Flapping Guage for Cockpit?
No reason for cockpit indication that I can think of, Lonewolf.
Main rotor shaft bending is a function of flapping and that is important during test operations in various parts of the flight envelope.
For articulated rotor heads with elastomeric bearings, it is important to balance the tail incidence and CG range such that cruise conditions will result in steady state flapping numbers below that of the elastomeric bearing endurance limit. ( Endurance limit defined as that number below which the fatigue loaded part has unlimited life ). Also, because of the flapping vs main rotor shaft bending relationship, this factor is relevant to keeping the steady state ( cruise condition ) main rotor shaft bending below its endurance limit.
Of course the performance engineers care only about ( well, maybe that's being a bit rough on them, but not by much ) keeping the fuselage level at cruise, and devil take the shaft bending, shaft life and bearing life, right? So, for the UH-60 with its FBW stabilator, we spent quite a few flights adjudicating this three cornered discussion. Finally made everyone happy.