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MHerder

Joined: 11 Feb 2008
Posts: 143
Location: Fort Worth TX

Posted: Fri Apr 25, 2008 7:22 am Post subject: Re: CH601 Yuba City Photos Link

 	  n85ae wrote: 	
		  If the wing attach was coming loose, or something else, it would not be

unusual to see radar returns +/- a few hundred feet before the breakup.

I don't know if the suggestion is that the pilot was climbing/diving, but

it could well be they were fighting for control before the breakup.



One more comment. Regarding the pic with the hinge with the missing

part. I tested the A4/A5 rivets by making a box out of four piece's of

1"x"4"x.025 6061. Two corners with A4's, an two with solids. I then

used a hydraulic jack to pull the box apart.



In all cases the A4's failed well before the solids, and in all cases the heads popped off. I repeated with A5's with the same results. The steel core 

makes them strong in shear, but once the structure bends they are very

poor in tension.



When I tested with Solids only, The structure itself failed by tearing 

around the rivet heads. The rivets did NOT fail. 



On my 801, I have replace all A4's and A5's on critical assemblies with

solids. Were I building a 601 I'd definetly be attaching hinges with solids.



That's not suggesting that was the failure, however EVEN if the the 

structure detached at impact - the rivets should NOT have failed. The 

metal should have torn away. 



I think the rivet system Zenith uses is basically good, however not for

everything.



Regards,

Jeff 	


I see your point here Jeff but to me it is not important how it failed (whether it is the rivets or the material).   Every assembly has its weakest link.  Personally I wouldnt care that the assembly failed, but rather I would seek to find out whether or not the assembly failed prior to achieving its design strength that was anticipated.  Take another look at it from that perspective.



An engineer will design for load x, and so log as load x is adequately carried the job is done.  If the design criteria is design all assemblies such that the sheets fail in bearing first, then obviously I would be concerned by your findings.  But I don't believe this to be the case.

_________________
Zodiac 601 HD
Jabiru 3300
Wood Sensinich 64x47
Finally Flying

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 8:51 am Post subject: Re: CH601 Yuba City Photos Link

I have had a few personal inquires about my my feelings etc.  I don't want this to be my personal sounding block and will try to give out only any pertinent information in the future.  This is a place for genuine information and I apologize.



Thank you so much for your heartfelt condolences.  I do not take anything that anyone says on the forum as insensitive, I have not read anything that made me feel distaste.  Someone thought the word "neat" was in bad form.  I took it more as a comment of astonishment.  I am just looking for answers.  I can't stand the idea of continuing fatalities.



I saw someone doing a loop with their Zodiac on YouTube and I just felt a pit in my stomach.  I know that many of you have worked extremely hard on your airplanes.  I have rebuilt a couple myself, but have not built one from scratch.  I can't say factually that any of these accidents were caused by the same thing.  I just feel that with all the information that is coming in the NTSB may be able to narrow in on something.



I am sure that everyone concerned is truly trying to come to the same conclusion.  I personally don't blame anyone.  I don't mean for anyone to take any of my comments negatively in such a way that would prevent them from completing their dream aircraft or prevent someone from purchasing a Zodiac 601 or Kit.  With all the expert people looking in to this, something will come up and I'm sure if there is a fix (if needed), everyone will be informed.



There was the Oakdale CA. incident and then my parents in Yuba City, Ca.  Followed up the Canadian, Texas breakup and the Polk City, FL tragedy.  Yes, it could be medical issues (My parents were in good health and my father had a current Medical).  My mother was capable of landing the plane, how to disconnect the autopilot ,and also new how to use the radio and GPS.



My father served in the U.S. Navy in the Pacific Theater during World War II.  He then transferred to the Army Air Corps and retired from the U.S.A.F.  My mother, bless her heart, would drag us six children around and create a loving new home for us (every couple years) as we changed duty stations throughout the world (Duty stations of Moses Lake, Washington - Alabama - Japan - Panama - South Dakota â€“ Nebraska â€“ California â€“ Okinawa - North Carolina â€“ Greece - West Germany - Spokane, Washington).



My father started flying after World War II, and it became a passion of his, mine, and two of my brothers.  My mother always enjoyed flying with him.  In 2005, at 78 years of age, my father and mother flew their plane from Sacramento, CA to their native state of Minnesota (where I live) and back in their Grumman Tiger.  We were all so proud of them.  We had watched them grow more and more in love with each other over the years.  On a beautiful day, while in cruise flight (November 4, 2006), they encountered a catastrophic in-flight breakup of their plane.  I will be eternally grateful that they left together.  I am also grateful that neither of them had to suffer a lingering illness, nor that one of them was left without the other.



