The plane went down on the western side of the Piz Segnas Mountain at an altitude of 2 540 meters reports Xinhua news agency.
The Swiss News Agency said the Junker Ju-52 was owned and operated by local airline JU-AIR which specializes in sightseeing flights.
Local Blick newspaper reported that the aircraft which can carry 17 passengers along with three crew members was fully booked for the flight from the canton of Ticino in southern Switzerland over the Alps to Dubendorf in the canton of Zurich.
--IANS mr/