Airlines add fees and some fees on top of fees

With some airlines charging fees on top of their fees, what's next?

As if charging $15 to check a bag weren't enough, two airlines are asking for $5 more beginning this summer if you pay at the check-in counter -- a fee on top of a fee.

Of course, you could always pay your baggage fee from home. The airlines call it the "online discount."

If airlines can get away with that, what's next? Rather than raise fares in the middle of a recession, they're piling on fees to make money -- fees for bags, fees to get through the line faster, even fees for certain seats.

Chicago-based United Airlines alone expects to rake in more than $1 billion this year in fees ranging from baggage to accelerated frequent-flier awards. That's more than 5 percent of its revenue. The most likely new fees are those that some airline, somewhere, has tried. Fees usually originate with one or two airlines, and competitors watch to see whether passengers accept them or revolt. For instance:

-- United and US Airways are hitting passengers up for $5 to pay their baggage fees at the airport instead of online. United implemented the fee June 10, while US Airways will put it into effect July 9.
-- If you want to select an exit row seat on AirTran and enjoy the extra legroom, expect to cough up $20.
-- Allegiant Air, a smaller national discount airline, charges a $13.50 "convenience fee" for online purchases, even though most other carriers encourage purchases direct from their Web site.
-- European discounter Ryanair charges for something everyone has to do if they want to fly: check in. It's 5 euros, or about $6.75, to check in online, double for passengers who pay at the airport. Ryanair plans to eliminate airport check-in desks.
-- Spanish airline Vueling charges a fee to pick a seat. Any seat at all. A "basic" seat behind the wing runs 3 euros. For 30 euros, travelers can choose an aisle or window seat and guarantee that the middle seat will remain empty.

Delta Air Lines Inc. and AirTran Holdings Inc. say they have no plans to tack a fee on to carry-on bags, an idea that would almost certainly annoy passengers just getting used to paying for checked baggage.

It would also put airline workers in the awkward position of deciding whether that bag on your arm is a big purse, presumably free, or a lumpy suitcase. Already, fees for checked bags have made finding space in the overhead bin tougher.