Airline baggage rules are the guidelines set by an airline regarding the size, weight and contents of bags that passengers are allowed to bring on a flight. These details vary from airline to airline, although the U.S. Transportation Security Administration has many nationwide regulations that are enforced by all airlines.
As of 2015, most airlines allow passengers to bring one carry-on bag and one personal bag onto the plane free of charge. Carry-on and personal bags are relatively small pieces of luggage that passengers may carry into the cabin when they board the plane. Each airline has its own size and weight requirements for these items. Checked baggage, which consists of larger luggage typically weighing no more than 50 pounds and measuring no more than 62 inches in length, is stored in a separate part of the plane and generally has a fee attached. Passengers with luggage heavier or larger than these specifications must pay a higher fee.
In general, the TSA does not allow passengers to store blades, tools, firearms or other weapons in carry-on and personal luggage; however, most of these items may be carried in checked baggage. Explosive and flammable items are almost entirely banned from all luggage. Liquids, gels and aerosols can typically be stowed in checked luggage. They may also be kept in carry-on and personal bags provided the contents are no more than 3.4 ounces.