Anti-icing system and aircraft

An anti-icing system, comprising:

• a piccolo tube that includes a flow path through which heated gas flows in a longitudinal direction from a rear end to a front end, and a plurality of ejection holes provided along the longitudinal direction to make the flow path communicate with an outside;
• and
• a supply source that supplies the heated gas toward the piccolo tube, wherein
• the piccolo tube is decreased in an area of the flow path in a stepwise manner or in a continuous manner in the longitudinal direction, and has a continuous side surface provided with the ejection holes being spaced apart along the continuous side surface from one another and from a surface subjected to ejection of the heated gas, and
• the piccolo tube is disposed such that a distance from each of the ejection holes to the surface subjected to ejection of the heated gas is constant along the longitudinal direction of the piccolo tube,
• wherein the piccolo tube is configured of a plurality of pipes that are connected with one another in the longitudinal direction while central axes of the respective pipes are eccentric to one another, the pipes having different inner diameters and different outer diameters from one another.