On the universality of the Carter and McLenaghan formula
  It is shown that the formula of the isometry generators of the spinor representation given by Carter and McLenaghan is universal in the sense that this holds for any representation either in local frames or even in natural ones. The point-dependent spin matrices in natural frames are introduced for any tensor representation deriving the covariant form of the isometry generators in these frames. 
Ion I Cotaescu