Carry-on luggage allows travelers flexibility and security. It provides a way to avoid the charges and lines associated with checking luggage. It allows travelers to bring all their necessities on the plane with them while avoiding the potential of lost luggage. Carry-ons are also easier to carry around than full-size bags.
When packing a carry-on, following certain rules will help you get through the security line without hassles. The TSA recommends that you pack your carry-on starting with a layer of clothes, then your electronics items, followed by another layer of clothes, and finally any heavier items on top. Liquids must be in one quart-size clear plastic bag with zip top, and each container of liquid must be 3.4 oz. or less. Any liquid medication larger than 3.4 oz. must be declared and kept separate from the other liquids.
Among the popular U.S. carriers, size requirements for carry-on luggage run from a maximum of 45 linear inches for Delta, Northwest, United, American and Continental up to a maximum of 56 linear inches for the JetBlue Airbus a320. Linear inches are defined as the width plus the length plus the height. Most airlines also require that the baggage fit in the overhead bins and under your seat. The carry-on size requirements for each airline are available on that carrier's website.
Airlines usually allow one personal item and one carry-on item. Outer garments, assistive devices such as crutches or wheelchairs, strollers and car seats for ticketed and lap children, and food for immediate consumption are allowed in addition to the carry-on and the personal item. If an item does not fit into the overhead bin or under the seat, the airline can choose to "gate check" the item, and it will have to be picked up upon exit or at baggage claim after the flight.
Items prohibited in carry-on luggage include: sharp objects, some sporting goods, guns and firearms, martial arts and self-defense items, tools, explosive and flammable materials, and disabling chemicals. Transportation Security Officers can use their discretion to deem other items that are not in these categories as prohibited. The following items are currently allowed as part of carry-on luggage: metal scissors with pointed blades that are shorter than four inches, tools that are seven inches or less in length, up to two fueled lighters as long as they are properly enclosed in a DOT-approved case, and one book of safety matches.
