Delta replaces APUs on more than 300 planes to curb cabin fumes

Delta Air Lines says it is replacing the auxiliary power units on more than 300 aircraft to curb the risk of toxic fumes entering cabins. The airline told the Wall Street Journal it is nearly finished upgrading APUs on its Airbus A320 family jets, a program aimed at preventing fumes from reaching flight decks and passenger cabins. The disclosures come as a Wall Street Journal investigation ties a rise in jet-fuel leaks to thousands of fume events across the U.S. airline fleet in recent years. The report notes that many of the incidents have involved Airbus A320 jets and that regulators have tracked a higher rate of such events over the past decade.

According to the WSJ, fume events have been reported to the FAA since 2010, and the Journal cites testimonies from people who say they were affected by fumes leaking into cabin air. One flight attendant, Florence Chesson, says she was diagnosed with traumatic brain injury and nervous-system damage after inhaling fumes on an A320. Her doctor, Robert Kaniecki, said the brain injuries she experienced bore striking similarities to injuries seen in NFL players after concussions. Kaniecki has treated dozens of pilots and flight attendants for similar injuries linked to fumes on aircraft over the past two decades. The Daily Mail noted it had contacted Airbus and JetBlue for comment as part of its coverage.

Delta’s plan centers on replacing the tail-mounted auxiliary power units, which generate electricity and pump conditioned air into the cabin when the two primary engines are not running. The carrier says safety remains its top priority, and Delta staff have indicated that the program is designed to reduce exposure to cabin air contaminants associated with fume events. A Delta spokesman told the Daily Mail that while safety comes first and instances of fumes are rare, the airline has no additional comment or guidance at this time.

The WSJ report links the broader uptick in fume events to incidents across several airlines, including a notable case earlier this year involving JetBlue, which the Daily Mail also flagged in its reporting. Separately, an April incident at Augusta Regional Airport in Georgia involved an American Airlines plane—operated by American Eagle on a Bombardier CRJ900—that landed with smoke in the cabin and prompted an evacuation. The FAA said it is investigating the incident, and there were no reported injuries. The Journal notes that the rate of fume events has risen in recent years, particularly on Airbus A320-family jets, though the overall incidence remains a small fraction of total flights.

As regulators continue to review exposure risks and airlines pursue engineering fixes, Delta’s announced engine-replacement program stands as one of the more visible actions aimed at addressing cabin air concerns. Industry officials say the challenges are multifaceted, involving aircraft design, maintenance practices, and monitoring systems for cabin air quality. Delta and other airlines have emphasized ongoing safety audits and fleet-wide inspections as part of broader efforts to minimize fume events, even as the aviation sector remains focused on reliability and passenger trust.