A 45-minute flight from San Diego to Los Angeles can get pricey — about $350 for one-way economy seats on American Airlines.

But an unusual travel site can get you there for about $200 less. The catch is you must book a flight from San Diego to Las Vegas, with a stopover in Los Angeles. Instead of continuing on to Vegas, you simply step off the plane in Los Angeles.

It’s a vexing concept for United Airlines and Orbitz, which have sued to stop the website Skiplagged.com from letting passengers use the money-saving tactic of booking "hidden city" destinations.

United and Orbitz accuse the site’s founder, Aktarer Zaman of New York, of "intentionally and maliciously" interfering with their operations and promoting "prohibited forms of travel," according to the suit.

The lawsuit, filed in U.S. District Court in Chicago last week, said passengers who exit the plane before it reaches its final destination "adversely affect United’s ability to estimate head counts, which can not only cause disruptions at the airport gate, but can also require mechanical tweaks, such as variations in the amount of jet fuel needed for each flight."

Orbitz sued because Skiplagged finds the fares and then directs travelers to book them on Orbitz, which has agreed not to book "hidden city" fares.

COACH SEAT TURNS INTO BUSINESS SUITE

For the past few years, airline interior designers have been inventing new ways to cram more passengers into an airline cabin.

But the winner of an airline industry award for innovation broke from that tradition with an economy seat that converts to a comfy business-class suite.

The Butterfly design is a set of two economy seats, slightly offset from each other. The two seats can become one business-class suite when the seat back on the window-side seat is flipped down, creating a flat couch area. It also reveals extra storage space above and below the seat.

The designer, James Lee of Hong Kong-based PaperClip Design, said the design enables carriers to add capacity by turning business-class suites into economy seats, if demand calls for it.

"Airlines will be able to boost capacity by up to 30 percent in some cases when facing extreme situations, such as right after a snowstorm when thousands are stuck at the airport, which is good news for both airlines and passengers," he said.

Hugo Martin, Los Angeles Times