Just when you thought airlines had run out of things to charge for, Spirit Airlines has become the first carrier to add fees for carry-on luggage.

Most major airlines now charge for checked bags, fees ranging from $20 to $30, but they allow a carry-on bag and one personal item for free.

Spirit, based in Miramar, Fla., and that flies out of Atlantic City but not Philadelphia International Airport, still permits one personal item - a purse, briefcase, backpack, or laptop computer that must fit beneath the seat.

Since airlines began charging to check bags in 2008, more passengers have crammed belongings into carry-on bags, filling the overhead bins, congesting aisles, and delaying departures.

No major airline said Tuesday that it planned immediately to follow Spirit's lead.

"It's something we are aware of," said US Airways Group Inc. spokesman Morgan Durrant, "but we have no plans to do anything like that."

Southwest Airlines Co. - the only large airline, along with JetBlue Airways, that does not charge to check bags - will "absolutely not" charge for carry-ons, said spokesman Paul Flaningan.

American Airlines said, "We cannot discuss what we may or may not do in the future - only what we have actually done. Accordingly, we cannot comment - other than to say we have not taken any such action."

AirTran Airways has "no immediate plans to make any changes to our carry-on-baggage policy," spokesman Christopher White said.

Robert Mann, an aviation consultant in Port Washington, N.Y., said Spirit was so far the only airline to deal with an "operational problem - overly full overhead bins and gate-checked bags - by making it equally unattractive to carry a bag on board."

The airline will make money because some people will pay for the convenience of carrying a bag on board. But Mann does not think it is likely that airlines catering to business and corporate travel will charge for carry-ons.

"Spirit is predominantly a leisure fliers' airline," he said. It has flights to Florida, South and Central America, Mexico, and the Caribbean.

"Business travelers want their laptop, carry-on, and valet bag on board," Mann said. "Charging for carry-ons is not something business travelers would latch onto kindly."

The carry-on-bag fees are $20 if prepaid online for members of Spirit's fare club, $45 if paid at the boarding gate, and $30 if paid by phone or at airport check-in. The fees took effect Tuesday for travel after Aug. 1.

At the same time, Spirit lowered fees to $15 for first and second checked bags, down from $19 and $25 for Spirit fare club members. (Non-club members pay $25 and $30 for checked bags.)

The policy will reduce the number of carry-on bags, "which will improve in-flight safety and efficiency by speeding up the boarding and deplaning process," said Spirit's chief operating officer, Ken McKenzie. "Bring less, pay less. It's simple."

The airline has daily flights from Atlantic City International Airport to Boston; five Florida destinations (Orlando, Fort Lauderdale, Fort Myers, West Palm Beach, and Tampa-St. Petersburg); Myrtle Beach, S.C.; and Nassau, Bahamas.

Contact staff writer Linda Loyd
at 215-854-2831 or lloyd@phillynews.com.