiberglass on, and balanced the surfaces, none have 

failed the structure in flight (even well past VNE).  There is a 

tremendous amount of "margins for error" designed into the Rutan 

canard.  I don't think such a margin exists in the 601XL spar/wing design.



My opinions only.

planecrazydld(at)yahoo.co
Guest

Posted: Thu Dec 20, 2007 3:22 am Post subject: 601 and wing failiers

or with a little redesign, the inboard leading edge couild easily become genuine wet wing fuel storage - more fuel, less weight - just more Proseal 890!



ashontz <ashontz(at)nbme.org> wrote:[quote] --> Zenith-List message posted by: "ashontz" 



I thought I saw the wing lockers in the HD in the center spar. My bad. Still, they're shorter wing panels.



Anyway, I'm done over analyzing the XL wing, but personally, I won't install the wing lockers. Something about it from a "seat of your pants" engineering style, it just looks "not right" to me. I also think making some other changes like the 15 gallon tanks which puts a nose rib out of alignment with a rear rib, especially in conjunction with a wing locker and a nose skin made of shorter skins is asking for trouble. Any one of them are their own isn't a problem (except Find them fast with Yahoo! Search. [quote][b]

planecrazydld(at)yahoo.co
Guest

Posted: Thu Dec 20, 2007 3:33 am Post subject: 601 and wing failiers

why could the lockers simply be moved completly to the next to last bay outboard? That would span load the weight of their contents and reduce the effect on panel bending. Of course, then you have higher polar moments for things like spins or upset recovery...



Martin Pohl <mpohl(at)pohltec.ch> wrote:[quote] --> Zenith-List message posted by: "Martin Pohl" 



Hello everybody!



I personally like the wing locker option: I'd rather have my 70 lbs baggage in the wings (wing lockers) and stress the wing spar at the wing/fuselage connection to a much lesser extent than when having all this stuff in my aft baggage compartment.



Nevertheless it is true of course that the wing structure itself is weakened by the lockers.



So lets go and start an effective diet and loose some pounds: that most probably is the best Find them fast with Yahoo! Search. [quote][b]

Iberplanes

Joined: 10 Dec 2007
Posts: 174
Location: Igualada - Barcelona - Spain

Posted: Thu Dec 20, 2007 4:55 am Post subject: 601 and wing failiers

Hi,



Is it possible not to install the wing lockers even if you have ordered 

them? I´m waiting my crate to arrive in january, but I´m re-thinking due to 

the comments I´m reading here on not to construct that part.



Please, tell me.



---

_________________
Alberto Martin
601 XL - Jabiru 3300
http://www.iberplanes.es
Igualada - Barcelona - Spain

notsew_evets(at)frontiern
Guest

Posted: Thu Dec 20, 2007 5:07 am Post subject: 601 and wing failiers

Yes.

You are the builder and do the actually cutting and installation.

I m just now finishing the lockers and the addition of the rear panel is 

beefy.  Probably stronger than the plain ol skin.

How



ever, even with the extra "baggage" space, I kinda wish I would have waited 

to hear the outcome of this thread before installing.....



Steve 601 XL QBK



---

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Thu Dec 20, 2007 5:27 am Post subject: Re: 601 and wing failiers

Ok, this is a little more sane and less emotional thread on the issue, that's good. It's nothing more than load analysis. Analyze the loads compression and tension for the whole wing as well as what would be happening between each rib station to make it fold and you can identify the stress points. Thinking of it as a big piece of Origami helps too. "If I attempt to fold this, which way do the connecting pieces need to move and with how much force, and what's keeping those connecting pieces from moving, and what does it take to move the connecting pieces to the connecting pieces."

bill_dom(at)yahoo.com
Guest

Posted: Thu Dec 20, 2007 6:03 am Post subject: 601 and wing failiers

I don't believe it has something to do with builder error, one of the failure cases was with a factory build AMD Zodiac. I don't believe this accident was due to an explosion as some people has mention, the report for this accident states "no evidence of fire was found" If there is a flaw in the design (I'm not sure there is one), I think it is one that only comes during very specific flight situation that provoke a failure when it shouldn't. Of course, this are just my beliefs based on info available and they can change as new info comes out.