Thanks again and best reards

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 9:06 am Post subject: Re: CH601 Yuba City Photos Link

By The way.   The Yuba City accident aircraft is in a secured area (since Nov. 5th, 2005).  All  parties having anything to do with maunufacturing the aircraft along with the NTSB have access to the aircraft.

An independent  investigation will not be allowed until the NTSB has released their findings.

At that time, if anyone is interested or not satisfied with the conclusions, maybe we can arrange to have some of the Zodiac 601 experts examine the wreckage.

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 9:08 am Post subject: Re: CH601 Yuba City Photos Link

Sorry (Nov. 5th 2006)

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 9:43 am Post subject: Re: CH601 Yuba City Photos Link

Another question.  Is the trailing edge of the flaps supposed to be higher than the ailerons (if neutralized)? Is that some kind of fix?

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

n85ae

Joined: 14 Mar 2007
Posts: 403

Posted: Fri Apr 25, 2008 10:11 am Post subject: Re: CH601 Yuba City Photos Link

Mherder -



Your point is valid, and I'm not trying to suggest that rivet failure had

anything to do with the crash. However when I see an assembly that an entire  row of fasteners failed this certainly demonstrates to me that the 

fasteners are weaker than the structure itself. Personally I think the 

pulled rivets are inadequate for critical structures, so I personally do

not use them for critical structures.



Purely from a speculative point, if for example the aileron fluttered,

and the rivets failed this could certainly be a contributor.



Sorry if this is a deviation from the main topic.



Regards,

Jeff



 	  Quote: 	
		  An engineer will design for load x, and so log as load x is adequately carried the job is done. If the design criteria is design all assemblies such that the sheets fail in bearing first, then obviously I would be concerned by your findings. But I don't believe this to be the case.

bobefx(at)yahoo.com
Guest

Posted: Fri Apr 25, 2008 10:11 am Post subject: CH601 Yuba City Photos Link

What a beautiful tribute to your parents. They must have been world class and we are all saddened by their loss, as well as yours.

  

 Bobefx

 601XL QB

 N642Z reserved

 ---

Afterfxllc(at)aol.com
Guest

Posted: Fri Apr 25, 2008 10:20 am Post subject: CH601 Yuba City Photos Link

When I build and rig the plane I make my aileron slightly higher than the  flap leading edge. But the XL has some play in the flap rods so they will lift  about 2 mm each and that evens them out.

  

 Jeff

  

  

  	  Quote: 	
		  Another    question.  Is the trailing edge of the flaps supposed to be higher than    the ailerons (if neutralized)? Is that some kind of fix?

	
 

  



Need a new ride? Check out the largest site for U.S. used car listings at AOL Autos.

  [quote][b]

cookwithgas

Joined: 06 Nov 2007
Posts: 159

Posted: Fri Apr 25, 2008 10:40 am Post subject: Re: CH601 Yuba City Photos Link

I have been looking at the photos for two days and two of them seem significant to me after Sabrina mentioned the extra threads.  I have to give Sabrina another gold star because it is a good catch.  



Photo #28 shows the longer bolt which appears to be located on the outboard side and on top of the center spar (near a pilot's left knee).   What Sabrina noted about the bolt threads is obvious to me but what took me a while to recognize was that there is a space between the two parts (drawing 6W4-3) where the wing spar is missing.  



Key to this realization is that the missing part is clearly shown in Photo #32.  I may have this wrong but I'm seeing photo #28 as the center spar still attached to the right wing and photo #32 as the mating part of left wing where it attaches to the very same bolt Sabrina mentioned.  So a break did occur at this long bolt with the extra threads.



These pictures are not random - I think the photographer is thinking the same thing I am.  However and I think it is important to realize that we don't know what chain of events cause this particular break as it could have happened after something else failed and even after impact with the ground as far as I know because I can't determine the debris path from the pictures.



If I am missing something or have the pictures backwards or turned around, let me know. 



Scott Laughlin

www.cooknwithgas.com

601XL / Corvair

Finished & Flying

52 hours

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Rickey B.

