Matronics Email Lists :: View topic - Tragic Accident

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Tragic Accident - more stupid conjecture.
Goto page 1, 2 Next

Matronics Email Lists Forum Index -> Zenith-List

View previous topic :: View next topic

Author Message

p.mulwitz(at)worldnet.att
Guest

Posted: Wed Mar 08, 2006 8:52 am Post subject: Tragic Accident - more stupid conjecture.

I had another strange idea about the cause for this structure 

failure.  I remember a post a few months ago about someone who bought 

a plane (parts?) and handed it over to his local auto paint shop 

where the rivets were all ground down flush with the skin to make it 

look better.



That sort of treatment would explain the fact that both wings failed 

in sequence.  None of the conjectures I have heard address the second 

wing folding.



Do not archive



Paul

XL wings

JAPhillipsGA(at)aol.com
Guest

Posted: Wed Mar 08, 2006 10:17 am Post subject: Tragic Accident - more stupid conjecture.

Paul, consider that both rear spars on the XL wings are attached with one 

bolt each (I think a 5/8 ? my plans are at the hanger so I'm unsure the size) 

When that bolt is removed and when holding the wing at the tip with all six main 

spar bolts torqued down, the wing is still very flexible. From the tip I can 

turn the whole wing an inch or so and the main spar is flexible enough to bend 

forward and rearward for adjustment. The lose of some skin might have caused 

such a colossal tragedy, but such a significant loss surely would have been 

observed. IE: " big pieces of wing skin fell off and fluttered down."  Surely the 

witnesses would have picked up on something like that if it occurred that 

way.

       Further, someone offered that the plane had only recently been bought 

and sold and perhaps the wings had been removed and replaced for some reason 

(transport or inspection). Of course that is possibly the reason especially if 

the bolts where installed incorrectly or the wrong bolts were used ?  Also, 

someone offered that the guys may have been performing acrobatics and bent 

something which caused the flight to end within 15 minutes and resulted in the 

crash on landing. I encourage all of us to not make such leaps without any 

evidence. Some NTSB wiz kid might read that and adopt it as their normal "pilot 

error" explanation. Bad business condemning another pilot without any evidence of 

misdeed, especially when the pilot(s) have gone on to the big FBO in the sky 

and can't respond. 

       Yes, we can all wait for the NTSB fellows to "give" us their answer 

and I'm sure they will do the best they can, but it might be months before they 

resolve their issues and they might also get it wrong so in the meantime it is 

very healthy that we builders and drivers brain storm what could have been 

the reason two friends died, and how it happened, and what we could do to 

prevent or remedy the cause. FWIW, Bill of Georgia N505WP

naumuk(at)alltel.net
Guest

Posted: Wed Mar 08, 2006 1:16 pm Post subject: Tragic Accident - more stupid conjecture.

---

larry(at)macsmachine.com
Guest

Posted: Wed Mar 08, 2006 1:59 pm Post subject: Tragic Accident - more stupid conjecture.

Bill+Rose wrote:

 	  Quote: 	
		  Subject: Re: Tragic Accident - more stupid conjecture.

>

>

All-

    For peace of mind, think back to the picture you've seen with 40 people 

sitting on a wing without failure. Why doesn't someone find out what sort of 

load test Zenith recommends, so we can perform it? I'm so busy I can barely 

check my e-mails a couple of times a month- how about one of you "Blissfully 

retired" folk?

                                                            Bill

Concerned as well but,

I'd not recommend speculation on anything until facts are in.  It's got 

to be something as simple as

an incorrectly fastened or fabricated spar.  The people investigating 

will be able to easily see

what gave it up in the first place.  Incorrect assembly will 

differentiate itself from outright failure as

strongly as a fatigued part or incorrect material, bolts etc.  The 

people that do these investigations are better at

it than we are and are seeing a lot more of it these days. I'd predict 

it's not going to be as hard as it sounds,

but will take a little more time.

 From the perspective of one that's blissfully retired going on 3 years now.

  Larry McFarland - 601HDS at www.macsmachine.com

  do not archive

naumuk(at)alltel.net
Guest

Posted: Thu Mar 09, 2006 4:19 pm Post subject: Tragic Accident - more stupid conjecture.

---

larry(at)macsmachine.com
Guest

Posted: Thu Mar 09, 2006 6:09 pm Post subject: Tragic Accident - more stupid conjecture.

