Overview

• The Wall Street Journal reported on Sept. 24 that Delta has replaced the auxiliary power units on the majority of roughly 300 A320-family jets it manages.
• The program began in 2022 following repeated in-flight fume events on the A320 series.
• Reported incidents involved smoke-containing gas entering cabins, with passengers and crew experiencing headaches and other ailments.
• Delta identified APU ingestion of main-engine exhaust as the likely mechanism that allowed contaminated gases to flow into the cabin.
• An APU is a small onboard engine that provides compressed air and electrical power separate from the main propulsion engines.