TIGHAR

Amelia Earhart Search Forum => Artifact Analysis => Topic started by: JNev on June 07, 2012, 04:30:17 PM

Title: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 07, 2012, 04:30:17 PM
I am starting this string to further explore the possibility of this artifact having NR16020 as a source.

The artifact (2-2-V-1 (http://tighar.org/Publications/TTracks/1998Vol_14/squareone.pdf)) was found in the 'Village' area of Nikumaroro during an early expedition (October 18, 1991) and is clearly an aircraft part.  Here is an earlier (original) report on the item (http://tighar.org/Publications/TTracks/1992Vol_8/2_2_V-1.pdf) as originally found and discussed, and another on some forensic analysis performed on the skin by the NTSB (http://tighar.org/Projects/Earhart/Archives/Documents/NTSB_Report/ntsbreport.html).

'What airplane' is of course a very good question.  It is not clear is that this 'skin' actually 'must' belong to NR16020 for a variety of reasons.  But some of its characteristics are consistent with a number of metal components that would have been in that plane (and of course many others), so the possibility is very interesting. 

What is not so clear is if the 'skin' is distinctive enough to be shown to have been attached to the Electra in the past: it may be a modification part that cannot be shown to match another plane, or the Electra, short of recovery of that airplane. 

My thought is to further examine the photographic evidence we have, and perhaps even another Electra (or more than one more) as an exension of the effort TIGHAR has already been able to make.  It does not appear that TIGHAR has been able to exhaust all possibilities - access isn't easy, and existing historic photographs have their limits.

Note too that even if the part were somehow definitively linked to Earhart's Electra, it still would not prove a presence of the airplane on Niku - it could have been transported there from another place.  But it would provide evidence of the airplane being in the vicinity - and either accessible by humans in the past, or in a place where it once gave up parts that washed ashore, etc.  This is also admittedly a very tough challenge: such skins don't bear serial numbers, etc.

Is it worth the chase?  I believe it is - for the education of the exercise, and for the long-shot chance it may yet prove to be a 'lead'.  Besides, it seems like a fun undertaking to be a part of the TIGHAR exercise.

I have a background in aviation maintenance, modification and repair, including extensive sheet metal training and work experience.  This makes a few notable things about this artifact stand out to me as indicators for possible fitment on the Electra (or another type perhaps, of course); as mostly mentioned in TIGHAR's data already, the following things can be observed:
- The sheet is .032" thick - if a repair item, the norm would be that it would not be used as a doubler or replacement for a skin or other component of greater thickness;
- The sheet bears rivet holes mostly of 3/32" diameter in neat rows, evenly spaced (and slightly tapered relative to each other implying this 'skin' would have been fitted to a 'transitional' area, i.e. where a fuselage or other structure tapers, etc.) -
J.N. Note: This is a rivet size that is not normally used in 'primary' structure, i.e. what we tend to think of as 'load bearing or carrying members' and including (oddly enough) fairings; there are exceptions to this: some airplanes use this size fastener in lightly-loaded sections of control surface skins where weight is critical and the 'tacking' task is not demanding.  The same is true in some fairing assemblies for the same reason, if only light stiffening qualities are required, etc.  This suggests a need to look in 'secondary' areas, i.e. places where such a broad skin might only be lightly reinforced by light-weight stringers or stiffeners, attached to relatively light structure with a minimal 'tacking' requirement present, etc.
- The sheet bears one surviving rivet which has a distinctive 'brazier' style head that is common prior to WWII; that style gave way to the AN470 'universal head' rivet around the time of WWII and is largely a 'pre-war' item.  It would not be common to find a brazier head rivet used in aircraft produced after war production was accelerated.
- The sheet is 'alclad' and bears markings that are consistent with pre-war aluminum production (a more automated process was begun during war-time production and the machine inked 'signature' is different).
- There are a very few larger diameter rivet holes surviving near at least one edge of the sheet which imply picking-up of a heavier attach point - perhaps an existing row of structurally significant rivets along a stringer or other such component.
J.N. Note: So few of these 'primary' sized holes may make a match extremely difficult as this may be the sole evidence of attachment to any primary / original portion of the parent airframe.

Ignoring for the moment 'other types' and focusing on the Electra for the simple purpose of examining a hypothesis of whether this might be from 'the' Electra, what areas of the airframe might include such an item?

One that I was not aware of prior to the symposium in Washington D.C. was a large window that was cut into the starboard side of the lavatory compartment in the Electra.  This was later covered-over in Miami, according to information in the 'Harney Drawings'.
Why consider this location for this sheet?
- Thickness: according to information in TIGHAR's material (linked above) the skins in this area are reduced in thickness from .040" forward to .032" aft; more importantly, a 'window' implies braced 'edges', and to cover it should only require a light skin of this sort in a non-pressurized airplane of the Electra's performance.
- Potential 'brace pattern' - the light rivets imply light bracing, or stiffening, across the 'membrane'; this would be needed to prevent 'oil canning' of such a cover in flight, once installed.
- Edge attachment: unfortunately not so clear, but the surviving larger rivet holes imply an 'edge' that may have been attached to heavier, braced structure which would be typical at the edge of such a window.
- While also appropriate in other areas for similar reasons, 'alclad' would be a desireable selection for an external 'panel' of this sort (so it does not 'prove' anything, but is 'consistent with' a logical choice for such an installation).

This is just one idea (and is one I am trying to investigate further at this time).  There are pictures of the starboard side of the Electra on the ground and in flight which show a tell-tale 'window cover' in the lav area as described (well aft of Fred's remaining starboard side 'nav window' in the aft cabin area), but so far I have not found a picture with enough fidelity, for me at least, to identify potentially-telling rivet / brace patterns, etc.

Any help with better pictures of this area would be appreciated, as would thoughts of additional areas where such a panel might find a 'home'.  There are of course a number of other possibilities for placement of such a skin.

Thoughts?  Ideas?  Better pictures of the starboard (right) side of the fuselage in this area (immediately aft of main cabin)?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 07, 2012, 05:27:39 PM
i know were that part goes on the Electra  :)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Tom Swearengen on June 07, 2012, 06:11:44 PM
Jeff---I have this thumbnail pic that I think was part of Purdue's archives. I dont know if this was during initial construction, or back at Burbank for the repairs after the Luke Field incident. The does appear to be a replacement panel near where the TIGHAR artifact archives place it. I think however, after seeing it in DC, that the curvature might be wrong. As I recall, the curvature flows perpendicular to the rivit lines, and in this picture, the sides of the fuselege are pretty flat, until it begins its curve near the top of the fuselege. In this case, it appears the panel isnt from that location, but might be from somewhere near it, that we cant see in the pics.
Wondering aloud---the repairs at Lockheed after Luke Field--I wonder how much -if any- skin replacement were done that far aft of the wing root, and pretty high on the fuselege.
Any thoughts?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 08, 2012, 06:26:14 AM
i know were that part goes on the Electra  :)

What is your idea, Richie?  I'm interested!

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 08, 2012, 07:02:43 AM
Jeff---I have this thumbnail pic that I think was part of Purdue's archives. ...after seeing it in DC, that the curvature might be wrong. As I recall, the curvature flows perpendicular to the rivit lines, and in this picture, the sides of the fuselege are pretty flat, until it begins its curve near the top of the fuselege. ...it appears the panel isnt from that location, but might be from somewhere near it, that we cant see in the pics.
Wondering aloud---the repairs at Lockheed after Luke Field--I wonder how much -if any- skin replacement were done that far aft of the wing root, and pretty high on the fuselege.
Any thoughts?

Thanks Tom!  Do you have a larger version of this picture?  I can't blow it up effectively for some reason -

I don't know if we can fully trust the apparent 'contours' we're seeing in the artifact today - one thing the analysis revealed was that it appears to have been subject to great force when torn away from the parent structure.  So there may be some distortion there that prevents accurate matching against contours.  It is a good point though, for sure, and I got the same impression you mention - that the 'stiffener' rows of small fasteners would likely run generally 'flat' and the skin might 'roll' perpendicular to them.  Seems logical as those things go on structures, generally.

The location I've so far suggested (lavatory compartment, starboard side - window) is where you've 'wondered aloud' about, somewhat.  I don't have any information that suggests any of that was replaced as part of the repair scheme.  What I do find is the note on the Harney Drawings about AE having a large window cut in the lav starboard skin after the Luke Field incident, then having the same window covered over in Miami before departing for the rest of the final world circumnavigation. 

Somewhere I found a photo that shows a 'panel' over that window - among the Purdue items I believe.  It is actually on another laptop (my kooky 'filing habits' will kill me one day...) - I'll look for it and post it ASAP. 

At any rate, that is one possibility.  Thanks for looking this over - there are many possibilities (including of course that it didn't even come from 'the Electra'... but how a distinctly pre-war chunk of alclad like that wound up on Gardner Island is extremely interesting, no matter how it happened or what it came from.   

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Tom Swearengen on June 08, 2012, 09:50:38 AM
Jeff---I'll what I can come up with. I thing I got that pic from the Purdue site, but I'll look around.
Tom
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 08, 2012, 11:33:53 AM
The letters A D on this artifact and, the type of rivet attached to it...

http://www.mlevel3.com/BCIT/rivetID.htm

http://zenithair.com/kit-data/ht-86-12.html (http://zenithair.com/kit-data/ht-86-12.html)
Any ideas?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 08, 2012, 01:11:28 PM
Is it just a coincidence that this sheet of Alclad has the letters A D on it or, does A D refer to the type of rivet to be used ?

