Tactics 101: Anti-Submarine Warfare (ASW)

[kaykay]

Thread of the year. Totally worth.

 

[Penguin]

Nowaday submarine doesn't need to get any where near its target. It can simply launch cruise missiles tens of kms away. It can also dive much deeper. So traditional sonar won't be able find it. Even if it is found, it can dive and depth charge won't be any use. It would be submarine vs submarine I guess.

See text above and pic below: there is a reason why surface ships carry an anti-submarine helicopter equipped with dipping sonar and sonar buoys as well as lightweight ASW torpedoes... embarked heli's can go out to more than the common missile range. Also, variable depth sonars can be lowered to considerable depth, avoiding thermal inversion layers.

One way to deal with the thermocline problem while still using undetectable passive SONAR is to use a towed variable depth sonar array. For a ship, that would be pulled along beneath the thermocline. For a sub, it would probably be deployed above the layer.

Another approach is to exploit convergence zones. Because of the nature of water under pressure, sound gets reflected off the ocean floor and back to the surface at intervals of 61 km. Sounds originating in one place can thus be best detected at points forming concentric circles.

Arms Uncontrolled - Frank Barnaby, Stockholm International Peace Research Institute - Google Boeken

SONAR and modern naval warfare

Sonar Propagation

Estimates of submarine detection ranges - Appendix 2 - The Future of Russia's Strategic Nuclear Forces - E.V. Miasnikov

 

[Rashid Mahmood]

A good read.
However, it's really tough in actual.

Locating and identifying a sub is the most important factor.
Coz as soon as you transmit, the sub will know.

 

[Penguin]

Submarine Hunting
By Roel Van de Velde
The following article is not to be considered as an instruction how to hunt and kill any submarine, but is intended to provide enthusiasts with an idea of how such a process works and what options there are.

Submarine Hunting

 

[Ra'ad]

Darf ich troll hier?

 

[Rashid Mahmood]

Anti-Submarine Warfare Helicopters

An ASW helicopter will traditionally team with a surface ship to prosecute an underwater target. The helicopter will deploy multiple sonobuoys and then utilize tactical sensor systems installed on both the surface ship and the helicopter in order to localize the target. The helicopter's crew can track and, if necessary, attack a submarine with torpedoes.

The ASW mission requires a helicopter crew to track submarines using sonobuoys. Sonobuoys are passive or active sonars that can localize a sound source. Sonobuoys are placed in patterns and provide the direction from which a sound is emanating underwater.Typical sonobuoys used by the Navy include Low Frequency and Ranging (LOFAR) and Directional Frequency and Ranging (DIFAR). Bathythermograph sonobuoys create a profile of water temperature versus depth. ASW aircraft are predominantly equipped with sonobuoy launcher systems which utilize cartridge-activated devices, such as pyrotechnic squibs or high-pressure gas bottles, as the energy source for ejecting the sonobuoys. Gas is discharged at high pressure for high reactive loads at low volume entailing very sophisticated breech and firing mechanisms within separate metal, plastic or filament-wound fiberglass sonobuoy launch containers.



Dipping sonar allows the helicopter to listen for and transmit underwater electronic signals while in a "hover" or stationary mode. The aircraft typically hovers at an altitude of 50 to 300 feet above sea level and lowers the transducer into the water using a powered reel system similar to a fishing reel. The transducer can be lowered to depths ranging from the water's surface to 2,500 ft. Once lowered to the selected depth, the transducer is activated, generating sound signals and receiving echoes from submerged objects. These echoes can then be processed to identify and locate potential underwater threats.

During the early part of World War II, the Navy Department initially visualized the helicopter as an aid in combating German submarines which were seriously menacing United States and Allied shipping. Original plans called for the helicopters, piloted by Coast Guard flyers, to accompany ocean convoys and operate as scout aircraft from platforms constructed on the merchant ships. The Navy accepted delivery of its first helicopter, the R-4 (HNX-1), on 16 October 1943 and assigned it to the United States Coast Guard, Coast Guard Air Station, Floyd Bennett Field, Brooklyn, New York.Testing of the helicopter's suitability as an antisubmarine weapon began the following month.

The helicopter could carry a MK IX 200-pound, fast-sinking-type depth charge and drop it after surface contact had been made. The helicopters could be based on destroyers and could be directed by radio to the subs. Then, by hovering until a sonar signature was obtained, they could drop a depth charge and be rearmed by the destroyer. The one thing that had not been considered was that if the helicopter was rushed into mass production, it would inevitably interfere to some degree with airplane production. Thus, the actual value of the helicopter had to be weighed before a production program could be approved. Production scheduling, however, was already a potential problem.

