The armies of Nepal and the US have launched a joint search operation to trace a Marine chopper that went missing since Tuesday afternoon from Sunkhani in Charikot district, 67 km northeast of Kathmandu.The US Defense Department said the missing UH-1 Huey, carrying six Marines and two Nepal Army soldiers, had dropped off supplies, including tarpaulins and rice, in one location and was heading to another when contact was lost.he Nepal Army said on Wednesday that a search operation was under way at various locations of the district including Bhote Koshi river.Immediately after contact was lost with the chopper, Marines in a V-22 Osprey searched near the last known location for about 90 minutes.The Tribhuvan International Airport confirmed that the chopper had lost contact with the control tower at 3 p.m. on Tuesday. Nepal Army spokesperson Jagdish Chandra Pokhrel said a search and rescue team had been dispatched to locate the chopper along its probable route. "We were not able to locate the missing chopper as of 9.30 p.m. on Tuesday," he said.Immediately after the earthquake on April 25, the US Air Force had dispatched two C-17 cargo planes loaded with personnel, cargo and supplies for disaster relief operations.Five US Marine Corps UH-1Y Huey helicopters and four MV-22 Ospreys have been dispatched to Nepal since.The US military has been working closely with the US Agency for International Development and the Office of Foreign Disaster Assistance.