Our mystery prop needs I.D.

Discussion in 'Aircraft Requests' started by AleutianCampaign, Aug 11, 2012.

  1. AleutianCampaign

    AleutianCampaign New Member

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    itemnumber.jpg fullpropresize.jpg rearhubresize.jpg Hello! I've got a prop that needs some ID help. The only helpful visible marking is the number "6477A-" and "0" or "8". I have attached pictures, and hope that may help. We did find a partial serial number, but it is completely corroded and difficult to read. Thanks for any help!
     
  2. A4K

    A4K Well-Known Member

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    #2 A4K, Aug 12, 2012
    Last edited: Aug 12, 2012
    Looks like a Hamilton Standard, a very common US prop, used on anything from Corsairs to Mitchell bombers. Will try and find something on the numbers.

    Edit post: First hit a B-17G, Hamilton Standard prop no. 6477A-6:

    B-17 Hamilton Standard 6477A-6 Propeller and Wright-Cyclone 9-Cylinder R-1820-97 Engine by Christine Krebs ยท 365 Project

    6477A-0, B-17F: http://digital.library.unt.edu/ark:/67531/metadc62488/m1/22/

    This from a forum site (6477A-0, B-24):
    'Most B-24/LB-30/C-87 types had some variant of the Hamilton Standard 23E50 prop with 6477A-0 blades'


    ...There are a ton of hits on that number on Google. If you can find any other ID numbers or details, please write them here.
     
  3. AleutianCampaign

    AleutianCampaign New Member

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    Thanks for the legwork. I'm over my head knowing where to look for this information. (Started this account simply because this forum came up when I started the search!)

    We know it came from Amchitka Island in the Aleutian chain. Thankfully, I did know that that blade number could come from just about any aircraft, but didn't know where else to look for serials, or more specific markings. Is there any chance someone knows something about the rest of the hardware, or arrangement? Is the fact that it is variable pitch narrow it down for us at all?

    Thanks for all the help already!
     
  4. evangilder

    evangilder "Shooter"
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    Known USAAF units assigned to Amchitka AAF were:

    HQ IX Bomber Command, 24 June-4 September 1943
    HQ 343d Fighter Group, 25 July 1943-22 January 1944

    11th Fighter Squadron, 27 March-17 May 1943; 23 March 1944-July 1945 (P-40 Warhawk)
    18th Fighter Squadron, 15 February 1943-28 March 1944 (P-40 Warhawk, P-38 Lightning)
    54th Fighter Squadron, 12 March-18 October 1943 (P-38 Lightning)
    344th Fighter Squadron, May-July 1943 (P-40 Warhawk, P-38 Lightning)

    632d Bombardment Squadron (Dive), 19 July-15 August 1943 (A-24 Banshee)
    633d Bombardment Squadron (Dive), 19 July-15 August 1943 (A-24 Banshee)
    635th Bombardment Squadron (Dive), 19 July-15 August 1943 (A-24 Banshee)

    21st Bombardment Squadron, 18 February-July 1943, (LB-30, B-24 Liberator)
    36th Bombardment Squadron, 4 May-13 September 1943 (B-24 Liberator)
    73d Bombardment Squadron, March-April 1943; June-30 August 1943 (B-25 Mitchell, B-26 Marauder)
    77th Bombardment Squadron, 11 September 1943-11 February 1944 (B-25 Mitchell, B-26 Marauder)
    404th Bombardment Squadron, 4 June 1943-26 February 1944 (B-24 Liberator)

    So there were a number of aircraft that operated from there during the war. Additionally, the US Navy operated Catalinas in the Aleutians.

    After the war, there were B-29s there and at least one C-47. They also supported refueling for long range bombers and for intercontinental transports. So there are a large number of possible aircraft it could have come from.
     
  5. evangilder

    evangilder "Shooter"
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    One additional ting I find interesting is that it looks as if the prop was feathered. Was it from a static site, or a crash site?
     
  6. AleutianCampaign

    AleutianCampaign New Member

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    #6 AleutianCampaign, Aug 12, 2012
    Last edited: Aug 12, 2012
    It appears to have been from a crash. However, the prop was found set up against a sign at the old Amchitka airfield. We (at our USFW Refuge) have photos of it on site as recently as 2000, from an Environmental Assessment performed to check on radiation levels and Remediation and Removal efforts. It appears in our reports with a significantly bent prop blade on one side, and the housing is very clearly ripped off, as you can see in the above photos.

