Children aged 5 years old (inclusive) to 12 years old (inclusive) can fly by themselves by applying for the unaccompanied child service, and those aged 12 years old and above can fly alone. In order to ensure safe and smooth flights for unaccompanied children, children aged 5 years old and under 12 years old traveling alone must go through the procedures related to unaccompanied child services before the airline can accept them for transportation. Aircraft: A heavier-than-air aircraft with one or more engine powerplants generating forward thrust or pull, with lift generated by the fixed wings of the fuselage, and flying through the atmosphere. The airplane is one of the most significant inventions of the early 20th century, recognized as having been invented by the American Wright brothers. Their flight on December 17, 1903 was recognized by the Fédération Aéronautique Internationale (FAI) as "the first controlled, sustained powered flight of a heavier-than-air aircraft", and in the same year they founded the "Wright Aircraft Company". Since its invention, the airplane has become an indispensable tool for modern civilization. It has profoundly changed and influenced people's lives, and opened up the history of people conquering the blue sky.