Fares, fees and destinations aren't the only things that vary by airline.
The width of your seat, the amount of legroom and the entertainment options available can make the time, well, fly by — or make a long flight feel a lot longer.
Legroom is important to many fliers. Seat pitch — the space between a point on one seat and the same point on the seat in front of it — can mean more legroom, but that is also affected by the thickness of the seat back. Most coach seats on major airlines are 17 to 18 inches wide. Seat pitch ranges from 30 to 34 inches in most cases, depending on airline and aircraft.
Industry expert Terry Trippler says a lot of passengers tell him you can't beat Northwest Airlines' Airbus A330 coach section seating. "No one is more than one seat from an aisle," he said.
Aircraft specs are often available on airline Web sites, and some airlines tell you at the time of booking what type of aircraft you will be flying.
SeatGuru.com offers information about airplane seating, in-flight amenities and other airline information.
Here's a look at how eight major U.S. carriers stack up in some comfort features for coach passengers, and the options and policies some have if you need more room.
- AirTran Airways
Currently, all of its coach seats are fabric, spokesman Christopher White said.
If a passenger has difficulty with seating, the airline will accommodate the person as it would anyone with a special need, White said.
AirTran has announced plans to have Wi-Fi available for a fee on all 136 of its aircraft by midsummer. Free satellite radio already is available on all its flights — and the earphones are free. Baby changing tables are available in the bathrooms.
- American Airlines
A majority of its aircraft have fabric seats in coach, though most also have leather headrests.
Spokesman Tim Smith said the seat backs on American's new planes are curved ergonomically and thinner to provide more room around the knees.
For larger passengers, the airline does not always or routinely charge for an extra seat unless there are no other options, Smith said.
American plans to have Wi-Fi service available on 300 planes within the next couple of years. Currently, it's on 15 aircraft.
- Continental Airlines
Expect fabric seats in coach. The airline offers free in-flight entertainment (prerecorded video and audio selections and games), but earphones cost $1. Pillows and blankets are free in coach. In general, free meals or snacks are served in economy class on flights over two hours that fall within standard mealtimes.
Customers in coach are required to buy an additional seat or upgrade if they can't properly attach, buckle and wear the seatbelt, with one extension if necessary, whenever the seatbelt sign is illuminated or as instructed by a crew member. Also, the airline says, customers must be able to remain seated with the seat armrests down for the whole flight and they can't significantly encroach upon the adjacent seat.
The airline has begun installing live television programming on more than 200 aircraft. It has not implemented Wi-Fi yet, spokeswoman Kelly Cripe said.
- Delta Air Lines
The airline has leather seats on its pre-merger Delta aircraft and will be putting leather seats on all Northwest Airlines aircraft, spokeswoman Betsy Talton said. Northwest is now a subsidiary of Delta.
The world's biggest airline operator has a wide array of aircraft types, and seat width and pitch vary. The width of the coach seats on the A330 that Trippler mentioned is 17.5 inches.
Delta works to accommodate passengers who need extra room and seat them next to an empty seat if possible. There may be situations where they are offered an additional seat at the lowest available fare when necessary, Talton said.
Delta currently expects to have Wi-Fi installed on 300 aircraft this fall.
- JetBlue Airways
The airline offers one class of service, and all of its seats are leather.
The airline does not have a formal policy regarding customers who need extra seating. A spokesman said crew members would handle situations on a case-by-case basis.
JetBlue only offers Wi-Fi on one plane currently (the service is free for passengers), but it does provide free satellite radio and 36 channels of television at every seat. On flights to the Caribbean and Latin America, where DirecTV service is not available, the airline offers a selection of free premium movies, spokeswoman Alison Croyle said. It charges for pillows and blankets. A set costs $7.
- Southwest Airlines
All of the discount carrier's seats are leather.
The airline doesn't charge for seat selection or for specific seats onboard. Some seats in the front and back of its planes are slightly narrower because of the shape of the fuselage, spokeswoman Beth Harbin said. The airline encourages passengers who can't fit in one seat to buy a second seat when they book their travel. The airline will refund the money for the second seat if the flight doesn't oversell.
The carrier is testing Wi-Fi on some aircraft.
- United Airlines
The airline has started to upgrade some of its seats in its coach cabins to leather, spokeswoman Robin Urbanski said.
If one of its customers doesn't fit in a seat with an extended seatbelt, can't put the armrests down or infringes on a neighboring seat, United will move the passenger to another seat that is next to an empty one at no charge. If there are no empty seats on the flight or subsequent flights, the passenger may be asked to buy a second seat to guarantee one is available.
United doesn't have Wi-Fi available on any of its aircraft, a spokeswoman said. It plans to have the service available on 13 aircraft in the second half of this year.
- US Airways
The airline has replaced seat cushions and covers on some aircraft with leather, and it is in the process of doing the same on most other planes, spokeswoman Michelle Mohr said.
The airline says it tries to accommodate customers who need an extra seat at no charge, though depending on seat availability they may have to purchase a second seat if they can't fit comfortably in one, Mohr said.
US Airways currently does not offer Wi-Fi.