The aircraft AN 32 of the Indian Air Force(IAF), which went missing on the July 22, over the Bay of Bengal lacked Underwater Locator Beacon(ULB). The device transmits signals at ultra low level frequencies which can travel through water. No AN 32 aircrafts have ULB installed.
The missing aircraft had two Emergency Locator Transmitters (ELT) one in the cockpit and the other in the tail fin. The battery life of the two ELT is not more than 72 hours and fails to function under water.
The IAF is now trying to install Underwater Locator Beacons in all the AN 32, as per the TOI.
According to the Indian Express, in the absence of the ULB, the search team has been looking for clues of any wreckage, oil slick of aviation turbine fuel or any other visual clue in the area.
The work horse of Indian Air force, AN 32, is well known for its capability to handle bad weather condition and serves in transporting cargo, passengers, firefighting and para-trooping.