Swiss Flight LX9 from Chicago to Zurich diverts to the Azores

Swiss spokesperson Oliver Buchhofer said the incident would be investigated. "Die Sicherheit unserer Passagiere und Crew hat oberste Priorität", said Buchhofer. He initially gave no further details on the cause of the mayday.

The Azores lie roughly 1,500 kilometers west of mainland Portugal in the Atlantic and are a frequently used diversion airport for transatlantic routes. According to the Portuguese aviation authority, the airport on Terceira hosts a NATO reconnaissance base.

From there, the aircraft was to be continued on to Zurich as quickly as possible once the technical investigation had been completed, according to sources close to the airline.

Authorities Involved

Parallel to the investigation of the incident, Swiss informed the relevant authorities in Portugal and Switzerland. The Swiss Transportation Safety Investigation Board (STSB) was also involved, according to the company.

The affected flight LX9 is one of the daily nonstop services Swiss operates between Chicago O'Hare and Zurich Airport. Because of the prevailing westerly winds over the North Atlantic, such routes usually pass via Iceland or the Azores.

Passengers waiting in Zurich for connecting flights had to expect delays. The airline announced that affected travelers would be informed of further steps and, if necessary, that overnight hotel stays would be arranged on site.

Consequences for Passengers

Swiss expressed regret over the inconvenience to travelers. The company said it was in close contact with the authorities and the crew on site to clarify the incident.

Buchhofer also pointed to the routine in such cases: When a mayday is issued over the Atlantic, the nearest suitable landing option must be flown to, which in this case was available on Terceira.

The incident on LX9 is part of a series of similar occurrences in which transatlantic flights have had to divert to the Azores in recent years. The Portuguese island group has several airports equipped for such cases.

Swiss said further information on the circumstances of the mayday and the technical cause would be published in the course of the investigation. The airline announced a statement as soon as verified findings were available.