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[Ric Gillespie]

Well, yeah. I hope some intrepid person with access to specs for the various Sikorsky types Pan American had at Dinner Key can research the thickness of aluminum on those birds.

Gonna be tough. That's not the kind of information usually included in specs, but I would be surprised if those airplanes did not use .032" ST24 ALCLAD.  .025" is lighter stuff and might be less common on a flying boat.  Maybe they used .032 for the patch because that's what they could get.

[JNev]

...Here's a thought:  Present a panel of people who routinely work with hyperspectral imaging (or one such person if in short supply as I suspect they are) with 10 or so black and white, severely cropped image files of vintage aircraft, including a crop from the Miami photo.  They, of course, wouldn't know which image was the Miami photo. Then request they identify the photo or photos that best match Jeff's hyperspectral scan of rivet patterns on 2-2-V-1.  This, to me, has the benefit of enhanced validity over the alternative idea of simply giving free access to Jeff's files and conclusions and asking other experts if Jeff's (now TIGHAR's) conclusions on the patch are right...
I trust Jeff implicitly, of course, but he's our longtime expert and recognized as such.  We need a way to allow source(s) as objective as possible to weigh in with unimpeachable credibility. 

Joe Cerniglia
TIGHAR #3078ECPR

Sounds like a plan to me.

[JNev]

Well, yeah. I hope some intrepid person with access to specs for the various Sikorsky types Pan American had at Dinner Key can research the thickness of aluminum on those birds.

Gonna be tough. That's not the kind of information usually included in specs, but I would be surprised if those airplanes did not use .032" ST24 ALCLAD.  .025" is lighter stuff and might be less common on a flying boat.  Maybe they used .032 for the patch because that's what they could get.

It should be among the bill of material details for those ships.  .032" is a common gage and I believe some of our earlier review of flying boats revealed some surprisingly thin material in the aft hull areas.

Per the published guidance of Earhart's day and today (which actually uses much of the sheet metal data developed in the '30's) it is commonly advisable to increase the gage of a repair skin by one thickness - in this case .025" to .032" would not be surprising to find.

[Jeff Carter]

Don't the following images (which others have posted before) suggest the patch was raised above the skin of the Electra.  Notice how the light hits the front edge and a shadow is visible along the lower edge.
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=284
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=501
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=787

[Mark Samuels]

I don't believe there has been a question that the patch was raised above the skin of the aircraft.  Conventional wisdom is that the coaming/frame was laid over the skin but was removed for the patch to be installed in its place.

[Dave Thaker]

Don't the following images (which others have posted before) suggest the patch was raised above the skin of the Electra.  Notice how the light hits the front edge and a shadow is visible along the lower edge.
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=284
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=501
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=787

The Darwin photo Jeff Carter linked to (1st link above--see attachment) shows very nicely where the patch is located on the Electra, but unless I'm mistaken this photo has not yet been utilized for that purpose.  I can see that the bottom edge of the Patch lines up with a rivet line that extends a considerable distance aftward of the patch.  It looks to me that this photo could be used to determine conclusive whether the bottom edge of the patch corresponds with the bottom of the Navigator's window 'coaming'.  Does anyone else agree? Ric?

[JNev]

The Darwin photo Jeff Carter linked to (1st link above--see attachment) shows very nicely where the patch is located on the Electra, but unless I'm mistaken this photo has not yet been utilized for that purpose.  I can see that the bottom edge of the Patch lines up with a rivet line that extends a considerable distance aftward of the patch.  It looks to me that the bottom edge of the patch corresponds with the bottom of the Navigator's window 'coaming'.  Does anyone else agree? Ric?

It has been referenced for quite some time as to that purpose.

The bottom edge most definitely does correspond to the bottom of the navigator's window (lavatory window) coaming - and that rivet line is a staggered row that does extend as you note, as has been studied for some time as well.

Which has also been pointed out up string here with other illustrations, of course.

