FILE PHOTO: A staff uploads packages on a Delta Air Lines plane at John F. Kennedy International Airport in Queens, New York City, U.S., April 23, 2025. REUTERS/Jeenah Moon/File Photo

By David Shepardson

WASHINGTON (Reuters) -Delta Air Lines warned that Trump administration tariffs on imported airplanes and parts could force the airline to stop buying foreign-made planes and eliminate flights that serve about 10 million customers a year.

The Atlanta-based carrier made the comments in a previously unreported U.S. Commerce Department filing late Tuesday in response to a recently opened national security investigation that could lead to additional tariffs.

Without time to adjust, potential tariffs would threaten U.S. manufacturing of aircraft and hurt Delta’s ability to purchase aircraft produced domestically or abroad, the carrier said.

The airline said that in 2023 and 2024 it took delivery of 47 Airbus aircraft produced in Canada, Germany and France.

If tariffs had forced Delta to cancel those deliveries, the airline would not have been able to operate flights serving 10 million customers a year, Delta said. A "similar impact could be expected going forward" if new national security tariffs are imposed, it said.

"Delta would likely be forced to cancel existing contracts and reconsider contracts under negotiation," the airline said, adding this "would also reduce manufacturing in the United States by both Boeing and Airbus."

The industry faces 10% tariffs on nearly all imported planes and parts after President Donald Trump announced sweeping duties in April. Any new national security tariff would raise that.

Delta said in April it planned to defer aircraft orders that faced tariffs. It was unclear what tariff rate would prompt it to cancel orders. Airlines and manufacturers have argued the sector should continue to face no tariffs.

Last month, the Commerce Department opened an investigation known as Section 232 looking at risks to U.S. national security from imported goods. That could be used as a basis for higher tariffs on imported planes, engines and parts.

Commerce Secretary Howard Lutnick said Wednesday that he expects the department to complete its review by the end of June then discuss it with Trump before a decision is made.

The aerospace and airline industries have said that new tariffs on imported commercial aircraft, jet engines and parts could put air safety and the supply chain at risk or trigger other unintended consequences.

Airlines and manufacturers have been lobbying Trump to restore a tariff-free regime under the 1979 Civil Aircraft Agreement, in which the U.S. sector enjoyed a $75 billion annual trade surplus.

The U.S. Chamber of Commerce in separate comments seen by Reuters urged Trump not impose additional aerospace tariffs, saying they would "weaken U.S. manufacturers."

The group noted last year 135 million U.S. airline passengers traveled on regional aircraft.

"While the United States has no domestic assembly of regional aircraft, imported regional planes all feature significant levels of U.S. content," the chamber wrote. "There is no commercial or national security justification for tariffs on such production."

Business Roundtable, a group of major U.S. CEOs, said tariffs could result in retaliatory measures that "could significantly disrupt the U.S. aerospace industry, which is strongly dependent on foreign customers, ultimately undermining the competitiveness of U.S. products."

(Reporting by David Shepardson; Editing by Cynthia Osterman)