Police official Basanta Rajauri said authorities have pulled out all 18 bodies. The only survivor was the pilot, who was taken to Kathmandu Medical College Hospital for treatment, said a doctor at the hospital who was not authorized to speak to media.
The pilot has injuries to the eyes but is not in any danger, the doctor said.
A press statement issued by the Civil Aviation Authority of Nepal said the Saurya Airlines plane had taken off at 11:11 a.m. from Kathmandu and was heading to resort town of Pokhara.
The plane had already taken off and turned right before it crashed in the eastern section of the airport, the statement said.
The bodies have been taken to the T.U. Teaching Hospital in Kathmandu for autopsy. The airline manifest showed there were two pilots and 17 passengers on board, among them there was only one female. The crew and 16 passengers were Nepali nationals with one identified as foreigner but no nationality was disclosed.
Tribhuvan International Airport, the main airport in Nepal for international and domestic flights, has been closed as emergency crew and investigators began their work.
It is monsoon rainy season in Kathmandu but was not raining at the time of the crash. Visibility was low across the capital, however.
Saurya Airlines operates the Bombardier CRJ 200 on domestic routes.
The Kathmandu airport, the main airport serving Nepal, is located inside a valley surrounded by mountains on most sides. It is considered a challenging airport for pilots and bigger planes have to come through an opening on the mountain to land. It is right next to the city. The airport is surrounded by houses and neighborhoods.
In 2019, a Bangladeshi airliner crashed at Tribhuvan airport, killing 51 people while 20 on board survived. An investigation confirmed the plane was misaligned with the runway and its pilot was disoriented and tried to land in "sheer desperation" when the plane crashed.
In 2015, a Turkish Airlines jet landing in dense fog skidded off a slippery runway at the airport. The plane was carrying 238 people but there were no serious injuries.