EC135 Cat A Switch

[semirigid rotor]

Could I ask that any RW TP's who have knowledge of the EC135; hop over to the rotorheads forum and have a read of the "EC135 increase in AUW" thread. It has digressed into a discussion about the theory behind ECD fitting a switch that increases the NR by about 3% for all CAT A flight profiles. A lot of confusion surrounding this kit is evident, and any help would be gratefully appreciated.

[chinook<NL>]

ab139 has a little bit the same, for a cat "A" departure you flip the switch, nr=103% for the little bit more lift to get CAT A qualified.