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Navigational aids in US bombers?

Discussion in 'Allied Aviation Of WWII' started by alberk, Feb 20, 2022.

  1. alberk

    alberk New Member

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    Hello,

    I did some online research and now understand that the "Air Position Indicator" allowed to establish longitude and latitude of the own position - but it was only used late in the war and in B-29 aircraft. Which technical devices would have been available to a navigator in a B-24 or B-17 to establish the own position?

    Why am I asking? Some Missing Air Crew Reports (MACR) give coordinates of aircraft "seen to crash" - how reliable would these be? Are they mere approximations? A navigator could do better than that - or could he? MACR were to be drafted within 48 hours of the incident. One would assume that witnesses of crashes would be fairly diligent in answering questions - it was about the fate of their comrades...

    I am researching crash sites of B-24 which were shot down doing a supply drop for "Operation Varsity" on March 24th, 1945 over Germany - 14 aircraft were lost that day.

    Thank you!
     
  2. OpanaPointer

    OpanaPointer I Point at Opana Staff Member Patron   WW2|ORG Editor

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    The Air Force Historical Society at Maxwell AFB may be able to help you.
     
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  3. ltdan

    ltdan Active Member

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  4. alberk

    alberk New Member

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    That's where I found the info about the Air Position Indicator...
     
  5. Takao

    Takao Ace

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  6. firstf1abn

    firstf1abn Member

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    Watch this training film on dead reckoning.



    If you are referring to map grid coordinates rather than long/lat, I presume you either have the wartime maps or the present day online calculator.

    If I recall correctly, 6 digit coordinates are +\- 100 yards in each plane. The MACR maps I have seen are drawn as an overlay on vellum and identify the base map. From the video, I'd guess an observed crash would be noted in flight log as to time and then, if the navigator is doing his job, should be fairly straightforward to establish a location from that data. Even easier would be to note it directly on navigator's map, then trace it onto vellum during MACR prep.

    The MACRs I have seen rely heavily on interviewing local civilians in the neighborhood of a crash (when there are any). If there was some high tech way of doing it, locals wouldn't be needed.
     
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  7. alberk

    alberk New Member

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    Hi Takao and firstf1abn,

    thank you for the link to the PDFs, Takao! I will take a closer lookat these!

    firstf1abn - you posted some very valuable information for me and your observations/assessments are a great help. Thanks for the youtube link!

    Best
    Alex.
     
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  8. mcoffee

    mcoffee Son-of-a-Gun(ner)

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    H2X radar was used as a supplement to navigation in Europe also. The Radar Observer's Bombardment Information File is among the collection at the link Takao provided, specifically:
    Item 000023 Detail

    Crash sites with MIA personnel were the subject of considerable postwar effort to locate. Individual Deceased Personnel Files (IDPF) of involved crew members would have more specific information regarding locations. HRC Homepage
     
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  9. alberk

    alberk New Member

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    mcoffee - thanks! I have access to some IDPFs of the crew members involved - indeed, they sometimes contain more and additional information, especially when unidentified bodies are the subject of further investigations. But at the moment it takes time an patience to order IDPFs.

    In my case, the IDPFs I have do not contain more exact information.
     
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  10. T. A. Gardner

    T. A. Gardner Genuine Chief

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    The Air Position Indicator and other tools described above were used for ded reckoning (no, not dead. Ded is short for Deduced). Anyway the API is one of several means the plane's navigator had to plot the aircraft's position. Most crews relied-- by 1944 on electronic navigation aids first like LORAN first and would use ded reckoning as a check and backup system if the LORAN receiver failed.

    Aircraft crash sites and reports are accurate to within maybe a mile or so of the site. This is because the reporting crews would be relying on a rough estimate of the crashed plane's location relative to their own. They wouldn't have exact measurements to go on.
     
  11. USMCPrice

    USMCPrice Idiot at Large

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    Actually "dead" is also correct, if you'll notice the official manuals Takao linked to has it as "dead". Ded shorthand for deduced was not a term until the early 1930's. "Dead" reckoning had been used to describe nautical navigation since the 1600's and was used exclusively in aviation navigation up until the Ded/Deduced term came into
    existence. "Dead' was still commonly used, as evidenced by the Air Corps Navigational manual linked to. I'm not sure of the etymology of the term "dead reconning", 1600's was pretty far back.
     
  12. Takao

    Takao Ace

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  13. USMCPrice

    USMCPrice Idiot at Large

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    Thank you. A good article that supports my post and gives me the history/etymology of the terms. I'm sure T.A. Gardner will appreciate it as well, his being an old "Chief". Chief's would tear you a new one for using improper nomenclature, insisting that laxity in language led to mistakes, misunderstandings, accidents, and overall poor performance. I tried to avoid them anytime I was on a ship. :kilroy:
     

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