The search and rescue operation for the missing An-32 aircraft entered the fifth day today even as hopes of finding the occupants on board faded as all the leads turned out to be bad.

“We are trying all our best resources to find out the leads. All leads til now have turned out to be false,” Defence Minister Manohar Parrikar said today.

A state of art high class research vessel, Sagar Nidhi, of the National Institute of Ocean Technology has been called for from Mauritius.

Sagar Nidhi comes with dynamic positioning system that keeps its position stable that is required for oceanographic research. “Deep vessels can go inside the sea. But cannot go and search per se,” he added.

Meanwhile Coast Guard officials said they have extended their operations till 300 nautical miles off Chennai Coast and to a depth of 3000 to 4000 metres. The absence of the elusive signal from the AN-32 aircraft’s Emergency Location Beacon (ELBA) that is considered critical, has made the operation extremely difficult.

The beacon is designed to emit signals over a particular frequency immediately after any crash or forceful impact.

The Indian submarines that are being pressed into service have limited range of only 1000 metres depth, that is again a set back in the search operations.