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  • What are These?

    Bryan Cobb, Helicopter Enthusiast
    Mfg.Engineer., Composites, Meggitt Aerospace, Rockmart, GA

  • #2
    Those are the washer that go under your teeter bols on the right and left side of the aluminum hub blocks on your head.
    Life,The leading cause of Death

    Live and Learn--OR--Die and be an example

    321.252.7705

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    • #3
      Life,The leading cause of Death

      Live and Learn--OR--Die and be an example

      321.252.7705

      Comment


      • #4
        My thick teter washers are just flat. They don't have the machined relief and I am not familiar with when or why Dennis did that. I don't see new washers in the mast support upgrade? Were these a change at the time Bravo went to market? What was the benefit or purpose of the relief?
        Bryan Cobb, Helicopter Enthusiast
        Mfg.Engineer., Composites, Meggitt Aerospace, Rockmart, GA

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        • #5
          The answers to your questions are I don't know.
          This is the bravo market upgrade, with aluminum pitch arms and mast support.
          Life,The leading cause of Death

          Live and Learn--OR--Die and be an example

          321.252.7705

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          • #6
            Looking at the picture it is interesting that the bolt head is in the relief cut area.

            Possibly to allow a shorter bolt?
            PRA member 41204
            PRA Chapter 16

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            • #7
              Click image for larger version

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              Thanks guys. I see those were a production change when Bravo came out. It's the only "new thang" that's not included on my helicopter.
              Why did Dennis feel like this was needed as a change?
              * Maybe so the same bolt could engage a few more internal threads of the spuds

              When the Bravo hit the market, Dennis believed the frame cracks were because owners flew them in an un-balanced condition and he had not
              came out with the Mast Support kit yet. Most Bravo changes centered around trying to fix that. From memory, Bravos included:
              * Cast aluminum pitch arms,
              * Thicker tubing on some frame tubes
              * A dynamically balanced centrifugal clutch
              * Strut-Saver insert tubes to strengthen the landing gear legs
              * Different preload in the blade cones
              * New Track and Balance Charts
              * Better Spherical Teter Bearings and these recessed washers
              * Different MRGB Pinion Bearing arrangement (Two dual row angular contact instead of 3 or 4 single row)
              * ??

              I still don't see why these recessed washers could have helped with any of the problems.
              Last edited by bryancobb; 07-11-2018, 01:48 PM.
              Bryan Cobb, Helicopter Enthusiast
              Mfg.Engineer., Composites, Meggitt Aerospace, Rockmart, GA

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              • #8
                Dennis Fetters just answered my question on why these two revised washers were introduced.

                His explanation was that the cast pitch arms were bulkier than the stamped steel ones and there was a chance, that if the
                cast arms were used, and if a large head-shift was needed to balance the rotor, the cast arms may have an interference
                and scrub the bolt head. By allowing the bolt head to go 1/8" deeper into the washer counter-bore, interference with the
                cast pitch arms is avoided, even if head-shift amount is large.
                Bryan Cobb, Helicopter Enthusiast
                Mfg.Engineer., Composites, Meggitt Aerospace, Rockmart, GA

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                • #9
                  "And that is the rest of the story" (Paul Harvey)
                  Best Regards,
                  Eddie Sigman,Polvadera,nm
                  (575) 835-4921

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