Flap hinge mechanism, method for manufacturing the same, and flap hinge apparatus

A flap hinge mechanism for attaching a flap to a helicopter rotor blade, comprising:

• a blade-secured portion secured to the blade,
• a flap-secured portion secured to the flap, and
• a coupling portion for coupling the blade-secured portion and the flap-secured portion so as to permit angular displacement,
• wherein the mechanism is constructed of a composite material in which fibers of the blade-secured portion and flap-secured portion are impregnated with a first matrix, and fibers of the coupling portion are impregnated with a second matrix having a composition that renders said second matrix lower in stiffness than the first matrix and thus renders said coupling portion softer than said blade secured portion and said flap-secured portion.

A method for manufacturing a flap hinge mechanism for attaching a flap to a helicopter rotor blade, comprising a blade-secured portion secured to the blade, a flap-secured portion secured to the flap, and a coupling portion coupling the blade-secured portion and the flap-secured portion so as to permit angular displacement, the method comprising the steps of:

• impregnating an area of a woven fabric to be the coupling portion with a soft resin;
• impregnating areas of the woven fabric to be the blade-secured portion and the flap-secured portion with an adhesive;
• and
• placing a distance adjustment jig between the blade and the flap, and adhesively securing the blade-secured portion and the blade, to adhesively secure the flap-secured portion and the flap together.