Dipping sonars are the underwater ear of naval helicopters. These systems have great importance for anti-submarine warfare missions.

Lockheed Martin, one of the leading defence companies of the USA, announced that a new order has been received from the aviation unit of the US Navy, NAVAIR (US Naval Air Systems Command). 39 AN/AQS-22 ALFS (Airborne Low-Frequency Sonar) systems will be received within the scope of the acquisition, which is a modification for the previously signed supply agreement. Seven of the sonars to be acquired under the 182 million USD addition will be integrated to Denmark choppers. Besides US Navy will receive eight and 24 for the Indian Navy MH-60R Sea Hawk helicopters.

ALFS, the number one submarine anti-submarine warfare equipment of the MH-60R Romeos, is an integrated dipping sonar system. In addition to submarine detection and tracking, the equipment, which has capabilities such as positioning and classification, can also perform tasks such as collecting data from the underwater environment and acoustic suppression of communications when necessary.