High-lift device of air vehicle

A high-lift device of an air vehicle, the high-lift device comprising:

• a flap body which is provided at a rear portion of a main wing of the air vehicle such that the flap body is deployed with respect to the main wing and stowed in the main wing and extends along a wingspan direction of the main wing,
• wherein the flap body includes a tip end portion which is an end portion in an extending direction of the flap body, and a body portion which is a portion other than the tip end portion;
• and
• a gap section having a shape in which an upper portion of a leading edge portion of the tip end portion is depressed relative to a leading edge portion of the body portion, to increase a gap between the rear portion of the main wing and a front portion of the tip end portion of the flap body in such a manner that the gap is larger than a space between the rear portion of the main wing and the front portion of the body portion in a state in which the flap body is deployed, the gap section provided so that air flowing along a lower surface of the main wing travels through the gap toward an upper surface of the flap body to weaken a swirling vortex from a lower surface of the flap body to an upper surface of the flap body, at the tip end portion of the flap body,
• wherein the gap section is open on a tip end portion side of the flap body.