William Dominguez

Zodiac 601XL Plans

Miami, Florida



Matt Ronics <e_jocular(at)yahoo.com> wrote:[quote] --> Zenith-List message posted by: "Matt Ronics" 



I'll flog the dead horse with my take.  I chose to build a 701 instead of 601XL over this issue.  I considered   a 601HD but found that the 701 was close enough to 601HD speeds to suit my needs.  I've previously built a canard composite.



The issue I have with the 601XL failures is simply that they are not adequately defined.  My talk with Sebastian didn't help this concern.



My totally unsubstantiated theory is that the design, as it currently exists, is intolerant of some combination of builder error.  A failure to design in enough "builder error tolerances" may explain why most 601XLs will fly forever (and test well with sandbags) and a few will catastrophically fail.  Who knows if you might make just the right combination of fatal flaws when building your 601XL.



Even in the event of pilot error, when reviewing other fleet aircraft, wings just don't seem to come off as often as with the 601XL.  I am not arguing that the Rutan canard is a superior aircraft, but there has simply not been an airframe failure in the canard  fleet, even though 2000+ airframes have [quote][b]

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Thu Dec 20, 2007 6:40 am Post subject: Re: 601 and wing failiers

The more I read people's input, the more I'm considering adding ribs. Granted, Zenith themselves say that you can overstress the structure with quick hard control inputs, specifically elevator. I don't think adding a few ribs would hurt or even be a big problem. In fact, I'm sure I can use the existing holes in the main spar where the hat stiffeners are to add ribs without drilling more holes in the main spar. More ribs would add more torsional strength as well as shortening the bending moments in the wing itself between rib stations. Wouldn't even be that hard to interpolate the dimensions for the new interim ribs, mostly just time making about 4 more rib forms. That with no wing locker and I think you're looking at a significantly stronger wing to make up for any possible design flaw or builder error nor would it push stress somewhere else that that stress shouldn't be going anyway. If it adds more stress to the root, oh well, that's the roots job, to hold the damn wing on, and in the reports there was no mention of the bolts at the root shearing. And if you wanted to beef up the root that would be pretty easy too, just add some plate to span more of the center spar and add more bolts. But that doesn't seem to be an issue.



[quote="bill_dom(at)yahoo.com"]I don't believe it has something to do with builder error, one of the failure cases was with a factory build AMD Zodiac. I don't believe this accident was due to an explosion as some people has mention, the report for this accident states "no evidence of fire was found" If there is a flaw in the design (I'm not sure there is one), I think it is one that only comes during very specific flight situation that provoke a failure when it shouldn't. Of course, this are just my beliefs based on info available and they can change as new info comes out.



William Dominguez

Zodiac 601XL Plans

Miami, Florida



Matt Ronics <e_jocular> wrote:[quote] --> Zenith-List message posted by: "Matt Ronics" 



I'll flog the dead horse with my take.  I chose to build a 701 instead of 601XL over this issue.  I considered   a 601HD but found that the 701 was close enough to 601HD speeds to suit my needs.  I've previously built a canard composite.



The issue I have with the 601XL failures is simply that they are not adequately defined.  My talk with Sebastian didn't help this concern.



My totally unsubstantiated theory is that the design, as it currently exists, is intolerant of some combination of builder error.  A failure to design in enough "builder error tolerances" may explain why most 601XLs will fly forever (and test well with sandbags) and a few will catastrophically fail.  Who knows if you might make just the right combination of fatal flaws when building your 601XL.



