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Author Topic: Grand Rapids trip (2-2-V-1)  (Read 135565 times)

Matt Revington

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Grand Rapids trip (2-2-V-1)
« on: January 21, 2014, 01:21:54 PM »

On the Facebook page Ric has posted that he is going to Grand Rapids to discuss an artifact recovered from Niku in 1991 with an FAA expert.  Which artifact is it and has something new come to light?
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Russ Matthews

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Re: Grand Rapids trip
« Reply #1 on: January 21, 2014, 01:40:14 PM »

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Ric Gillespie

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Re: Grand Rapids trip
« Reply #2 on: January 21, 2014, 01:46:43 PM »

This is a tremendously complicated artifact containing tons of information about where it came from and how it ended up looking the way it does now. It fits best on the belly opposite the cabin door but the rivet pattern is just a wee bit off - and that's an absolute disqualifier UNLESS there is rational explanation for why the rivet pattern is the way it is.
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Chuck Lynch

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Re: Grand Rapids trip
« Reply #3 on: January 22, 2014, 08:16:02 AM »

Good luck. This seems very exciting all of a sudden.
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Patrick Dickson

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Re: Grand Rapids trip
« Reply #4 on: January 22, 2014, 09:02:29 AM »

This is a tremendously complicated artifact containing tons of information about where it came from and how it ended up looking the way it does now. It fits best on the belly opposite the cabin door but the rivet pattern is just a wee bit off - and that's an absolute disqualifier UNLESS there is rational explanation for why the rivet pattern is the way it is.

Could the variation in the rivet pattern be exclusively due to the extent of the damage suffered by the Electra in the Luke Field "incident" ?  Is it possible that the supporting framework behind the repair panel was distorted or deformed enough to cause the variation in the rivet pattern ?   Would Lockheed repair technicians consider this area "non-critical" and allow the slight deformation of the ribs in the effort to make a quicker repair ?
 
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Ric Gillespie

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Re: Grand Rapids trip
« Reply #5 on: January 22, 2014, 06:11:49 PM »

Whatever was done had to conform to approved practices.  Aircraft repairs, then as now, were closely regulated and had to pass government inspection.  The question I hope we can answer is whether there were approved repair techniques that would result in the rivet pattern we see on the artifact.
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JNev

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Re: Grand Rapids trip
« Reply #6 on: January 23, 2014, 10:04:52 AM »

Whatever was done had to conform to approved practices.  Aircraft repairs, then as now, were closely regulated and had to pass government inspection.  The question I hope we can answer is whether there were approved repair techniques that would result in the rivet pattern we see on the artifact.

I wish you luck with this effort, whatever is being done to identify the origins of this metal panel.  "Approved Practices" and vigorous inspection requirements certainly did apply and were taken seriously, so I personally doubt that an impromptu repair of lessor skin thickness and smaller rivet size would have been employed in an area of primary stressed skin (see Airworthiness Bullitin 7H from the "Air Commerce Regulations" days of Earhart's time).

That does not preclude that 'anything is possible', or that exceptions could have been made, of course.  I also understand and appreciate how the 'best fit' was determined by having read of the effort on this site, but have doubts about that location.  This is due to the thickness (.032 being less than the original .040 skin in that area) and the irregular "#3" rivet hole pattern evident on the piece (which are also undersized compared to the 1/8th inch "#4" rivets originally used in that area of primary structure).  For another thing, #3 rivets have long been considered less-than adequate for primary structure and generally are not used in stressed skin situations (this taught me from early days in A&P school, granted some years after Earhart's time - but a long-standing practice).

On the positive is the era of this 'skin' - the markings suggest pre-WWII production and the remains of brazier head type rivets also suggests an older craft, pre-dating the war-time AN470 universal-type head (both in terms of production and any repairs).

As to a 'likely fit' I am more biased toward the curious covering that was installed over the Electra's large, one-off 'navigation window' in the head while the ship was in Miami, prior to the last world flight attempt.  This window was located on the right side of the fuselage - cut out and braced for a larger aperture than the other cabin windows, and actually placed in the lavatory area.  This large window was in a zone of .032 skin since it was AFT of the station where ".040" skins stopped and .032 was the norm.

