Nepal's government announced a judicial probe into the helicopter crash in the mountainous north that killed all 24 people on board on Saturday.
The seven-member investigation team, headed by Kesari Raj Pandit, an appellate court judge, also includes senior government and army officials as well as a meteorology expert.
The investigators would submit a preliminary report within 15 days, followed by a detailed one in 45 days.
The crash of domestic carrier Shree Airlines' MI-17 helicopter soon after taking off from Ghunsa village in northern Taplejung district, killing all 20 passengers as well as four crew members, is the worst disaster in Nepal's aviation history.
It exceeds the toll in an earlier tragedy four years ago when an aircraft belonging to another private operator, Shangri-la Airlines, crashed in an area called Kristi Nachne Chaur, killing 18 people.
According to the investigation data with the Civil Aviation Authority of Nepal, an overwhelming 99 per cent of the air crashes have been due to pilot errors.
In the last five years, Nepal suffered 18 air accidents, of which 10 involved helicopters.
The helicopter, chartered by World Wildlife Fund (WWF) for a programme at the Kanchanjunga base camp area in northern Nepal, was being flown by Russian pilot Kim Klim and had a Nepali pilot on board as well.
Bad weather continued to thwart attempts to bring the bodies back to Kathmandu.
Nepal's official media on Tuesday said the chopper had crashed on a hill 13,000 feet above the surrounding area and then fallen down on a ridge.
It was impossible for the rescue helicopters to land at the crash site. A rescue team, comprising skilled mountaineers from the Nepal Mountaineering Association and two WWF officials, that had reached the spot, would probably have to bring the bodies down to Ghunsa village.
Most of the bodies were charred beyond recognition, the official media confirmed.
After the bodies are brought back to the capital, DNA tests would have to be conducted to identify them, it said.
Only one body was identifiable as that of Gopal Rai, Nepal's minister of state for forest and soil conservation.
Besides Rai, the others on board included his wife Meena Rai, Finland embassy charge d'affaires Pauli Mustonnen and deputy director of American government's aid agency USAID Margaret Alexander.
WWF's country director in Nepal, Chandra Gurung, was also on the flight along with conservation director for WWF's British chapter, Jill Bowling, British coordinator Jennifer Headley, programme officer for US chapter Matthew Preece and managing director of US chapter's Eastern Himalayan Programme Mingma Norbu Sherpa.
Nepal also lost its noted geographer and anthropologist Harka Gurung and conservationist Tirthaman Maskey, who had recently received an international award.