Famed economist Milton Friedman once said “There’s no such thing as a free lunch.”

But for decades airlines provided passengers with free lunch, dinner, breakfast and snacks– until doing away with the perk several years ago due to a combination of rising costs and the ability to charge for ancillary fees as a new revenue model.

Now, low fuel prices over the last three years have triggered a huge profit increase for the airlines, and some say they are considering returning some of that goodwill to its customers.

Case in point: Delta Air Lines has been quietly considering the return of free meals on flights.

The Atlanta-based carrier revealed Wednesday that it has been testing complimentary meals in the Main Cabin on trans-continental flights between New York’s John F. Kennedy International and Los Angeles International Airport and San Francisco International Airport.

The testing period began Nov. 1 and ends Dec. 15 as part of the airline’s focus to explore other avenues to enhance the customer experience.

“We are constantly actively listening to our customers and employees, gathering their feedback and testing new products on board to continuously improve the overall experience,” Allison Ausband, Delta’s Senior Vice President of In-Flight Service, said in a statement.

“Testing meals on Transcon flights is part of our commitment to be thoughtful about our offerings and make decisions based on customers’ needs.”

The carrier has also been experimenting with some very specific items including a Honey Maple Breakfast Sandwich or Luvo Breakfast Medley on morning flights. For afternoon flights, it is offering either a Mesquite-Smoked Turkey Combo with chips and a brownie bite, or Luvo Mediterranean Whole Grain Veggie Wrap with grapes and a cookie on afternoon flights.

Once it evaluates the results, Delta said it will announce whether they will move forward with complimentary fresh meals in the Main Cabin on trans-continental flights.

Airlines have been slowly returning some perks to passengers. Earlier this year, Delta began providing on-board entertainment options for free, as did American Airlines. In February, United began its program of free snacks on North America and Latin America routes.