Each lower bracket has 4 bolts. I have seen the exploded view of the assembly with barbi plate but it does not show the 12 bolts. Are these bolts attached to individual nuts or screwed into a female thread that is part of the fittings/airframe ? Can the bolts vibrate their way back out if they become loose or are they nylocked / cotter pinned / or other design safetied ? Torque checks implies to me that they can be removed with a single wrench.