KATHMANDU , Nepal ( CNN ) -- Pilot error caused the crash of a U.N. helicopter in March which killed 10 people , a Nepalese investigating official said Wednesday . A U.N. worker at the site of the March helicopter crash that killed 10 people in Nepal . The helicopter was traveling from a camp for former Maoist rebels in eastern Nepal to the capital , Kathmandu , when it crashed on March 3 . The crew did not consult the weather forecast , nor did it plan a route before taking off , said Nagendra Prasad Ghimire , the joint secretary of the civil aviation ministry and part of the investigation commission . Once the helicopter encountered bad weather , the pilot 's unfamiliarity of local terrain compounded the problem , Ghimire said , summarizing the commission 's findings . `` He thought that , 'If I climb into the clouds , I will be safe above the terrain and continue to Kathmandu , ' '' he said . Instead , the crew found itself unable to control the aircraft . But the pilot kept the helicopter on auto-pilot mode . `` The pilot should have manually handled the aircraft to rotate safely to the ground , '' Ghimire said . `` Unfortunately , he did n't . '' The chopper crashed in a mountainous region near Bhawasa , about 145 km ( 90 miles ) east of Kathmandu . The U.N. mission said three victims were Nepalese citizens . The others included four international arms monitors from Gambia , Indonesia , South Korea and Sweden . The air crew , from a Russian company , comprised of two Russians and one Belarussian , the U.N. mission said . The helicopter was returning from inspecting a camp for former Maoist rebels who fought a 10-year civil war to end Nepal 's monarchy . More than 13,0000 people died in the fighting . The rebels signed a peace deal with the government in 2006 , joined mainstream politics and won the most seats in April 's election for the Constituent Assembly . The victory transformed Nepal from a monarchy to a republic after 239 years of autocratic rule .
Pilot error caused U.N. helicopter crash killing 10 people , probe finds . Crew did not consult weather forecast nor plan a route before taking off . Air crew comprised of two Russians and one Belarussian .