Darwin Airline (Lugano) has written to Switzerland's Federal Office of Civil Aviation (FOCA) questioning the legality of Swiss' plans to engage Austria's Tyrolean Airways (Innsbruck) to operate Swiss domestic flights.

Earlier this year, Swiss announced plans to replace Darwin with a pair of wet-leased Tyrolean Dash 8-400s on its Lugano to Zurich flights effective November 1, and to compete with Darwin on Lugano to Geneva flights effective March 30, 2015. Swiss justified the move stating Etihad Airways' recent entry into Darwin's shareholding rendered the carrier, also known as Etihad Regional, a competitor and therefore an unsuitable partner.

However, Darwin CEO Maurizio Merlo said he understood that Swiss had intended the wet-lease arrangement to be long term and not simply an arrangement to cover the temporary unavailability of suitable Swiss-registered aircraft.

“In our letter to FOCA, we have questioned the legal right of Tyrolean, as an Austrian-licensed airline, to operate domestic flights in Switzerland under the European Union-Swiss Air Transport Agreement, or under surviving conditions of the previous Swiss-Austrian bilateral air services agreement,” he said.

Merlo went on to claim that it was not FOCA's policy to allow local operators to use non-Swiss registered aircraft on any other basis other than a temporary one.

“Darwin Airline's serious concern is that Swiss International Air Lines may be able to use non-Swiss registered wet lease capacity to serve domestic destinations in a manner which could be inconsistent with Swiss International Air Lines' legal duty not to abuse its dominant position,” he ended.