Navy makes order of submarine-hunting sonobuoys for helicopters and patrol aircraft

U.S. Navy anti-submarine warfare (ASW) experts are buying 9,400 AN/SSQ-53F advanced passive sonobuoys from ERAPSCO Inc. in Columbia City, Ind. under terms of a $7.2 million contract modification announced Monday.

The AN/SSQ-53F directional frequency and ranging (DIFAR) sonobuoy, which is dropped from fixed-wing aircraft or helicopters, uses four hydrophones -- each one a multichannel directional piezoelectric ceramic transducer -- that operate at depths of 90, 200, 400, and 1,000 feet to listen for potentially hostile submerged enemy submarines.

Aircraft can drop a pattern of sonobuoys, which relay information back to the aircraft by radio link, to determine the exact locations of enemy submarines.

Read more