Delta Air Lines (NYSE:DAL) said Thursday that it is reinstating two transatlantic flights, with demand for air cargo service driving the push to restore service.

The airline said that beginning May 21, it will operate three weekly round trips between Frankfurt and Atlanta, and three between London and Detroit. The flights will also be available for customer travel.

"Keeping global supply chains open is more important now than ever and these new services will enable suppliers to meet the needs of their customers," Delta Cargo vice president Shawn Cole said in a statement. "We're receiving daily requests for shipments of medical supplies as well as goods that keep businesses in operation. By also opening these services to passengers, we can facilitate essential travel between the U.K., Europe and United States."

Delta execs with cut ribbon in front of new plane

Image source: Delta Air Lines.

Cargo will be transported between Frankfurt and Los Angeles by way of Atlanta and between London and Chicago by way of Detroit. Delta said it is also launching a scheduled cargo-only flight between New York and Mumbai, India, on May 16, which will complement existing cargo-only service between South Korea and U.S. airports.

Delta's decision is a modest positive for the company, and a hopeful sign for airline investors who face significant uncertainty about the industry's future. The COVID-19 pandemic has caused travel demand to all but evaporate, and the airlines could face liquidity issues if demand does not rebound in the months to come.

Delta clearly does not see demand rebounding to pre-pandemic levels any time soon. The airline also said on Thursday that it would retire its fleet of 18 Boeing 777s by year's end. The 777s have some of the longest range in Delta's fleet, and the airline has no other airplane type that can fly some of the 777 pre-pandemic routes without a fuel stop, an indication the airline expects its schedule to be permanently altered by the crisis.

Delta said the restored Frankfurt service will be operated using an Airbus A330-300 aircraft with 31 tons of cargo capacity, while a Boeing 767-300 with 26 tons of cargo capacity will fly to London.