Even in the event of pilot error, when reviewing other fleet aircraft, wings just don't seem to come off as often as with the 601XL.  I am not arguing that the Rutan canard is a superior aircraft, but there has simply not been an airframe failure in the canard  fleet, even though 2000+ airframes have  	  Quote: 	
		  [b]

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Thu Dec 20, 2007 7:33 am Post subject: 601 and wing failiers

Just because there was no evidence of a fire does not mean there  

wasn't an explosion. It is entirely possible to have an explosion  

without a fire and without leaving any signs of heat damage. An  

explosion does most of its damage because of the extreme pressures  

produced, not from the heat. Debris from the explosion is often not  

exposed to the heat for long enough to be damaged by it. Explosions in  

real life don't necessarily act like they do in the movies.

On Dec 20, 2007, at 8:56 AM, William Dominguez wrote:



 	  Quote: 	
		   I don't believe it has something to do with builder error, one of  

 the failure cases was with a factory build AMD Zodiac. I don't  

 believe this accident was due to an explosion as some people has  

 mention, the report for this accident states "no evidence of fire  

 was found" If there is a flaw in the design (I'm not sure there is  

 one), I think it is one that only comes during very specific flight  

 situation that provoke a failure when it shouldn't. Of course, this  

 are just my beliefs based on info available and they can change as  

 new info comes out.




	




-- 

Bryan Martin

N61BM, CH 601 XL,

RAM Subaru, Stratus redrive.

do not archive.

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Thu Dec 20, 2007 7:58 am Post subject: Re: 601 and wing failiers

And if there was an explosion, it's more than likely that the tank leaked somehow and fumes accummulated in the wing structure. An explosion is more likely when there's less fuel to air ratio. An outright explosion of the tank is unlikely, a small amount of fuel in the wink with a lot of air would make a bigger boom.



 	  bryanmmartin wrote: 	
		  Just because there was no evidence of a fire does not mean there  

wasn't an explosion. It is entirely possible to have an explosion  

without a fire and without leaving any signs of heat damage. An  

explosion does most of its damage because of the extreme pressures  

produced, not from the heat. Debris from the explosion is often not  

exposed to the heat for long enough to be damaged by it. Explosions in  

real life don't necessarily act like they do in the movies.

On Dec 20, 2007, at 8:56 AM, William Dominguez wrote:



 	  Quote: 	
		   I don't believe it has something to do with builder error, one of  

 the failure cases was with a factory build AMD Zodiac. I don't  

 believe this accident was due to an explosion as some people has  

 mention, the report for this accident states "no evidence of fire  

 was found" If there is a flaw in the design (I'm not sure there is  

 one), I think it is one that only comes during very specific flight  

 situation that provoke a failure when it shouldn't. Of course, this  

 are just my beliefs based on info available and they can change as  

 new info comes out.

	




-- 

Bryan Martin

N61BM, CH 601 XL,

RAM Subaru, Stratus redrive.

do not archive.

paulrod36(at)msn.com
Guest

Posted: Thu Dec 20, 2007 9:34 am Post subject: 601 and wing failiers

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  Not necessarily. An explosion is just a very fast fire, yes, but it also  has a compressive aspect to it, due to the speed of the flame front. There  will almost always be indications of heat (I say "almost", but have never seen  one that didn't) and will always show, if in an enclosed space, deformation of  the surfaces in an outward, although not necessarily spherical, shape. The flame  front of an exploding substance is moving too fast to escape out of any  openings, and will, in series, escape out of the weakest points of the  enclosure, after deforming them Typically, a seam bursts, followed by tearing  of a surface, with combustion residue applied to the interior  surfaces.   The extreme pressures are a function of the resistive  strength of the material trying to contain the heat of combustion.  An  "explosion" in the combustion chamber doesn't deform anything, due to the  strength of the cylinder wall and head, but you hear the fast-moving flame front  when it escapes through the exhaust. Just my two cents worth.

