How do aircraft carriers defend against torpedoes?

Helicopters with dipping sonars and land-based patrol planes drop sonar buoys to patrol a wide perimeter searching for submarines which they can then engage with air-dropped homing torpedoes. Carriers also deploy acoustic decoys like the towed SLQ-25 Nixie designed to attract torpedoes to them.

Can a nuclear-powered submarine “sink” a carrier?

Despite these precautions, diesel and nuclear-powered submarines have repeatedly succeeded in evading detection and “sinking” U.S. carriers during naval exercises. The new generation of Air-Independent Propulsion and/or Lithium-Ion Battery powered submarines are relatively cheap yet remain very quiet and have weeks of underwater endurance.

How do we defend against submarines?

Submarines and torpedoes, of course, are harder to track at a distance, and existing defensive systems against them are not quite as dense. Helicopters with dipping sonars and land-based patrol planes drop sonar buoys to patrol a wide perimeter searching for submarines which they can then engage with air-dropped homing torpedoes.

What happened to the Nimitz-class super-carriers?

Starting in 2013, the Navy installed the system on five Nimitz-class super-carriers —the George H. W. Bush, Harry Truman, Nimitz, Dwight D. Eisenhower and Theodore Roosevelt. You can see a photo of one being fired from its six-cell launcher here. But in September 2018 the Navy concluded testing and began removing the systems from the ships.

How does the US Navy hunt for submarines?

Helicopters with dipping sonars and land-based patrol planes drop sonar buoys to patrol a wide perimeter searching for submarines which they can then engage with air-dropped homing torpedoes. Sub-hunting frigates and destroyers form a closed perimeter around the carriers and cruisers they are escorting.