All aircraft flying over sea to be fitted with ULBs

Amid reports that the missing IAF Antonov-32 (AN-32) transport aircraft flying over the Bay of Bengal to Port Blair did not have signalling equipment on board that could function underwater, the government has ordered that all aircraft conducting over-sea and maritime operations be fitted with Underwater Location Beacons (ULBs) as an emergency measure.

“All aircraft likely to fly over sea or vast expanses of water are being fitted with ULBs on an emergency footing. In effect, all aircraft undertaking operations along the Andaman-Nicobar route are now carrying these beacons,” a top source told this newspaper.

“As these ULBs are not available at such a short notice, so they are being taken from aircraft or helicopters that do not need the underwater equipment as of now.”

The source also told this newspaper that trials to fit the ageing AN-32s and IL-76s with ULBs were already on when the AN-32 went missing east of the Chennai coast on July 22 with 29 people on board. “It was unfortunate that the event had to happen even before the fitment process could be completed,” the source added.

The aircraft, at about 150 nautical miles away from Tambaram, veered to the left and then suddenly descended from a height of about 23,000 feet.

The AN-32 carried three signalling systems — an ARTEX C-406-1 transmitter that is carried in the rear of the aircraft, a portable KANNAD 406AS transmitter that is kept inside the cockpit and is manually operated, and beacons on the inflatable dingies that the aircraft always carries. None of these equipment can operate deep underwater resulting in massive odds for the search and rescue missions to locate the aircraft.

The ULBs are specially designed to emit signals when submerged. Such transmitters and ULBs are inbuilt and integrated in all modern aircraft. Moreover, while the battery life of ULBs is about 32 days, ARTEX C-406-1 and the KANNAD 406AS transmitters have a battery life of about 72 hours only while the one on dingies keep on sending signals for about 18-22 hours. The medium tactical transport aircraft of Russian origin, AN-32s are used mainly by IAF for troop and cargo transportation, para-dropping and casualty evacuation. Inducted in a seven-year period from 1984-1991, the Total Technical Life (TTL) of the aircraft is 20,000 flying hours, 25 years and 15,000 landings.

From 2010 onwards, the IAF took up a programme to extend the TTL of the then-existing 105 aircraft from 25 to 40 years by overhauls and upgrades. While 40 aircraft were re-equipped and overhauled in Ukraine’s Kiev between 2009 and 2013, 65 aircraft were upgraded in India between 2011 and 2015.

The present aircraft was overhauled and upgraded in September 2015 at the Base Repair Depot (BRD) in Kanpur and had flown just 280 hours since then. On being contacted, BRD Kanpur did not respond to this newspaper’s queries.

Nor was the missing aircraft in the best of its health. An inspection report had shown that on July 2, throttle movement was found to be sluggish, on July 7, there was a hydraulic leakage from the port wing root and on July 14, pressure was found to be leaking from the port door of the craft.

BULLET POINTS: AN-32 carried three signalling systems—an ARTEX C-406-1 transmitter, a portable KANNAD 406AS transmitter and beacons on the inflatable dingies. All these cannot operate underwater

Most modern aircraft have integrated Underwater Location Beacons that emit signals for 32 days

All aircraft flying over large water swathes are now fitted with ULBs

Missing AN-32 was overhauled and upgraded in September 2015. It had flown 280 hours since then.