  

 Paul Rodriguez

 DO NOT ARCHIVE

 [quote]   ---

bill_dom(at)yahoo.com
Guest

Posted: Thu Dec 20, 2007 10:05 am Post subject: 601 and wing failiers

And just because a witness heard the sound of an explosion is not evidence than an explosion occurred. Other than the witness account, there is no other mention of an explosion  in the report. There are reasons why NTSB takes witness accounts with a grain of salt.

Bryan:

Thanks for the warning, but I'm fully aware that real life is not like in the movies. Heck, life some times is not like in the news.

William Dominguez

Zodiac 601XL Plans

Miami Florida

ashontz <ashontz(at)nbme.org> wrote:[quote] --> Zenith-List message posted by: "ashontz" 

And if there was an explosion, it's more than likely that the tank leaked somehow and fumes accummulated in the wing structure. An explosion is more likely when there's less fuel to air ratio. An outright explosion of the tank is unlikely, a small amount  of fuel in the wink with a lot of air would make a bigger boom.

bryanmmartin wrote:

[quote] Just because there was no evidence of a fire does not mean there  

 wasn't an explosion. It is entirely possible to have an explosion  

 without a fire and without leaving any signs of heat damage. An  

 explosion does most of its damage because of the extreme pressures  

 produced, not from the heat. Debris from the explosion is often not  

 exposed to the heat for long enough to be damaged by it. Explosions in  

 real life don't necessarily act like they do in the movies.

 On Dec 20, 2007, at 8:56 AM, William Dominguez wrote:

 >  I don't believe it has something to do with builder error, one of  

 >  the failure cases was with a factory build AMD Zodiac. I don't  

 >  believe this accident was due to an explosion as some people has  

 >  mention, [quote][b]

Jaybannist(at)cs.com
Guest

Posted: Thu Dec 20, 2007 10:41 am Post subject: 601 and wing failiers

I'm amazed at how many news reports there are of witnesses that say the airplane was on fire as it came down, when, in fact, it actually didn't catch fire until it hit the ground.  I think that is probably related to the phenom where a driver speeds up when you try to pass him on the highway.  It is a somewhat unconscious, unintended and unrealistic reaction to reality.  

It is also common for non-aviation people to think of a stall in terms of their car engine stalling, and they are totally ignorant of the aerodynamics of an aircraft stall, and what one looks like.

Jay in Dallas

Do not archive

William Dominguez <bill_dom(at)yahoo.com> wrote:

 	  Quote: 	
		  And just because a witness heard the sound of an explosion is not evidence than an explosion occurred. Other than the witness account, there is no other mention of an explosion  in the report. There are reasons why NTSB takes witness accounts with a grain of salt.

Bryan:

Thanks for the warning, but I'm fully aware that real life is not like in the movies. Heck, life some times is not like in the news.

William Dominguez

Zodiac 601XL Plans

Miami Florida

ashontz <ashontz(at)nbme.org> wrote: 

And if there was an explosion, it's more than likely that the tank leaked somehow and fumes accummulated in the wing structure. An explosion is more likely when there's less fuel to air ratio. An outright explosion of the tank is unlikely, a small amount of fuel in the wink with a lot of air would make a bigger boom.

bryanmmartin wrote:

> Just because there was no evidence of a fire does not mean there  

> wasn't an explosion. It is entirely possible to have an explosion  

> without a fire and without leaving any signs of heat damage. An  

> explosion does most of its damage because of the extreme pressures  

> produced, not from the heat. Debris from the explosion is often not  

> exposed to the heat for long enough to be damaged by it. Explosions in  

> real life don't necessarily act like they do in the movies.

> 

> 

> On Dec 20, 2007, at 8:56 AM, William Dominguez wrote:

> 

> 

> >  I don't believe it has something to do with builder error, one of  

> >  the failure cases was with a factory build AMD Zodiac. I don't  

> >  believe this accident was due to an explosion as some people has  

> >  mention, the report for this accident states "no evidence of fire  

> >  was found" If there is a flaw in the design (I'm not sure there is  

> >  one), I think it is one that only comes during very specific flight  

> >  situation that provoke a failure when it shouldn't. Of course, this  

> >  are just my beliefs based on info available and they can change as  

> >  new info comes out.

