Amelia Earhart Search Forum > Artifact Analysis
A Piece Of The Electra?
Bill Lloyd:
--- Quote from: moleski on February 12, 2011, 08:39:19 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?
--- End quote ---
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.
Martin X. Moleski, SJ:
--- Quote from: Bill Lloyd on February 12, 2011, 09:10:08 PM ---
--- Quote from: moleski on February 12, 2011, 08:39:19 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?
--- End quote ---
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.
--- End quote ---
"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.
Brad Beeching:
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.
Gums
Walter Runck:
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..
Ric Gillespie:
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.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version