Joined: 22 Mar 2008
Posts: 70

Posted: Fri Apr 25, 2008 11:25 am Post subject: CH601 Yuba City Photos Link

Hi, List,

		Sorry to be a bother, but I somehow have lost the

addresses to the pictures we are talking about. Can someone help here?  

			Thanks, Rick.

John Bolding

Joined: 23 May 2006
Posts: 281

Posted: Fri Apr 25, 2008 11:27 am Post subject: CH601 Yuba City Photos Link

Jeff,

 No deviation from my feeble point of view.



 Those of you that studied Jon Croke's 701 wreckage pictures also saw some 

of the same type thing. Rows of rivets pulled out with almost zero 

deformation of the structure. The holes weren't even deformed much. Seat 

belt attach pulled out (doubler since added) for the same reason.  It's 

amazing how small and insignificant you think something is yet it causes a 

reaction to something larger that ends up biting you in the butt.    I'm 

sure it's been mentioned here before but the wing flutter that disassembled 

Steve Wittman's O&O Special was caused by a small piece of loose fabric 

forward of the aileron, causing it to flutter , causing the wing to flutter. 

If we only knew how close to the edge we really are sometimes.......



 Only pulled rivets in my 701 are the ones I absolutely can't get to with a 

bucking bar.

Pretend that previous sentence was deleted.



Progress is slow on the engineering front, I'm gonna call Thurston and see 

if he's interested in the project in case the academic doesn't pan out. He 

may want something useful to do in his spare time.

 Ya'll choose up a point man so if somebody says they are ready to do it 

there won't be any fumbling around. I think it needs to be a 601 guy in the 

middle of this as there might be some back and forth.



There has been a lot of discussion concerning the NTSB and the FAA, 

somebody might want to dig into this a little deeper but having hung around 

homebuilts pretty intensely for 35 yrs or so I don't remember much from 

either agency in the way of in depth engineering as to cause and effect, 

maybe I just missed it (entirely possible) but if it was commercial or even 

just certified G.A. the story would be different but homebuilts are pretty 

much left to their own devices,  or that's my impression anyway.  Hope I'm 

wrong but I wouldn't be putting all my chips on either of them to tell me 

what happened ,why and CERTAINLY NOT how to fix it.

John



 	  Quote: 	
		   Mherder -



 Your point is valid, and I'm not trying to suggest that rivet failure had

 anything to do with the crash. However when I see an assembly that an 

 entire  row of fasteners failed this certainly demonstrates to me that the

 fasteners are weaker than the structure itself. Personally I think the

 pulled rivets are inadequate for critical structures, so I personally do

 not use them for critical structures.



 Sorry if this is a deviation from the main topic.



 Regards,

 Jeff

japhillipsga(at)aol.com
Guest

Posted: Fri Apr 25, 2008 11:43 am Post subject: CH601 Yuba City Photos Link

Don, I can speak only for myself, but the opportunity for several builders to examine the wings and attachments might prove valuable. I'm sure really smart NTSB folks will "solve" the mystery, but we who have built a XL know were every bolt and rivet is supposed to be. I would fly to there for the opportunity in my XL. Thanks and best regards, Bill Phillips

 do not archive

 

 --

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 11:49 am Post subject: Re: CH601 Yuba City Photos Link

John,



  I have heard the same thing about Homebuilt aircraft and the amount of time that is spent investigating them.  The Yuba City aircraft is one of the first certified S-LSA's.  I have been told theere would be a thorough investigation, because of that fact.  Let's hope so.



Don

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 11:52 am Post subject: Re: CH601 Yuba City Photos Link

Hi Bill,



I have a call in right now to see if it is at all possible, for me or anyone else to aquire photos from the NTSB or if I or a family member could go to the secured sight and take very detailed pictures.  I know they must have a diagram of the debris field etc.



Don

 	  japhillipsga(at)aol.com wrote: 	
		  Don, I can speak only for myself, but the opportunity for several builders to examine the wings and attachments might prove valuable. I'm sure really smart NTSB folks will "solve" the mystery, but we who have built a XL know were every bolt and rivet is supposed to be. I would fly to there for the opportunity in my XL. Thanks and best regards, Bill Phillips

 do not archive

 

 --

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

jerry(at)jerryhey.com
Guest

Posted: Fri Apr 25, 2008 11:58 am Post subject: CH601 Yuba City Photos Link

This is just speculation.  Amazing how someone can state it as a well  

known fact.   The cause of  the O & O  Special crash has never been  

determined.  This is cautionary for those trying to understand the XL  

crashes.  Don't jump to conclusions.    Jerry

On Apr 25, 2008, at 3:24 PM, John Bolding wrote:



 	  Quote: 	
		   I'm sure it's been mentioned here before but the wing flutter that  

 disassembled Steve Wittman's O&O Special was caused by a small piece  

 of loose fabric forward of the aileron, causing it to flutter ,  

 causing the wing to flutter. If we only knew how close to the edge  

 we really are sometimes.......