    After looking at the bolt arrangements on the front and comparing to modern photos of restored B-24s, it looks like we might have a winner. But, the search goes on. Anyone know where to look for a serial number that might help to track it to a specific model, or even aircraft?

    Also, would the min and max angles be the same for every blade, or specific to the aircraft? It appears we have a 16 Low and 80 High stenciled on our blades. Modern photos of B-24s have the same numbers stenciled. Is that blade-specific, or aircraft-specific?
     
  7. evangilder

    evangilder "Shooter"
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    Not sure on how to track a serial number on a prop blade to any specific aircraft as many of them were used on multiple aircraft and if it was a spare, it may only track to a depot level. I'm not sure if records exist that would track a serial number of a part to a specific aircraft or not.

    For the minimum and maximum angles, that's beyond my area of expertise.
     
  8. A4K

    A4K Well-Known Member

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    With Eric, I doubt you'll get the aircraft serial from the prop, unless by some miracle you find an aircraft sevicng book with the exact prop construction no. listed!

    I think it will be hard enough to pinpoint the type as it is, but if we can, records of the type downed in the area may help ID the aircraft's serial.
     
  9. AleutianCampaign

    AleutianCampaign New Member

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    Thanks for the help. After some closer looks, we think we are looking for a setup like a 23E50-473-6477A-6. Searches bring back B-17 or B-24.

    Does anyone kno where to look for actual serial numbers on this piece?
     
  10. A4K

    A4K Well-Known Member

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    If you mean the prop, then like I said, you won't find the serial there. If by chance any other remains have been found in the area (ideally another prop) and the numbers match up, it should go some way to help identifying the type, and maybe the specific aircraft serial, depending on numbers of said type lost in the area.
     
  11. AleutianCampaign

    AleutianCampaign New Member

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    There is a part (I'd call it a bellhousing) that is at the rear of the propeller blades, and it appears to have been ripped off of the engine assembly--either from a crash, or some other means. On that part there is a set of barely visible numbers. Would that be a serial? Would that number be part of the prop assembly, the engine, or plane?

    Again, I know very little about it, so I'd appreciate some understanding about not knowing lingo or names of parts. The blades have inventory part numbers, which I understand are related across many different applications during the war. The rest of the assembly (including that "bellhousing" piece) could possibly lend some hints toward ID of the plane type.

    If we get just an aircraft type, that is great. Specific aircraft ID would be a miracle, I understand. But, any help knowing where to look for any other ID numbers, serials, or possible identifiers from the type of assembly, size, shape, etc would be nice.
     
  12. A4K

    A4K Well-Known Member

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    That's also most likely the part identification no./ construction no. Components such as these were standard common items (as Eric also said I think) so wouldn't have received an individual aircraft's serial no.
    The aircraft's servicing book however would/ or should have had the construction no. of the prop fitted listed on fitting, if filled out correctly.

    Like you said, that number could help positively identify the type, so see if you can take a tracing (if hard to make out) and let us know here.

    Cheers,
    Evan
     
  13. CATCH 22

    CATCH 22 New Member

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    #13 CATCH 22, Sep 10, 2012
    Last edited: Sep 10, 2012
    Hi AleutianCampaign!
    The pitch settings are identical for all blades and they are specific for the aircraft. If you can check some structural and repair manuals for the a/c in question (B-24, B-17), there must be a section with all details about the blades, pitch settings etc.
    I have several B-25 manuals and here is what I found in 2 of them:
    B-25 C/D: Diameter 12'7", pitch settings 22 low, 90 high, hub assembly # A-97960, blade assembly # 6349A-18
    B-25 J: Diameter 12'7", pitch settings 22 low, 90 high, hub assembly # 23E50-473, blade assembly # 6359A-18
    As you see even by the same type of a/c, but with different models the blades can be different. In any case the propeller in question is obviously not from a "Mitchell".
    I believe many of the writing fellows in this forum can find similar information about the other possible planes (bombers or fighters). I also believe the pitch settings for B-24 and B-17 are different - see for B-24 here Prop B-24 | Flickr - Photo Sharing! and for B-17 here http://3.bp.blogspot.com/-d7oipv3Qc6U/TniuH8SNsoI/AAAAAAAACs0/UOeiwf8WOe8/s1600/091811a.JPG and IMHO your propeller shows the settings for a B-24.
    Regards!
    Yves Marino
    P.S. I already posted the same answer @ forum.armyairforces.com
     
  14. Pete_Homer_AK

    Pete_Homer_AK Member

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    #14 Pete_Homer_AK, Sep 24, 2012
    Last edited: Oct 7, 2012
    Hi All,
    I am working with Aleutian Campaign on the prop search and have posted on the army airforces forum in the past but will stick to this venue as we seem to have all the same (most excellent) posters here.

