Chennai: The defence authorities on Monday began searching in the deep sea for the Indian Air Force (IAF) AN-32 that disappeared more than two weeks ago. The deep sea exploration will be conducted with the help of Sagar Nidhi, the National Institute of Ocean Technology (NIOT) vessel.

‘Sagar Nidhi’ is a fully-automatic diesel-electric propulsion vessel, with high-tech searching equipment. The deep sea search operation was supposed to commence last week, but was delayed due to bad weather.

The authorities are perplexed by the fact that even after searching for more than 300 nautical miles off the Chennai coast, they haven’t found any tell-tale signs of oil slick on the waters, indicating the presence of the aircraft debris.

A senior Coast Guard official, on conditions of anonymity, said that Sagar Nidhi could be very helpful because “there is no trace from the disappeared aircraft’s Emergency Location Transmitter (ELT) signals.”

The defence authorities now suspect that the aircraft must have crashed deep into the sea bed, with layers of clay covering it, and this was probably why the ELT signals were not being transmitted.

The search operation is very likely to get delayed with the weather department forecasting heavy rains and off-shore winds of about 45-55 KMPH speeds.

The AN-32 plane went missing on July 22, on its way to Port Blair from Tambaram, with 29 people.