Size Restrictions

• Airlines' baggage allowances vary according to whether the flight is domestic or international. For domestic flights, American Airlines allows passengers one carry-on bag of up to 22 inches long, 14 inches wide and 9 inches high. Checked bags that are larger than 62 inches and 50 pounds may incur a charge. For long-distance flights to destinations such as India, American Airlines prohibits bags weighing more than 70 pounds.
  
  

Exceptions

• Some airlines, such as American, allow active U.S. military personnel and military dependants to check as many as three pieces of baggage without charges.
  
  

Security

• The U.S. Transportation Security Administration prohibits many types of potentially dangerous items from being carried onto a plane by a passenger. These include sharp objects such as knives and box cutters, sporting goods such as baseball bats, guns and firearms, tools such as hammers and drills and various martial arts items.
  
  

Fees

• Most airlines charge fees for bags that must be checked into the plane's cargo bay. On domestic flights, American Airlines charges $25 for the first checked bag, $35 for the second and $100 per piece for the third, fourth and fifth bags. US Airways charges between $25 and $100 per bag depending on the destination and number of bags, while Delta charges $23 and over for bags, depending on the destination.