Garry Morris was at Minneapolis-St. Paul International Airport on Thursday when he discovered he'd have to pay a new $15 fee to check even one bag on his Northwest Airlines flight.

Morris, who was flying to Las Vegas to play in a softball tournament, called the charge ridiculous. "Just charge more for the ticket, don't nickel and dime these people," said Morris, who owns a carpet installation company in Excelsior.

As oil prices repeatedly reached new highs this year, airlines have scrambled to cover their fuel costs. Over several months, they've boosted fares and fuel surcharges. More recently, they've turned to adding and increasing fees.

Northwest's one-checked-bag fee -- announced in early July -- took effect Thursday. Several other airlines also are charging for a single bag, although Delta still allows one free checked bag and Southwest permits two.

"There are clearly some customers who would prefer that all fees are simply rolled into the price of the ticket for reasons of simplicity," said Jim Cron, a Northwest senior vice president. But, he noted that some passengers want to keep their travel costs as low as possible, so they are willing to pack light and let others pay bag user fees.

American Airlines was the first big carrier to introduce the first-bag fee. Some observers speculated that customers would get into on-board conflicts over bin space for carry-on bags.

But Mark DuPont, vice president of airport services planning at American, which began charging passengers in mid-June for a first checked bag, said there's only been a "slight increase" in carry-on bags on flights. He added that the new bag fees are not causing flight delays.

"Gate agents have done a very good job of monitoring the carry-on bag compliance," he said. Passengers who are toting large suitcases or carrying too many bags are intercepted and their luggage is checked before they reach gate areas, he said.

DuPont said there has only been a small number of flights in which bags have been checked on airport ramps after overhead bins were filled.

At Northwest, Cron said that about 15 percent of customers traveling within North America check a second bag. But about 60 percent check one bag. Northwest is charging $15 each way for one bag and $25 each way for a second bag.

"It is a certainty that in the future fewer customers will check bags," Cron said.

Teresa Muehlstedt, a marketing operations manager from Golden Valley, intends to join that group. She was traveling to Miami for a vacation Thursday and was surprised that she had to pay a fee for her bag.

"I will plan to do a carry-on in the future," Muehlstedt said. "I never expect to check two again -- ever."

Connie Mettille, head coach of the Winona State University women's volleyball team, has even bigger concerns about the new fees. On Thursday, she was leading a group of 22, most of them players in purple warmup suits, to a volleyball tournament in Denver.

The Winona State delegation didn't pay any $15 first bag fees on Thursday, because the school purchased tickets before a July 10 deadline. Tickets bought on or after that date, for Northwest travel in late August or later, are subject to the new fee.

But Mettille said that Thursday's trip was a "trial run" for the team, because members attempted to pack as little as possible.

The new fee "definitely has changed how we pack," she said. "We carry on everything we possibly can."

Tom Parsons, who operates the website, said that many passengers are going to be "very irritated for the first couple of times they fly" and pay the fee. But then he said that people will adapt and "learn how to pack lighter."

On a recent American flight between Tampa and Dallas, Parsons said about 85 percent of the passengers "were pulling a carry-on."

Overall, DuPont said, about 35 percent of American's passengers check one bag on domestic flights.

Delta Air Lines, which plans to acquire Northwest by the end of the year, has focused on changing customer behavior by discouraging its passengers from checking more than one bag.

In early August, Delta doubled its fee for a second bag, so a customer would pay $100 round trip to check a second bag. A third bag would be $250 on a round trip ticket. But a briefcase, carry-on suitcase and one checked bag are all still free on Delta.

CEO Richard Anderson, in a recent message to Delta employees, said, "We're not a cargo carrier, we're a passenger carrier."

Spokesmen for Delta and Northwest declined to say whether Delta would get rid of Northwest's first-bag fee after the expected merger.

Some customers already are avoiding Northwest's fee. About 10 to 15 percent of Northwest customers are exempt from the new bag fees because they are WorldPerks Elite members, who have high rates of annual travel.

But don't expect the fee to vanish if you are traveling on many coach tickets.

"Although the oil price has dropped somewhat of late, it remains extremely high vs. the business plan," Cron said. "We are not reconsidering these fees at this time."

Some low-fare carriers, including Mendota Heights-based Sun Country Airlines, have a $25 second-bag fee. Now that Northwest is charging $15 for the first bag, Sun Country's Wendy Blackshaw said her carrier is considering the same fee.

Liz Fedor • 612-673-7709