Originally Posted by
JimEli
FWIW, calling it a “trim tab” implies it would be trimmable. It is fixed and not adjustable. It simply increases the chord of the airfoil and therefore the thrust-- remembering the equation for lift.
I believe it was added as an appendage starting with the BA version primarily as a consequence of increased power/gross weight. The yaw-load compensator followed shortly thereafter on the B1.
Initially the tab was attached via rivets, and subject to a recurring inspection for cracks initiating at the rivet holes. The rivets were eliminated sometime around the introduction of the B3 Mod or B3/2B1 aircraft. To my knowledge, the majority of the newer, rivet-less tail rotors are painted gray while the older style are typically blue.
Okay..... by increasing the chord size helicopter is getting that extra lift which can be used at pressure altitude 6 KM above especially near Himalayas wherein winds around 17knots is very common. Maybe that extra rudder margin.....can somebody throw more light on this....