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Author Topic: A Piece Of The Electra?  (Read 16698 times)

Brad Beeching

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A Piece Of The Electra?
« on: February 12, 2011, 04:10:16 PM »

I read a post in another section about a lady who was going to attempt to recreate the world flight. In the thread, someone mentioned that she had a piece of the Electra. I seem to remember a show on the History Channel or Discovery where a gentleman did indeed have a piece of the skin that came off when she crashed at Luke. I was wondering if having a sample would help identify artifacts from Niku? ..... or am I five years behind the times?  :-\

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Martin X. Moleski, SJ

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Re: A Piece Of The Electra?
« Reply #1 on: February 12, 2011, 05:22:01 PM »

I read a post in another section about a lady who was going to attempt to recreate the world flight. In the thread, someone mentioned that she had a piece of the Electra.

See "Grace McGuire planning to re-create AE's flight with 10-E."

Quote
I seem to remember a show on the History Channel or Discovery where a gentleman did indeed have a piece of the skin that came off when she crashed at Luke. I was wondering if having a sample would help identify artifacts from Niku? ..... or am I five years behind the times?  :-\

See "A Piece of the Grail?" for the full story of the History Detectives episode (2009, I believe).

I am personally doubtful that the authenticated piece of the Luke Field wreck could be used to "fingerprint" other pieces of aluminum found on Niku.  YMMV.
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Ric Gillespie

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Re: A Piece Of The Electra?
« Reply #2 on: February 12, 2011, 07:35:00 PM »

There is, in fact, a process called neutron activation analysis by which we might be able to confirm that one or more of the aluminum artifacts we've found on the island came from the same batch of aluminum as the piece of Luke Field wreckage. It wouldn't be "smoking gun" conclusive but it would be pretty darn good.  The owner of the piece, however, will not let us use it because he read an article that quoted me as saying that the purpose of our investigation is not to honor Amelia Earhart.  That quote is correct but was taken out of context.  Our purpose is to conclusively solve the mystery, not honor Amelia Earhart.  AE is already an icon.  She doesn't need any help from us.
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Bill Lloyd

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Re: A Piece Of The Electra?
« Reply #3 on: February 12, 2011, 08:30:45 PM »

There is, in fact, a process called neutron activation analysis by which we might be able to confirm that one or more of the aluminum artifacts we've found on the island came from the same batch of aluminum as the piece of Luke Field wreckage. It wouldn't be "smoking gun" conclusive but it would be pretty darn good.  The owner of the piece, however, will not let us use it because he read an article that quoted me as saying that the purpose of our investigation is not to honor Amelia Earhart.  That quote is correct but was taken out of context.  Our purpose is to conclusively solve the mystery, not honor Amelia Earhart.  AE is already an icon.  She doesn't need any help from us.
It appears that the gentlemen's reasons are rather frivolous. Perhaps he could be persuaded if he were made an attractive offer that he could not refuse.
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Martin X. Moleski, SJ

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Re: A Piece Of The Electra?
« Reply #4 on: February 12, 2011, 08:39:19 PM »

There is, in fact, a process called neutron activation analysis by which we might be able to confirm that one or more of the aluminum artifacts we've found on the island came from the same batch of aluminum as the piece of Luke Field wreckage.

That argument depends on the assumption that all of the aluminum in the airframe would have come from the "same batch" as the Luke Field sample.  

I don't see any reason to make that assumption, unless, by chance, some of the Niku aluminum is from the same part of the plane as the Luke Field piece.

So, for example, I don't see any reason to suppose that the heat shields would have been made from the "same batch" of aluminum as the cowling.  

How big is a "batch"?  All the aluminum refined in the U.S. in the year the raw materials for the plane were created?  All the aluminum during that time frame from one supplier?  

Here is a prohibitively expensive and possibly even impossible test of the neutron activation analysis: take a vintage airframe whose parts are known to be entirely original.  Pick aluminum samples at random from pieces of the skin and airframe.  If they've all got the same fingerprint, I guess that would allay my doubts.

How strong an argument would you get from a match?  Would it be the case that a single airframe would exhaust "one batch" of aluminum?  If not, how many other aircraft would share the same fingerprint?

How strong an argument would it be if there is a mismatch?  Would TIGHAR accept it as definitive proof that none of the aircraft aluminum recovered from Niku was from NR16020 if none of it matched the Luke Field sample?
LTM,

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Bill Lloyd

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Re: A Piece Of The Electra?
« Reply #5 on: February 12, 2011, 09:10:08 PM »

How strong an argument would you get from a match?  Would it be the case that a single airframe would exhaust "one batch" of aluminum?  If not, how many other aircraft would share the same fingerprint?
It could be argued that a match is persuasive circumstantial evidence and that combined with all the other circumstantial evidence presented in this case, continues to tip the scales in favor of the theory that the Earhart Electra came to earth on Gardner Island.
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Martin X. Moleski, SJ

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Re: A Piece Of The Electra?
« Reply #6 on: February 13, 2011, 04:18:10 AM »

How strong an argument would you get from a match?  Would it be the case that a single airframe would exhaust "one batch" of aluminum?  If not, how many other aircraft would share the same fingerprint?
It could be argued that a match is persuasive circumstantial evidence and that combined with all the other circumstantial evidence presented in this case, continues to tip the scales in favor of the theory that the Earhart Electra came to earth on Gardner Island.

