Delta Air Lines has issued a stark warning that proposed tariffs under a national security investigation could severely disrupt its operations, potentially grounding flights for millions of passengers annually.In legal documentation submitted to the US government and shared with Fox News Digital, Delta objected to possible tariffs stemming from a Commerce Department probe into the national security implications of imported aviation equipment.The airline cautioned that “without providing time to adjust, any potential tariffs would not only threaten US manufacturing of aircraft, it would also inhibit Delta’s ability to purchase aircraft produced domestically or abroad.”Delta emphasized that new tariffs imposed under Section 232 of the Trade Expansion Act would function as a sudden tax on long-standing purchase agreements, jeopardising both existing and future aircraft deals. “If Commerce were to recommend tariffs under Section 232, the action would also impose an unexpected tax on Delta’s purchases of aircraft contracted years in advance,” the airline stated. “Delta would likely be forced to cancel existing contracts and reconsider contracts under negotiation.”In 2023 and 2024, the organisation received 47 Airbus aircraft manufactured in Canada, Germany or France, according to the document. It stated that the inability to accept these aircraft due to tariffs would have necessitated flight cancellations, affecting approximately 10 million passengers each year.“A similar impact could be expected going forward if Commerce were to recommend Section 232 tariffs,” the filing stated.The document further warned that the tariffs would undermine Delta’s ongoing efforts to grow its skilled manufacturing services and compromise its ability to maintain a modern, competitive fleet for US consumers.White House spokesman Kush Desai confirmed to Fox News Digital that the administration remains committed to addressing national security concerns via the ongoing investigation. The Commerce Department has not issued further comment.According to the formal notice, “On May 1, 2025, the Secretary of Commerce initiated an investigation under Section 232 (19 U.S.C. 1862) to determine the effects on national security of imports of commercial aircraft and jet engines, and parts for commercial aircraft and jet engines.”Delta CEO Ed Bastian had already hinted at the company’s concerns. During an April earnings call, he noted that Delta would postpone accepting deliveries subject to tariffs, a signal of potential ripple effects across the airline’s operations and customers.