The Army was alerted and several helicopters were sent out from Chabua, Tezpur and Jorhat but search operations had to be called off due to poor visibility after sunset. The search will resume early tomorrow.

Incidentally, it was only today that Arunachal Pradesh handed over eight ALGs, including the one at Mechuka, to the Ministry of Defence — Defence Secretary Vijay Singh and Chief Secretary Tabom Bam signed a memorandum of understanding in the presence of Chief Minister Dorjee Khandu at Itanagar. The other ALGs are at Walong, Tuting, Vijayanagar, Aalo, Ziro, Tawang and Pasighat.

IAF sources said the Russian-built AN-32, a reliable workhorse, took off at 2 pm from Mechuka but lost radio contact soon. The aircraft had six IAF personnel and “six or seven” other passengers, said to be from the Army. There is no motorable road to Mechuka.

Three IAF officers are among those on board. Names and ranks of those in the aircraft have not been released.

“Aircraft taking off from Mechuka normally take some time to come into radio contact with Jorhat or Chabua. The Jorhat base suspected something was wrong when the aircraft did not make contact within the expected time,” an IAF spokesman said.

IAF Vice-Chief Air Marshal PK Barbora told a Guwahati-based TV channel: “There is a high percentage of possibility that the aircraft might have crashed. But you never know, it may have landed somewhere. We can say for sure only tomorrow.”

India has close to 100 AN-32 aircraft. Eight have been lost in accidents since induction in 1984. The last crash in which casualties took place was in March 1999 when an AN-32 crashed near Delhi, killing 22 people. The last time an AN-32 crashed without any casualty was also in Arunachal Pradesh — at the Vijayanagar ALG in March 2000.