It was reported that a Mr. Bill Prymak of Broomfield, CO held the repair records for AE plane – had you contacted him?
I've known Bill Prymak since 1989 when I turned down his application to be on our first Earhart expedition team. If he has repair records for NR16020 they're the same ones we have. They're part of a standard Earhart file that anyone can get from the FAA.
Finch is reported to have received “detailed” drawings from Lockheed via microfilm concerning the rebuild of her aircraft. Have we looked at these drawings?
Finch had a set of the microfilmed engineering drawings. We have those drawings in a digitized, cleaned-up, searchable database - far better than reels and reels of hard-to-read microfilm.
How do the rivets on the “Dados” compare to that of 2-2-V-1? Do they suggest that this was a common rivet size used by Lockheed in the construction of AE’s plane? Dados were reported as being .032 thickness same as 2-2-V-1!
Attached is the section of the NTSB Lab report relating to Artifact 2-1-18, known at that time as the "Dado" but now thought to be a heat shield. Another extremely complex artifact and far more fragile than 2-2-V-1. This was an internal, non-load bearing structure. The rivets, now badly corroded, were 3/32nd Round Heads.
There is a “Google” thread out there “Walt Disney 1942 Riveting” that seems to indicate how to rivet WWII aircraft, and I am wondering if you have looked at it in light of trying to eliminate WWII sources for 2-2-V-1?
Thanks. I had never seen that. It's a great example of how the country responded to wartime demands.
I have also found references to proper rivet selections: i.e. rivet length = sum of material thickness (.032 + .042) + 1.5 the diameter. Also, max dia. of rivet = max thickness of sheet to be riveted e.g. .032 and .042 you use a .042 diameter rivet. How does this formula work with 2-2-V-1 plus the stringer section (the rivet length) found on your training trip?
The skin is .032" and the tail on the existing rivet indicates that it was riveted to a structure .06" thick (which also happens to be the thickness of the stringer from the Idaho Electra), so the total thickness would be .092. 3/32nds is .0935" so it looks like #3 rivets would be okay. Any idea when this guideline dates from?
This seems to be a different guideline than the line quoted by John Ousterhout:
"A rivet should have a diameter of at least three times the thickness of the thickest sheet being joined." (Aircraft Rivets and Special Fasteners) appears to be much newer than 1937, but if the rule was being applied when any particular aircraft seen in a museum was made, then the "thickest sheet" joined using 1/8th inch (dash-4) rivets would be no more than 0.042 inch, and a -3 would be used for skins no thicker than 0.031 inch."
In which case, a #3 rivet in a .032" skin would NOT be okay. Is this the change in guidelines we're looking for?