PLAV8R

Joined: 22 Apr 2008
Posts: 30
Location: Prior Lake, Minnesota

Posted: Fri Apr 25, 2008 12:03 pm Post subject: Re: CH601 Yuba City Photos Link

Also from Polk City NTSB report:

Detailed examination of the left wing revealed that the lower main wing spar cap was fractured at the wing root.

_________________
Donald J. Dennnehey Jr.
don.dennehey@gmail.com
Prior Lake, Minnesota
Cessna 175 N7656M
Cessna 140 N90123

planecrazydld(at)yahoo.co
Guest

Posted: Fri Apr 25, 2008 12:08 pm Post subject: CH601 Yuba City Photos Link

..part of well designed structure is that when failed there should be both bearing and shear failures, that is, there should be sheet metal torn away through some of the fastener holes and fasteners sheared by the sheet metal. I was amazed by the rows of rivet buts pulled throught the rib flanges...and all the rows of rivets missing entirely from either component... that suggests head popping failure modes that can be exacerbated by excessive pitch between fasteners.



John Bolding <jnbolding1(at)teleshare.net> wrote:[quote] --> Zenith-List message posted by: "John Bolding" 



Jeff,

 No deviation from my feeble point of view.



 Those of you that studied Jon Croke's 701 wreckage pictures also saw some 

of the same type thing. Rows of rivets pulled out with almost zero 

deformation of the structure.  The holes weren't even deformed much. Seat 

belt attach pulled out (doubler since added) for the same reason.  It's 

amazing how small and insignificant you think something is yet it causes a 

reaction to something larger that ends up biting you in the butt.    I'm 

sure it's been mentioned here before but the wing flutter that disassembled 

Steve Wittman's O&O Special was caused by a small piece of loose fabric 

forward of the aileron, causing it to flutter , causing the wing to flutter. 

If we only knew how close to the edge we really are sometimes.......



 Only pulled rivets in my 701 are the ones I absolutely can't get to with a 

bucking bar.

Pretend that previous sentence was deleted.



Progress is slow on the engineering front, I'm gonna call Thurston and see 

if he's interested in the project in case the academic doesn't pan out. He 

may want something useful to do in his spare time.

 Ya'll choose up a point man so  if somebody says they are ready to do it 

there won't be any fumbling around. I think it needs to be a 601 guy in the 

middle of this as there might be some back and forth.



There has been a lot of discussion concerning the NTSB and the FAA, 

somebody might want to dig into this a little deeper but having hung around 

homebuilts pretty intensely for 35 yrs or so I don't remember much from 

either agency in the way of in depth engineering as to cause and effect, 

maybe I just missed it (entirely possible) but if it was commercial or even 

just certified G.A. the story would be different but homebuilts are pretty 

much left to their own devices,  or that's my impression anyway.  Hope I'm 

wrong but I wouldn't be putting all my chips on either of them to tell me 

what happened ,why and CERTAINLY NOT how to fix it.

John



[quote] Mherder -



 Your point is valid, and I'm not trying to suggest that rivet failure had

          Be a better friend, newshound, and  [quote][b]

bjohnson(at)satx.rr.com
Guest

Posted: Fri Apr 25, 2008 12:35 pm Post subject: CH601 Yuba City Photos Link

I believe this is why the Sonex uses the Stainless Steel Cherry rivets.



-Bruce Johnson

--

frankroskind(at)HOTMAIL.C
Guest

Posted: Fri Apr 25, 2008 12:38 pm Post subject: CH601 Yuba City Photos Link

S. Wittman Accident report link: http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001207X03218&key=1

 Text of probable cause:

 HISTORY OF FLIGHT

On April 27, 1995, about 1210 central daylight time, a Wittman O&O (Ocala and Oshkosh) experimental airplane, N41SW, registered to a private owner, operating as a 14 CFR Part 91 personal flight, experienced an in-flight breakup about 7 miles south of Stevenson, Alabama. Visual meteorological conditions prevailed and no flight plan was filed. The commercial pilot and pilot-rated passenger were fatally injured. The airplane was destroyed. The flight originated about 2 hours 40 minutes before the accident. The airplane was reported overdue on April 28, 1995, and was located on April 29, 1995.