Of further interest to me is the general layout of the rivets - the interim "#3" rivet layout is as if done "free hand" by someone in a hurry to address an oil canning effect over a large, secondary 'cover'.  What is 'suggested' by what I see is a rapid attempt to cover a large aperture simply for security / weather protection, but where structural considerations were not paramount; perhaps after a flight it was realized (or simply 'predicted' and addressed) that oil canning might be an issue: hence light-weight secondary rivets that could have attached light-weight stiffeners to prevent that.

Earhart was weight conscious; someone decided that window was no longer needed and it was covered while in Miami (details of that unknown).  The larger rivet holes on the periphery of the 'skin' suggest attachment to established, well-braced structure (such as the peripheral bracing of the described window); the interior rivet patterns appear 'hand laid' and are light-weight in character, i.e. secondary consideration - weight savings but adequate for light bracing.

Of course all of this is speculation on my part - but based on the reasons I've given, which are based on a career in maintenance, alteration and design.  The practices I've described are also consistent with the earliest guidance we have (see the "Aeronautics Bulletins" of old on FAA's Regulatory and Guidance Library site), right through current sheet metal practices (actually little has changed in eight decades as to those practices except materials and fastener types, e.g. brazier head giving way to universal, etc.).

So in my thinking there is no way to know this for sure short of having NR16020 to hold this up against for an absolute match - belly or window covering, or something else - but the 'window cover' came to make sense to me after seeing the artifact in D.C. June of 2012 and learning something of the Miami window covering exercise, and more about the structure in that area.

Best of luck with whatever investigative effort is going on - I agree it is loaded with information, if it can be teased out somehow.  I've always wondered if it might be a silent witness to this loss and somehow finally a key: there should not have been a great surplus of that kind of pre-war Dural with brazier rivets in it lying about in that part of the Pacific IMO, however it got there.
- Jeff Neville

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« Last Edit: January 23, 2014, 10:08:39 AM by Jeffrey Neville »
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Greg Daspit

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Re: Grand Rapids trip
« Reply #7 on: January 23, 2014, 01:00:37 PM »

This is due to the thickness (.032 being less than the original .040 skin in that area) and the irregular "#3" rivet hole pattern evident on the piece

Jeff
Was the skin for 35R originally .032 or .040?
I thought the original skin in that area matched the artifact from 1992 Tighar Tracks Vol 8?
“• Skin thickness: Identical to Skin #35R.”
 
In regards to the 35R:
Is there something that shows the discrepancy ?
Which row or rows are off, how much and to which side are they not aligned?
(I could only find a comparison of the panel on top near the air vent)
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JNev

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Re: Grand Rapids trip
« Reply #8 on: January 23, 2014, 02:23:58 PM »

This is due to the thickness (.032 being less than the original .040 skin in that area) and the irregular "#3" rivet hole pattern evident on the piece

Jeff
Was the skin for 35R originally .032 or .040?I thought the original skin in that area matched the artifact from 1992 Tighar Tracks Vol 8?
“• Skin thickness: Identical to Skin #35R.”
 
In regards to the 35R:
Is there something that shows the discrepancy ?
Which row or rows are off, how much and to which side are they not aligned?
(I could only find a comparison of the panel on top near the air vent)

I can't authoritatively dispute the TIGHAR Tracks bulletin regarding 35R. 

My understanding has been that the skins were .040" thick back to Sta. 293, where it transitioned to .032" thick; that would be consistent with this sort of stressed skin design - the forward section of the fuselage being relatively reinforced to carry passenger and other direct loads, tapering to less structure some distance out by moment / arm. 

But TIGHAR may have better information on the original skins than I do.  The drawings "know", if any can be found for this area - and TIGHAR has examined other Electras and may have direct knowledge of this as gained from other airplanes like Earhart's.

I wish Ric luck on this - the 'skin' has long fascinated me as a possible 'grail' item if a firm match could be made somehow.
- Jeff Neville

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Greg Daspit

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Re: Grand Rapids trip
« Reply #9 on: January 23, 2014, 03:28:35 PM »

Another reason it can be thinner is as the ribs get closer together as the fuselage tapers, there is less distance to span for the skin.
I like this artifact too. The dating of the type of aluminum used is significant and the 2-2-V-1 wire found entangled in it. I think the dating of aluminum and the wire suggest possible 1937 aircraft debris nearby. Pretty exciting stuff all together. I look at where the aircraft skin was found, combined with Emily's seeing aircraft debris and the Bevington photo and the data from the last trip and think TIGHAR is closing in on it!