As far as I know, Zenith doesn't suggest a process or method for static 

testing wings or spars.

Few builders would know what to do with static testing if they were 

furnished and required as in Finland

the U.K. and other places.   I'd not encourage anyone to suggest that 

FAA should consider it either!



If built, loaded and flown within specifications, the engineering 

drawings and guidance by the designer

should take care of that.  Doesn't mean you can't think for yourself, 

but I'd only static test something

I introduced that wasn't covered well enough by the design.



Larry McFarland - 601HDS

do not archive



Bill+Rose wrote:



 	  Quote: 	
		  Larry-

    Trying to Scotch any speculation. What does Zenith recommend for static 

testing?

                                                            Bill

  



>Concerned as well but,

>I'd not recommend speculation on anything until facts are in.  It's got

>to be something as simple as

>an incorrectly fastened or fabricated spar.  The people investigating

>will be able to easily see

>what gave it up in the first place.  Incorrect assembly will

>differentiate itself from outright failure as

>strongly as a fatigued part or incorrect material, bolts etc.  The

>people that do these investigations are better at

>it than we are and are seeing a lot more of it these days. I'd predict

>it's not going to be as hard as it sounds,

>but will take a little more time.

>

>From the perspective of one that's blissfully retired going on 3 years 

>now.

>

> Larry McFarland - 601HDS at www.macsmachine.com

> do not archive

>

>    

>

mike.sinclair(at)ATT.NET
Guest

Posted: Thu Mar 09, 2006 7:35 pm Post subject: Tragic Accident - more stupid conjecture.

For what it's worth, and from what I understand from working in the commercial

aviation & general aviation airplane building business for quite a few years,

and from general bull sessions with many friends and co-workers in both sectors,

plus numerous articles and films I've seen showing this kind of testing, a

static test is a test of destruction. This testing is a process to find at what

point the structure will fail.  So I suspect that if you don't want to invest

the money to buy (and build) a second airframe and set of wings that will be

destroyed in the process of testing, any thought of doing a true static test is

a mental excercise only. And therefore probably not very productive. Surely you

don't want to try bending your wings to the point that they might possibly fail,

and then put those same wings on your airplane. I also don't believe you are

going to want a bunch of lard butts standing on your wing just to show how

strong it is in negative g's, and then again, go put those same wings on an

airplane you intend to fly. I sugest that if you have any concerns about the

actual failing point of these structures, then you contact the designer about

any testing he may have done along these lines.

Mike Sinclair

LarryMcFarland wrote:

 	  Quote: 	

 As far as I know, Zenith doesn't suggest a process or method for static

 testing wings or spars.

 Few builders would know what to do with static testing if they were

 furnished and required as in Finland

 the U.K. and other places.   I'd not encourage anyone to suggest that

 FAA should consider it either!

 If built, loaded and flown within specifications, the engineering

 drawings and guidance by the designer

 should take care of that.  Doesn't mean you can't think for yourself,

 but I'd only static test something

 I introduced that wasn't covered well enough by the design.

 Larry McFarland - 601HDS

 Bill+Rose wrote:

 >Larry-

 >    Trying to Scotch any speculation. What does Zenith recommend for static

 >testing?

 >                                                            Bill

thilo.kind(at)gmx.net
Guest

Posted: Thu Mar 09, 2006 8:36 pm Post subject: Tragic Accident - more stupid conjecture.

Hi Mike,

static testing does not need to be destructive. In many countries static

testing up to the design load is required by the authorities for

experimentals. For that, the wing is turned up side down and mounted to a

jig (or you might also turn the whole plane upside down). Next, the wing is

then loaded with sandbags up to the designed wing loads. In a 601 HDs, that

would be 6 g or 3 times gross weight per wing.

Destructive testing is required, if you want to know the ultimate load.

Airbus just did it with a wing from their new A 380. I don't know the load,

but they bend the wing tip 7 m (21") before breaking it.

Happy building / flying

Thilo Kind

 	  Quote: 	
		   --- Ursprngliche Nachricht ---

 Von: Mike Sinclair <mike.sinclair(at)ATT.NET>

 An: zenith-list(at)matronics.com

 Betreff: Re: Tragic Accident - more stupid conjecture.