According to friends of the pilot, this was his annual return flight to Oshkosh, Wisconsin. One of the friends stated that he conducted a preflight inspection of the airplane, and did not discover any problems. According to another friend, the pilot had planned his flight to avoid flying through controlled airspace, and the need to establish radio contact. The flight departed without incident. No radio communication was reported between air traffic and the flight. 

At the approximate time of the accident, several local residents reported hearing an airplane in the vicinity of the accident site. These witnesses were located in a valley and on a mountain ridge; none of the witnesses actually saw the airplane in flight. Their accounts varied from hearing a high revving engine to hearing an explosion. One witness at the Stevenson Airport reported hearing a sonic boom, but did not see or hear a jet aircraft in the vicinity of the airport. According to Memphis Air Route Traffic Control Center, there were no military aircraft operating on the military training routes at the approximate time of the accident. 

On April 28, 1995, friends of the pilot became concerned about the location of the airplane, since it never arrived at the planned destination. The Federal Aviation Administration (FAA) issued an alert notice, and a search for the missing airplane was initiated. On April 29, 1995, at 1830, debris from N41SW was located in the vicinity of strip mines, south of Stevenson. A massive ground and aerial search located the main wreckage early the following morning. 

PERSONNEL INFORMATION

Information about the pilot is included in this report under the data field labeled "First Pilot Information". A review of the pilot's airmen records disclosed that he had acquired several pilot ratings which included certified flight instructor. The pilot had also held an airframe and powerplant (A & P) mechanic's rating. The pilot's flight logs were not recovered for examination. 

Medical history on the pilot was limited, since his attending physician died several months before this accident. A review of the pilot's FAA medical records failed to disclose a dramatic shift in the pilot's medical condition. During his last flight physical examination, the pilot had an elevated blood pressure reading. The pilot was requested to provide additional medical information to the FAA Aeromedical Division. On May 12, 1995, the FAA reviewed the additional data and declared that Mr. Wittman was medically qualified to hold a second class airmen medical certificate. According to friends of the pilot, he maintained a fit lifestyle, and they could not recall any extended medical treatment the pilot had received in recent years. 

Information on the second pilot is included in this factual report as NTSB Form 6120.4, Supplement E. 

AIRCRAFT INFORMATION

Information about the aircraft is included in this report under the data field labeled "Aircraft Information". According to the chairman and founder of the EAA, the Wittman O & O experimental airplane was a one-of-a-kind aircraft, and there was no design or performance information available for airplane. A review of aircraft data revealed that Mr. S.J. Wittman was issued the experimental operating limitations for the O & O experimental airplane on January 6, 1985. 

METEOROLOGICAL INFORMATION

Visual meteorological conditions prevailed at the time of the accident. Weather information is contained in this report under the data field labeled "Weather Information". According to the weather study conducted by the National Transportation Safety Board, the 1200 weather plot showed southwest surface winds with wind speeds variable between 10 and 20 knots. Upper level winds between the surface and 10,000 feet in the vicinity of the accident site, were out of the southwest between 15 and 20 knots. The weather study also concluded that no significant wind shear was likely, but occasional light to moderate low level turbulence was possible in the vicinity of the accident site. 

WRECKAGE AND IMPACT INFORMATION

Debris from the airplane was scattered in a ravine over an area 1.25 miles long, on Sand Mountain (see the wreckage distribution diagram). Examination of the accident site and wreckage disclosed that the airplane separated into four major components: both wings, the empennage section, and the main fuselage. They were scattered within an area .25 miles long. Other wreckage debris was scattered over an additional mile.

Examination of the accident site disclosed that wreckage debris was scattered on a southwesterly heading. The first pieces of the wreckage debris were found in the coal mining area near the location of the emergency management command post (see the wreckage diagram). A piece of aircraft skin, with the letters O and O printed on it was recovered with the debris near the coal mines. This piece of skin material was subsequently identified as part of N41SW. Other debris located in the vicinity of the strip coal mines included plexiglass material and yellow painted fabric material. The southwest trail of debris, which included aircraft fabric, paint chips, personal items of the occupants, and flight charts, continued for about a mile where the larger pieces of the airframe were located. 

