Years after Delta Air Lines, like all U.S. carriers, removed substantial free food from domestic economy class, the carrier is testing snacks, such as sandwich wraps, on some flights between the East Coast and California.

Delta is coy with details, declining to say on exactly which flights passengers can expect food, or even how long the temporary program will last. But a spokeswoman confirmed the airline is “currently testing complimentary meals” on some trans-continental flights.

During the test, the spokeswoman said, Delta is comparing customer satisfaction scores on flights with food to scores on flights without it “to determine the impact on the in-flight experience.” Once the process is completed, Delta will share more details about its plans, the spokeswoman said. Presumably, if customers are noticeably happier on free food flights, snacks might remain.

[Editor’s note: Since this story published, Delta shared more details on its plans. The program is taking place between Nov. 1 and Dec. 15 on two routes — New York to Los Angeles and New York to San Francisco. On morning flights, Delta is offering a breakfast sandwich or “breakfast medley” with various healthy options. On afternoon flights, passengers can choose a turkey sandwich or veggie wrap.

Delta’s test comes as U.S. airlines continue to be a less stingy with what they offer passengers. American, Delta and United now give substantial free snacks to their most lucrative economy class passengers. American and Delta hand out food to their most elite frequent flyers, while Delta feeds customers seated in its Comfort Plus section.

But changes for regular domestic coach passengers has come slower. Delta has long given small, shelf-stable snacks to passengers — its Biscoff cookies are popular —but it long ago stopped providing fresh food, except on longer flights to Hawaii. Continental Airlines was the last carrier to feed coach passengers with substantial snacks and meals, and it stopped in 2010.

Airlines tend to prefer buy-on-board programs, calculating they can produce more revenue than free food. But if Delta can prove passengers will pay a little extra for an all-inclusive experience, it may decide to return snacks on longer flights. Free food may help Delta further distinguish itself from ultra low cost carriers, such as Spirit and Frontier, which charge for nearly everything, including soda.

In other regions of the world, many full-service airlines are going the opposite direction, removing free food. In January, British Airways will stop serving food on short-haul flights from London’s Gatwick and Heathrow airports. By ending free food service, British Airways is betting it will be more competitive with discounters on cost.

Still, the U.S. and European markets are different. Delta’s flights from New York to the West Coast take about six hours, far longer than Athens-London, which, at around four hours, is among the longest flights in Europe.

“We waste an awful lot of food, so our view is, we probably got to the point where we weren’t giving the customer the right choice,” Willie Walsh, CEO of International Airlines Group, the company that owns British Airways, said in a November interview. “What we found was customers aren’t concerned about paying for something — so long as it’s something they’re choosing to buy, rather than being forced to buy.”

Blogger Gary Leff first reported Delta’s test, quoting a traveler who had noticed passengers being offered a turkey or vegetable wrap on flight from San Francisco to New York. Another reader reported that he had been given free food on one transcontinental segment, but not on his return flight.

Photo Credit: Delta gives free pretzels and peanuts to passengers. Now it is testing whether it should go further and provide substantial snacks on long flights. Yuichi Sakuraba / Flickr