First World War The first aircraft that would now be identified as maritime patrol aircraft were flown by the
Royal Naval Air Service and the French
Aéronautique Maritime during the
First World War, primarily on anti-submarine patrols. 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. At first,
blimps and
zeppelins were the only aircraft capable of staying aloft for the longer ten hour patrols whilst carrying a useful payload while shorter-range patrols were mounted with landplanes such as the
Sopwith 1½ Strutter. A number of specialized patrol balloons were built, particularly by the British, including the
SS class airship of which 158 were built including subtypes. As the conflict continued, numerous aircraft were developed specifically for the role, including small flying boats such as the
FBA Type C, as well as large
floatplanes such as the
Short 184, or
flying boats such as the
Felixstowe F.3. Developments of the Felixstowe served with the
Royal Air Force until the mid 20s, and with the
US Navy as the
Curtiss F5L and
Naval Aircraft Factory PN whose developments saw service until 1938. During the war,
Dornier did considerable pioneering work in all aluminium aircraft structures while working for
Luftschiffbau Zeppelin and built four large patrol flying boats, the last of which, the
Zeppelin-Lindau Rs.IV, influenced development elsewhere resulting in the replacement of wooden hulls with metal ones, such as on the
Short Singapore. The success of long range patrol aircraft led to the development of fighters specifically designed to intercept them, such as the
Hansa-Brandenburg W.29.
Second World War maritime reconnaissance flying boat Many of the
Second World War patrol airplanes were converted from either
bombers or
airliners, such as the
Lockheed Hudson which started out as the
Lockheed Model 14 Super Electra, as well as older biplane designs such as the
Supermarine Stranraer, which had begun to be replaced by monoplanes just before the outbreak of war. The British in particular used obsolete bombers to supplement purpose-built aircraft for maritime patrol, such as the
Vickers Wellington and
Armstrong-Whitworth Whitley, while the US relegated the
Douglas B-18 Bolo to the same role until better aircraft became available. 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. A number of special-purpose aircraft were also used in the conflict, including the American-made twin-engine
Consolidated PBY Catalina flying boats, and the large, four-engine British
Short Sunderland flying boats of the
Allies. In the
Pacific theatre, the Catalina was gradually superseded by the longer-ranged
Martin PBM Mariner flying boat. For the
Axis powers, there were the long-range Japanese
Kawanishi H6K and
Kawanishi H8K flying boats, and the German
Blohm & Voss BV 138 diesel-engined trimotor flying boat, as well as the converted
Focke-Wulf Fw 200 Condor airliner landplane. To finally close the
Mid-Atlantic gap, or "Black Gap", a space in which Axis submarines could prey on Allied shipping out of reach of MPAs, the British
Royal Air Force, the
Royal Canadian Air Force, and the
US Army Air Forces introduced the American
Consolidated B-24 Liberator bomber, which had a very long
range for the era. 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. 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. 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, 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.
Cold War era In the decades following the Second World War, the MPA missions were partially taken over by aircraft derived from civilian airliners. These had range and performance factors better than most of the wartime bombers. 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. The main threat to NATO maritime supremacy throughout the 1960s, 1970s, and the 1980s was
Soviet Navy and
Warsaw Pact submarines. These were countered by the NATO fleets, the NATO patrol planes mentioned above, and by sophisticated underwater listening systems. 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. Air bases for NATO patrol planes have also been located in these areas: U.S. Navy and Canadian aircraft based in Greenland, Iceland, and Newfoundland; British aircraft based in Scotland and
Northern Ireland; and Norwegian, Dutch, and German aircraft based in their home countries. During the late 1940s, the RAF introduced the
Avro Shackleton a specialised MPA derivative of the
Avro Lancaster bomber in anticipation of a rapid expansion of the
Soviet Navy's submarine force. An improved model of the Shackleton, the
MR 3, was introduced, featuring various structural improvements, along with homing torpedoes and
Mk 101 Lulu nuclear depth bombs. 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 2000s, an improved model, the
BAE Systems Nimrod MRA4, was in development, but was cancelled and eventually substituted for by the
Boeing P-8 Poseidon. The U.S. Navy flew a mixture of MPAs, including the land-based
Lockheed P2V Neptune (P2V) and the
carrier-based Grumman S-2 Tracker. During the 1970s, the P2V was entirely replaced by the
Lockheed P-3 Orion, which remained in service into the early twenty-first century. The P-3, powered by four
turboprop engines, is derived from the 1950s era
Lockheed Electra airliner. In addition to their ASW and SAR capabilities, most P-3Cs have been modified to carry
Harpoon and
Maverick missiles for attacking surface ships. American P-3s were formerly armed with the
Lulu nuclear
depth charge for ASW, but those were removed from the arsenal and scrapped decades ago. Produced in
United States,
Japan and
Canada, the P-3 has been operated by the air forces and navies of United States, Japan, Canada, Australia, Iran, Brazil, Germany, the Netherlands,
New Zealand,
Norway, Spain, and Taiwan. The Canadian version is called the
CP-140 Aurora. Beginning in 2013, the P-3 was replaced in U.S. service and that of several other countries by the
Boeing P-8 Poseidon, a derivative of the Boeing 737 airliner. During the 1960s, in response to
North Atlantic Treaty Organization (NATO) issuing a
Request for Proposals (RFP) for a new MPA, the
Breguet 1150 Atlantic was developed by a French-led multinational consortium, ''Société d'Étude et de Construction de Breguet Atlantic
(SECBAT). Operators of the type include the French Navy, the German Navy, the Italian Air Force, the Pakistan Navy, and the Royal Netherlands Navy. 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. By 2005, French manufacturer
Dassault Aviation had decided to terminate marketing efforts for the Atlantic, promoting a MPA variant of the
Dassault Falcon 900 corporate jet instead. Japan has developed multiple purpose-designed MPAs during this period. The
Shin Meiwa PS-1 flying boat was designed to meet a Japanese requirement for a new ASW platform. A modernised derivative of the PS-1, the
ShinMaywa US-2 amphibian, was introduced during the early twenty-first century to succeed the PS-1. The land-based
Kawasaki P-1 was introduced during the 2010s by the
Japan Maritime Self-Defense Force (JMSDF) as a replacement for the aging
P-3C Orion. Both the
Royal Australian Air Force and the
Royal Australian Navy met their early postwar MPA needs via a stretched-fuselage modification of the
Avro Lincoln bomber. However, the type was soon supplemented and eventually replaced by new aircraft, such as the P2V and later the P-3C, which later became the sole ASW type operated by the service. The
Soviet Union developed the
Ilyushin Il-38 from a civilian airliner. Similarly, the
Royal Canadian Air Force derived the
Canadair CP-107 Argus from a British airliner, the
Bristol Britannia. The Argus was superseded by the CP-140 Aurora, derived from the Lockheed Electra. 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. Those still in service are still used for search-and-rescue, counter-smuggling, anti
piracy, antipoaching of marine life, the enforcement of the
exclusive economic zones, and enforcement of the
laws of the seas. ==Armament and countermeasures==