 Datum: Thu, 09 Mar 2006 21:24:03 -0600

 For what it's worth, and from what I understand from working in the

 commercial

 aviation & general aviation airplane building business for quite a few

 years,

 and from general bull sessions with many friends and co-workers in both

 sectors,

 plus numerous articles and films I've seen showing this kind of testing, a

 static test is a test of destruction. This testing is a process to find at

 what

 point the structure will fail.  So I suspect that if you don't want to

 invest

 the money to buy (and build) a second airframe and set of wings that will

 be

 destroyed in the process of testing, any thought of doing a true static

 test is

 a mental excercise only. And therefore probably not very productive.

 Surely you

 don't want to try bending your wings to the point that they might possibly

 fail,

 and then put those same wings on your airplane. I also don't believe you

 are

 going to want a bunch of lard butts standing on your wing just to show how

 strong it is in negative g's, and then again, go put those same wings on

 an

 airplane you intend to fly. I sugest that if you have any concerns about

 the

 actual failing point of these structures, then you contact the designer

 about

 any testing he may have done along these lines.

 Mike Sinclair

 LarryMcFarland wrote:

 > 

 <larry(at)macsmachine.com>

 >

 > As far as I know, Zenith doesn't suggest a process or method for static

 > testing wings or spars.

 > Few builders would know what to do with static testing if they were

 > furnished and required as in Finland

 > the U.K. and other places.   I'd not encourage anyone to suggest that

 > FAA should consider it either!

 >

 > If built, loaded and flown within specifications, the engineering

 > drawings and guidance by the designer

 > should take care of that.  Doesn't mean you can't think for yourself,

 > but I'd only static test something

 > I introduced that wasn't covered well enough by the design.

 >

 > Larry McFarland - 601HDS

 >

 > Bill+Rose wrote:

 >

 > >Larry-

 > >    Trying to Scotch any speculation. What does Zenith recommend for

 static

 > >testing?

 > >                                                            Bill

-- 

Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer!

Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer

JAPhillipsGA(at)aol.com
Guest

Posted: Thu Mar 09, 2006 8:36 pm Post subject: Tragic Accident - more stupid conjecture.

 	  Quote: 	
		  From a XL assembler and driver who takes his best friends up, his Wife and 

Son up and Grandson up, that flew 2.3 hours last Saturday and will probably 
	


exceed that this week end, yes the wings crumpling up on a XL and killing a couple 

fellows really concerns me and the fact that no one has much to offer as 

answers concerns me as well. This list should be for more than for beating which 

dammed scotch bright pad to use to death or how many fuel pumps between the 

tanks, in the wing root, behind the firewall and in front of the firewall equals 

a vapor lock !  Some of you guys are engineers and airplane designers. Frank 

has 10,000 hours on every plane there is and some of you all even more. Get in 

here and give us XL'ers your best shot. Screw waiting for some egg head from 

the NTSB. I want to fly this weekend. Who has some ideas that we who are 

actually flying XLs can employ to make our birds more safe this weekend ? Anybody 

care to speculate what failed and what we could be looking at while NTSB takes 

another coffee break and delivers their "guess" six months from now.  Yes, I'm 

in a piss mood, 72 hours without tobacco and an airplane that the wings may 

fall off. Do Not Archive.

zodierocket(at)hsfx.ca
Guest

Posted: Thu Mar 09, 2006 9:49 pm Post subject: Tragic Accident - more stupid conjecture.

Yup any man that has quit smoking is not worth being near for at least a

month. Being a constantly quitting smoker I would suggest not flying

during the first month of stress you are now under. Having said that I

personally don't want to hear speculation on the 601 incident. I KNOW

that Chris does testing on every model of plane he has ever built and he

also builds in a safety factor that he will not claim to. Think, the

601XL has a rating of ultimate +/- 6G's I would bet my house that the

actual ultimate is quite a bit higher. I hate to blame a builder, and

there doesnt seem to be any other known situation acting upon this

incident BUT we are talking about CHRIS HEINTZ here and I am dam sure it

is not a structural design flaw. SO we need to wait for the donuts to be

finished to find out what was omitted by the builder or what outside

circumstance led to the incident. Bantering it about on this E-Mail list

will resolve nothing and only stain a reputation of a designer that has

never tarnished before, it will also end up in disrespect for the

deceased with wild guesses of which I would not want to see. Their are

many other XL's out there with multiple 100's of hours on them and no

problems, I would suggest that your plane built to the designers specs

is safer then 1/2 the 150's I ever strapped my butt into.



