Baggage fees — the add-on charges that passengers love to hate — have turned into a financial bonanza for Hawaiian Airlines.

They have become an increasingly important part of the airline’s revenue, often turning losses into profits as they did in the first quarter when the largest carrier in Hawaii collected $16.1 million from checked, oversize and overweight bags, according to recent data from the U.S. Bureau of Transportation Statistics.

Bag fees enabled Hawaiian to report a first-quarter profit of $7.3 million and represented 3.7 percent of the airline’s $435.5 million in revenue.

Hawaiian is now well on its way to eclipsing the company-record $56.6 million in fees it collected in 2011.

The airline’s first-quarter bag fee collections were up 19.4 percent from $13.5 million in the year-earlier period. The $16.1 million was a record for Hawaiian for one quarter, surpassing the $15.1 million collected in the third quarter of 2010.

Hawaiian also generated $4.6 million in the first quarter from reservation cancellation and change fees, up 3 percent from $4.5 million in the year-earlier period.

The Bureau of Transportation Statistics is not scheduled to release airlines’ second-quarter bag, reservation cancellation and change fees until Sept. 25.

Hawaiian spokeswoman Ann Botticelli said the increase in baggage revenue was primarily the result of an increase in the number of passengers and because its North America flights were fuller in the first quarter of this year than they were in the first quarter of 2011.

"We all realize that the economics of the airline industry have changed since deregulation (in 1978)," Botticelli said. "Customers are interested in lower average ticket prices, which since deregulation have not kept pace with inflation. To keep fares as low as possible, carriers provide customers with the option to pay for certain services they want to use. Baggage revenues are one of those options."

The federal Airline Deregulation Act was signed into law on Oct. 24, 1978, to remove government control of fares, routes and the entry of new airlines.

But industrywide fees for first and second checked bags didn’t begin until 2007 when fuel prices soared to all-time highs. Some airlines such as Miramar, Fla.-based Spirit Airlines and Las Vegas-based Allegiant Air, which now flies to Hawaii from secondary cities in the West, now charge for carry-on bags. Spirit plans to increase its carry-on bag fee to $100 apiece in November, up from $45, while Allegiant charges up to $35 per carry-on bag. Those two airlines don’t charge, however, for any bag that can fit underneath the seat.

Botticelli said the $16.1 million Hawaiian collected in the first quarter wasn’t all profit because of costs associated with handling and transporting baggage.

Airline industry analyst Robert Mann of Port Washington, N.Y.-based R.W. Mann & Co. said bag fees help offset other expenses.

"Basically, in the same way a wide variation of fares and terms maximizes revenue, an array of optional fees for unbundled services take this to an additional dimension," Mann said. "Separately, carriers do spend significant sums on baggage handling; sortation and loading, unloading and delivery, when mishandled; and loss and damage claims, some of which is defrayed by the fees," he said.

Last year Hawaiian raised its checked-bag fees for interisland travel and slightly revised its checked-bag fees for mainland flights.

On Sept. 1 the airline began charging $17 apiece for first and second checked bags for interisland travel, up from the $10 for the first bag and $17 for the second bag that it previously charged.

For mainland travel it changed its policy on Jan. 16 last year and began charging $25 for a first checked bag and $35 for a second checked bag. Previously the charge was $23 for online check-in and $25 at the airport.

The airline doesn’t charge for the first or second checked bag on international flights.

Hawaiian, which is required to report its baggage, cancellation and change fee information to the U.S. Department of Transportation, doesn’t separately break out those fees with its financial results. Its second-quarter earnings report is due to be released after the stock market closes Tuesday.

The 15 major U.S. airlines made $815.8 million from bag fees in the first quarter, up 4.1 percent from $783.7 million in the year-earlier period. For all of 2011, domestic airlines pocketed $3.4 billion in bag fees.

Although not as lucrative, fees for reservation cancellations and flight changes also provided some pocket change for airlines. Domestic airlines made $631 million in such fees in the first quarter, up 5.5 percent from $597.8 million in the year-earlier period. For all of last year, domestic airlines brought in $2.4 billion in cancellation and change fees.

Hawaii economist Paul Brewbaker, principal for TZ Economics, doesn’t begrudge airlines for charging fees for baggage and other items.

"Airlines are operational efficiency masters, using technology to keep fares down, adding routes and city pairs, deploying more fuel-efficient equipment and rationalizing air travel pricing, like luggage, food, etc., so that people have to pay their marginal cost," Brewbaker said. "This is efficient, because it means that commercial passenger carriers can focus on doing their job best, and leaving to restaurants and air freight carriers what they do best.

"I know that passengers love to complain about paying for baggage, etc. but if you think about it for a minute, it’s more efficient now. It only seems like a pain because it was so inefficient before, when people were free-riding off the carriers."