The Transportation Safety Administration (TSA) prohibits certain items from being carried on board a commercial passenger airplane. These items include sharp items, guns and firearms, sporting goods, tools, martial arts and self defense items, explosive and incendiary items. In addition, gel inserts in shoes must be removed from all passengers' shoes prior to boarding the airplane.
The TSA has a rule referred to as the "3-1-1 Rule" for carrying liquids on board the airplane. According to this rule, a passenger is permitted to have three ounces or smaller containers, in a one-quart size clear zip-top bag, for each traveler. There are some minor exceptions for children and medications. Baby foods, formula or other liquids are permitted in reasonable quantities, as well as prescribed liquid medications.
Luggage that is checked at the airport counter and stowed in the cargo area of the airplane can contain most of the prohibited items that are unable to be carried in personal luggage on board. However, explosives and incendiary devices are prohibited. In addition, any potentially harmful item must be wrapped in protective covering such that any TSA workers who may check the luggage will not be harmed.