The left wing assembly was located in a heavily wooded area about a mile southwest of the wreckage debris at the mining area. The left wing was located on a steep ridge near a creek. An examination of the left wing assembly disclosed that the main wood spar was fractured through the lateral plane of the bolted wing-to-fuselage attachment fitting. The fracture plane extended from the inboard end of the spar about 34 inches outboard. 

The front wing-to-fuselage spar attachment fitting was bent aft about 3 degrees and twisted about 5 degrees in the wing leading edge down direction. Both the front and the rear wing-to-fuselage spar attachment fittings exhibited damage, eg., twisting, bending, rear wood spar fracture, or damage to fuselage clevis tang attachment webs.

About 6 inches of the wing lift strut stub remained attached to the fuselage. The lift strut exhibited some slight column buckling (downward) about 16 inches from the spar attachment fitting.

The left wing aileron and flap were missing in their entirety. The outboard aileron hinge attachment bolt/washer had broached a clean round hole, about 1-inch in diameter, through the secondary (false) rear spar and hinge block. 

The entire wing tip structure assembly (including dope/fabric) was relatively intact and remained attached to the remainder of the wing. The fabric remaining on the top and bottom surfaces of the wing was, for the most part, doped in place except in those areas adjacent to the wing skin fracture lines. The dope was distressed or missing on the aft inboard portion of the wing upper surface and along the entire length of the top of the main spar.

The right wing was located on the mountain ridge about 200 yards southwest of the left wing assembly. The main wood spar was cracked/split through the lateral plane of the bolted wing-to-fuselage attachment fitting. The primary fracture plane extended from the inboard end of the spar to about 43 inches outboard (to the wing lift strut reinforced area). The spar, outboard of this section, was cracked and twisted throughout its entire length. All wood ribs aft of the main spar were missing.

The front wing-to-fuselage spar attachment fitting was attached to the fuselage clevis rear tang. The forward clevis tang was pulled out of the fuselage.

The right aileron was missing. The outboard portion of the flap, from the center hinge outboard, was bent down about 10 degrees. The inboard area of the flap exhibited rearward bending distress/buckling. The flap inboard and middle hinge fittings were intact but pulled out of the secondary (false) rear spar; the outboard fitting was broken off.

The flap and aileron bellcrank clamps remained attached to the inboard end of the concentric flap and aileron tubes. The aileron tube was fractured at the outboard flap hinge station. The aileron upper bellcrank was broken at the clamp. The flap push-pull control rod was missing and the bellcranks had broken at the upper (clamped) and lower ends.

The entire fabric covering on the upper and lower surfaces of the wing had delaminated from the wing skin. The doped finish was severely distressed and mottled. 

The empennage section was located about 200 yards further up the mountain ledge from the right wing assembly. Examination of the empennage revealed that the left horizontal stabilizer and elevator assembly was missing. The left horizontal stabilizer forward attach bolt was fractured; a threaded portion of the bolt was still in the nut plate. The right horizontal stabilizer and elevator assemblies were attached to the airframe. 

The vertical fin was attached to the airframe but had been deflected 90 degrees right from its installed position. The rudder, with the fixed trim tab and rudder horn, was attached to the airframe. The tailwheel assembly was attached to the airframe at the accident site. 

The fuselage examination also determined that a 33-inch section of the tubular truss fuselage had fractured, aft of the baggage compartment, and was missing. The cabin and cockpit areas sustained impact damage which reduced the livable space. The examination of the airframe revealed that the fractured tubes showed evidence of multiple bending failures in random directions. 

Examination of the flight control stick assembly disclosed that the aileron torque tube near the bolted connection immediately below the middle stick was fractured. The fracture faces exhibited rotational scuffing. 

MEDICAL AND PATHOLOGICAL INFORMATION

Post-mortem examination of the pilot was conducted by Dr. Joseph H. Embry, Alabama Department of Forensic Sciences, Birmingham, Alabama, on May 2, 1995. The cause of death was multiple blunt force injuries.

