The Question of 2-2-V-1

[John Ousterhout]

Friction heating is a good thought, but couldn't persist for enough time without leaving clear signs of dragging on the ground.  A different scenario that occurs to me is  proximity to an exhaust pipe.  Does the Electra cowl ring have a rivet pattern anything close to 2-2-V-1?  I only have Beechcraft examples, and they're not even close (pictures to follow).
Here's a hypothetical scenario (please apply whatever caveats will keep me out of jail) - an aircraft with heat-effected cowl ring makes a water landing near Gardner Island (possibly on the Reef, in early July 1937).  Water spray during landing compresses the cowling internally (as a strut fails and the cowling dips into the water), pushing the heat-affected portion of the cowling out of alignment with the rest of the structure.  Subsequent wave action fatigues the loosened piece of aluminum until it breaks loose and washes to shore, where it hides in the sand until TIGHAR finds it.  If it had a nose and thumb it would use them to say "THBBBBBBBBB" to you all.  Perhaps luckily for us, it doesn't have those appendages.
I now return to studying Japanese aircraft of the era....

[Greg Daspit]

Friction heating is a good thought, but couldn't persist for enough time without leaving clear signs of dragging on the ground.

See attachment in reply here
(option A)
The overlap of the port skin would probably be the layer that gets more scratched up. I suspected the port layer would transmit the heat thru to 2-2-V-1 but evidently that would still not generate enough heat. Plus it would likley be under water if being pushed. I did some research and found interesting topics like "underwater friction welding" but nothing that related well to this theory. Still that study of the overlap was useful to me because I wanted to see why 2-2-V-1 wasn't more scratched from sliding sideways to make the first tear at the keel. I suspect it did not slide so much when pushed really hard, but more picked up some, and then when the waves lowered it, is when it got damaged. So a little upward impact force from a projection into the bottom of the keel. As indicated by the blue arrow in the attachment to the reply here

[richie conroy]

Hi All

I have been wondering if area of heat marks could be due to underbelly impacting ground, As the heated area line is too straight to of been used on a open fire  ?

Richie
Ric said the heat is more than what would be generated from friction. see reply here
Where is that picture of the belly from?

it's off Purdue the picture is a plane stationary on runway I think the plane number was nx or nc it was taking in 1936

Don't know how to copy an paste on iPhone

[richie conroy]

If u go on Purdue type electra in search box image 96 page 4 or 5

Cheers richie

[JNev]

If I had to chose a plane on Tighar's list of Canton airplane wrecks as the source of 2-2-V-I, I think the one I'd put my money on is the PBY-2 that went down on 16 March 1940. I say this based on Ric's comment that 2-2-V-I appears to have spent time in a surf environment. The PBY-2 is listed as 'hit reef on takeoff' , so this seems the likeliest of the Canton plane crashes to have left parts on the reef, where the edges were smoothed off by mother nature until, a la the beachcomber hypothesis a Gardner Island worker collected it and brought it home with him — the lack of sharp edges would have made it easier to schlep home on the Viti (or whatever colonial ship was in use then) than a piece of sharp-edged wreckage from a purely terrestrial crash site.

Why not the example of 27 March 1943 - USN  PBY-5A of VP-54 - Destroyed in Japanese bombing attack on Canton -

2-2-V-1 also bears evidence of severe trauma in terms of forced removal from the mother structure and signs of heat damage (loss of ductility) in some areas.  It does not bear the tell-tale pock-marks of explosive damage per one expert who looked at it (upstring - the gent who worked TWA 800 before being retired from NTSB), but perhaps another modus of explosive force, e.g. gasoline creating a rupturing scenario, etc. could have done it (whew - run on...).

Oddly enough, BTW, given the heat damage and suggestion of explosive force, I've found myself wondering a bit lightly whether Hooven might have been right...  8)

That said, the main problem I have with the PBY is that we've already looked at the manual for it and the fastener size and type is wrong, unless somebody put a really light, down-scale patch on something for some reason I cannot imagine: the entire structure uses heavier fasteners than what we see in 2-2-V-1.