"May the Lord the giftee gee us
to see ourselves as others see us."

The amount of weight that a match would carry depends on how big "a batch" is and how many airplane parts could be made from "a batch."  How long does it take to exhaust "a batch"?  Would one company get the whole of "a batch" or would several companies? 

Would one airframe have parts from different "batches"? 

Al-clad has an outer and inner layer.  Do both have the same neutron analysis fingerprint?  Is the fingerprint a combination of the two?

It seems to me that these are the kinds of questions skeptical observers might make about the claim that "we have found a match."  Anticipating skeptical questions is part of making a good case in the court of reason, whether is it is based on circumstantial evidence or not.

I'm not saying there aren't answers to these questions.  But if there are, they haven't been entered into the record as yet.
LTM,

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Brad Beeching

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Re: A Piece Of The Electra?
« Reply #7 on: February 13, 2011, 06:53:12 AM »

As far as I am aware, when the ingot is rolled out and cut into sheets, they are shipped on pallets, OR rolled up into a large roll. I would guess that several pallets or rolls of material would share the same properties. The next question would be "How did Lockheed create the parts, from a roll of material or a sheet?" My guess will be "Both". As a supplier of aluminum in 1936, if I recieved an order for material, I would just grab the nearest stuff on the dock that met the requiremnts and ship it. My guess is that a fair amount of material would match.

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Walter Runck

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Re: A Piece Of The Electra?
« Reply #8 on: February 13, 2011, 07:01:24 AM »

Any of this stuff is going to be inconclusive however supportive it may be. 

Any met lab could provide basic chemistry on a piece of metal.  You might be able to match it up with the original mill certs, if they still exist somewhere, but it will just identify the alloy and provide the relative fractions of aluminum and whatever alloying elements (copper, manganese, magnesium, etc.) were present in that particular heat.  Mill certs will sometimes provide a reading of grain structure and hardness if a material has been heat treated.

Lockheed would have had multiple heats (batches if you prefer) of material available to them, even if they all came from the same supplier.  Different heats could end up on the same plane; material from one heat could have ended up on different planes, even one from a builder other than Lockheed.  Also, different heats can have identical chemistry, so without an unbroken paper trail to correlate the lab results, no smoking gun.

Further, Alclad was a sheet material and the chemistry would be different from the forging or casting alloys used for heavier structural components.

Since Neutron Activation Analysis is non-destructive, it's a pity that the owner won't allow testing.  I know some materials engineers who would love to get a shot at this.

Has NAA been performed on any of the pieces found to date?  You could start building a database of known heats based on what you already have.  First check for repeatability from area to area on the same artifact, then to similar artifacts, then dissimilar (different gauge but still Alclad) artifacts, then  other aircraft (Grace McGuire), etc..
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Ric Gillespie

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Re: A Piece Of The Electra?
« Reply #9 on: February 13, 2011, 08:19:58 AM »

Factors we have considered in contemplating NAA:

- Earhart's Electra, like every other Electra and nearly all stressed-skin aluminum aircraft before, during and after WWII, was covered with 24ST Alclad (today known as 2024 Alclad). In 1936 when Earhart's Electra was built, there was only one supplier of Alclad - ALCOA.  The same was true in 1937 when the aircraft was repaired following the Luke Field accident. Later, during the huge wartime expansion of the aircraft industry, the government mandated that ALCOA release its patented process to other suppliers (Reynolds, Kaiser, etc.).

- Lockheed's use of aluminum in aircraft production and repair in 1936/37 was miniscule compared to what it would be just a few years later.

- In 1996 ALCOA did basic metallurgical analyses of our large piece of Alclad (the famously controversial Artifact 2-2-V-1), a piece of known B-24 Alclad, and a piece of known B-17 Alclad and found that all three pieces were essentially the same. (The B-24 and B-17 pieces were not from "restored" aircraft.) Distinguishing a difference requires a process as specific as NAA.

- There are many reasons that a non-match between Niku aluminum and a known piece of NR16020 could be a false negative, but it's difficult to construct a credible explanation for how a match could be a false positive.  You'd have to say that aluminum from a batch (or "heat") that was being used in 1936 was still being used to build or repair airplanes during the explosion in aircraft production that began in 1939.