> > 

> > 

> > 

> 

> 

> -- 

> Bryan Martin

> N61BM, CH 601 XL,

> RAM Subaru, Stratus redrive.

> do not archive.

--------

Andy Shontz

CH601XL - Corvair

www.mykitlog.com/ashontz

Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=153272#153272

ter_turn(at)yahoo.com
Guest

Posted: Thu Dec 20, 2007 12:25 pm Post subject: 601 and wing failiers

I'm going to put a couple of one inch access holes in my wings and when I close them up I'll pump them full of concrete for added stiffness.



Do not archive!



Terry 



ashontz <ashontz(at)nbme.org> wrote:[quote] --> Zenith-List message posted by: "ashontz" 



The more I read people's input, the more I'm considering adding ribs. Granted, Zenith themselves say that you can overstress the structure with quick hard control inputs, specifically elevator. I don't think adding a few ribs would hurt or even be a big problem. In fact, I'm sure I can use the existing holes in the main spar where the hat stiffeners are to add ribs without drilling more holes in the main spar. More ribs would add more torsional strength as well as shortening the bending moments in the wing itself between rib stations. Wouldn't even  be that hard to interpolate the dimensions for the new interim ribs, mostly just time making about 4 more rib forms. That with no wing locker and I think you're looking at a significantly stronger wing to make up for any possible design flaw or builder error nor would it push stress somewhere else that that stress shouldn't be going anyway. If it adds more stress to the root, oh well, that's the roots job, to hold the damn wing on!

 , and in the reports there was no mention of the bolts at the root shearing. And if you wanted to beef up the root that would be pretty easy too, just add some plate to span more of the center spar and add more bolts. But that doesn't seem to be an issue.



[quote="bill_dom(at)yahoo.com"]I don't believe it has something to do with builder error, one of the failure cases was with a factory build AMD Zodiac. I don't believe this accident was due to an explosion as some people has mention, the report for this accident states "no evidence  of fire was found" If there is a flaw in the design (I'm not sure there is one), I think it is one that only comes during very specific flight situation that provoke a failure when it shouldn't. Of course, this are just my beliefs based on info available and they can change as new info comes out.



William Dominguez

Zodiac 601XL Plans

Miami, Florida



Matt Ronics  wrote:[quote] --> Zenith-List message posted by: "Matt Ronics" 



I'll flog the dead horse with my take.  I chose to build a 701 instead of 601XL over this issue.  I considered   a 601HD but found that the 701 was close enough to 601HD speeds to suit my needs.  I've previously built a canard composite.



The issue I have with the 601XL failures is simply that they are not adequately defined.  My talk with Sebastian didn't help this concern.



My totally unsubstantiated theory is that the design, as it currently exists, is intolerant of some combination of builder error.  A       Be a better friend, newshound, and  [quote][b]

daveaustin2(at)primus.ca
Guest

Posted: Thu Dec 20, 2007 1:38 pm Post subject: 601 and wing failiers

Can I suggest changing all 6061T6 to 2024T3 for greater strength and making 

everything twice as thick?

Dave Austin  601HDS - 912

psm(at)ATT.NET
Guest

Posted: Thu Dec 20, 2007 2:14 pm Post subject: 601 and wing failiers

Hi Dave,



I figure that would make the empty weight twice as much so you would 

be over gross weight before adding any payload.



Paul

XL fuselage

do not archive



At 01:36 PM 12/20/2007, you wrote:



 	  Quote: 	
		  Can I suggest changing all 6061T6 to 2024T3 for greater strength and 

making everything twice as thick?

Dave Austin  601HDS - 912

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