"The chopper made two sorties for over two hours since 6:00 am, but had to return due to inclement weather. The aerial search can resume, only when the weather clears," Defence Spokesman Wing Commander Ranjeev Sahoo told PTI in Shillong.
"The Mi17 helicopter from Tawang searched the Bhutan areas besides the Tawang-Itanagar route," he said.
Two Cheetah helicopters were on stand-by at Tezpur and another Mi17 at Gwwahati, which could not take off because of the weather, he said.
Defence sources said 30 columns of the Indian Army comprising 2,400 personnel from Tawang and Tenga were searching on the ground for the missing helicopter on the Indo-Bhutan border.
Six ITBP teams with 25 personnel each also joined the ground search operations.
The four-seater single-engine Pawan Hans helicopter AS-B350-B-3 went missing yesterday 20 minutes after takeoff from Tawang at 9:56 am.
Besides Khandu, the others on board were pilots Captain J S Babbar and Captain T S Mamik, Khandu's security officer Yeshi Choddak and a lady Yeshi Lhamu, sister of Tawang MLA Tsewang Dhondup. The chopper was to land at Itanagar at about 11:30 am.
The Guwahati air traffic control had reportedly received the last radio communication from it when it was flying near Sela Pass 20 minutes after takeoff.