    Have taken a little different tack on ID the mystery prop. after discovering aircraft accident reports for Amchitka at this site: Accident-Reports Amchitka The most promising report was for a B-24D that lost a prop during a landing accident. It looked like the source for our mystery propeller but...as luck would have it, the accident report included a photo of the lost prop and it was not feathered, as was ours. Very disappointing discovery.

    But all is not lost. The list includes a number of other prospects including a number of C-47 aircraft and a few B-25. ( BTW thanks Yves for the info on the B-25's). Here is a list of aircraft that have the 6477 blade . Might be one of the other various models of that aircraft use the 6477A-6 propeller.

    Am waiting for the host of the accident-report website to search the microfilm and see if there are any other candidates for our prop. It should be noted that the website page quoted only goes from 1943 to 1955. Amchitka was used for a variety of programs after that and was serviced by both military and civilian aircraft. One of those could have contributed our mystery prop...but one thing at a time. Lets hope we get a hit from that list.

    Will post results of current search when I get results from accident-reports.com host.

    Took a closer look at our mystery prop and have deduced that the serial number is: SN-NK-S847? the ? could be a "6" or a "G" The S looks a little out of place but that is what it appears to be. Also the feather specs on the stencil are MIN-18 MAX_88.

    The exact prop is specified in the C-47 Flight Operating Instructions Nov 1942. That gives me a warm fuzzy feeling that one of the many C-47 accidents could be a candidate for our mystery prop.

    Have also emailed Hamilton-Standard asking for info on production/shipping info but didn't get an answer.

    Pete
    (sailman)
     
  15. Pete_Homer_AK

    Pete_Homer_AK Member

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    #15 Pete_Homer_AK, Oct 3, 2012
    Last edited: Oct 7, 2012
    Hi,

    Based on new info from the prop manufacture, our blade is a 6477A-0. Have found this thread at the warbirds information exchange site that includes a list of aircraft using our prop derived from T.O. No. 03-20-1. I will include it here for convince:

    ...............................................................................................................................................................................

    T.O. No. 03-20-1 has the blade 6477A-0 for

    B-17F G on R-1820-97's - full assembly type designations are 23E50-473-6477A-0, 23E50-505-6477A-0 and 23E50-573-6477A-0

    B-24D on R-1830-47 - full assembly type designations are 23E50-473-6477A-0, 23E50-505-6477A-0

    B-24G, H, J on R-1830-43, -45, -65 - full assembly type designation is 23E50-505-6477A-0

    B-24K on R-1830-75 - fully assembly type designation is 23E50-573-6477A-0

    C-47A C-53D on R-1830-92 - full assembly type designation is 23E50-473-6477A-0 and
    C-47B on R-1830-90B - full assembly type designations are 23E50-505-6477A-0 and 23E50-573-6477A-0

    other types included C-76 (R-1830-92), C-87 (R-1830-43), C-105 (R-1830-11)


    Suspects from this list are the B-24D and C-47. From records and writings, the other aircraft did not appear to be used on Amchitka.
    .........................................................................................................................................................................................

    Have emailed the Air Force Historical Research Agency for assistance. Their workload has delayed a response but hope is they have records from the archives that may shed light on the search for origins of the mystery prop. Also still waiting for accident report search.

    Will post more as information becomes available.

    Pete
     
  16. A4K

    A4K Well-Known Member

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    Great results there Pete!

    Be keen to see the list of accidents in the area if you could post them (controlled pancake, considering the feathered state of the props). Fingers crossed you get your bird!
     
  17. Pete_Homer_AK

    Pete_Homer_AK Member

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    #17 Pete_Homer_AK, Oct 6, 2012
    Last edited: Oct 7, 2012
    Deleted due to unintentional duplicate post. See #19 .

