The Pawan Hans helicopter that went missing with Arunachal Pradesh Chief Minister Dorjee Khandu and four others on Saturday morning remained untraced till Sunday night.
The big search by the Army, Air Force, Indo-Tibetan Border Police (ITBP), Sashastra Seema Bal (SSB) and Royal Bhutan Army yielded no result.
Two Sukhoi-30 fighter jets from the Bareilly base in Uttar Pradesh mapped the possible locations of the helicopter.
The satellite imageries taken by the Indian Space Research Organisation could not spot anything because of thick layers of cloud, according to information received by the Arunachal Pradesh government.
The government said permission was obtained from Bhutan for conducting an aerial search over its space. Official sources said a radio signal was detected, but it was yet to be analysed to confirm whether it came from the transponder of the helicopter that went missing 20 minutes after taking off from Tawang at 9.56 a.m.
Twenty-five Army teams, along with 300 SSB and ITBP personnel and hundreds of villagers, marched through the rugged terrains of the frontier State in Tawang, East Kameng and West Kameng districts to locate the helicopter. The government has also sought the assistance of the National Disaster Response Force.
Ranjeeb Sahoo, IAF spokesman at the Eastern Air Command headquarters in Shillong, told The Hindu that inclement weather hampered the aerial search, which resumed for the second day at 6 a.m. on Sunday. Sorties by two Mi-17 (one from Guwahati and the other from Tawang) and two Cheetah helicopters from Tezpur were planned. However, the Mi-17 from Tawang returned to the base after two sorties, while the Mi-17 from Guwahati could not fly any sortie because of the inclement weather.
The two Cheetah helicopters carried out two sorties each, but the operations were called off after the visibility level dropped in the afternoon.
The aerial search would resume at 5 a.m. on Monday, he said.
Coordination with Bhutan
Union Ministers Mukul Wasnik and V. Narayanasamy, deputed by Prime Minister Manmohan Singh to oversee the search operations, reached Itanagar.
They met the Crisis Management Cell, headed by the Chief Secretary, and Ministers and other senior officials.
Mr. Narayanasamy told journalists in Itanagar that all measures to locate the helicopter and rescue Mr. Khandu and the others had been initiated by the Ministries of Defence, Home and External Affairs, in coordination with the State government and Bhutan. However, inclement weather hampered the operations.
On Saturday, initial reports said the helicopter had landed in Bhutan.
However, the Bhutanese authorities denied either sighting or tracing any Indian helicopter in their territory, while the Arunachal Pradesh government said no contact could be established with anyone on board the helicopter.