Mark Townsend

Can-Zac Aviation Ltd.

president(at)can-zacaviation.com

www.can-zacaviation.com 



do not archive.



--

ggower_99(at)yahoo.com
Guest

Posted: Thu Mar 09, 2006 10:01 pm Post subject: Tragic Accident - more stupid conjecture.

Is great you gave up smoking...  Congratulations, we (me at least) can handle your mood in exchange of better life...  And your wings from your XL  will not fell off.  I am sure.  Enjoy your wonderfull airplane!

   

  Saludos

  Gary Gower

  701 912S 

  Building a 601 XL  Hope to having soon

  Flying feom Chapala, Mexico.



JAPhillipsGA(at)aol.com wrote:

  



 	  Quote: 	
		  From a XL assembler and driver who takes his best friends up, his Wife and 

Son up and Grandson up, that flew 2.3 hours last Saturday and will probably 
	


exceed that this week end, yes the wings crumpling up on a XL and killing a couple 

fellows really concerns me and the fact that no one has much to offer as 

answers concerns me as well. This list should be for more than for beating which 

dammed scotch bright pad to use to death or how many fuel pumps between the 

tanks, in the wing root, behind the firewall and in front of the firewall equals 

a vapor lock ! Some of you guys are engineers and airplane designers. Frank 

has 10,000 hours on every plane there is and some of you all even more. Get in 

here and give us XL'ers your best shot. Screw waiting for some egg head from 

the NTSB. I want to fly this weekend. Who has some ideas that we who are 

actually flying XLs can employ to make our birds more safe this weekend ? Anybody 

care to speculate what failed and what we could be looking at while NTSB takes 

another coffee break and delivers their "guess" six months from now. Yes, I'm 

in a piss mood, 72 hours without tobacco and an airplane that the wings may 

fall off. Do Not Archive.

			

---------------------------------

 Use Photomail to share photos without annoying attachments.

mike.sinclair(at)ATT.NET
Guest

Posted: Thu Mar 09, 2006 10:19 pm Post subject: Tragic Accident - more stupid conjecture.

Thilo



Appreciate the response. And I do have a definite appreciation about testing a

large aircraft wing to ultimate load. I watched the test videos of taking the

Boeing 777 wing to failure. I don't remember the total flex at the tip, but when

the wing let go it was explosive! I am curious about the process of testing all

experimental aircraft for design load in the other countries though and have a

couple of questions about this process. Are there standards for placement of the

sand bags to distribute the load over the whole wing and for how the structure

is secured before the test? Are there varying standards for the different

designs? Do the designers have any input on this testing, and if not, how are

testing standards dictated? How thoroughly is the post load tested wing

inspected? And what would concern me here is that inspecting a completed wing

after the test would be very difficult in most cases as the wing has been closed

up, and some internal failures could go undetected. Is there then any required

x-ray or other inspection required to ensure that the wing is really safe. And

finally, does any of the designers testing of structural strength to ultimate

failure get considered. I'm sure that I have seen pictures somewhere of a Zenith

wing being tested by a very heavy looking load of sandbags. Can't say what

aircraft the wing was off off, but would have a concern that someone could get a

little overzealous on loading sandbags and cause some damage, that undetected,

could have very serious consequences. For myself, I guess I'm pretty much stuck

with taking Zeniths word on the design limits of the airplane, and then just

making sure that I get nowhere near those limits, but do get a little nervous

when a bureaucracy run by some that know little, but have the need to feel

important, gets involved. Guess that was more than a couple of questions, but

when you get started it is kind of hard to stop sometimes. Bet that if I took a

little longer I could come up with a few more. Still waiting for the wind to die

down a bit so I can go get in some more air time!



Mike



Thilo Kind wrote:



 	  Quote: 	
		   



 Hi Mike,



 static testing does not need to be destructive. In many countries static

 testing up to the design load is required by the authorities for

 experimentals. For that, the wing is turned up side down and mounted to a

 jig (or you might also turn the whole plane upside down). Next, the wing is

 then loaded with sandbags up to the designed wing loads. In a 601 HDs, that

 would be 6 g or 3 times gross weight per wing.



