It seems restrictions on air travel get tighter and tighter. First you had to take off your shoes at security; then you couldn't take liquids on the plane with you; then airports introduced full-body scanners. It's hard to keep track of what is and isn't allowed. American Airlines, which in 2009 was second only to Southwest in its number of passengers, has carry-on rules that may vary slightly from those of other domestic carriers.


As more airlines, including American, have started charging for checked bags, passengers are trying to get around the fees by limiting their luggage to carry-ons. The New York Times reports that in 2009, a quarter of all passengers didn't check any bags, up from 17 percent in 2008. How long this tactic will work remains to be seen. In April 2010, the small carrier Spirit announced carry-on bags that don't fit under the seat will garner a charge of up to $45. The country's five largest airlines, including American, promised not to follow suit, but didn't say for how long.


You can't just throw everything in your big suitcase into a smaller bag, however. The rules for carry-on bags are far more restrictive than those for checked luggage. You can take liquids, gels and creams through the security checkpoint only in bottles smaller than 3.4 oz., and only as many as fit in a quart-size zippered plastic bag. Hit the trial-size section of your local drugstore before your trip to buy shampoo, toothpaste and other limited products. After you get past security, you can buy a beverage or other liquid and carry it on the plane. Other exceptions include baby formula, liquid medicines and duty-free purchases.

If you have extra batteries with you, keep them in their original package. If they are loose, put tape over the ends to prevent them from short-circuiting. Incidentally, American requires that spare batteries be placed in your carry-on bag, not in checked luggage.

Other items that can be checked (with some limitations) but not carried on include ammunition and firearms, any sort of cutting tool and scissors with blades longer than 4 inches. Tools such as wrenches and screwdrivers are allowed in your carry-on luggage; crowbars, hammers and saws are not. You can take just one book of safety matches on the plane with you, as well as regular cigarette lighters; however, wind-proof and torch-like lighters are not allowed, and neither are "strike anywhere" matches.

Amount and Size

American Airlines allows one carry-on bag and one smaller bag, such as a briefcase or purse, in the cabin per passenger. The smaller bag must fit under the seat. You must be able to fit the larger bag into the sizers American provides near the ticket counters. The total dimensions of the bag, adding up length plus width plus height, must not be more than 45 inches. That breaks down to a maximum of 22 inches long, 14 inches wide and 9 inches tall.

Allowed Extras

American allows several other items that do not count toward the two-bag limit. These include coats and other outerwear; approved safety seats for children; a pillow or blanket; an umbrella-type stroller for children; diaper bags; and medically necessary devices such as wheelchairs, walkers, CPAP machines and oxygen. American will provide the oxygen.


If the U.S. government enacts rules that are more restrictive than American Airlines', those trump the carrier's. Airline employees may impose new limits depending on the plane's capacity, and may even do this after passengers have started boarding. In addition, the regulations may be more strict at certain airports. Be prepared before you fly, but also be prepared to be flexible.