The three main things that affect the comfort of big people who are flying are seatbelt extenders, seat space and restroom facilities.

Seatbelt Extenders

If the seatbelt on an airplane doesn't fit you, you need to use a seatbelt extender. All airplanes carry them -- flight attendants use them to demonstrate how to fasten your seatbelt. Airlines win points for being discreet and polite with seatbelt extenders. If you get a pre-assigned seat, you may be able to ask the airline or your travel agent to put an extender on the belt for that seat in advance. Otherwise, you can ask the flight attendant for one.

If you prefer to bring your own extender, LivingXL and Extend-ITs each sell various styles of seatbelt extenders that work with most airplane seatbelts. The ones they sell are somewhat longer than the ones passed out on planes.

Seat Space

Airlines win points for being polite and helpful about trying to save an empty seat beside a big person, and for telling folks where the roomiest seats are and trying to seat them there.

Seat size varies from plane to plane (even within the same airline and model). New planes are likely to have similar-sized seats. But if an airline uses older planes or a variety of models, there's no predicting what size the seats will be. The airline service reps can tell you the type of plane that you will be flying on. Propellor and turbo-prop planes tend to have narrower seats than jets.

Editor's Note: Check out SeatGuru for seat measurements on airline body types of all major airlines.

Bulkhead or door seats do not have a row of seats in front of them, so you get more leg room, and no one will lower their chair into your face. However, the tray tables fold out of the arm rests and you can't raise the arm rests.

On a small plane with no physical divider between first class and coach, the seats directly behind the first class seats tend to have the same pluses and minuses as bulkhead seats.

On a larger plane, such as a 767 or 777, the seats tend to be about an inch wider and there may be as much as two extra inches of legroom.

On all sizes of planes, exit row seats sometimes have more leg room. First class or business class seats tend to be wider with more leg room, but the arm rests usually can't be raised.

If you prefer first or business class, you may want to ask about the possibility of an upgrade. Some airlines will let you upgrade for a small charge, some will upgrade you for no extra charge; some will let you upgrade if economy class is full. Frequent travelers report that it's easier to get an upgrade if you wear business clothing.

To get a few extra inches of space, board as soon as possible, and when you sit down, immediately lift the arm rest. If someone sits next to you, they generally won't bother to put the arm rest back down, and you'll both have more room.

To increase your chance of having an empty seat next to you, try the following:

• Travel on middle of the week flights and red-eye (late night) flights, which are rarely full.
• Ask to be seated in an aisle or window seat toward the back of the plane (they fill the plane from front to back). However, note that the seats in the last row usually don't recline.
• If you are traveling with someone, ask for a window and an aisle in the same row. If someone ends up in the middle, they will probably be happy to switch with one of you.
• Tell the airline when you make your reservation that you're a large person and ask to be seated next to an empty seat. (One person says, "I'm a large person, and while one seat is plenty, I know I'd be more comfortable, and so would the person you place next to me, if I could be placed next to an empty seat instead.")
• Check in early (usually the gate check-in opens an hour before the flight) and ask to be seated next to an empty seat. You don't need to explain why you want one. People of all sizes want to move their seats and asking to be seated next to an empty seat is a common request.
• Ask if you can buy an empty seat or upgrade.

If you are very large, some airlines require you to buy two seats. Call ahead so they don't surprise you at the gate. Some airlines will sell you the second seat for half price. Others will only make you buy the second seat if the flight is full.

If you think you may have trouble negotiating the aisles, get on when pre-boarding is announced. On many planes, you can fold down a seat by pushing on the back, which can provide extra room for settling yourself in your chair.

Airplane tray tables get in the way of the stomachs of some fat people. Try these solutions:

• If you're seated next to an empty seat, use that seat's table.
• Tilt your seat all the way back.
• Balance the tray on a pillow on your lap.
• Bring your own food and avoid using the tray table.
• Ask the person seated beside you if you can put your drink on their table.

Restroom Facilities

Airplane restrooms are very small and often uncomfortable for some larger bodies. Depending on where you carry your weight, some restrooms may be impossible for you to use. Consider these two tips:

• When reserving your seats, request a seat near the disabled-access restroom. These restrooms tend to be a little larger and provide a little more entry and exit room for larger bodies.
• Try to avoid having to use the restroom altogether, using the airport restroom immediately before and after your flight.

Original copyright held by Stef Jones (stef@bayarea.net). Article updated by grandstyle.com.

GrandStyle also has great tips on selecting a size-friendly airlines.