* Be reasonable about the amount of carry-on luggage that you bring. FAA rules require airlines to limit the amount of carry-on baggage, and if you try to carry too much with you, the crew may insist that you check in some items. (There is no universal limit; it depends on the aircraft type and the passenger load.) A bag that is not properly stowed could turn into an unguided missile in an accident or block the aisles during an evacuation. Check for size and weight restrictions before you go.

* Be careful about what you put into the storage bins over your seat. The overhead compartment doors may pop open during an accident or even a hard landing, spilling their contents. Also, passengers in aisle seats have been injured by heavy items falling out of these compartments when people are stowing or retrieving belongings at the beginning or end of a flight. Please be considerate of others and put hard, heavy items under the seat in front of you; save the overhead bins for coats, hats, and small, soft bags.

* As soon as you sit down, fasten and unfasten your seat belt a couple of times. Watch how it works. There are several kinds of belts, and in an emergency you don't want to waste time fumbling with the buckle.

• Before take-off, there will be a briefing about safety procedures, pointing out emergency exits and explaining seat belts, life vests and oxygen masks. Listen carefully and if there's anything you don't understand ask the flight attendants for help. Seasoned travelers keep their seatbelt secured during the entire flight.

The plastic card in the seat pocket in front of you will review some of the safety information announced by the flight attendant. Read it. It also tells you about emergency exits and how to find and use emergency equipment such as oxygen masks.

As you're reading the card look for your closest emergency exit, and count the number of rows between yourself and this exit. Remember, the closest exit may be behind you. Have a second escape route planned in case the nearest exit is blocked. This is important because people sometimes head for the door they used to board the plane, usually in the front of the first class cabin. This wastes time and blocks the aisles.

Oxygen masks aren't the same on all planes. Sometimes they drop down in front of you. On some aircraft, however, you'll have to pull them out of a compartment in front of your seat. In either case, you must tug the plastic tube slightly to get the oxygen flowing. If you don't understand the instructions about how the mask works, ask a flight attendant to explain it to you.

When the plane is safely in the air and has reached its cruising level, the pilot usually turns off the "fasten seat belt" sign. He or she usually suggests that passengers keep their belts buckled anyway during the flight in case the plane hits rough air. Just as seat belts should always be worn in cars, they should always be fastened in airplanes.

Follow these simple tips and have a safe flight and a Merry Christmas.