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« Last Edit: January 23, 2014, 06:57:31 PM by Greg Daspit »
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Tim Mellon

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Re: Grand Rapids trip
« Reply #10 on: January 23, 2014, 07:26:01 PM »

Greg, it's a shame Ric won't allow you to see the three landing gears, the cockpit, the propeller blade and the various cylinder, intake and exhaust valves.

I guess it's all in the name of "scientific method."

Tim
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Greg Daspit

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Re: Grand Rapids trip
« Reply #11 on: January 23, 2014, 09:36:50 PM »

#3 rivets have long been considered less-than adequate for primary structure and generally are not used in stressed skin situations (this taught me from early days in A&P school, granted some years after Earhart's time - but a long-standing practice).

Jeff
That is interesting. Could the #3 rivets also be used to fasten a large patch to a damaged piece that may have a few small holes or abrasions but not damaged enough to take off and replace?(probably not). Then the patch rows might be parallel to where the original rows were because they only went through the skin. I wonder if the patch rivets may need to be close to the ribs but not have to go thru the rib. And if the top of the original heads may have left a scar on the inside of the patch if that were the case(probably not a good way to laminate two pieces). I'm very interested in what the results of the trip are for repair practices. The more details you point out about it, the more interesting this piece becomes. I'm glad you mentioned the rivet type. (pre war type from what I read). So much about this fits the era of the plane even if an exact fit can't be found. And why would a patch or repair "fit" exactly anyway?
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« Last Edit: January 24, 2014, 08:31:29 AM by Greg Daspit »
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Ric Gillespie

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Re: Grand Rapids trip
« Reply #12 on: January 24, 2014, 09:46:27 AM »

Productive meeting in Grand Rapids yesterday.  Aris Scarla is Manager of the FAA District Flight Standards Office.  He has 30+ years of experience as an accident investigator and repair/modification inspector.  He also has an interest in the history of aircraft construction and repair regulations and practices.  Of course, Mr. Scarla's observations and opinions were offered as an individual, not as an FAA spokesperson.

I'll be writing up a full report but, to cut to the chase:
Previous dismissals/disqualifications of Artifact 2-2-V-1 as being from NR16020 were based upon comparisons of the rivet pattern with existing Model 10s - but we know that the area on NR16020 that best matches the artifact did not look like standard Model 10s.  We have the repair orders that describe, in general terms that work that was approved to be accomplished.  The final report of what was actually done is missing and may or may not still exist.  In any case, there are a number of factors and common repair techniques that could account for the slight discrepancy in the rivet pattern between the artifact and a standard Model 10.  In other words, the artifact cannot be disqualified based on the rivet pattern. All other aspects of the aluminum sheet and surviving rivet exactly match a particular location on the belly of NR16020. In addition, the way the structures failed and the present condition of the artifact are entirely consistent with the Electra's hypothetical breakup in the surf.   

Bottom line:  Unless the missing report turns up, 2-2-V-1 cannot be considered a "smoking gun," but neither can it be dismissed.  We've not been able to find any place on any other aircraft that even comes close.  Like so many other aspects of our investigation, there seems to be no conclusive connection to Earhart but neither does there seem to be a viable alternative explanation for its presence on the island.
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Tim Gard

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Re: Grand Rapids trip
« Reply #13 on: January 25, 2014, 12:53:50 AM »

neither does there seem to be a viable alternative explanation for its presence on the island.

Encouraging news.
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Monty Fowler

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Re: Grand Rapids trip
« Reply #14 on: January 25, 2014, 07:20:34 AM »

The report is out there, somewhere ... and it will turn up at the most opportune moment. Look at all the other bits of paper and whatnot that are STILL turning up about Amelia and Fred - the Chater Report, the New Zealand photos, Betty's notebook ...

If it had Amelia's name on it, someone, somewhere, probably kept it.

LTM, who pushes paper for a living,
Monty Fowler, TIGHAR No. 2189 CER
Ex-TIGHAR member No. 2189 E C R SP, 1998-2016
 
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