TIGHAR
Amelia Earhart Search Forum => General discussion => Topic started by: Ric Gillespie on September 03, 2016, 10:41:52 AM
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A commenter on the TIGHAR Facebook page wrote:
"There is a USN chemical analysis report of 24ST dated 1938 freely available online that shows the same chemical analysis of your 1935 sample tests - The artefact is then clearly shown to be post 1938 production and obviously then of WW2 origin, and hence the nearby C87 (B-24) wreck becomes the most credible source - the preponderance of other B-24 parts Tighar has found supports that as the logical conclusion."
If there is such a report and it says what he says it says, it disqualifies the artifact as dating from 1937. I have asked him to post a link to the 1938 USN report but he hasn't yet. I can't find such a report on line but I may not be looking in the right place or in the right way.
If the report confirms that the formula for 24ST in 1938 was the same as the formula found in our 1935 Electra samples then the question of what aircraft 2-2-V-1 came from is academic.
We need to find that report.
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A commenter on the TIGHAR Facebook page wrote:
"There is a USN chemical analysis report of 24ST dated 1938" ...
We need to find that report.
I haven't been able to turn up anything using various search terms derived from that sentence.
It is pretty obvious that the person making the claim is antagonistic and does not want to have his or her reading of the document checked by others.
There is a table that shows the "nominal chemical composition" of 24S, but it is not from 1938: "Corrosion of Metals Used in Aircraft," (http://nvlpubs.nist.gov/nistpubs/jres/25/jresv25n1p75_A1b.pdf) p. 76.
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Is this it?
I think that's probably the source of the allegation. It's a discussion thread about 2-2-V-1 on a forum that is ostensibly about aviation mysteries but spends most its time bad-mouthing TIGHAR in general and me in particular. Many of the participants are exiles from the TIGHAR forum and the level of vitriol (and misconception, distortion, and crazy speculation) is something to behold. I can guarantee that this posting will be copied and posted to that forum with scathing commentary.
A 1938 Naval Aircraft Factory report is referenced in a long, eyes-glaze-over tirade about 2-2-V-1 dating from a year ago and featuring what appear to be screen captures from various documents posted but there are no links to the actual documents. Without being able to see the original documents there is no way verify their accuracy and context. Three of the tables that are reproduced purport to show the percentage of various elements in the 24ST alloy in 1935, 1936, and 1938.
To summarize:
1935 - Copper 4.2%, Manganese .5%, Magnesium 1.5%, Zinc 0%. Nickel 0%, Chromium 0%
1936 - Copper 4.2%, Manganese .5%, Magnesium 1.5%, Zinc 0%. Nickel 0%, Chromium 0%
1938 - Copper 4.4%, Manganese .5%, Magnesium 1.5%, Zinc 0%. Nickel 0%, Chromium 0%
The percentage of various elements in the 24ST alloy in the samples tested for TIGHAR by Lehigh Testing Laboratories were:
1935 Electra sample 1 - Copper 4.29%, Manganese .43%, Magnesium 1.49%, Zinc .008%. Nickel <.0006%, Chromium .001%
1935 Electra sample 2 - Copper 4.06%, Manganese .48%, Magnesium 1.46%, Zinc .007%. Nickel <.0007%, Chromium .001%
1936 Electra - Copper 3.55%, Manganese .45%, Magnesium 1.46%, Zinc .006%. Nickel .0008%, Chromium .001%
1936-1941 Electra Jr. - Copper 4.48%, Manganese .59%, Magnesium 1.49%, Zinc .007%. Nickel <.0006%, Chromium .003%
If the numbers in the first group above represent the standard formula for the designated year, we can see that (not surprisingly) there was some variation in the actual alloy produced. Copper, in particular, seems to have wandered a bit and Zinc, Nickel, and Chromium were present in small amounts. They appear to be impurities rather than part of the formula.
WWII B-24 1943(?) - Copper 4.14%, Manganese .51%, Magnesium 1.42%, Zinc .021%. Nickel .003%, Chromium .024%
WWII B-17 1943 (?) - Copper 4.3%, Manganese .45%, Magnesium 1.31%, Zinc .024%. Nickel .004%, Chromium .018%
The WWII samples show more variation in the percentages of the basic elements of the alloy (Copper, Manganese, and Magnesium) and greater amounts of Zinc, Nickel, and Chromium.
How about 2-2-V-1? - Copper 4.49%, Manganese .62%, Magnesium 1.48%, Zinc .013%. Nickel .002%, Chromium .015%
More Zinc, Manganese and Magnesium than the 1935/36 aircraft but not as much as the WWII aircraft.
So what do we know?
• Assuming that the tables reproduced on the Aviation Mysteries forum are correct, the actual aluminum in Lockheed Electras varied somewhat from the standard formula and contained small amounts of impurities - Zinc, Nickel, and Chromium.
• The aluminum in the two WWII aircraft had virtually the same amounts of Copper, Manganese and Magnesium as the pre-war aircraft but greater amounts of Zinc, Nickel, and Chromium. What we don't know is whether this is due to a change in the formula or poorer quality control due to the huge volume of wartime production.
• 2-2-V-1 falls somewhere between the two groups,
So the allegation on the TIGHAR Facebook page:
"There is a USN chemical analysis report of 24ST dated 1938 freely available online that shows the same chemical analysis of your 1935 sample tests - The artefact is then clearly shown to be post 1938 production and obviously then of WW2 origin" is not supported by the available evidence.
We'll never be able prove that 2-2-V-1 is the Miami Patch but we may be able to conclusively disqualify it. We're not there yet.
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Good morning to all,
It has been a few years since I have looked for updates concerning 2-2-v-1.
Are there any recent developments, either confirming the authenticity of the skin panel, or disproving it as the panel from Amelia's Electra?
Thank you as always,
Bill Mahoskey
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Are there any recent developments, either confirming the authenticity of the skin panel, or disproving it as the panel from Amelia's Electra?
No decent developments. We've been busy working on less frustrating avenues of research.