Toxicological samples were shipped to the Federal Aviation Administration Aeronautical Center for examination. According to the manager of the Toxicological and Accident Research Laboratory, the toxicological samples arrived in very poor condition, and the findings were possibly the result of postmortem putrefaction. The toxicological examinations detected the following levels of ethanol, 1-butanol, and acetaldehyde:

34.000 mg/dl and 37.000 mg/dl of ethanol in muscle and lung samples 4.000 mg/dl of butanol in both muscle and lung samples 3.000 mg/dl of acetaldehyde in the lung sample.

TEST AND RESEARCH

Several fractured components from the airframe were submitted to the NTSB Materials Laboratory Division for examination, (see the Metallurgist Factual Report for list of components examined). The examination of the listed components revealed no evidence of preexisting cracking, and all fracture areas were representative of overstress separations. The left horizontal forward attach bolt also failed in overstress.

A small section of the wing wood and fabric material was removed for examination. "The examination disclosed that the mahogany plywood had been coated with clear Nitrate Dope". Next, the builder covered the plywood withStits 150 pound poly-fiber. The builder next brushed a coat of nitrate dope over the layer of poly-fiber followed by a clear coat of butyrate dope. Finally, several coats of poly-spray and yellow poly-tone were sprayed over the coat butyrate dope. According to Mr. Ray Stits, President of Stits Aircraft, the above stated process does not provide the best adhesive qualities. The builder should have first applied two coats of poly-brush on the bare plywood, (see the Poly-Fiber Covering and Painting Manual). 

Primary radar data from Memphis Air Route Traffic Control Center was recovered for examination. A review of this data disclosed that N41SW was flying a northerly heading at an unspecified altitude when radar contact was lost. The radar data study could only recover ground speed and magnetic heading information. During the last three minutes of the recorded data, the ground speed increased from 150 knots to 190 knots. The radar data also indicated the airplane had entered a turn. The rate and direction of turn was not determined. Turn Information was based upon the change in radar reflection of the target. The radar data also revealed that the last radar hit was north of where the aircraft wreckage was located on the ground. The wreckage distribution was 180 degrees from the original flight heading. (See the Specialist report of investigation conducted by the NTSB Office of Research and Engineering).

The aircraft wreckage was released to Mr. Paul H. Poberezny, EAA, Founder/Chairman of The Board,POB 3086, Oshkosh, Wisconsin, 54903.

 do not archive

 	  Quote: 	
		   From: jerry(at)jerryhey.com

 To: zenith-list(at)matronics.com

 Subject: Re: Re: CH601 Yuba City Photos Link

 Date: Fri, 25 Apr 2008 15:55:23 -0400

 --> Zenith-List message posted by: Jerry Hey <jerry(at)jerryhey.com>

 This is just speculation. Amazing how someone can state it as a well 

 known fact. The cause of the O & O Special crash has never been 

 determined. This is cautionary for those trying to understand the XL 

 crashes. Don't jump to conclusions. Jerry

 On Apr 25, 2008, at 3:24 PM, John Bolding wrote:

 > I'm sure it's been mentioned here before but the wing flutter that 

 > disassembled Steve Wittman's O&O Special was caused by a small piece 

 > of loose fabric forward of the aileron, causing it to flutter , 

 > causing the wing to flutter. If we only knew how close to the edge 

 > we really are sometimes.......

 <======================

In a rush? Get real-time answers with Windows Live Messenger.  [quote][b]

gfmjr_20(at)HOTMAIL.COM
Guest

Posted: Fri Apr 25, 2008 1:01 pm Post subject: CH601 Yuba City Photos Link

The 601XL flaps are designed to be 3mm higher than the trailing edge of the wing. The ailerons are flush with the trailing edge of the wing

  

 George May

 601XL 912s



 	  Quote: 	
		   Subject: Re: CH601 Yuba City Photos Link

 From: donald.j.dennehey(at)seagate.com

 Date: Fri, 25 Apr 2008 10:43:38 -0700

 To: zenith-list(at)matronics.com

 

 --> Zenith-List message posted by: "PLAV8R -" <donald.j.dennehey(at)seagate.com>

 

 Another question. Is the trailing edge of the flaps supposed to be higher than the ailerons (if neutralized)? Is that some kind of fix?

 

 --------

 Donald J. Dennnehey Jr.

 donald.j.dennehey(at)seagate.com

 Prior Lake, Minnesota

 Cessna 175 N7656M

 Cessna 140 N90123

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=179166#179166

 

 

 

 =======================

&g========================> 
	


 	  Quote: 	
		   

 


	


Back to work after baby– how do you know when you’re ready?  [quote][b]

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