Delta Air Lines is set to replace engines on over 300 Airbus aircraft following incidents where toxic smoke contaminated cabin air, affecting both crews and passengers. The airline has been working on replacing the auxiliary power units (APUs) responsible for these issues since 2022.
The APU is essential for providing electricity and cabin air when the main engine isn’t operational, although it doesn’t help with flight. Currently, Delta has reportedly completed around 90% of the work on its A320 jets.
A malfunctioning APU can leak oil into the aircraft’s airflow system, resulting in the spread of potentially harmful smoke and odors, even when the APU isn’t active. Airbus acknowledges that the design of the APU is a significant issue, but other engines can also leak oil.
There’s been an increase in air quality incidents involving Delta and other U.S. carriers, particularly with the Airbus A320 family. Reports from earlier this month highlighted that smoke exposure is linked to various health problems and has led to flight diversions, with some pilots requiring oxygen masks.
One JetBlue flight attendant suffered a traumatic brain injury similar to a concussion after encountering toxic fumes, describing the smell as “dirty feet” while on a flight to Puerto Rico. Another unfortunate incident involved thick smoke filling a Delta flight cabin in February due to substantial oil leaks from one of its engines, leading to emergency responses.
A lawsuit filed on September 3 by three former JetBlue attendants targets the airline, Airbus, and Honeywell, alleging that harmful smoke leaked into the cabin over several years, causing serious health issues, including tremors and memory problems.
Interestingly, not every incident gets reported, and airlines have varying standards when notifying the Federal Aviation Administration (FAA). Internal records indicate that manufacturers and regulators have been aware of APU sealing problems for decades. Major suppliers like Honeywell and Pratt & Whitney have faced issues within the A320 model related to oil leakage prevention.
Although Honeywell plans to implement another update this year to reduce smell issues and enhance passenger comfort, experts warn that simply replacing old APUs won’t entirely solve the problem, as main engines can also contribute to oil leaks in the cabin.
Airbus found that most fume-related events with the APUs stem from oil entering through the air intake. The company aims to address this by relocating the inlet on new aircraft, potentially reducing these incidents by 85%, but this solution wouldn’t apply to existing planes.
In response to concerns, Delta indicates that such fume events are infrequent and emphasizes that they take them seriously. Meanwhile, Airbus maintains that its aircraft comply with regulatory standards and is committed to ensuring a safe cabin environment for passengers and crew.
