There was still no sign on Sunday of the Indian Air Force transporter aircraft that went missing two days ago with 29 people on board, a spokesman for the air force said.
A massive search for the aircraft entered its third day with 18 vessels from the navy and the coast guard, as well as eight aircraft including dorniers and helicopters.
Search operations were ongoing, Vice Admiral HCS Bisht of the Indian Navy said. "The only challenge we are facing is of monsoon conditions, rough seas and another factor is depth in the area," he said.
The Antonov-32 transporter took off from the southern city of Chennai early Friday on a three-hour flight to Port Blair in the Andaman and Nicobar Islands in the Bay of Bengal.
It made its last radio contact about 15 minutes after take off from the Tambaram Air Force station, air force spokesman Anupam Banerjee said.
No debris or wreckage has been sighted, Banerjee said.
The Indian space agency plans to use its Radar Imaging Satellite that can see through the clouds to locate the missing plane, Indian Space Research Organisation (ISRO) Chairman AS Kiran Kumar was quoted as saying by IANS news aagency.
The people on board included six crew members, 15 personnel of the army, navy and coastguard, and eight mebers of their families.
"I feel my father is safe. I want all of you to pray they all come back unharmed," Ashutosh Singh, son of Bhupath Singh, who was on the missing AN-32 aircraft, said in an appeal through NDTV.