A Beechcraft 1900D aircraft, operated by Nepal’s Buddha Air, crashed in the Kathmandu Valley on Sept. 25, killing all 19 people on board.

Flight BHA-103 lost contact with the Tribhuvan International Airport tower in the capital of Kathmandu at 7:31 a.m. local time, soon after it had made a flight around Mount Everest. It crashed 4 min. later about 15 km (9.5 mi.) south of the airfield, according to Civil Aviation Authority of Nepal (CAAN). The turboprop plane was broken into pieces, and the rescue efforts were hampered by bad weather.

Investigators found the flight data recorder several hours after the accident, and the police say an investigation is under way to establish the cause of the crash. Buddha Air has initiated an internal investigation while CAAN has formed a three-member inquiry committee headed by its former chief Rajesh Raj Dali.

Aviation experts said the crash was a typical case of Controlled Flight Into Terrain (CFIT). According to an aviation expert Hemant Arjyal, clouds were low but not moisture-laden. The aircraft would have taken the visual approach and the pilot must have flown “in and out” of the cloud. The aircraft seemed to have been too close to a hill and touched it.

According to estimates, 95% of aviation crashes in Nepal — a landlocked Himalayan state bordering India and China — are due to CFIT, and occur in the rainy season when clouds cover the mountains. Some 201 people have been killed in Nepal in 22 domestic airplane accidents, including Sunday´s Buddha Air crash, since the country adopted the Liberal Aviation Policy in 1992 to ease the emergence of private-sector air transport companies, according to reports reaching from Kathmandu. Eighteen of the aircraft in the 22 accidents were operated by private companies, the report said.