An AN-32 transport aircraft of the Indian Air Force (IAF) with 29 people on board went missing on Friday over the Bay of Bengal off the Chennai coast, and remained untraceable till evening despite a full-scale search and rescue mission.
Those on board included six crew members and personnel from the IAF, army, navy and Coast Guard.
The aircraft took off from Tambaram Air Force Station in Chennai at 8.30 a.m., and was expected to land at Port Blair in the Andaman and Nicobar Islands at 11.30 a.m., officials said, describing it as a "routine sortie".
A massive search and rescue operation involving aircraft, helicopters, ships and a submarine was launched immediately to find the plane that went missing around 300 km off Chennai, and will continue through the night.
The last contact with the aircraft was established roughly around 15-20 minutes after the take-off, sources said. A little after 9 a.m., the plane went off the radar.
"The aircraft departed at 8.30 a.m. and was due at Port Blair at 11.30 a.m. but it did not reach its destination," Defence Ministry officials said.
A Coast Guard official told IANS that the last contact with the aircraft was 60 nautical miles from the Indian shores.
Reports, meanwhile, said the plane might have gone down from its altitude of 23,000 feet.
As the aircraft went missing, a full-scale search and rescue operation was launched immediately.
The Eastern Naval Command (ENC) deployed two P8I long-range maritime surveillance aircraft with advanced electro-optics and radars, two Dornier aircraft and 12 ships with integral helicopters to join the search operations.
Four ships of the ENC, deployed in the Bay of Bengal on different missions, were diverted to the search area while eight ships of the Eastern Fleet, which were on return journey from the South China Sea, were also made to proceed to join in the operations.
A submarine at sea was diverted as well for locating transmissions from the emergency locator beacon onboard the aircraft.
Emergency locator beacons usually get activated in case a plane crashes.
Ships deployed for the search include Shivalik-class stealth frigate INS Sahyadri, guided-missile destroyers INS Rajput and Ranvijay, corvettes Kamorta, Kirch, Karmuk, Kora, Kuthar, fleet tankers INS Shakti and INS Jyoti, amphibious warfare vessel INS Gharial and patrol vessel INS Sukanya, the Indian Navy said.
The incident comes a year after a Coast Guard Dornier aircraft with three crew members on board for a routine surveillance flight went missing.
The search team found its black box nearly a month later. The skeletal remains and personal belongings of the crew members were recovered from the sea bed off the Tamil Nadu coast.
India bought 125 AN-32 aircraft in 1984. The IAF at present has a fleet of over 100 AN-32s.
The Russian-origin aircraft is known for its excellent take-off characteristics in hot and high conditions, and is suitable for use as a medium tactical military transport. The twin-engine aircraft is primarily used for transporting cargo, passengers, including skydivers and paratroopers.
After India decided to get the aircraft upgraded, 40 were upgraded in Ukraine and the rest in India.
The IAF and the Ukrspetsexport, a Ukrainian state-owned arms trading company, signed the $400 million upgrade contract in 2009. The first batch of five modified An-32s aircraft was handed over in May 2011 followed by a second batch of five in September 2011.
The final batch of upgraded AN-32RE aircraft was delivered last year, and the modifications have increased the life of these aircraft by 15 years, expected to be in service till 2035, according to experts.
The programme of modernising the aircraft in India, meanwhile, faces a setback due to the crisis in Ukraine and shortage of spare parts.