    Pete
     
  18. nuuumannn

    nuuumannn Well-Known Member

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    Hi Pete, I don't know if this info will help at all, but the HS 23E50 prop was actuated by differential oil pressure working against a piston inside the dome, which moved a cam backwards and forwards with teeth at its base that in turn changed the blade angles - this was the patented 'Hydromatic' propeller. On aircraft that used these props feathering was done electrically, with feathering button energising a solenoid, which opened a valve allowing oil pressure in the propeller to build up and act against the piston, so very difficult to feather or unfeather the prop if the aircraft system is not energised. When the aircraft crashed it is almost certain that the pilots would have put the props into feather, so I reckon that your assumption that props were not in feather then entered into feather on the ground is slightly askew. Once in feather the system powered down and aerodynamic forces kept the blades in feather. To unfeather them the electrics needed to be energised to allow oil pressure to build up in the hub to enable it to happen.

    I hope this helps in some way.
     
  19. Pete_Homer_AK

    Pete_Homer_AK Member

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    #19 Pete_Homer_AK, Oct 7, 2012
    Last edited: Dec 1, 2012
    Had a question posed by an accident report researcher. "I'm wondering if a prop can shear off the front of the engine if it was not under power. Could the blades have turned when it broke off?"

    It seems there are a number of accidents with props that come off but none were in the feathered position. Is it possible the prop could have somehow been forced into the feathered position after it came off?

    For those interested in the crash reports including poster A4K, a list of the most promising have been attached in a PDF document. While the reports are not readily available, the document includes basic information including type of aircraft, serial number, pilot and so on. Also here is the website the list was assembled from: Aircraft Archeology (location- Amchitka)

    Got a response back from the prop manufacturer, Hamilton-Standard (now Hamilton Sundstrand). Here it is in full:

    We have reviewed our historical archives in an attempt to identify the aircraft type that used the propeller in your possession. The diameter of 139 inches is correct ,however, the blade designation should be 6477A-0. There were many aircraft that used the 23E50 propeller with 6477A-0 blades. We first tried to match the serial number you provided. We were not able to find it. Then we looked for 23E50/6477A-0 propellers with a min angle setting of 16 degrees and max angle setting of 88 degrees to limit the possibilities. The aircraft listed below meet that criteria:

    Douglas C-47, C-53, DC-3, R4D

    Consolidated B-24

    Waco C-62

    Budd RB, C-93

    Curtiss Wright C-76

    Sorry we could not identify the specific aircraft.


    One important finding is that the correct part number for our prop is 23E50/6477A-0 (not -6). Am disappointed they couldn't relate the S/N to date of manufacture or destination.

    Any comments or suggestions on the search to identify our mystery prop are most welcome.

    Here is the current status of aircraft researched as possible candidates for our mystery prop:

    Aircraft Accident Reports Amchitka
    Candidates for Mystery Propeller

    DATE TYPE S/N ACTION DMG PILOT Mystery Prop Status

    470421 C-47D 44-77252 TACMFW 3 Kintze, Carl delete-no prop dmg
    430414 C-47 42-38640 LAC 3 Keiser, W.L. delete-no prop dmg
    430519 B-24D 42-40093 LAC 5 Zartman, W.V. Research in progress
    440107 C-47 42-24276 LAC 5 Fleischman, R,S. delete-no feathered prop
    430724 C-47 41-38640 TOA 3 Fell, Dale J delete-no feathered prop
    450312 C-47A 42-24275 TOA 4 Egan, D. E. delete-no feathered prop
    461210 C-47B 45-5988 TOA 3 Taylor, H.B. delete-no feathered prop
    450327 C-47A 42-23963 TAC 3 Whitby, N.W. delete-no feathered prop
    470729 C-47D 45-788 TAC 2 Livermore, R.E. awaiting accident report

    NOTES:

    1. Date is year/month/day
    2. DMG is damage to aircraft on scale 1-5 with 5 being written off.
    3. Action Code: TACMFW- Taxing Accident and Mechanical Failure due to Weather
    LAC- Landing Accident
    TOA-Take Off Accident
    TAC-Taxing Accident
    4. The mystery prop was in the feathered position when it detached from aircraft. To be a candidate an accident report must indicate prop feathering, damage, and loss.

    list updated 11/13/2012


    Pete
     

    Attached Files:

  20. Pete_Homer_AK

    Pete_Homer_AK Member

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    Thanks for the info Nuuummann. Thought that might be the case but had to ask the question just to make sure all bases were covered. It is disappointing that all the accident cases so far had props in the unfeathered position.

    Pete
     
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