Among other maritime surveillance resources, such as satellites, ships, unmanned aerial vehicles (UAVs) and helicopters, the MPA is an important asset.
[1] To perform ASW operations, MPAs typically carry air-deployable sonar buoys as well as torpedoes and are usually capable of extended flight at low altitudes.
France, Italy and Austria-Hungary used large numbers of smaller patrol aircraft for the Mediterranean, Adriatic and other coastal areas while the Germans and British fought over the North Sea.
[18] Blimps were widely used by the United States Navy, especially in the warmer and calmer latitudes of the Caribbean Sea, the Bahamas, Bermuda, the Gulf of Mexico, Puerto Rico, Trinidad, and later the Azores.
[31][32] The B-24 was also used at the basis for the PB4Y-2 Privateer, a dedicated MPA variant adopted in large numbers by the US Navy, which saw service late on in the Pacific theatre.
[33][34] During the conflict, there were several developments in air-to-surface-vessel radar and sonobuoys, which enhanced the ability of aircraft to find and destroy submarines, especially at night and in poor weather.
[35][36][37][38] Another area of advancement was the adoption of increasingly effective camouflage schemes, which led to the widespread adoption of white paint schemes in the Atlantic to reduce the warning available to surfaced U-boats,[39] while US Navy aircraft transitioned from an upper light blue-gray and lower white to an all-over dark blue due to the increasing threat of Japanese forces at night-time.
[citation needed] In the decades following the Second World War, the MPA missions were partially taken over by aircraft derived from civilian airliners.
The latest jet-powered bombers of the 1950s did not have the endurance needed for long, overwater patrolling, and they did not have the low loitering speeds necessary for antisubmarine operations.
These span the so-called "GIUK Gap" of the North Atlantic that extends from Greenland to Iceland, to the Faroe Islands, to Scotland in the United Kingdom.
[43] During the late 1960s, a jet-powered replacement in the form of the Hawker Siddeley Nimrod, a derivation of the De Havilland Comet airliner, begun to be introduced.
During the 1980s, an updated version, the Atlantic Nouvelle Génération or Atlantique 2, with new equipment and avionics was introduced, which included a new radar, sonar processor, forward-looking infrared camera turret, and the ability to carry the Exocet anti-shipping missile.
Since the end of the Cold War, the threat of a large-scale submarine attack is a remote one, and many of the air forces and navies have been downsizing their fleets of patrol planes.
As technology progressed the bombs and depth charges were supplemented with Acoustic torpedoes that could detect, follow and then explode against an enemy submarine.