 Destructive testing is required, if you want to know the ultimate load.

 Airbus just did it with a wing from their new A 380. I don't know the load,

 but they bend the wing tip 7 m (21") before breaking it.



 Happy building / flying



 Thilo Kind

thilo.kind(at)gmx.net
Guest

Posted: Thu Mar 09, 2006 11:52 pm Post subject: Tragic Accident - more stupid conjecture.

Hi Mike,

can't say, that I am an expert on the regs in other countries - my 601 HDS

was built, inspected, and registrated in the good ol' US. However, in the

meantime I relocated to Germany (with plane) and have contact to local

builders here. Also looked into the local regs, since the building itch is

back again and I might build another plane.

When building an airplane here in Germany, you will first get approval from

the authorities through the OUV, which is the equivalent of the EAA. Next

you have to submit the stress calculation, which you might obtain through

the designer or have an aeronautical engineer do that. During the building

process there will be three inspections (before closing stuff up). The final

inspection will include the load test. For that, sandbags are loaded evenly

onto the wing. I guess, some cardbord, foam, etc. can be used to protect the

wing's surface.

Before loading the sandbags, the height of the wingtip above ground is

measured. The total load is a result of the max g and the gross weight of

the plane. The height of the wing tip is measured under load. There are

limits on the allowable flex, depending on wing span, construction method,

etc. After de-loading the wing, the height is measured again. The wing is

not inspected any further using x-ray or similar. If height of wing tip

before and after loading is the same for a metal wing like on the Zodiacs I

wouldn't be concerned about any internal damage. 

 	  Quote: 	
		  From what I understand, the inspectors doing the pre-closing inspections and

the load tests are not with the LBA (the equivalent of the FAA). Those

people are real airplane guys and thus pretty okay. Guess, like the DAR's in

the US. The problem seems more the paperwork with the buerocrats.

I believe, Peter is still monitoring the list. He is currently building a

601 HDS in the southern part of Germany. Maybe he can chime in a bit...

Thilo Kind

 	  Quote: 	
		   --- Ursprngliche Nachricht ---

 Von: Mike Sinclair <mike.sinclair(at)ATT.NET>

 An: zenith-list(at)matronics.com

 Betreff: Re: Tragic Accident - more stupid conjecture.

 Datum: Fri, 10 Mar 2006 00:18:46 -0600

 Thilo

 Appreciate the response. And I do have a definite appreciation about

 testing a

 large aircraft wing to ultimate load. I watched the test videos of taking

 the

 Boeing 777 wing to failure. I don't remember the total flex at the tip,

 but when

 the wing let go it was explosive! I am curious about the process of

 testing all

 experimental aircraft for design load in the other countries though and

 have a

 couple of questions about this process. Are there standards for placement

 of the

 sand bags to distribute the load over the whole wing and for how the

 structure

 is secured before the test? Are there varying standards for the different

 designs? Do the designers have any input on this testing, and if not, how

 are

 testing standards dictated? How thoroughly is the post load tested wing

 inspected? And what would concern me here is that inspecting a completed

 wing

 after the test would be very difficult in most cases as the wing has been

 closed

 up, and some internal failures could go undetected. Is there then any

 required

 x-ray or other inspection required to ensure that the wing is really safe.

 And

 finally, does any of the designers testing of structural strength to

 ultimate

 failure get considered. I'm sure that I have seen pictures somewhere of a

 Zenith

 wing being tested by a very heavy looking load of sandbags. Can't say what

 aircraft the wing was off off, but would have a concern that someone could

 get a

 little overzealous on loading sandbags and cause some damage, that

 undetected,

 could have very serious consequences. For myself, I guess I'm pretty much

 stuck

 with taking Zeniths word on the design limits of the airplane, and then

 just

 making sure that I get nowhere near those limits, but do get a little

 nervous

 when a bureaucracy run by some that know little, but have the need to feel

 important, gets involved. Guess that was more than a couple of questions,

 but

 when you get started it is kind of hard to stop sometimes. Bet that if I

 took a

 little longer I could come up with a few more. Still waiting for the wind

 to die

 down a bit so I can go get in some more air time!