We've tried, but have so far been unable, to learn how much aluminum was a single "heat" represented in 1936/37. 
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Ric Gillespie

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Re: A Piece Of The Electra?
« Reply #10 on: February 13, 2011, 08:23:08 AM »

Has NAA been performed on any of the pieces found to date?  You could start building a database of known heats based on what you already have.  First check for repeatability from area to area on the same artifact, then to similar artifacts, then dissimilar (different gauge but still Alclad) artifacts, then  other aircraft (Grace McGuire), etc..

No NAA has been done to date.  Building a database would be interesting but expensive and, as you say, ultimately inconclusive.  The bottom line is that we need to find the rest of the airplane.
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Walter Runck

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Re: A Piece Of The Electra?
« Reply #11 on: February 13, 2011, 08:35:28 AM »

Alclad is a co-rolled or clad material used for aircraft skin and other sheet applications.  It is two sheets of different types of aluminum alloy smashed together during the hot rolling process.  Take a coil of structural grade aluminum (aluminum alloyed (melted) with some copper, magnesium and manganese).  This is a strong material, but not the most corrosion resistant.  Now take a coil of relatively pure aluminum, which forms an oxide layer that protects itself, but does not have much strength (I have a 1/2 inch bar of 99.999 pure aluminum that I could bend with my hands).  Lay one on top of the other, heat and run them through rollers under pressure.  Viola, an open faced aluminum sandwich!  Strong on one side, shiny on the other!  But right from the start you will have different NAA signatures from each side of the sheet.

For our purposes, batches correspond to mill heats.  This is the last time the material is melted and mixed with various elements to improve various properties.   It's like making soup. The size of the batch is determined by the size of the pot.  Probably on the order of hundreds of cubic feet or tens of thousands of pounds each.  but you would have at least two heats for each sheet of Alclad used in construction.  Aluminum is fluffy stuff, so this is a lot of product by volume.

Fab shops using this kind of material would probably buy it by the sheet rather than the coil (heavy) and it would be packed on pallets.  Handling stuff way bigger than you need is a pain, my guess is that Lockheed was taking 4 x 8 or 5 x 10 mill sheets and starting from there.
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Walter Runck

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Re: A Piece Of The Electra?
« Reply #12 on: February 13, 2011, 09:00:35 AM »

Factors we have considered in contemplating NAA:

- There are many reasons that a non-match between Niku aluminum and a known piece of NR16020 could be a false negative, but it's difficult to construct a credible explanation for how a match could be a false positive.  You'd have to say that aluminum from a batch (or "heat") that was being used in 1936 was still being used to build or repair airplanes during the explosion in aircraft production that began in 1939.

We've tried, but have so far been unable, to learn how much aluminum was a single "heat" represented in 1936/37. 

If all we are getting from artifacts and other samples is basic chemistry, there is no reason why a mid war heat from Kaiser might not have the same composition as a pre-war heat from ALCOA.  The specs for 2024 allow for minimum and maximum percentages of the desired alloying elements as well as TOA (Total of All Others), so any combination within those limits would have been possible. Manufacturing processes strive for repeatability, so having two different heats with the same chemistry is not only possible, it was desirable and probably strove for.

To our advantage, each piece of Alclad has two signatures, so the odds of matching both sides of two samples would greatly reduce, but cannot eliminate, the chances of a false positive (believing that two samples were drawn from the same lot when they were drawn from different lots).
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Ric Gillespie

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Re: A Piece Of The Electra?
« Reply #13 on: February 13, 2011, 05:30:19 PM »

You know a lot more about the manufacturing process than I do. Are you also familiar with neutron activation analysis?   I'm no expert, but my understanding of is that NAA yields a highly individual "fingerprint" that includes specific trace element profiles that is not likely to be duplicated in a different batch of metal.
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Walter Runck

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Re: A Piece Of The Electra?
« Reply #14 on: February 13, 2011, 06:22:49 PM »

You know a lot more about the manufacturing process than I do. Are you also familiar with neutron activation analysis?   I'm no expert, but my understanding of is that NAA yields a highly individual "fingerprint" that includes specific trace element profiles that is not likely to be duplicated in a different batch of metal.

My experience with metallurgy is from a commercial perspective (recertifying tool steel to support a marketing effort),  rather than research or artifact analysis, so I only know as much as I've had to learn to get the job done in the past.  That said, if NAA provides sufficient resolution on the TOA contributors, you'd have to set up a statistical test to see whether the variability within NAA analyses of a sample is small enough to differentiate one specimen from another.  I'll ask around.

BTW, I owe the forum some corrections on ALCLAD and request permission to revise and extend my remarks.  It's a full sandwich, not an open face, with one sheet of structural material between two sheets of CP (Commercially Pure) aluminum.  Hot rolling, heat treating and cold working all contribute to diffusion (mixing) of the alloying elements in the structural center into the CP outer layers.  Significance to us, I would expect NAA surface testing results to varying depending on the life history of the sample, not just the original heat chemistry.  The more heating and beating, the more homogenous the material.  Or, the longer the trip, the soggier the sandwich!

You make a good point; find the plane and all will be revealed (or overcome by events).  Hope I can help.
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