Boss Raptor,
Well, I still donīt agree with you. MSG-3 is a method to analyze a technical system, a C-check -can- be the result of that (summing up several tasks that fit into the same FH/FC/Calendar Time regime).
The A380 is currently subjected to MSG-3, and as you may know, there wonīt be any letter checks in the MRBR...! So, where is the link between MSG-3 and letter checks...?
Cheers,
J.V.