Airline passengers who have been inundated over the last few years with scores of fees to check bags, order food and even to print out a boarding pass may be surprised to hear about an airline offering a service for free.

Southwest Airlines last week began offering free live television and more than 50 on-demand shows on most of its flights — a service for which the carrier had previously charged $5 per day.

Passengers on most Southwest flights can now switch on their mobile devices and log into the plane’s broadband signal to watch live television, sponsored by the satellite company Dish Network. The planes, however, are not equipped with onboard power outlets, so fliers should be prepared to run out of juice on their mobile devices.

Southwest began last summer to offer live TV, via satellite, but it charged passengers $5 per day and $5 per device.

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The old television fee on Southwest was among dozens of charges that generated $27.1 billion in revenue for the world’s airlines last year. Spirit Airlines, for example, collects nearly 30 percent of its revenue from passenger fees, including a $10 charge to print out a boarding pass.

The new free service is offered on 425 Southwest planes, or about 75 percent of the carrier’s fleet that is equipped with satellite wireless Internet. Under the deal, Dish Network will be able to promote its home satellite services to Southwest passengers.

Southwest is not the first to offer free live television. Virgin America, Delta Air Lines and JetBlue Airways already provide the free service while other airlines offer free on-demand entertainment on seatback devices.

But Southwest officials say they are the first to offer free television on mobile devices brought on board by passengers.

“We started with Wi-Fi and now have expanded to television,” said Kevin Krone, chief marketing officer at Southwest.