 Mike

 Thilo Kind wrote:

 > 

 >

 > Hi Mike,

 >

 > static testing does not need to be destructive. In many countries static

 > testing up to the design load is required by the authorities for

 > experimentals. For that, the wing is turned up side down and mounted to

 a

 > jig (or you might also turn the whole plane upside down). Next, the wing

 is

 > then loaded with sandbags up to the designed wing loads. In a 601 HDs,

 that

 > would be 6 g or 3 times gross weight per wing.

 >

 > Destructive testing is required, if you want to know the ultimate load.

 > Airbus just did it with a wing from their new A 380. I don't know the

 load,

 > but they bend the wing tip 7 m (21") before breaking it.

 >

 > Happy building / flying

 >

 > Thilo Kind

-- 

Bis zu 70% Ihrer Onlinekosten sparen: GMX SmartSurfer!

Kostenlos downloaden: http://www.gmx.net/de/go/smartsurfer

jim(at)pellien.com
Guest

Posted: Fri Mar 10, 2006 3:33 am Post subject: Tragic Accident - more stupid conjecture.

The problem with "armchair conjecture" is that we do not have the data to

make any sort of reasonable analysis.  NTSB has the data, the photos, the

up-close visual inspection etc.  I suspect that this is why we have not

heard from the Zenith Aircraft folks. They probably do not have the data

either.



We all will just have to be patient.  One thing that I will say is that we

have an airframe that has proven its structural integrity for over 20

years....hundreds are flying around the world and have flown safely for

probably over a million flight hours.  I know of no other in-flight

structural failure on any 601.  



Patience is the word.



Jim 



 



Jim Pellien

Mid-Atlantic Sports Planes

The Mid-Atlantic Region of SportsPlanes.com

www.MASPL.com

703-313-4818



--

steveadams

Joined: 10 Jan 2006
Posts: 191

Posted: Fri Mar 10, 2006 5:01 am Post subject: Re: Tragic Accident - more stupid conjecture.

If this was a new design I would be worried, but the 601 and CH have a long track record of safe design. So if you rule out a design flaw leading to failure, in my mind it has to be one of three things. One, faulty construction. Two, faulty maintenence (ie - attachment bolts loose, missing or improper hardware, corrosion etc). Three, the wing had been over stressed at some point either during this flight or previous flights. I guess the forth possibility is a defective critical part, but if the proper hardware was used and parts were closely inspected during construction, this is unlikely. Any of them are tragic, but likely unique to this particular aircraft. If your airplane was built to plan specs using the called out hardware, you maintain it well, and you fly within the design limitations, I doubt anyone has to be worried about flying their 601.

d3dw(at)msn.com
Guest

Posted: Fri Mar 10, 2006 6:38 am Post subject: Tragic Accident - more stupid conjecture.

Okay, Here goes. I will give you an analysis of the deadliest scenario one may encounter.

"Screw waiting for some egg head from the NTSB. I want to fly this weekend.

Who has some ideas that we who are

actually flying XLs can employ to make our birds more safe this weekend."



  Literally, this attitude is the one which kills more pilots than any other. It is the attitude of "wanting what I want right now" and reducing the experts to "eggheads". I would suggest that mature deliberation regarding the flightworthiness of your own aircraft is the guiding factor. If one does not have that knowledge in examining his aircraft even after going through the building process, perhaps he is an egghead.

  As for this weekend, your plane is as safe as it has been, but the attitude expressed above may get you in trouble. That attitude expressed during the building process has also killed a few folks. So "screw" your head on straight, and go fly.

   Don Walker    HDS, TD  385 hrs     do not archive

  



  ----Screw waiting for some egg head from



  the NTSB. I want to fly this weekend. Who has some ideas that we who are

  actually flying XLs can employ to make our birds more safe this weekend ?

  - Original Message -----

  From: Jim Pellien<mailto:jim(at)pellien.com>

  To: zenith-list(at)matronics.com<mailto:zenith-list(at)matronics.com>

  Sent: Friday, March 10, 2006 5:32 AM

  Subject: RE: Tragic Accident - more stupid conjecture.

  



  The problem with "armchair conjecture" is that we do not have the data to

  make any sort of reasonable analysis.  NTSB has the data, the photos, the

  up-close visual inspection etc.  I suspect that this is why we have not

  heard from the Zenith Aircraft folks. They probably do not have the data

  either.