But that's not to disclaim it away - if we get to examine one I'd happily clambor all over it to see what can be learned (a bit tongue in cheek... no worries Ric, I realize the museum will have some limits on how much touch is allowed and I won't embarrass the family...  ;D).

Jeff,

I was just trying to connect Ric's observation about 2-2-V-I appearing to have been in a shoreline environment with the list of Canton wrecks, and on that sole basis, the PBY-2 looked like the best fit.

Understood.  I was merely throwing in that the other example might provide some notion of heat / mechanical distress as a victim of a bombing raid.

By the way, at this site is a brief mention of a PBY wreck on the beach:

"Thomas S. Equels adds:
While working for contractor H&N on Canton Island in 1971, we saw the hull of the troopship and nearby on the beach was the fuselage of a PBY with a radial engine close by";

So this wreck was on the seaward, high energy surf environment shore, but which of the wrecked PBYs was it?...I definitely think every Canton plane type should be considered a possible donor and carefully researched. And, if clambering over a PBY to research is fun research, all the better...

But, thinking about how narrow the rim of Canton is, I suppose it might not have just been seaplanes that ended up in Canton's nearshore environment. Looking the airphoto of the island at this site you  can see how close the runways were to the water (I know I've seen better photos of this, but this is what I came up with).

I suppose many things are possible; what we need to do is pinpoint the real likelihoods, IMO.

[JNev]

I believe we have to be thorough about eliminating other potential sources for 2-2-V-1, and a potential 'donor' 350 miles away is strong, IMO.

Now lies this PBM wreckage with a stiffener arrangement of some sort visible through a gaping hole cut in the side of a PBM wing float where metal was removed... The history of this wreck is colorful - deliberately beached on coral and destroyed by fire - and by the old repairs visible on the float, 'hard service' suggests a history of dings and patches. 

While later than the Electra, the PBM is arguably of appropriate vintage (entered service September 1940) as we now understand the decline of the brazier-head rivet to be about a decade later than previously thought, and that some of these seaplanes had surprisingly thinner metal on the hull skins that previously believed (see links up-string).

"...someone 'cut' metal from the side of that float - and a bit crudely, look at the jagged edges - and must have gone to some trouble to do so, for some reason."

So we have vintage-reasonable wreckage within 300 miles or so of Gardner which bears evidence of old repairs and later 'harvesting' (my term) of some portions of metal from the remains... My belief is that we cannot ignore this hulk as a possible source anymore than we'd shy from visiting the AF museum for a comparison. 

Jeff,  I agree the PBM on Howland Island is still in the running as a potential donor.  Ric's list of "Aircraft lost in the vicinity of Nikumaroro" includes another PBM that "Hit reef while taxiing at Canton," on Dec. 15, 1942.  That is an interesting lead that should be looked into carefully.  An accident report probably exists somewhere.

You are an excellent finder of stuff, Mark - can you perhaps locate such a report?

Maybe more to the point of the PBM - which I agree circumstances make intriguing - can you find technical specifics as you have on other types like the PBY and B-17?

I say by 'circumstances' because we have visible PBM wreckage within an arguable 'reasonable distance' of Niku with very suggestive repair / salvage evidence showing.  But will it stand the scrutiny of technical data?  The review of the PBY data revealed much heavier construction throughout, and a lack of the appropriate rivet type.  Although we now know a brazier might have been substituted for other types in a repair scheme, not so much so smaller than original rivets.

The PBM would have to carry #3 rivets in original structure to be convincing.  Having now seen how the PBY is built, I have my doubts.  But we have a surviving exmample at Pima - and perhaps the manuals, if you can find them, may tell us something...

http://tighar.org/wiki/Aircraft_lost_in_the_vicinity_of_Nikumaroro

You bring up a very interesting question; who could have removed that piece of metal from the float on Howland Island? The island was un-occupied at the time that PBM was beached and burned.   

"Anyone" could have, one supposes; it is intriguing to think of Niku islanders doing so, but I'm not sure we're there yet on that. 

I've found some information about the skin plating on the PBM-5.  As in the case of the PBY, it turns out to be thinner than might be expected.  I suspect the 'hull side and crown' had large areas of .032 material.  The wings may also have .032 skin plating, but this report does not go into that unfortunately.   

