Helicopter

A vertical tail of a helicopter,

• the helicopter comprising:
• a main rotor;
• and
• a tail rotor for generating anti-torque to cancel torque generated by rotation of the main rotor,
• the vertical tail having:
• a leading edge;
• a trailing edge concave toward the leading edge;
• and
• spoilers attached to a left side and a right side of the vertical tail respectively, the spoilers suppressing generation of vortices around the concave trailing edge by separating airflow on left and right surfaces of the vertical tail respectively,
• wherein the concave trailing edge has a cover made of a flat plate, the flat plate being disposed not so as to protrude from the concave trailing edge.

A method of improving anti-torque by a tail rotor of a helicopter,

• the helicopter comprising:
• a main rotor;
• the tail rotor for generating the anti-torque to cancel torque generated by rotation of the main rotor;
• and
• a vertical tail having a leading edge and a trailing edge, the tail rotor being attached to a distal portion of the vertical tail,
• the method comprising:
• improving the anti-torque by decreasing an area of the vertical tail that blocks a jet flow generated from the tail rotor in a rotation axis direction of the tail rotor, the area being decreased by making the trailing edge have a shape cut out so as to be concave only within a range within which the vertical tail overlaps a circular region, formed as a rotation range of the tail rotor, in the rotation axis direction of the tail rotor, the trailing edge being concave toward the leading edge.