The 2117-T rivet is designated as an “AD” rivet, and has a dimple on the head.

http://www2.tech.purdue.edu/at/courses/at308/Technical_Links/Ac43-13-1B/CH4_4.pdf (http://www2.tech.purdue.edu/at/courses/at308/Technical_Links/Ac43-13-1B/CH4_4.pdf)

Just a thought
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 08, 2012, 03:11:51 PM
sorry to keep u waiting Jeff, was mad busy last night and forgot i had commented on this thread will post u some pic's that have similar patterns

a.s.a.p  :)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Ricker H Jones on June 08, 2012, 05:22:19 PM

... pictures of the starboard (right) side of the fuselage in this area (immediately aft of main cabin)?
Here is a "Before" photo of the starboard side of the Electra (http://www.google.com/imgres?hl=en&sa=X&biw=1241&bih=606&tbm=isch&prmd=imvns&tbnid=FiJ5JnAcwsXc3M:&imgrefurl=http://www.thisdayinaviation.com/05/31/1-june-1937/amelia-earharts-lockheed-electra-10e-nr16020-is-refueled-at-miami-florida-1-june-1937/&docid=mgKVowc4pxeujM&imgurl=http://www.thisdayinaviation.com/wp-content/uploads/2012/05/Amelia-Earharts-Lockheed-Electra-10E-NR16020-is-refueled-at-Miami-Florida-1-June-1937.jpg&w=634&h=454&ei=gnvST8rsHcry2QXC95yBDw&zoom=1&iact=rc&dur=494&sig=118445534989792804119&page=1&tbnh=127&tbnw=154&start=0&ndsp=20&ved=1t:429,r:2,s:0,i:81&tx=89&ty=72) taken in Miami.  An "after" photo taken in Lae  (http://tighar.org/news/images/stories/earhart_project/1055.jpg)is on the TIGHAR site, and shows the starboard side.
Here is one more "before" photo (http://www.pacificaviationmuseum.org/blog/wp-content/uploads/2009/11/plane1.jpeg).
 
 
 
 
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 08, 2012, 06:30:18 PM
Jeff

Does anyone know if the partition wall's in this photo are aluminum ?

i think the skin u have posted either belongs under the mono tail or directly under cabin side windows ?

Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Bruce Thomas on June 08, 2012, 06:43:38 PM

... pictures of the starboard (right) side of the fuselage in this area (immediately aft of main cabin)?
Here is a "Before" photo of the starboard side of the Electra (http://www.google.com/imgres?hl=en&sa=X&biw=1241&bih=606&tbm=isch&prmd=imvns&tbnid=FiJ5JnAcwsXc3M:&imgrefurl=http://www.thisdayinaviation.com/05/31/1-june-1937/amelia-earharts-lockheed-electra-10e-nr16020-is-refueled-at-miami-florida-1-june-1937/&docid=mgKVowc4pxeujM&imgurl=http://www.thisdayinaviation.com/wp-content/uploads/2012/05/Amelia-Earharts-Lockheed-Electra-10E-NR16020-is-refueled-at-Miami-Florida-1-June-1937.jpg&w=634&h=454&ei=gnvST8rsHcry2QXC95yBDw&zoom=1&iact=rc&dur=494&sig=118445534989792804119&page=1&tbnh=127&tbnw=154&start=0&ndsp=20&ved=1t:429,r:2,s:0,i:81&tx=89&ty=72) taken in Miami.  An "after" photo taken in Lae  (http://tighar.org/news/images/stories/earhart_project/1055.jpg)is on the TIGHAR site, and shows the starboard side.
Here is one more "before" photo (http://www.pacificaviationmuseum.org/blog/wp-content/uploads/2009/11/plane1.jpeg).

I'm puzzled by those two pictures.  The one purports to have been made on May 20, 1937, as AE prepared to take off from Miami for Puerto Rico.  Two windows are quite visible aft on the starboard side.  But in the picture identified as being taken in Lae, I only see the one window.  When, after leaving Miami, would there have been any skinning done to cover over the other window?

Looking at the clothing worn in the picture purported to have been taken in Miami, I find those folks dressed as if it's cold.  Yes, the ground is also wet, but some of that clothing seems to be protection against lower temperatures, and that's not the Miami I've experienced in late May.  I wonder if the locale for this picture has been misrepresented by the website displaying it?  Looking at a picture showing first-day covers being presented to AE by the Oakland postmistress (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=392&CISOBOX=1&REC=2) on March 17, 1937, the ground is similarly wet and the people (including Paul Mantz) are bundled up against the normal SF Bay area chill.  And I wonder:  does the presence of three sailors helping with the refueling further tilt the location towards Oakland and away from Miami?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Malcolm McKay on June 08, 2012, 09:39:13 PM
Jeff

i think the skin u have posted either belongs under the mono tail or directly under cabin side windows

No, if you examine the rivet spacing in the recovered piece, the number of rows is wrong and also that  there is no multiple rivet row as in the top and fourth rows on the skin under the cockpit window. 
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 09, 2012, 08:19:04 AM
Have I missed something in this thread? Where has the idea that this piece of Alclad originates from a Lockheed Electra come from? Is there something unique that tells us it's Electra?
For sure it's airplane material, design and construction technique but that alone doesn't make it Electra. Maybe I missed something?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Chris Johnson on June 09, 2012, 08:28:01 AM
Have I missed something in this thread? Where has the idea that this piece of Alclad originates from a Lockheed Electra come from? Is there something unique that tells us it's Electra?
For sure it's airplane material, design and construction technique but that alone doesn't make it Electra. Maybe I missed something?

I could be wrong but i think the idea is to discuss the object to try and prove yes or no thta it comes from the electra.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 09, 2012, 09:08:13 AM
I see Chris, just checking to make sure I didn't miss something.
I guess it would be good idea to start at the beginning then and try to identify the features which point to a particular era, make and model of aircraft or, anything else about it that makes it unique.
Here's my first point:
Is it a repair section or, a mass produced sub-section and, how would we be able to tell the difference?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 09:38:39 AM
...Where has the idea that this piece of Alclad originates from a Lockheed Electra come from?

The idea that it might originate from an Electra - namely NR16020 - came from TIGHAR finding the item on Niku in the village during an early expedition there.  As you state, it is an idea only, so far.

Quote
Is there something unique that tells us it's Electra?

No, only that it appears to be a pre-war aircraft related item because of what could be discerned of how it is marked, what material it is and by the characteristic of the one surviving rivet (a brazier head type - common to pre-war rivets).  It could be from an Electra - or any number of other airplanes as well.  It is possible, however remote, that we could eventually show that it came from the Electra; we'd likely never prove what else it may have come from.

Quote
For sure it's airplane material, design and construction technique but that alone doesn't make it Electra. Maybe I missed something?

No - you are correct.  My reason for raising this discussion was simply to explore the possibility of it being identified as something that came from the Electra by examination of primary and secondary structural elements and possible fitment as part of original, repair or a modification scheme on that plane. 

I'd say that any eventual 'success' in that exercise is likely to be a very long-shot, but it makes an interesting exercise to me and I thought others might enjoy the 'chase' too.

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 09:43:01 AM
Jeff

i think the skin u have posted either belongs under the mono tail or directly under cabin side windows

No, if you examine the rivet spacing in the recovered piece, the number of rows is wrong and also that  there is no multiple rivet row as in the top and fourth rows on the skin under the cockpit window.

I agree, Malcolm.

I think we need to examine other, likely more obscure areas (many more easily viewed areas have been examined - and I think 'secondary structure' needs closer attention due to the light construction character of this panel). 

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 09:52:11 AM
Jeff

Does anyone know if the partition wall's in this photo are aluminum ?

i think the skin u have posted either belongs under the mono tail or directly under cabin side windows ?

Richie, I think the partition bulkhead behind the navigator is a possibility as a 'light structure' that could have been built with such light fasteners to hold light stiffeners - but I see one thing in the artifact that suggests that would be a remote possibility: the neat rows of 3/32" rivets are tapered as they progress one end to the other.  This suggests that the part lay in some area where the lines of structure tended to taper in that way, or in some zone of transition.  That's not out of the question for such a partition, but I wouldn't expect it. 

One problem we have with that photo to is that the bulkhead appears to be covered with soft goods, so we'd need to find one without the interior being finished (or find 'an Electra' in that condition that we could examine).

My current focus is on the added window in the lav - very large - and said to have been covered-over in Miami prior to departure, at least by information in the Harney Drawings.  Ricker has provided a couple of pictures of that, and somewhere (still trying to dredge it back up) I have one or two showing the 'covered' window.  One 'problem' with that big lav window is that at least the outer edges (upper and lower) appear to be parallel - which offsets the notion of the 'tapered' lines for the small rivets.  That said, the window does lie in a tapered section where surrounding elements tend to converge as they transition aft, so whoever covered that window could have easily adapted any stiffener placement to better match the surrounding structure elements in their alignment.  A good shot of that covered window is what we need to examine this idea further.

The lavatory window is of course simply another possibility, and there are no doubt many others.  Good work - keep looking!  Can you get a clear picture of that window in its covered state?  Ricker's are a good start but maybe we can get a closer more clear shot of the area with the 'cover' in place?

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Ricker H Jones on June 09, 2012, 10:20:56 AM
The lav bulkhead may have been of similar construction as the cockpit bulkhead shown in this photo. (http://www.corbisimages.com/stock-photo/rights-managed/U350053ACME/amelia-earhart-in-interior-of-the-flying?popup=1)
 
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 10:41:42 AM
The lav bulkhead may have been of similar construction as the cockpit bulkhead shown in this photo. (http://www.corbisimages.com/stock-photo/rights-managed/U350053ACME/amelia-earhart-in-interior-of-the-flying?popup=1)

Excellent, Ricker - thanks for this and the other photos!  This is worth studying.

Here are some other photos of the lavatory window - open and in the covered state.  I have marked some to emphasize the area in question.  A crafted-cover is evident in the 'covered window' shots; it is beyond my abilities to accurately judge, but the 'added skin' cover appears to display some slight waviness as the light interacts with the surface in one of these shots - suggestive of a fairly light, hand-crafted covering. 

I cannot make out any 'stiffener lines / 3/32" rivet lines' so far either, but they would be very small if there.  I want to study this picture more closely - and if there are better ones available of the area they might yield a clue.

Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Chuck Varney on June 09, 2012, 11:43:54 AM
I'm puzzled by those two pictures.  The one purports to have been made on May 20, 1937, as AE prepared to take off from Miami for Puerto Rico.  Two windows are quite visible aft on the starboard side.  . . .  And I wonder:  does the presence of three sailors helping with the refueling further tilt the location towards Oakland and away from Miami?

Bruce,

The first “Before” link that Ricker provided doesn’t work for me, but if this is the photo in question (http://www.thisdayinaviation.com/05/31/1-june-1937/amelia-earharts-lockheed-electra-10e-nr16020-is-refueled-at-miami-florida-1-june-1937/), it was not taken in Miami on 1 June 1937 (or on 20 May 1937). The aircraft is in its first-world-flight configuration so the photograph was taken on or before 20 March 1937, the date of the Luke Field takeoff attempt.

Going on your Oakland assessment for the location, I found this photo taken in Oakland (http://www.kansas.com/2011/01/29/1694595_a1694368/amelia-earhart.html) during preparations for the first world flight. It is a port side view of the scene shown from the starboard side in the link above. It seems likely that the date is 17 March 1937, the day of departure for Hawaii.

Chuck
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 12:11:10 PM
It sure appears that the two photos you've shared are the same plane, same event, same people, same day, Chuck - just different views.  Good catch.

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Chuck Varney on June 09, 2012, 12:32:47 PM
Jeff---I have this thumbnail pic that I think was part of Purdue's archives. I dont know if this was during initial construction, or back at Burbank for the repairs after the Luke Field incident.

Tom,

I didn’t see your thumbnail among the photos in the Purdue collection, but I found this one (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=%2Fearhart&CISOPTR=529&DMSCALE=12.5&DMWIDTH=600&DMHEIGHT=600&DMMODE=viewer&DMFULL=0&DMX=40&DMY=0&DMTEXT=&DMTHUMB=1&REC=6&DMROTATE=0&x=332&y=228) that appears to have been taken about the same time as your photo (during initial construction in 1936). It shows quite a bit of skin detail.

Chuck
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 12:54:02 PM
Good find, Chuck.

If we can find any that are further aft - of skins behind the station that defines the aft-edge of the door it would help us see rivet patterns in that area.  That would coincide with the lavatory area (and starboard or port side skins are probably similar in a 'stock' airplane).

What would be really telling about the covered-over lavatory skin are any photos of this quality in that area that show that detail.  That could tell us something about the larger rivets and how they are spaced - whethere there may be a match to the larger rivet hole pattern on the artifact (and how it would have attached to the parent structure).

It probably will be important ultimately to get photos of the as-modified airplane because just sticking an 'after-market' skin over a window opening does not guarantee that any original structure would be 'picked-up' by the installer other than at the edges - it (former structure) wouldn't be there in the middle of the aperture.  Accordingly, whoever installed the covering 'skin' to close the window on NR16020 may have improvised lightweight stiffeners over the middle of the 'membrane' formed by the panel, and only approximated fuselage taper when laying the fastener rows out. 

If my thought on how the window 'blank' was installed over the opening is correct, what would have been important more than anything else is damping 'oil can' effects in the new skin.  When able I'll try to make a sketch of this 'notion' and post it here to give a graphic idea of what I'm trying to describe.

Thanks for digging out these photos - very helpful!

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Bruce Thomas on June 09, 2012, 01:50:07 PM
I'm puzzled by those two pictures.  The one purports to have been made on May 20, 1937, as AE prepared to take off from Miami for Puerto Rico.  Two windows are quite visible aft on the starboard side.  . . .  And I wonder:  does the presence of three sailors helping with the refueling further tilt the location towards Oakland and away from Miami?

Bruce,

The first “Before” link that Ricker provided doesn’t work for me, but if this is the photo in question (http://www.thisdayinaviation.com/05/31/1-june-1937/amelia-earharts-lockheed-electra-10e-nr16020-is-refueled-at-miami-florida-1-june-1937/), it was not taken in Miami on 1 June 1937 (or on 20 May 1937). The aircraft is in its first-world-flight configuration so the photograph was taken on or before 20 March 1937, the date of the Luke Field takeoff attempt.

Going on your Oakland assessment for the location, I found this photo taken in Oakland (http://www.kansas.com/2011/01/29/1694595_a1694368/amelia-earhart.html) during preparations for the first world flight. It is a port side view of the scene shown from the starboard side in the link above. It seems likely that the date is 17 March 1937, the day of departure for Hawaii.

Chuck

Awesome find, Chuck!  Good job!
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 09, 2012, 02:36:06 PM
Jeff, there's a lot of stills on this link that show the inside of the Electra viewed from outside the fuselage door. You can see the FN's navigation window and, where the other original window should be but isn't. Looks like these images were aquired after the skinning over.

http://www.criticalpast.com/video/65675063657_Amelia-Earhart-Putnam_Fred-Noonan_transatlantic-flight_Fred-Noonan (http://www.criticalpast.com/video/65675063657_Amelia-Earhart-Putnam_Fred-Noonan_transatlantic-flight_Fred-Noonan)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Chuck Varney on June 09, 2012, 02:50:58 PM
If we can find any that are further aft - of skins behind the station that defines the aft-edge of the door it would help us see rivet patterns in that area.  That would coincide with the lavatory area (and starboard or port side skins are probably similar in a 'stock' airplane).

Jeff,

The best rivet detail I found in the Purdue collection for your aft region of interest was in this
 port side (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=%2Fearhart&CISOPTR=378&DMSCALE=25&DMWIDTH=600&DMHEIGHT=600&DMMODE=viewer&DMFULL=0&DMX=586&DMY=295&DMTEXT=%2520electra&DMTHUMB=1&REC=15&DMROTATE=0&x=413&y=394) shot (first-world-flight configuration).

Chuck
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 09, 2012, 03:01:25 PM
"Whilst pure aluminium has low specific gravity, good corrosion resistance and excellent thermal and electrical conductivity it is too weak and ductile to be used on its own. In 1906 Dr Alfred Wilma, a German metallurgist, discovered that aluminium alloyed with copper and heat treated correctly could be made far stronger. The alloy of aluminium with 4% copper is called Duralumin and the heat treatment process is called precipitation hardening. These alloys have typically low specific gravity (around 2.7) and high strength (450 MPa). They are limited by a maximum service temperature of about 660°C. Since then, other heat treatable aluminium alloys have been developed for aircraft use. These include a range of complex aluminium-zinc alloys which develop the highest strength of any aluminium alloy. These alloys have led to modern aircraft design where the skin of the fuselage and wings are stressed aluminium alloy members which reduces the overall weight.
The aluminium alloys mentioned above have the disadvantage of not being as corrosion resistant as pure aluminium so a thin layer of pure aluminium is often pressure welded to both sides of the alloy. This material is called Alclad."


http://hsc.csu.edu.au/engineering_studies/focus/aero/2580/aluminium_alloys.html (http://hsc.csu.edu.au/engineering_studies/focus/aero/2580/aluminium_alloys.html)


Alclad is a trademark of Alcoa used as a generic term to describe corrosion resistant aluminium sheet formed from high-purity aluminium surface layers metallurgically bonded to high strength aluminium alloy core material. These sheets are commonly used by the aircraft industry.[1] The first aircraft to be constructed from Alclad was the all-metal Navy airship ZMC-2, constructed in 1927 at Naval Air Station Grosse Ile.[2]
 
"Described in NACA-TN-259,[3] of August 1927, as "a new corrosion resistant aluminum product which is markedly superior to the present strong alloys. Its use should result in greatly increased life of a structural part. Alclad is a heat-treated aluminum, copper, manganese, magnesium alloy that has the corrosion resistance of pure metal at the surface and the strength of the strong alloy underneath. Of particular importance is the thorough character of the union between the alloy and the pure aluminum. Preliminary results of salt spray tests (24 weeks of exposure) show changes in tensile strength and elongation of Alclad 17ST, when any occurred, to be so small as to be well within the limits of experimental error." In applications involving aircraft construction Alclad has proven to have increased resistance to corrosion at the expense of increased weight when compared to sheet aluminum.[4]"
http://en.wikipedia.org/wiki/Alclad (http://en.wikipedia.org/wiki/Alclad)

Aluminium alloys have been around for quite some time (1903) and, are still in use today. A good example being Alclad (1927)which comes in varying thickness and flavours and, is still the main choice in Aerospace development. A few exceptions, Titanium being one for mach 2+ applications.
So I wouldn't expect to be able to match this piece to the electra on the basis of the material it is made from.
The 2117 AD rivet has also been around as long as aluminium alloys and Alclad and again, is still available and in use today. So the rivet also could be from any aircraft manufactured from 1927 to this day.
Suffice to say there is an excellent chance that this artifact came from one of the aircraft that went missing in this area of the pacific and, I suspect the only way to confirm that is to match the rivet patterns, size, orientation and quantity to one of them. I'll get started.



Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 03:16:46 PM
Jeff, there's a lot of stills on this link that show the inside of the Electra viewed from outside the fuselage door. You can see the FN's navigation window and, where the other original window should be but isn't. Looks like these images were aquired after the skinning over.

http://www.criticalpast.com/video/65675063657_Amelia-Earhart-Putnam_Fred-Noonan_transatlantic-flight_Fred-Noonan (http://www.criticalpast.com/video/65675063657_Amelia-Earhart-Putnam_Fred-Noonan_transatlantic-flight_Fred-Noonan)

Wow - thanks Jeff Victor!  Lot's to go through here - excellent.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 03:19:53 PM
Jeff,

The best rivet detail I found in the Purdue collection for your aft region of interest was in this
 port side (http://earchives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=%2Fearhart&CISOPTR=378&DMSCALE=25&DMWIDTH=600&DMHEIGHT=600&DMMODE=viewer&DMFULL=0&DMX=586&DMY=295&DMTEXT=%2520electra&DMTHUMB=1&REC=15&DMROTATE=0&x=413&y=394) shot (first-world-flight configuration).