"...Plating on the bottom of the hull from the bow to the main step is varied from .051 to .072 in thickness. Afterbody bottom plating varies from .040 to .051 in thickness. Hull side and crown skin varies from .020 to .045 in thickness."

Design Analysis of the Martin PBM-5 Mariner
http://legendsintheirowntime.com/PBM/PBM_IA_4509_DA.html



Interesting photos of a PBM wreck in Truk Lagoon can be seen here- (No, I'm not proposing 2-2-V-1 came from this area-  I believe it most likely came via Canton Island- where aircraft wrecks were probably piled high.)

http://warbirdinformationexchange.org/phpBB3/viewtopic.php?f=3&t=17105

Interesting, but essentially anecdotal (like so many things, I know) - now if we could just find more specifics...

As to the PBY, it didn't pan out so well in my view: while some light plating is there in places, the rivet sizing and type is way off.

Specifics needed.  How far are you (or any reading this) from Pima?  There sits a PBM... I think the sole survivor, in fact.

[Tim Collins]

According to the ALCOA metallurgists, the loss of ductility was caused by the sort of heat you would expect from relatively brief exposure to flames - more than from friction but not an intense fire.  I don't recall any mention of how many times this may have happened.  The loss of ductility was noticed when they cut out three "coupons" for testing.  The procedure they used was to cut two parallel lines with snips and then bend the tab up enough to snip the third side.  That worked fine for two to the coupons but when they tried to bend up the third one it snapped off instead. 


Unfortunately ALCOA didn't give us a written report. Their research and comments were done in the context of TV shoot by WGBH as part of a planned NOVA special.  ALCOA was helping us as a courtesy (and to get some good PR) so we didn't press them for a written report. We had it all on video. But then WGBH reneged on the deal we had with them and the NOVA special never got made.  All we were left with was the notes we took at the time. 

Wait a minute, that was how they "determined" there was a loss of ductility?!! Just off the cuff because a piece snapped off rather than bending?  Incredible, simply incredible.  If that's how it was determined then  I would sooner believe that any loss of ductility was due to environmental exposure and corrosion. By the way, what again is the evidence that it was used for cooking?

[JNev]

According to the ALCOA metallurgists, the loss of ductility was caused by the sort of heat you would expect from relatively brief exposure to flames - more than from friction but not an intense fire.  I don't recall any mention of how many times this may have happened.  The loss of ductility was noticed when they cut out three "coupons" for testing.  The procedure they used was to cut two parallel lines with snips and then bend the tab up enough to snip the third side.  That worked fine for two to the coupons but when they tried to bend up the third one it snapped off instead. 


Unfortunately ALCOA didn't give us a written report. Their research and comments were done in the context of TV shoot by WGBH as part of a planned NOVA special.  ALCOA was helping us as a courtesy (and to get some good PR) so we didn't press them for a written report. We had it all on video. But then WGBH reneged on the deal we had with them and the NOVA special never got made.  All we were left with was the notes we took at the time. 

Wait a minute, that was how they "determined" there was a loss of ductility?!! Just off the cuff because a piece snapped off rather than bending?  Incredible, simply incredible.  If that's how it was determined then  I would sooner believe that any loss of ductility was due to environmental exposure and corrosion. By the way, what again is the evidence that it was used for cooking?

I can appreciate your point, Tim - micro-pitting or attack / weaking of the alloy (remember this is 'clad' skin) could facilitate a brittle fracture as I think you are thinking of.  But the zonal depiction Ric gave implies more 'findings' than described here.

Ric, how did the zonal depiction of ductile characteristics get developed?  Was there a survey of the part by hardness testing or similar?  Are you able to notice distinctly varying degrees of malleabiltiy in different areas as you handle the sheet?

Personally, I find the 'heated' prospect for this item interesting as to it's history, but am not sure how vital it is to answer whether 2-2-V-1 came from NR16020 or not.

[Ric Gillespie]

Does the Electra cowl ring have a rivet pattern anything close to 2-2-V-1?

