Fan Blade, BK SVCE, 5 prop, 5 1/2" (501R, 501F)
  501R    Use Regardless of Serial Number
  501F    Use From #M663116/P679466 to #M/P1004775
          Except Between #M960170-M960319 And
          #M996400-M996574. Prior to #M663116/
          P679466 See 7014711. Starting With
          #M/P1004775 And Between #M960170-M960319
          And #M996400-M996574 See 7016390.