A stowaway is a person who secretly boards a vehicle, such as an aircraft, bus, ship, cargo truck or train, to travel without paying and without being detected.
Stowaways face dangerous situations. Since they are not legally on board, they must sometimes spend days without water or food when traveling by ship, risking death. A much greater risk of death is taken when trying to board an aircraft. Usually, a stowaway tries to jump into an aircraft by hanging on to the airliner's landing gear as the plane takes off, and the force of the wind can easily make a stowaway fall to his or her death. Because people flying on aircraft as stowaways must stay within the landing gear area, they face other risks, such as being crushed in a confined space when the gears retract, falling when the plane is landing, or dying from the heat produced by the engines of the aircraft. Deaths from hypothermia, caused by the extreme cold at high altitudes, or anoxia (lack of oxygen) are also possible and probable.

FAA spokesman Ian Gregor said in 2007, that since 1947, there have been 74 known airplane stowaway attempts worldwide. Only 14 of the individuals survived.[1]
Stowaways also risk imprisonment, as it is illegal in most jurisdictions to embark on aircraft, boats or trains as stowaways. Airports, sea ports and train stations are typically marked as "No Trespassing" or "Private Property" zones to anyone but customers and employees. Seaports, train stations, and airports often attempt further security by designating restricted areas with signs saying "Authorized Personnel Only".

There are several different reasons for which a person might try to become a stowaway, among them free transport and illegal immigration. Some also become stowaways as a dare or a way to get a thrill.
Since the September 11 attacks, it has become more difficult to be a stowaway on board transportation