Chuck

Chuck, this is outstanding - thanks!

My belief without more information is that the starboard and port skins and bracing should essentially be symetrical in this section of the fuselage.  This should provide an excellent starting point to compare rivet size and pitch along the visible fastener lines.  Excellent - many thanks!

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 03:30:58 PM
Here is a 'paint' illustration of the close-up of the covered window to illustrate the area I've been describing (lavatory starboard skin).  It is based on the photo that shows the cover panel - which is now a bit obscured by my 'crayon' work, but I wanted to lay out the idea of how the artifact might fit.

Note the size of the window covering - approximately 20" high by 26" wide (as best I can scale it from the fuselage stations (given in inches) and from the photo).  The artifact is smaller than the opening.  Since 2-2-V-1 is a smaller piece than whatever it was originally a part of, a fit here within the bounds of this panel is not out of the question.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Chuck Varney on June 09, 2012, 03:41:54 PM
Jeff, there's a lot of stills on this link that show the inside of the Electra viewed from outside the fuselage door. You can see the FN's navigation window and, where the other original window should be but isn't. Looks like these images were aquired after the skinning over.

Jeff V. H.,

The video clip and stills in your link show the aircraft prior to departure for Hawaii in March 1937. The starboard window configuration at that time was as shown in this link (http://www.pacificaviationmuseum.org/blog/wp-content/uploads/2009/11/plane1.jpeg), posted earlier in this thread by Ricker Jones.

Chuck
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 09, 2012, 04:10:57 PM
the reason i suggested the tail section is because there appears to be large sections with just rows of rivets

here is some images for you to look over hope they help  :)

Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 09, 2012, 04:17:31 PM
more pic's
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 09, 2012, 05:04:37 PM
has anyone checked this area out
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 09, 2012, 05:19:00 PM
here is side view
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Ricker H Jones on June 09, 2012, 05:26:20 PM
See the Ameliapedia for other previous work done on 2-2-V-1 HERE (http://tighar.org/wiki/2-2-V-1) and HERE (http://tighar.org/Publications/TTracks/14_1/Back_to_Square_One.html).
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 05:41:50 PM
Thanks Ricker!  There is quite a bit of information on this item at TIGHAR - well worth reviewing all of it.

Here is one more sketch based on a reversed image of the photo Chuck came up with (detail of left side ('port') aft of door.  So far I am getting 1.5" rivet spacing in each row of the 'double row' (as shown) and about 1.25" vertical rivet line spacing - based on measurements from the known stations / distances in the picture.



Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Tom Swearengen on June 09, 2012, 08:43:23 PM
Jeff---recall us looking at this in person ALOT---remember talking about the contour of the roll on the panel? Looking at the pics posted here, I think the shape is wrong. For it to fit on the aft window, the rivit lines we saw would have to be vertical, which is ok, but the contour to fit from the side of the fuselege towards the top need to have a slight roll in the vertical direction with the rivit line. The piece we saw in DC was opposite; the roll was perpendicular to the rivit line.
NOW---- thats not to say that it didnt come from the Electra, or from the window patch repair. Being it was found in the village, it 'could' have been altered. The length and width appear to be correct, but the contour bothers me.
Maybe we should make a run to Pensecola to look at the Electra there, and see if we can figure this out.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Tom Swearengen on June 09, 2012, 09:05:11 PM
UPDATE: Jeff  the rivit lines in the artifact more closely resemble the wing walk area of the wing root. The contour is still off, but we're getting closer. I dont think its from a fuselege side panel ; not enough rivit lines.
Tom
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 10:34:44 PM
...the rivit lines we saw would have to be vertical,

I don't think so -

Quote
...the contour to fit from the side of the fuselege towards the top need to have a slight roll in the vertical direction with the rivit line.  The piece we saw in DC was opposite; the roll was perpendicular to the rivit line.

Look again - see what the NTSB report  (http://tighar.org/Projects/Earhart/Archives/Documents/NTSB_Report/ntsbreport.html) says about 2-2-V-1.

In part, as you look at the photos of 2-2-V-1 in the NTSB report, consider the 'convex' view - it places the larger diameter, outer edge row of fasteners at the top - with the 'stiffener' rows (if that's what they are) tapering from narrow at left to wider at right: this could be a good fit for the fuselage in that area (the large rivet holes don't match the pitch of the lower window edge: 1.25" vs. 1.5" pitch). 

Also, while the window appears to have been very close to a true rectangle, the fuselage taper in that area does not follow that pattern: look at the pix - the upper window edge departs the natural tapering 'waterline' slightly.  It is the tapering nature of that section of the fuselage that suggests the taper we see in the stiffener lines.

Quote

NOW---- thats not to say that it didnt come from the Electra, or from the window patch repair.

Good candidate I believe - still looking at that and far from exhausting the possibility. 

The wing-walk area is intriguing - possible; but I am holding with the window cover panel for now until I can exhaust that - the key may be the stiffener pattern and whether we can get a view of that 'patch' with enough resolution to see if any were present, what the line layout was, etc.  Edge fasteners are also important - but the one surviving edge we see does not match the known pitch of the fasteners along that double-row at the lower water line of the window (artifact edge rivets pitch = 1.25", NR16020 rivet pitch along that water line appear to be more like 1.5", if I'm getting it right from the stations and rivet count).

Of course this thing could still have come from any number of other airplanes somehow.  No definite match to the Electra, no dice.

Quote
Being it was found in the village, it 'could' have been altered.

It well could have been - but not likely in an 'aircraft' kind of way, i.e. rivet holes added in uniform pattern, etc.

Bending?  Easily.  Despite what we may each think of the 'contours'.  For one thing you have to be careful about trusting the 'contour' anyway - this thing's been mauled pretty badly, and we don't know what from.  It could have been hacked and peeled away from whatever the parent structure was by someone who wanted it for salvage - and that includes 're-making' the contour in any number of ways.  The NTSB report does note that it was bent about 90 degrees at one place; there could have been alot of different angular forces working against it.  Some force appears to have been exerted in a hydraulic fashion against the panel to press it outwards from its fasteners by what I am reading in the NTSB report, so that 'contouring' is evident too.

Quote
The length and width appear to be correct, but the contour bothers me.
Maybe we should make a run to Pensecola to look at the Electra there, and see if we can figure this out.

Back to the NTSB report and what I've said above - and considering that we may not be seeing a normal contour. 

Actually - when you consider the NTSB report and what I recall of the artifact when we saw it, the stiffener lines to seem normal to the 'flat' span and the curve is natural (rolling perpendicular to the 'stiffener' lines, i.e. stiffeners would lie 'straight' more or less (fore and aft), but skin would 'roll' as it progressed vertically.  We may recall it differently, so not to say I'm right - but I'm looking carefully at the pictures I took while there and trying to recall nuance as best I can.  The NTSB report is helpful in interpreting what I saw.

Pensacola - eventually may do that if we can get the right door open to get close (I don't think the Museum of Naval Aviation will let us crawl all over their Electra without some arrangement...), that is if we don't have something better to compare it to after July (long shot, but hey...).

Interesting, huh?  ;)

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 09, 2012, 10:55:08 PM
UPDATE: Jeff  the rivit lines in the artifact more closely resemble the wing walk area of the wing root. The contour is still off, but we're getting closer. I dont think its from a fuselege side panel ; not enough rivit lines.
Tom

Not an original skin panel, that's not what I'm talking about.

You have to keep in mind that the skin cover would not necessarily match anything about the 'stock' airplane except two rows of edge fasteners:
- the horizontal, lower row where it appears to pick-up that existing line of rivets, and
- the vertical row at Sta. 320 where the aft edge of the window panel appears to overlap the frame / existing rivet holes.

Unfortunately, we don't have all the edges, of course... but -

The forward and upper edges don't appear to attach to any existing rivet lines -
- The forward edge appears to butt up immediately behind (faired in) the skin lap at Sta. 307, so that may be (probably is) a unique pattern (by not picking up existing fasteners);
- the upper edge rivet line flies along what was originally an unbraced section of skin - an open area membrane with no internal bracing along that line in the original structure; something had to be added there to accomodate the upper edge of the new window at the time it was put in; the cover would most naturally pick-up that same added fastener line.

The intermediate (mid-panel) 'stiffener' rivet lines - no pattern in original structure:

If the intermediate rivet lines do relate to added stiffeners (I suspect that strongly) their placement would not be so critical - they would not match any existing structure on the airplane because there wasn't any, before the mod or after: this area had a different brace pattern - heavier - before the window was added; once the window was in, it was all, well, 'window'.  After the window was covered, the sole purpose of such stiffeners as I see it would be to stiffen the large, thin metal panel membrane against oil canning and slipstream, vibration, etc. - that's all.  It would act much as a light fairing.

Of course this is all theory - but it makes sense given what we can observe.  It does not make sense in 98 percent of the structure to expect 3/32" rivets to pick-up primary support structure, but they could work well as I have described - and would be effective for the light stiffeners needed to stop a large membrane from vibrating or oil-canning in flight, etc.  This would keep the weight down as well.

Think that over and I think you'll see where I am coming from in this possibility of 2-2-V-1 being a window blank.  I am still a long way from abandoning the possibility of this location, although any possibility is of course welcome.  Likewise, if someone sees a 'fit' on another bird that could be a source, I'd like to know that too: it's 'truth' that I'm after.

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 11, 2012, 02:33:23 PM
Studying the rivet patterns on the Electra again and considering the rivet pitch with a better means of scale, I can see two things:
1) The existing vertical rivets are pitched closer to 1.05" apart, not 1.25".
2) That tells us little if anything about the 'artifact' being a 'fit' - there do not appear to be any remaining rivet holes in the artifact that match any existing rivet patterns in this area of the Electra.

That means short of having the Electra 'in hand' in which case the artifact becomes little more than an interesting item that might be shown to have come from it... or -

Matching the artifact to an as-yet-to-be found picture that will reveal any 'field' rivet lines that may be consistent with those on the artifact.

So I need a good picture... but will relax if the wreck is found in July (and not holding breath, but hey...)  ;)

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Andrew M McKenna on June 11, 2012, 03:36:45 PM
Jeff

There has been a lot of work done to try to match this piece to the Electra.  I wish Ric or Jim Thompson could chime in here as they did the lion's share of the effort.

I'm curious what you think of the attempt to match the skin to the roof of the Electra over the cabin door.  This seemed to be the best match we could find, although the air vent scoop seems to discount the possibility.  Maybe with your background you can see a match in a way that we didn't.

 (http://tighar.org/aw/mediawiki/images/3/37/Top%282%29.png)

you can also find in the Ameliapedia other material such as rivet pattern rubbings, and photos of the roof and air scoop from other Electras that we were trying to match

http://tighar.org/wiki/2-2-V-1 (http://tighar.org/wiki/2-2-V-1)

Thoughts?

Andrew
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Randy Reid on June 11, 2012, 05:59:06 PM
Jeff,

do you know if the rivet holes are still nominal size or have they been enlarged(torn) as the piece was removed from the sub-structure? If the holes are still nominal size, it indicates the rivets were removed prior to removing the sheet, possibly prior to replacing it. When we repaired damaged sheet stock, most of the time at least some of the sub-structure could be reused. This artifact may have been the scrapped pieces from another aircraft repair, maybe even from another island.

Also I do not think this is fuselage or wing skin as it is too thin, even for a patch. Although I have seen duct tape used ;D and it is pretty thin. From the number of support structure members, my guess is that the sheet would be a load bearing shelf, or possibly floor boards or cargo floor.

anyway, luck to you if you can figure it out, and if there is an A&E on the forum, maybe he can chime in.

Randy
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on June 13, 2012, 09:08:03 AM
There's quite a few places where the artifact could fit in to the Consolidated PB4Y-1, size, rivet patterns, distance between rows of rivets and convergence of rows of rivets...?

(http://)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 14, 2012, 01:09:52 PM
Jeff

There has been a lot of work done to try to match this piece to the Electra.  I wish Ric or Jim Thompson could chime in here as they did the lion's share of the effort.

I'm curious what you think of the attempt to match the skin to the roof of the Electra over the cabin door.  This seemed to be the best match we could find, although the air vent scoop seems to discount the possibility.  Maybe with your background you can see a match in a way that we didn't.

 (http://tighar.org/aw/mediawiki/images/3/37/Top%282%29.png)

you can also find in the Ameliapedia other material such as rivet pattern rubbings, and photos of the roof and air scoop from other Electras that we were trying to match

http://tighar.org/wiki/2-2-V-1 (http://tighar.org/wiki/2-2-V-1)

Thoughts?

Andrew

Thanks Andrew.

I respect the excellent work that has been done so far and have reviewed at least most of it, but am needing to review further I am sure.  One question I have for that review is: "was the possibility of a cover for the lav window considered", hence this string.  I don't see that it was - and I see that possibility as a prime candidate (and very hard to find direct evidence by which to 'match' - we're stuck looking for photos of that NR16020-unique feature).

The top section you have shown is an intriguing area due to the stringer lines, etc.  On the positive - it is 'similar'.  The negative for this area may be that the artifact itself displays an irregular pattern compared to what I'd expect to find 'match-drilled' to existing structure: the original skins on the Electra appear to be fixture-controlled - very neat rows, generally; it would follow that the existing stringers there would duplicate that neat fixture pattern.  The 'field' rivet lines in the artifact are more irregular than I would expect to find on the original airframe.  The small #3 rivet holes tend to suppor this too - I don't believe you'd find that in the primary skin / stringer structure in that area - not as a reasonable repair.

Could a 'patch' over a damaged area work like that?  Yes, if you discounted the 'match-drilling' to pick-up existing stringers, etc.

My thought about the 'window cover' is actually an extension of that thought: given that a large opening is being covered, the mechanic was somewhat 'free' to place 'field rivets' as he chose; the logical approach when doing such field work would be to follow nearby patterns - but not necessarily duplicate them perfectly. 

That could explain some of the irregular lines / spacing that we see in the artifact: irregular tapering, and slightly less-than straight lines.  A hand-fit installation is very much suggested by what I see - and that would be consistent with a 'cover panel' to cover such a window.  No existing stringers or stiffeners would be present in the middle of the window, and the thought is that light stiffeners may have been added to offset the vibration / oil can effects one finds in a large light gage sheet.

I need to go back into the Wiki and study what TIGHAR has done in more detail.  I don't know that they're 'wrong' in any regard - but I do still see a 'covering' for that 'weird window' in the lav as a strong candidate for the reasons mentioned.

Randy,

The holes appear mostly intact (not elongated, torn or oversized by force).  A few appear to have been drilled to 'next size', i.e. occasionally you will find a couple or three in a row that were 'drilled up' to a #4 rivet (AWG #30 hole / about 1/8").  Many of the holes were observed to be slightly 'dimpled' by stress - as if the skin and whatever was behind it were somewhat forcibly separated from each other.

I agree that the skin is not too thin for a 'patch' - the question is 'where would .032" be appropriate' and therefore expected to be found: not where there are .040" skins, at least as a norm (it is not normal to go down in gage for a repair or alteration for reasons of strength and stiffness).  The skin could be a patch therefore in an area where .032" skin was originally used - if convention followed.  It could also therefore logically be used for the 'window cover' I've described - either as consistent with surrounding skins aft of the cabin area, or as a stand-alone sufficient covering for the intention of covering the window opening, as we can see was done at some point (we see the window in early shots, the window covered in others, apparently later).

I would love to hear from other A&Ps (or AE's).  I have my experience, but many others have theirs, of course - and that makes the base wider and deeper, of course.

Jeff Victor -

I agree there are areas on the PB4Y-1 where the skins appear to have similar patterns.  I think TIGHAR has looked at this, but it may be worth re-visiting.  One thing that would make me consider that prospect critically would be the apparent vintage of the artifact (pre-war, lower production rates) compared with that of the Consolidated bird (WWII - mass production goods, different markings as I understand it).  But, if a 'match' is made, it could tell us a great deal!

Thanks guys.  I'm going to keep digging - into the TIGHAR materials Andrew suggested and for more pix of the Electra: the more I consider this the more convinced I am that we have a non-original pattern here, and that's the 'place' to look - where would a non-original skin go on NR16020.  I don't want to overlook other areas, but the aft lav window still sticks out as a candidate to me.

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Ricker H Jones on June 16, 2012, 04:56:27 PM
The Harney drawings show skinned over escape hatches (both sides) centered above the trailing edge of the wing root.  The drawing doesn't indicate whether this was done during initial construction or as a later retrofit.  The rivits as shown do not appear to match the artifact, however.
Rick J
 
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeffrey Pearce on June 17, 2012, 05:54:31 AM
For a newcomer, is there something like a final report that discusses the effort to match the large piece of material that looks like part of an aircraft exterior to other electras of Earhart's model?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Martin X. Moleski, SJ on June 17, 2012, 11:17:08 PM
For a newcomer, is there something like a final report that discusses the effort to match the large piece of material that looks like part of an aircraft exterior to other electras of Earhart's model?

I've collected some material on the wiki (http://tighar.org/wiki/2-2-V-1).  I'm not sure how up-to-date it is.  It does not include any of the recent discussions here since the symposium.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Greg Daspit on June 18, 2012, 04:41:17 PM
http://tighar.org/Publications/TTracks/14_1/Back_to_Square_One.html
Is it possible the repair theory is still correct, only they changed their mind about adding stiffeners and removed them? Then covered the thin patch with a another thin layer.  This doubled the thickness and therefore they did not need the stiffeners. In the post repair pictures you only see the outer layer, but could the repair layer theorized still be below serving as an inner laminated layer?
edit: maybe the structure below, not seen on the inner layer is an opening in the outer layer to allow adjustment of the inner layer so holes could align.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on June 19, 2012, 06:09:11 AM
Gregory -

A lot of things are possible - NR16020 was not only extensively repaired but was an experimental airplane by her licensed use - the "NR" registration amounted to 'restricted' for that reason.

What you surmise is perhaps quite possible if a given area of repair was also affected by some need to do a local modification.  It would be unusual to simply delete stringers or stiffeners, but a doubler would be a rational substitute if it was necessary.  The small field rivets would seem odd - but that is a possibility.

I still favor the possibility of a window cover (lavatory area, right side) for now - but that's my notion of a 'rational' site for now.  What you have described is a very good possibility.

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeffrey Pearce on June 21, 2012, 10:43:13 AM
How is a replacement piece of a plane's exterior attached to the plane to secure it into position?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Tim Collins on June 21, 2012, 11:00:22 AM
Jeff

There has been a lot of work done to try to match this piece to the Electra.  I wish Ric or Jim Thompson could chime in here as they did the lion's share of the effort.

I'm curious what you think of the attempt to match the skin to the roof of the Electra over the cabin door.  This seemed to be the best match we could find, although the air vent scoop seems to discount the possibility.  Maybe with your background you can see a match in a way that we didn't.

 (http://tighar.org/aw/mediawiki/images/3/37/Top%282%29.png)

you can also find in the Ameliapedia other material such as rivet pattern rubbings, and photos of the roof and air scoop from other Electras that we were trying to match

http://tighar.org/wiki/2-2-V-1 (http://tighar.org/wiki/2-2-V-1)

Thoughts?

Andrew

I wouldn't be so sure that the air scoop vent necessarily discounts the possibility of this location. The question should be what is the shape of the vent hole beneath the scoop ? What may be overlap of the scoop housing with the skin of the plane?  Is there a margin of error associated with the positioning of the air scoop in the drawings - say, within +/- an inch or two either way? I'd like to think this has already been considered, but I think it's nonetheless important to reiterate.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Andrew M McKenna on June 21, 2012, 11:24:14 AM
Here is the vent hole as seen on the NEAM L-10

http://tighar.org/wiki/File:NEAM_04.JPG (http://tighar.org/wiki/File:NEAM_04.JPG)

It does not reach back to the apparent end of the scoop, or into the territory of 2-2-v-1, the hole is all forward of the stringer / structural element forward of the artifact as projected on the overlay.

Andrew
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Ted G Campbell on June 21, 2012, 11:51:37 AM
Andrew,
The black "cord like" material running along the stringer look much like the "cord, wire, cable, etc." we see in the rov stills.

Do we have other photos in this series?

Ted Campbell
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Andrew M McKenna on June 21, 2012, 12:16:47 PM
Only what is in the Wiki

http://tighar.org/wiki/2-2-V-1 (http://tighar.org/wiki/2-2-V-1)

Jim Thompson may have more.

amck
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Greg Daspit on June 21, 2012, 12:29:29 PM
http://tighar.org/wiki/2-2-V-1

What I find interesting is the holes that attach the rear of the scoop in the picture attached don't show up on 2-2-V-1.
However, the fasteners in this picture of another plane (I assume another plane)shows the fasteners at the rear of the scoop are of a different type where they should overlap the 2-2-V-1 panel than the fasters at the front part of the scoop.

Maybe they put the different rear fasteners in at a later time when they determined they needed them? However on AE's plane they did not get the chance to see the need for the rear fasteners?

Is it known who put the fasters in this picture and when? Who's plane is it?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeffrey Pearce on June 21, 2012, 01:12:47 PM
So a plate of metal that is affixed to the exterior of the fuselage sometime after the plane was built is accomplished solely by riveting the new plate into parts of the existing plates and nowhere else?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeffrey Pearce on June 21, 2012, 01:28:48 PM
Has consideration been given toward trying to find the concern/concerns that made alterations,repairs to Ms. Earhart's Electra?
Title: Artifact 2-2-V-1 - aluminum 'skin'
Post by: John Ousterhout on June 22, 2012, 01:32:30 PM
Some photos of a Japanese aircraft showing tapered lines of rivets can be seen here. (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/55_WreckPhotoResolved/55_WreckPhotoResolved.htm)  The link also shows a similar aircraft that has shed some of its aluminum pieces.  The missing pieces bring to mind the 2-2-v-1 artifact.
What do we know about Japanese aircraft construction?  Did they use thinner aluminum than was normal for Allied aircraft?  Would the rivet holes be diistinctively different in size, or would there be only subtle differences?  Would the normal spacing be distinctive?  For that matter, would Japanese aluminum be chemically distinct from Allied aluminum?  The NTSB report (http://tighar.org/Projects/Earhart/Archives/Documents/NTSB_Report/ntsbreport.html) identified it as clearly Alclad, and had remnants of two letters visible ("AD").  Would these characteristics definitely rule-out a Japanese aircraft as the source?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: John Ousterhout on June 23, 2012, 07:43:47 AM
Jeffrey,

Do you mean by  "...the concern/concerns...." the company that made the alterations?  As I understand it, that was Lockheed.  I've read that TIGHAR have looked, but the records of work done on the aircraft are pretty slim.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Bruce Thomas on June 23, 2012, 08:29:09 AM
Jeffrey,

Do you mean by  "...the concern/concerns...." the company that made the alterations?  As I understand it, that was Lockheed.  I've read that TIGHAR have looked, but the records of work done on the aircraft are pretty slim.

Yesterday I was asking myself if either of the engines was replaced after the Luke Field crash.  The Aircraft Inspection Report dated May 19, 1937, gives their serial numbers.  But is there an earlier AIR to compare those numbers against?  Then I found a summary of 1999 Forum postings, with an entry from Ric saying this:
Quote
Although both props were severely damaged in the Luke Field crash, there is no indication in the repair records or inspection report that either engine was replaced or overhauled. The engine serial numbers remain identical to those in the original inspection done prior to the airplane's delivery in July 1936. Likewise, the prop hubs were not changed but the report does confirm that new blades were installed.

So, I figure there is a goldmine of records at TIGHAR HQs!   ;D
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeffrey Pearce on June 23, 2012, 03:58:36 PM
John,

The 1st thing that comes to mind is the people who did the work. There might be a record of the metal used, it's thickness, where the work was done on the plane, a description of the piece itself. Back then, were reports required to be filed when work on an aircraft was performed? Information loke this could possibly contribute to linking 2-2-V-1 to Ms earhart's plane?

No respect, no respect at all.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: richie conroy on June 23, 2012, 05:42:34 PM
i have wondered about the engine propeller covers, for a while now

pic 1 is of before luke field crash

pic 2 is after the crash

so it is just a cover cap ?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Daniel Paul Cotts on July 01, 2012, 09:38:56 PM
New thread references another site Interesting Info (http://butthisisdifferent.com/Interesting_Info.html) with pics of the Electra. One taken in Miami shows the right side of the aircraft and a shiny area that seems to be the covered window.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: C.W. Herndon on July 02, 2012, 08:31:23 AM
i have wondered about the engine propeller covers, for a while now

pic 1 is of before luke field crash

pic 2 is after the crash

so it is just a cover cap ?

Richie, what you are showing in your pictures is commonly called a "spinner" and only covers the propeller hub to afford a small amount of streamlining. It made it a little harder to perform maintenance on hub. Spinners from that era also had a tendency to slip and allow the propeller openings to turn against the propeller blade which could cause damage to the blade if not corrected quickly. I would only hazard a guess that AE decided that they weren't worth the extra hassle and had them removed.

From what I have read and the pictures I have seen, I would guess that the "propeller covers" were made of some type of fabric material, canvas maybe, and were cut and fitted to slide over each of the propeller blades (to protect them from the elements while parked?). Why they went to all of that trouble is beyond me.

http://earchives.lib.purdue.edu/u?/earhart,380 (http://earchives.lib.purdue.edu/u?/earhart,380) 
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Bruce Thomas on July 02, 2012, 08:54:50 AM
From what I have read and the pictures I have seen, I would guess that the "propeller covers" were made of some type of fabric material, canvas maybe, and were cut and fitted to slide over each of the propeller blades (to protect them from the elements while parked?). Why they went to all of that trouble is beyond me.

http://earchives.lib.purdue.edu/u?/earhart,380 (http://earchives.lib.purdue.edu/u?/earhart,380)

Woody, the picture you've included with your posting is not related to "propeller covers." 

What's shown in the picture is AE being handed a package containing "first day covers" from the postmaster ("postmistress"?) of Oakland, California.  While this photo was taken before the First World Flight, I'm willing to bet that a similar package went along on the Second World Flight ... and ended up all soggy and ruined!

Those first-day covers would have been considerably more valuable than the local first-day covers that didn't get carried aloft -- here's a link to a first-day cover related to AE's solo crossing (http://www.fdclessons.com/img/AmeliaEarhart440.jpg) of the Atlantic in 1932, issued in NYC after her flight and subsequent return to the U.S.

Another example (http://historical.ha.com/c/item.zx?saleNo=6057&lotNo=35564&short=6057-33026) is a first-day cover issued to mark her first flight across the Atlantic in 1928 as "a sack of potatoes."  It bears her signature and sold last year for more than $500. 
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: C.W. Herndon on July 02, 2012, 09:11:53 AM
I guess I misunderstood what was in the package.

Must have been a whole bunch of those little postcards.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: C.W. Herndon on July 03, 2012, 12:26:23 PM
Jeff, no telling what one would be worth.

The note would have been great!!! Who knows, we may find it yet.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Kirstin M. Campbell on July 31, 2012, 07:43:44 PM
I'm new to the topic so I apologize if I tromp through old territory.  I'm still trying to catch up on what analysis has been done along with learning to navigate the site to that information.  Just from my background in aviation metal work and repairs there are some things I'd like to know that I have not come across so far.  Or I missed it.

Do they have Lockheed's 10E complete rivet pattern blueprints or their metal repair manuals?  If they still exist.  These were among the tools we used in mishap investigations to match sections.

Do they have this 10E's Aircraft Log Book which should show what mods and Depot level repairs have been done?

Have they done deeper alloy analysis on the 2024 alloy aluminum of various metal parts and cross checked with a surviving 10E built around the same time?  If such an aircraft exists.  Salt water immersion may have altered the aluminum too much but since not all Alclad is the same between batches I was just curious.  The fact I didn't see the tempers included in their analysis may be my clue that there is too much damage.

Thx :)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Martin X. Moleski, SJ on July 31, 2012, 10:09:01 PM
Do they have Lockheed's 10E complete rivet pattern blueprints or their metal repair manuals?  If they still exist.

So far as I know, TIGHAR has never found such blueprints or manuals.

Quote
Do they have this 10E's Aircraft Log Book which should show what mods and Depot level repairs have been done?

I don't think so.

Quote
Have they done deeper alloy analysis on the 2024 alloy aluminum of various metal parts and cross checked with a surviving 10E built around the same time?  If such an aircraft exists.

TIGHAR worked with History Detectives (http://tighar.org/wiki/History_Detectives) to help authenticate a piece of cowling from the wreck at Luke field. 

I don't think the identification is absolute.

Even if it is taken to be reliable, it's not clear how that sample would relate to random samples from NR16020.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: pilotart on August 01, 2012, 12:16:50 AM
KC,

Welcome to the forum!

Marty has some excellent FAQ's on this site for finding files etc.  For me; the easiest has been just to look on the TIGHAR home website's "Site-Map" and scroll down it.

I have attached a pdf (of 164 pages) which is a copy of the FAA's file on the Electra in question.  This is a public document and you can order one (for any US Reg. AC) from OKC on a CD with the exact same pdf for $10 including shipping.  Takes a month or so (they have to photograph each microfiche page back/front and burn the CD) and has no better resolution than the online version.  I downloaded this one from AvWeb (I think) and don't know if TIGHAR has a copy for download on site.

In addition to all the certification records, it contains what we now refer to as "337's", scroll down to page 59-71 to see what was submitted by Lockheed to the FAA (CAB back then) for the airframe repairs after the ground loop.  I have no idea what the policy was for 1937, but the FAA has gone back and forth on the requirements for submitting "Engineering Drawings" for repairs.

I would check Perdue's Archives for possible Maintenance Log copies, they should exist.

As far as rivet patterns, I'm sure you know from your background but for the benefit of some other readers:  No two aircraft will ever have the exact same rivet locations, when you replace a section of skin or airframe, you start with a blank (as far as holes are concerned) and must drill each rivet hole to exactly match the existing corresponding hole from where the old panel was removed.

There has been a lot of forum discussion on metallurgy testing for found aluminum,  on the site-map you will see many years of archived 'email-forums' by the month, no 'threads' or 'topics', you just have to do a Key-Word Find to read a specific topic within a month.  If you just want to read the whole archive, I found it best to copy/paste each month from the Browser into MS Word, where you can easily control the view, layout, font and format as well as save anything you want to keep.

****************************************************
Well all the excitement must be overloading the TIGHAR Servers as I have tried five times to post this (with the attachment) and it just creeps up to 100% in three minutes and then kicks me back.  Here is a download link:

http://www.planefaxreports.com/pfr/pdf/n16020/16020-Registration.pdf (http://www.planefaxreports.com/pfr/pdf/n16020/16020-Registration.pdf)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Kirstin M. Campbell on August 01, 2012, 07:17:32 AM
Nice.  Thx Martin and Pilotart.  Given the time period I suspected this was the case on blueprints and manuals.  I'm more familiar with the 1940's on and still trying to catch up on 1930's procedures.

Pilotart, yes I am aware but I'm thinking in the broader sense of similarities coming off the assembly line rather than exact rivet placement which never happens.  It was just info gathering to jump start my brain by jumping into the middle while I catch up on all the other information.  Thank you for the PDF!  That is exactly the sort of thing I was looking for to catch up with everyone else and all the engineers here who have far more qualifications than my hangar wrench turning lends me.  :)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Tom Swearengen on August 01, 2012, 06:41:39 PM
KC---several of us looked at this piece pretty good (through the glass case!) while in DC at the symposium. Several of us had different ideas on where it 'might' have come from. Might, is the operative word here, because it hasnt been positively established that it came from NR16020. There are a couple of 10E's in musuems, but that doesnt mean that they didnt have some skin work done on them prior to being placed in the museum. Happens a good bit, because as museum pieces, they generally arent flight ready.

But----we can surely use all the help we can get, so jump in---the waters' fine.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Kirstin M. Campbell on August 02, 2012, 09:23:52 AM
Thx for the welcome in.  I'll be off reading for a while  ;D
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on August 08, 2012, 11:27:25 AM
The 'rivet placement' on this piece tends to be 'very poor' and does not come close to Lockheed production patterns on the L10 - it is distinctly 'hand craft' as if done in a pinch.

I do not believe we are going to find any patterns on this artifact that match any stock rivet patterns on the Electra - AE's or otherwise.  That is one reason I have thought of this piece, IF it relates to NR16020, as a candidate for the covering over the large lavatory window.  As best as I can determine (primarily by the Harney prints and texts therein) that window was covered in Miami before the last world flight attempt continued on its way.  AE was only there a few days, and whatever covering may have been done, if that information is accurate, had to have been done relatively quickly.  It may therefore be a candidate for a quickly done one-off piece-work job, complete with hastily added stiffeners (in Miami - or perhaps later if 'oil-canning' was noticed in flight along the way and dealt with later...). 

The 'stiffener' lines (I don't know that they were present but the rows of #3 rivet holes is suggestive of light stiffeners) are consistent with that approach.

If that is what this artifact truly is then the only 'match' we'll get to factory rivet lines is where the panel may have picked-up existing rivets along the stiffener at the lower edge of that window, or next candidate possibly the forward row if it picked up the former / bulkhead flange on the forward edge of the panel.  Otherwise, it is whatever pattern the installer established - and possibly matching any fastener holes used for the window edges if other stiffening / window bounding elements were placed there.

The window I speak of is plainly visible in many photos of the right-side of NR16020; it is also distinctly covered in later pictures by a panel of about the size of this artifact (the artifact fitting within the bounds of the visible panel - the artifact does not represent the whole of what it once was).  032" T would be a natural for that application, as would the lighter rivets for something like light-weight stiffeners installed behind such a large panel.

One key to better understanding what 'window cover' and details were actually on NR16020 at that place would be a good photo by which we could discern rivet patterns... so far I've not found one of that kind of detail.

So - IMHO, getting to a museum L10 might help as far as trying to match edge rivet patterns, but that is about it.  This is a unique piece due to the irregular rivet pattern, wherever and on whatever it was installed.  Factory metal work was far and away advanced enough by many years for that pattern to not be a product of any factory floor.  Handcraft at a local shop for a quick cover job?  Absolutely within reason.  Question is 'what location' and most of all, 'what airplane'?

I still view NR16020's RH lavatory window (oversized - apparently for nav use and later not needed) as a strong candidate - but need information about how covered including pictures, if it can be found.

LTM -
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on August 08, 2012, 11:36:28 AM
Some photos of a Japanese aircraft showing tapered lines of rivets can be seen here. (http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/55_WreckPhotoResolved/55_WreckPhotoResolved.htm)  The link also shows a similar aircraft that has shed some of its aluminum pieces.  The missing pieces bring to mind the 2-2-v-1 artifact.
What do we know about Japanese aircraft construction?  Did they use thinner aluminum than was normal for Allied aircraft?  Would the rivet holes be diistinctively different in size, or would there be only subtle differences?  Would the normal spacing be distinctive?  For that matter, would Japanese aluminum be chemically distinct from Allied aluminum?  The NTSB report (http://tighar.org/Projects/Earhart/Archives/Documents/NTSB_Report/ntsbreport.html) identified it as clearly Alclad, and had remnants of two letters visible ("AD").  Would these characteristics definitely rule-out a Japanese aircraft as the source?

The 'AD' marks are disqualifying as Japanese unless they were getting their sheetmetal from the states - those surviving marks are distinctly from American made stock.

I have no idea of the reliability of trying to trace via chemical or spectra signature.  That may vary enough lot-by-lot among what we know of as 'Alclad' so as to not be a good way, but interesting idea anyway.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on August 08, 2012, 11:39:59 AM
Jeffrey,

Do you mean by  "...the concern/concerns...." the company that made the alterations?  As I understand it, that was Lockheed.  I've read that TIGHAR have looked, but the records of work done on the aircraft are pretty slim.

If this panel turns out to be what I have theorized it to be (covering over lavatory window made and installed while in Miami during last world flight) then it would not have been Lockheed.

As to the post Luke Field accident repairs - I have not been able to discern anything in the repaired belly areas that has any erratic fastener patterns on the order of what we see in this artifact.  Nor do I see a convincing case for using the .032" T material where the normal thickness is .040" minimum.  I don't believe this artifact is a strong candidate in those areas.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Scott on September 01, 2012, 03:10:45 PM
I still view NR16020's RH lavatory window (oversized - apparently for nav use and later not needed) as a strong candidate - but need information about how covered including pictures, if it can be found.

Very interesting theory. How hard have you searched for photos of these window covers?
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on September 13, 2012, 03:22:48 PM
I still view NR16020's RH lavatory window (oversized - apparently for nav use and later not needed) as a strong candidate - but need information about how covered including pictures, if it can be found.

Very interesting theory. How hard have you searched for photos of these window covers?

As hard as I've been able - via internet.  No time or direct access to other files so far.  I have been through all the Purdue pictures of AE's plane that I could get to online.

If you have some better sources / time I would love the help!
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Mark Pearce on September 19, 2012, 12:36:50 PM
It’s an elementary question- but I have to ask; has the PBM wreckage on Howland Island been carefully studied and eliminated as the source of artifact 2-2-V-1?

See photo here-
http://tighar.org/aw/mediawiki/images/c/c1/Plane_wreckage.jpg

...and another from 1993-
http://www.flickr.com/photos/theroadtothehorizon/384603754/sizes/o/in/set-72157594524395169/



Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Alan Harris on September 20, 2012, 12:40:21 AM
Mark, that seems like some good out-of-the-box thinking to me.  Of course I'm as green here as you are, and that study may have been done in spades years ago and I wouldn't know it.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Mark Pearce on September 20, 2012, 09:45:13 AM
Alan,
As far as I can tell after searching the archives, no one from TIGHAR has ever been to Howland Island.  The photo of the PBM wing tip float was apparently taken by a tourist visiting the island sometime around 2008.  That same photo shows a large wing panel, with a few areas of missing skin, lying off in the distance. 

More photos of Howland Island taken by “joann94024” can be seen here-

http://www.flickr.com/photos/72923065@N00/page2/
[see page 9 for a close-up of ‘Earhart Lighthouse’.]

For a report on the 1944 PBM accident [#8 on the list,] go to-
http://www.vpnavy.com/vp16_mishap.html
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Jeff Victor Hayden on September 20, 2012, 11:59:09 AM
Certainly worth further investigation Mark. The Howland Mariner PBM 3-D was manufactured circa early 1944 for the 3-D versions with the Improved R 2600 engines. The wing floats used to take a pounding and were constantly patched up.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Mark Pearce on September 21, 2012, 06:18:06 PM
Certainly worth further investigation Mark. The Howland Mariner PBM 3-D was manufactured circa early 1944 for the 3-D versions with the Improved R 2600 engines. The wing floats used to take a pounding and were constantly patched up.