[Dave Thaker]

Don't the following images (which others have posted before) suggest the patch was raised above the skin of the Electra.  Notice how the light hits the front edge and a shadow is visible along the lower edge.
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=284
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=501
http://e-archives.lib.purdue.edu/cdm4/item_viewer.php?CISOROOT=/earhart&CISOPTR=787

The Darwin photo Jeff Carter linked to (1st link above--see attachment) shows very nicely where the patch is located on the Electra, but unless I'm mistaken this photo has not yet been utilized for that purpose.  I can see that the bottom edge of the Patch lines up with a rivet line that extends a considerable distance aftward of the patch.  It looks to me that the bottom edge of the patch corresponds with the bottom of the Navigator's window 'coaming'.  Does anyone else agree? Ric?

It has been referenced for quite some time as to that purpose.

The bottom edge most definitely does correspond to the bottom of the navigator's window (lavatory window) coaming - and that rivet line is a staggered row that does extend as you note, as has been studied for some time as well.

Which has also been pointed out up string here with other illustrations, of course.

Sorry, Jeff, I didn't mean to slight your earlier posts.

So then, where on Ric's professionally scaled overlay:

http://tighar.org/smf/index.php/topic,1490.msg33775.html#msg33775

is the bottom edge of the Patch— is it close to the rivet hole on the ‘tab’, or is it where Ric’s arm is cut off, or somewhere in between? 

And, where is the top edge of the Patch? 

I think it would be very helpful if the professionally scaled overlay could be re-posted with the upper and lower borders indicated.

[Ric Gillespie]

I think it would be very helpful if the professionally scaled overlay could be re-posted with the upper and lower borders indicated.

Yes, that would be nice to have, but as I think I explained earlier, there is insufficient resolution in the patch photo to see precisely where the borders of the patch are.  All we can do is make assumptions about what underlying structures the borders were riveted to.

[Mark Samuels]

So then, where on Ric's professionally scaled overlay:

http://tighar.org/smf/index.php/topic,1490.msg33775.html#msg33775

is the bottom edge of the Patch— is it close to the rivet hole on the ‘tab’, or is it where Ric’s arm is cut off, or somewhere in between? 

And, where is the top edge of the Patch? 

I think it would be very helpful if the professionally scaled overlay could be re-posted with the upper and lower borders indicated.

Mr. Thacker,

It might be worth your time to study the attached image.  The margins of the patch are, I believe, up for interpretation.  I don't believe that anything is cast in concrete as to how the fit is, as of yet.

Edited to add:  Apparently I was too slow in composing this post.  Sorry Mr. G.

[JNev]

Sorry, Jeff, I didn't mean to slight your earlier posts.

...

No slight, just thought you might not have been aware - I closed that string a long time ago.  But site exploration is encouraged - tons of stuff lying about on this and so much else 

As Mark and Ric have pointed out, we have some fair estimates - but it's darn hard to get to brass tacks without the bird or without a crystal clear picture of the patch.

Somehow I get the idea Earhart didn't care much for good pictures to be made of the patch - and then again, it was only installed just before she left Miami.  For whatever reason it didn't get much detailed public attention - which makes it all the harder for us now.

[Jeff Carter]

In honor of Darwin's finches (http://en.wikipedia.org/wiki/Darwin%27s_finches), a bit of a plumage diagram for the Electra at Darwin.
http://i.imgur.com/O9oWrcx.jpg

[JNev]

Just studying the evidence of an unriveted vertical member on 2-2-V-1 and question arose -

Isn't that evidence on the outside of the patch, not inside, where one would think?  Or have I somehow gotten disoriented in viewing this?

[Ric Gillespie]

Isn't that evidence on the outside of the patch, not inside, where one would think?

That's correct. It's easiest to see on the outside and even so it's very subtle.  It's much harder to see on the inside.  Doesn't make sense to me either.

[Greg Daspit]

Isn't that evidence on the outside of the patch, not inside, where one would think?

That's correct. It's easiest to see on the outside and even so it's very subtle.  It's much harder to see on the inside.  Doesn't make sense to me either.

That could be because the vertical member was a channel with the legs notched with the flat part continuous over the top of the horizontal members.  Since the flat part of the narrow vertical channel stuck out more than the horizontal channel, it could be that it dented more if an outside force hit it (or just with the sheet being pressed down by adjacent rivets). Also since its area is more narrow(3/8”), it may be more likely to make a dent than a wider ¾” member. Then, if the piece is dragged and moved around on the reef, it could get worn on the protruding dent's edges. If it protrudes on the outside and not the inside, wear may be more evident on the outside than the inside.