Swiss Flight LX9 Diverts to Azores After Cabin Odour Sends Six for Medical Checks

SWISS flight LX9 from Chicago to Zurich diverted to Lajes Airport in the Azores on 25 August after a pungent odour developed in Economy Class, with five passengers and one crew member later undergoing precautionary medical checks.

The Boeing 777, registration HB‑JNF, landed safely at 6.30am local time and taxied off the runway under its own power, the airline said.

Six People Checked After Landing

SWISS said 222 passengers and 16 crew members were on board, including two pilots and 14 cabin staff. Five passengers and one crew member reported symptoms after the incident. These included eye irritation, nausea and headaches.

All six received precautionary medical checks after landing. SWISS said none required further treatment. The crew declared an emergency while coordinating with air traffic control, giving the aircraft priority as it diverted to Lajes Airport.

Passengers and crew left the aircraft normally after landing. SWISS reported no evacuation and no injuries requiring hospital treatment.

Cause of Cabin Odour Remains Unknown

SWISS has not confirmed what caused the pungent smell. The airline said specialists would inspect the Boeing 777 before it returned to service.

A company spokesman said technicians would examine the aircraft thoroughly. SWISS also cautioned against drawing conclusions before those checks were completed.

LX9 was operating its scheduled service from Chicago O'Hare International Airport to Zurich. The odour developed while the aircraft was crossing the North Atlantic.

The crew decided to divert rather than continue to Switzerland. Lajes Airport on Terceira provided an available landing point in the Azores.

The emergency declaration did not state a confirmed mechanical failure. SWISS said the diversion was precautionary because the source of the odour remained unclear.

Replacement Flight Sent to Terceira

SWISS arranged a replacement aircraft from Zurich to collect the passengers and crew. The relief flight was scheduled to leave Zurich at around 1.00pm on 25 August.

It was expected to return to Zurich at about 10.15pm. The airline said it aimed to bring the affected passengers and crew to their destination as quickly as possible.

The diversion also affected other SWISS services. Flight LX8 from Zurich to Chicago was cancelled that day. A subsequent Chicago‑to‑Zurich service was also cancelled because it was due to use the same aircraft rotation. SWISS said it was arranging alternative travel for affected customers.

Boeing 777 Landed Safely in the Azores

The diverted Boeing 777 was carrying 238 people in total. It landed without further incident and remained able to taxi under its own power. SWISS reported no fire or aircraft damage linked to the event. Everyone on board was able to leave the aircraft normally.

The six people who reported symptoms did not need continuing medical care. The aircraft remained on Terceira for technical inspection. Lajes Airport is located on Terceira, one of the islands in Portugal's Azores archipelago. Its North Atlantic position makes it suitable for diversions by aircraft operating transatlantic routes.

SWISS has not announced a confirmed cause for the cabin odour. The airline said it would avoid speculation while specialists examined the aircraft. Until those inspections are complete, the source of the smell remains unresolved. The airline has not reported evidence of a wider safety issue involving its Boeing 777 fleet.