  We all will just have to be patient.  One thing that I will say is that we

  have an airframe that has proven its structural integrity for over 20

  years....hundreds are flying around the world and have flown safely for

  probably over a million flight hours.  I know of no other in-flight

  structural failure on any 601. 



  Patience is the word.



  Jim



  



  Jim Pellien

  Mid-Atlantic Sports Planes

  The Mid-Atlantic Region of SportsPlanes.com

  www.MASPL.com<http://www.maspl.com/>

  703-313-4818



  --

planejim(at)bellsouth.net
Guest

Posted: Fri Mar 10, 2006 7:05 am Post subject: Tragic Accident - more stupid conjecture.

List,



Working with designer Wayne Ison back in the late 1970s I designed and built 

the one and only all metal PDQ ( an Ison design). The original was wood and 

fabric. We did the static load test using the Sandbag method. I used a 

publication from EAA that described the whole process. I don't know if that 

pamphlet is still available. The predicted wing deflection at each G (we 

tested up to 3 Gs) and the premanant set came out exactly as predicted. The 

process of placement of the sandbags was also prescribed. Of course we did 

not test to destruction. Neither my helper nor I are engineers. We're A&P 

mechs.



Now for the final results. The airplane came to the ground unplanned because 

of an engine problem caused my ME!

The wings took a beating after taking a 6" dia. branch off of an oak tree 

( the same ones we tested)  but otherwise held up fine. That's a heck of a 

way to do the ultimate test. Never rebuilt it either!



The whole process of design, build and test was very enjoyable and 

rewarding. However, as for these Zenith aircraft we fly, I have talked with 

Chris many times ( I visit with him at SunNFun amd AirVenture every year) 

and am satisfied he does all the testing necessary to produde safe aircraft. 

I take many friends and family up in my  601HD and feel fine about it.



I don't think we need to do those static load tests on Zenith aircraft. 

Those of you in countries which make you do this on proven designs (as 

opposed to one of a kind original design) a fighting bureaucrats justifying 

their jobs. Not proving a thing!



Jim Hoak 601HD 502hrs 9 years flying



do not archive

---

JAPhillipsGA(at)AOL.COM
Guest

Posted: Fri Mar 10, 2006 9:14 am Post subject: Tragic Accident - more stupid conjecture.

Mark, thanks, but speculation can be healthy. Remember, we all want the "e" 

in experimental to be a small "e". If  NASA  did a little more speculation and 

grasping we might have a couple more space shuttles parked around Florida. 

This body of builders has a boundless collective knowledge and experience. We 

should encourage the thought process. If you follow the NTSB reports you will 

note very quickly that many, many accidents have no definitive resolution. I have 

read hundreds of accident reports that NTSB offered no reason. We assemblers 

of XLs need to be proactive in an effort to determine what would cause such an 

event and self inspect. The prudent pilot and assembler would be remiss not 

to try. Best to you, Bill of Georgia

JAPhillipsGA(at)aol.com
Guest

Posted: Fri Mar 10, 2006 9:43 am Post subject: Tragic Accident - more stupid conjecture.

Don, this is not about me, this is about figuring out what could cause one 

then another wing on a XL to fold up and turn perpendicular to the fuselage of 

an established flying aircraft as it is in the pattern to land. If you are an 

NTSB employee and I hurt your feelings go find the folks working the issue and 

tell them to get busy and provide the resolution we are paying for. 

Bill

rsq2424(at)yahoo.com
Guest

Posted: Fri Mar 10, 2006 9:53 am Post subject: Tragic Accident - more stupid conjecture.

 	  Quote: 	
		   NTSB offered no reason. We assemblers of XLs need to be 

 proactive in an effort to determine what would cause such an 

 event and self inspect.


	


I couldn't agree more. While the NTSB guys probably know what they're doing, their reports usually leave a lot to be desired. And normally, the cause or contributing cause is some government mumbo jumbo like "a factor was pilot's failure to avoid contact with the ground" or something equally obvious. So, there's no harm in self-inspecting -- although endless debates on wing loading for a design that has been around for years probably won't result in anything productive.



Mike Fortunato

601XL



do not archive



		

---------------------------------

Bring photos to life! New PhotoMail  makes sharing a breeze.

Display posts from previous:

	Matronics Email Lists Forum Index -> Zenith-List	All times are GMT - 8 Hours Goto page 1, 2 Next
Page 1 of 2

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum