Each passenger is allowed one or two pieces of stowed luggage. Your cabin bag must fit under your seat, or in the appropriate storage space provided. All hand-held luggage is scanned and security checked before you board your flight, and airport staff may ask to see the contents of your stowed luggage.
There are strict rules for the size of allowable stowed luggage. According to the International Air Transport Association, a carry-on bag must not be more than 22 inches long by 18 inches wide and a depth of 10 inches. The overall measurements must allow for the widest point; including wheels, handles and protruding pockets. These are guideline maximum measurements, and individual airlines can stipulate smaller dimensions for stowed luggage to suit available storage space. American Airlines cabin bags must not exceed 22 inches by 14 inches by 9 inches.
The Transportation Security Administration states that you are allowed to transport small quantities of liquid in your stowed luggage if the liquids are in 3.4 oz. clear bottles and placed inside a zipped, 1 quart, clear plastic bag. All other liquids must be packed in your main luggage and checked in.
Some dangerous items are prohibited in an aircraft cabin, according to the International Air Transport Association, and you are not permitted to carry knives or sharp objects onto the airplane for safety reasons. Check with your airline for a comprehensive list of what you are allowed to transport to avoid confiscation of items at the airport.
