The AN/AQS-22 is normally carried by the U.S. Navy's MH-60R anti-submarine helicopter, which is a navalized version of the army UH-60. The crew spends a lot of time just operating their computers, sonar, and radar in their search for submarines. This work involves staring at a screen most of the time, while manipulating the sensors and computers to detect and locate subs. Once you have a solid location fix, you can launch a torpedo and sink the enemy vessel.
The MH-60R is also equipped with a radar system for detecting subs on the surface or just beneath the surface (with only the periscope or snorkel, which provides air for the diesel engine and gets rid of the exhaust fumes). The sonar system consists of a dipping sonar and sonobuoys that are dropped and communicate wirelessly.