Yes, it’s a bit surprising a close look at this PBM wreck has been put off all this time.  There’s been chatter about 'recovering' the wreckage at this link. (http://www.usaircraft.proboards.com/index.cgi?action=display&board=general&thread=4006&page=1)

About float repair- there is a good photo of that being done to a PBY here. (http://www.history.navy.mil/photos/prs-tpic/af-amer/seatl-ac.htm)
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Greg Daspit on September 21, 2012, 07:33:08 PM
The wrecked PBM on Howland is mentioned in forum archives (http://tighar.org/Projects/Earhart/Archives/Forum/Highlights121_140/highlights123.html). The 1st post of this thread and it's linked reports indicate the artifact to likely be pre-WWII AD aluminum based on the lettering and it had a rivet still attached of a style likely discontinued before WWII.  The PBM was scheduled for delivery in late 1943. It is not likely an old type of rivet and old stock of AD aluminum were kept and then used on the PBM 3-D scheduled for late 1943 delivery (http://www.airvectors.net/avmars.html). Also the artifact was washed up on the shore between visits by Tighar. Prevailing ocean currents don't seem to favor it getting from Howland to Gardner.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on September 21, 2012, 08:26:38 PM
Mark,

I think it would be great to have a close look at whatever remains at Howland if it can be done.  I know it's a sanctuary but there is some allowance for visitors.  It could not hurt and if it didn't confirm that wreckage as a sort at least we'd eliminate one source for certain.

I think it would be a long-shot, mainly for the reasons Greg cites here.  The material and rivet type are older pre-war articles - it is not likely for that kind of stuff to find its way onto a WWII ship.  Not impossible - just not likely.

Thanks for those links - very interesting and worth the study.  The picture of the float being repaired suggests a couple of things -
- Those floats were fairly stout and well-braced with rivets that appear to be 5/32" or better.
- The internal bracing consisted of fairly closely placed frames and stiffeners - closer than would be what I'd expect to find for the relatively large, light gauge sheet that 2-2-V-1 is.

Which is not to say the idea is impossible - I just believe it to be a long-shot.  If I had a chance to get me or anyone to Howland to examine that wreckage I'd love to do it.  While I've been focused on this artifact to see what could be learned, I'm not expert at all in mounting such activities and I realize TIGHAR's got limits as well.  My thought is to keep digging for photos of possibilities.

The 'holy grail' of photos for the panel at the moment, in my mind anyway, would be a closer shot at the area that I think is a strong candidate on the Electra: the right side of the lavatory where the large window was first installed and later covered.  That is my working theory for the moment about where this skin may have come from.  The idea being that the material is typical of what might have been used in 1937 on an area opening of that size, and the apparent light-bracing pattern is suggestive of the same thing - an improvised cover hastily installed in Miami - which is where we're told the window was re-covered just before the world flight went on.

Of course any 'find' that can show a source would solve this - Electra or not, so if we could see that Howland wreckage it might be interesting.  But I would surely love to have that close-up of the Electra's lav-area skin (right side) if anyone runs across such a critter.  So far I've not found a clear enough shot to make any judgment.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Martin X. Moleski, SJ on September 21, 2012, 09:27:50 PM
Yes, it’s a bit surprising a close look at this PBM wreck has been put off all this time.

Think cost/benefit.

Think 700 miles roundtrip from Niku to Howland.

Think of the danger of leaving folks on Niku while you take 60 to 70 hours to make the roundtrip (not counting time ashore).

If you decide not to leave them stranded on Niku, think of the time lost hauling the whole Niku team to and from Howland.

I personally don't find it the least bit surprising that TIGHAR hasn't made the trip.

If you pony up the funds, I'm sure TIGHAR would be happy to help you do the search.  That's what "Contract Services" (http://tighar.org/Contract_Services/cshome.html) is for.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Mark Pearce on September 22, 2012, 09:01:20 AM

Think cost/benefit.

think of the time lost hauling the whole Niku team to and from Howland.


If a trip to Howland Island finally ended all the speculation/discussion about artifact 2-2-V-1, [going on over twenty years now?], it would be well worth the cost. 

The whole crew doesn’t have to go, Jeff has already volunteered, but Tighar will have to cover his expenses. That’s not my department.   :)

Mark,

I think it would be great to have a close look at whatever remains at Howland if it can be done...  It could not hurt and if it didn't confirm that wreckage as a sort at least we'd eliminate one source for certain.

If I had a chance to get me or anyone to Howland to examine that wreckage I'd love to do it... 

Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on September 22, 2012, 02:45:09 PM
Well, Mark, what I'd "love to do" and reality are too different things very often - and this is another good case of it I am afraid.  Marty's points are the reality.

Sure, it'd be great to see what that stuff could tell us - but as I mentioned I have a low confidence level that it is a source for the 'skin' we're talking about.  Recall we're talking about materials that are typical of pre-war, light skinned type.  The floats for the wreck at Howland are likely heavier / not likely repaired with such light grade, pre-war material.  Also take a look at the quality of the repair work being done on that float in the picture you linked: very regular hole pattern - 'by the book'.  That's not to say crazy things don't happen in the field out of necessity - they certainly do; that's actually one reason I've wondered so much about the Miami 'skin-over' - something done quickly, maybe on the ramp with a minimum of shop time.

I still think it is more productive to keep looking for photographic evidence that might tell us something.  If it is out there, it beats the travel! 

If we went to Howland and looked at whatever is there we'd have a chance to prove a couple of different things -
- that the metal DID come from there, which would be surprising to me for reasons mentioned, or
- the metal did NOT come from any of the remaining wreckage at Howland (which is not the same as saying it could not have come from some other part that is no longer present).

I suspect short of a) finding a definitive photograph placing this article on a definite airplane (slim chance), or b) finding NR16020 and b) finding the thing fits, we likely won't ever know.  One thing is clear - it is not production article stuff due to the hole pattern irregularities, etc. so it would be extremely hard to find barring a great deal of luck - or one of the above possibilities.

In any case, Marty makes the underlying sound point - so far (and not likely to change) there's no good way to go look at Howland.
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Mark Pearce on September 26, 2012, 12:39:49 PM
Setting aside questions about the wreckage on Howland for the moment, is the large piece of aluminum shown in this video from long ago the very same piece of aluminum we are talking about today?  The piece in the video seems to be labeled '2-2-V-1' but it appears to have far more corrosion than the piece known as '2-2-V-1' today.

http://www.youtube.com/watch?v=t0OlSPkZF_Y&feature=related


------------------------------------
"...The infamous section of airplane skin, Artifact 2-2-V-1, has a rivet of a style that was common before the war but went out of general use fairly early in the war and the skin has manufacturer’s markings that, according to Alcoa, likewise indicate that its an OLD piece of aluminum. And yet the only places where corrosion has penetrated through the .032 thickness is in one small spot where there was some kind of corrosive deposit (battery acid? bird dung?)."
http://tighar.org/Projects/Earhart/Archives/Forum/Highlights1_20/highlights11.html

Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: Martin X. Moleski, SJ on September 26, 2012, 03:02:06 PM
Setting aside questions about the wreckage on Howland for the moment, is the large piece of aluminum shown in this video from long ago the very same piece of aluminum we are talking about today?  The piece in the video seems to be labeled '2-2-V-1' but it appears to have far more corrosion than the piece known as '2-2-V-1' today.

http://www.youtube.com/watch?v=t0OlSPkZF_Y&feature=related (http://www.youtube.com/watch?v=t0OlSPkZF_Y&feature=related)

Yes, I think it is the same 2-2-V-1 (http://tighar.org/wiki/2-2-V-1).
Title: Re: Artifact 2-2-V-1 - aluminum 'skin'
Post by: JNev on February 05, 2014, 11:43:50 AM
Since I started this string I now feel compelled toi update it with a closing statement -

In my opinion as an A and P Mechanic / IA of some 36+ years - 33 of those in various roles at a major airframer including engineering, compelling evidence has surfaced that suggests that this artifact could very well have originated from the belly repairs done to NR16020 prior to the world flight. 

I pursued the lav window location as a possibility because of the light guage metal and presence of light (no. 3) rivets in the majority of rows thereon; this was not consistent with primary structure in the typical case.  The Lockheed L10 proves herself a stand-out in yet another way: her belly skins do include a large number of no. 3 rivets as primary strucural fasteners. 

For that reason, and because there is now reason to also doubt a match to the lav area, and because of the relatively unique fastener on the L10 as I now understand it, I now believe this artifact is a strong candidate for having been a repair piece on none other than NR16020.

Are there other possibilities?  Of course - but a time has come for me to seriously suggest that they are very limited indeed: AN 455 brazier rivets of no. 3 size coinciding with a similar feature in the L10 is not so common, nor are the pre-war markings we find on this sheet.

One realizes that this sheet of ruined metal 'could be anything' to many eyes and minds - but training, experience and now observation and acceptance of some hard data (photographic - see later 2-2-V-2 posts in 'General Discussion' panel) make this complex item very pointed in its meaning.  The scales have tipped - if there is a better explanation as to where this came from given the web of circumstantial (but substantial to this writer) evidence we have - including plexiglass of correct curvature and thickness, etc. - I would respectfully ask the challenger to provide evidence of it.

This is of course my humble opinion, but I suggest the skeptic study and look hard if they'd offer a better idea of what became of the flight.  As to where found and how it got there - a worthy consideration, consider what now appears to be strong provenance as to this part: if it came from the Electran, but not at Niku - then where else?

I merely (but now strongly) suggest that there is not a wealth of other possibilities.  The reader must of course draw his own conclusions.  But mine, after quite a journey, is that somehow a unique piece of aviation repair history managed to beach itself on the shores of Niku - among other nested things that support the circumstance of a stranded L10E belonging to Amelia Earhart.

More will follow as for me this is a most peculiarly complex artifact and it is as if it tells me more now than I can readily put to words in one sitting.  It is my own opinion - others may of course play the odds as they will, but TIGHAR's pain-staking efforts have produced plausible material that reaches beyond reasonable doubt for me.  I will close this string once I have provided what I just promised elsewhere on this site. 

Hats off to those who care about and search for the lost aviators, whether they agree or not - may they always be reasoned and reasonable in their arguments.

This topic locked 1/6/2014 - see later discussions on this artifact / consideration of Electra belly skin repair.