No.  The rivets in the 10E cowl appear to be #3s.  Dunno about the gage of the sheet metal but the rivet pattern is nothing like 2-2-V-1. The photos are of a 10E cowling that were to be used on the replica of NR16020 that was being constructed from Lockheed 10A c/n 1130 by the National Museum of Naval Aviation in Pensacola, FL.  The museum decided not to complete the replica and never used the big cowlings.

[Greg Daspit]

I can appreciate your point, Tim - micro-pitting or attack / weaking of the alloy (remember this is 'clad' skin) could facilitate a brittle fracture as I think you are thinking of.  But the zonal depiction Ric gave implies more 'findings' than described here.

Ric, how did the zonal depiction of ductile characteristics get developed?  Was there a survey of the part by hardness testing or similar?  Are you able to notice distinctly varying degrees of malleabiltiy in different areas as you handle the sheet?

Personally, I find the 'heated' prospect for this item interesting as to it's history, but am not sure how vital it is to answer whether 2-2-V-1 came from NR16020 or not.

Well said Jeff
I'm also curious about how the red heated areas were determined although I could not possibly have worded it that well.  I can't see how 3 test snip "coupons" could define the areas of heat well. Maybe the bend it by hand, flexible here and rigid there, best guess method?
I also am not sure about how vital it is to answering  whether 2-2-V-1 came from NR16020. I think not much at all but maybe what could be considered lagniappe, the extra being a loose fit to a description of something like 2-2-V-1 being used for cooking by colonist who also described aircraft wreckage on the island when they got there. I have the heat element way down the list. 
Reasonable rivet pattern match consistent with repair of original area
Rivet size
Rivets type
Aircraft skin thickness
Aircraft skin type
Is where it went missing within reasonable access of the colonist in the time they had access.
If the donor was repaired in that area before 2-2-V-1 coming off
Is how it broke up consistent with how the donor broke up (the heat may or may not be applicable here).
The lagniappe for me is how much the break up fits TIGHAR's theory of what happened on that reef.

[Ric Gillespie]

The lagniappe for me is how much the break up fits TIGHAR's theory of what happened on that reef.

That's actually what prompted me to re-open Pandora's Box.  To explain how the airplane went over the reef edge (leaving the Bevington Object behind), sank out of sight, but left behind pieces that would later wash up to be found and used by the locals, we had to knock the airplane down onto its belly, push it across the reef flat, tear it up in the surf and sink whatever remained beyond the edge of the first underwater cliff.  It was only after we had developed that hypothesis that I thought, "Wait a minute.  That sounds like our old friend 2-2-V-1." 

[JNev]

I can appreciate your point, Tim - micro-pitting or attack / weaking of the alloy (remember this is 'clad' skin) could facilitate a brittle fracture as I think you are thinking of.  But the zonal depiction Ric gave implies more 'findings' than described here.

Ric, how did the zonal depiction of ductile characteristics get developed?  Was there a survey of the part by hardness testing or similar?  Are you able to notice distinctly varying degrees of malleabiltiy in different areas as you handle the sheet?

Personally, I find the 'heated' prospect for this item interesting as to it's history, but am not sure how vital it is to answer whether 2-2-V-1 came from NR16020 or not.

...The lagniappe for me is how much the break up fits TIGHAR's theory of what happened on that reef.

Love that word, e.g. the gratis "thirteenth donut" in a bought dozen...

[Ted G Campbell]

All,
Would the heat tempered area of 2-2-V-1, shown by Ric, be consistent with sliding down the runway in Hawaii?  Suppose that what we are looking at is the remnants of the original belly skin that wasn't too terribly damaged i.e. original construction not a repair piece.  The repair panel was on the starboard side of the belly instead of the port side.

The starboard side of the plane in the Luke Field photos seem to have taken the bulk of the damage.

Ted Campbell

[Ric Gillespie]

Suppose that what we are looking at is the remnants of the original belly skin that wasn't too terribly damaged i.e. original construction not a repair piece.  The repair panel was on the starboard side of the belly instead of the port side.

But the artifact doesn't fit the port side. 

[Ted G Campbell]

Ric,
Is the "heated" edge of 2-2-V-1 towards the keel or out board?
Ted