by Jane Briggs-Bunting

Flying the friendly skies got a lot more expensive over the last three years, and it’s not just due to fluctuating oil prices and a lousy economy. Airline revenues are soaring, in part, because of all those extra charges tacked on for baggage check-in, snack packs, preferred seating, earlier boarding and extra legroom which added up to nearly $22 billion to carriers’ bottom lines this past year.

Bring a pint-sized Fido or Fifi along for the trip, and, on some airlines, their ticket price could exceed your own–and they don’t get a seat (they get crammed under the seat). They don’t get water, a soda or juice or even a tiny bag of pretzels, and you can’t get credit for their miles either. Cha-chang!

Discount airline Spirit now plans to charge $5 for anyone printing out boarding passes at the airport. The discount airliner makes more than 20 percent of its revenue from $5 here, $15 there. So passengers may get a great ticket price but then all those little extras starting adding up and up and up.

The major airlines are raking in dollars using the same methods, as well. This particular boondoggle started in 2008 when checked bags and food became add-ons. Then the legroom got squeezed, so what to do but charge for preferred seating with more legroom.

The Wall Street Journal and Bloomberg News reported that United Continental added $5 billion to its coffers in fees in 2010, Delta collected $3.7 billion and American snared $1.9 billion, according to a study by Amadeus IT Group SA and IdeaWorks Co.

Want to sit in an exit row? Book that early and you pay for the privilege of possibly opening that 40 lb. door in an emergency. Airlines used to hold back on assigning the exit rows until they could eyeball you for fitness. On a recent Air Tran flight, the seat by the emergency door was occupied by an elderly woman who kept putting her shopping bag between her legs despite repeated requests by the flight attendants that it had to go under the seat in front. In the exit row behind her sat two adults with their child between them. The flight attendant, to her credit, made them change seats. Now, for an extra fee paid in advance, you can sit in the exit row and get to load early depending on the airline.

Expedia.com has a list of fees charged by major airlines.

Then there’s that annoying issue of carry-on luggage. As the fees start piling on, more and more people bring their luggage on board with them, bench pressing them into overhead bins, slowing boarding and exiting the plane. And in the event of a very rough landing or even a crash, the possibility of that very same luggage becoming very large missiles injuring passengers and clogging the aisle ways in an emergency is a reality.

I am not in favor of all these extra fees, but I grudgingly will pay so my knees aren’t slammed up against the seatback in front of me. I would be in favor of charging for carry-on luggage (not daypacks, briefcases or diaper bags) and allowing travelers to check their first bag free. It would make planes safer, speed boarding and deplaning and probably make life a little less stressful for flight attendants.

And I bet the revenues would continue to grow and grow and grow while the food, even the stuff I now pay for, never seems to improve.