Despite the mounting threat to shipping, the development of helicopters slowed for a year, due to differences between the Army and Navy. The Army felt that it was not its function to develop the helicopter for anti-submarine warfare. The Navy, on the other hand, felt that the Army had been given the job of developing the helicopter and that until this was done, the Navy should not butt in. The Navy based its limited interest in rotary-wing aircraft on the thesis that a helicopter could never be built large enough to carry a sufficient load to be of any value.

To expedite the evaluation of the helicopter in antisubmarine operations, In May 1943 the Commander in Chief, U.S. Fleet directed that a "joint board" be formed with representatives of the Commander in Chief, U.S. Fleet; the Bureau of Aeronautics; the Coast Guard; the British Admiralty and the Royal Air Forces. The resulting Combined Board for the Evaluation of the Ship-Based Helicopter in Anti-Submarine Warfare was later expanded to include representatives of the Army Air Forces, the War Shipping Administration and the National Advisory Committee for Aeronautics. Navy representatives witnessed landing trials of the XR-4 helicopter aboard the merchant tanker Bunker Hill in a demonstration sponsored by the Maritime Commission and conducted in Long Island Sound. The pilot, Colonel R. F. Gregory, AAF, made about 15 flights, and in some of these flights he landed on the water before returning to the platform on the deck of the ship.

In an attempt to make helicopters more proficient in the role of a submarine hunter, a project began in April 1944 to equip them with a "dipping sonar" similar to what blimps carried. The major concern was the noise transmitted to the water by the wash from the helicopter's rotors. Working off the Cobb, it was found that the noise level was insignificant and did not interfere with equipment operation. During flight operations, it was discovered that the HNS-1 helicopter was extremely helpful when used as a target for the alignment of fire-control radar, anti-aircraft radar and loran testing. This use was so helpful, in fact, that it later became the chief operational function during the war.

Had the submarine menace increased rather than declined in 1942, more resources might have been poured by the United States into the development of the helicopter as an anti-submarine-warfare weapon. The allies eventually solved the problem of the air-gap in the Atlantic Ocean with long-range bombers and escort carriers. Planes from the escort carriers in particular played the role that had originally been envisioned for the helicopter. Rotary-winged aircraft appeared on the scene about two years before the helicopter could be adapted for any type of active anti-submarine warfare role.

As it was, helicopters remained largely untested and undeveloped and thus never played the role that many envisioned for them during the war. Given the declining submarine threat, those that wanted to develop the helicopter found it difficult to shift national policy. Perhaps more important was the fact that technology is evolutionary rather than revolutionary. The helicopter could not be developed fast enough to be effectively used and, so it sat out the war.

In 1946 the Anti-Submarine Helicopter Dipping Sonar program was run by the Naval Research Laboratory in Washington, DC. Helicopters were used during the successful testing of a special "dipping" sonar, a device that is still in use today by Navy ASW helicopter squadrons.

Beginning in the 1950s, the carrier-based air ASW community was one of the driving forces behind helicopter development, and within the HUK groups, HS squadrons deploying active, dipping sonars became a key new addition to the combined arms ASW team. HS squadrons gave the HUK group an active sonar platform with the speed and mobility of an aircraft. The original attraction of an airborne dipping sonar was in cooperative operations with radar-equipped aircraft in operations against snorkelers. The latter would often detect a snorkel, but the submarine would submerge and be lost when it went on battery because no destroyers were within range to hold the contact with active sonar. The ASW helicopter with a dipping sonar filled this gap by holding the contact until destroyers with the endurance to hold the submarine down until its batteries were exhausted arrived.

As ASW against nuclear submarines became more important, HS squadrons also were useful because they could operate in noisy environments where passive acoustics were much less effective, but where screening forces were still necessary, as in the inner screen of a carrier battle group or within a convoy.

Lightweight torpedoes became the weapon of choice for the air ASW community, while heavyweight torpedoes were developed for submarines. Surface ships initially carried both, but came to rely mostly on "thrown" (ASROC) or air-delivered (DASH, LAMPS) lightweight torpedoes.

The culmination of this first phase of the helicopter's use as an ASW platform was the SH-3 Sea King. The Sea King was too big to be deployed on all but the largest surface combatants of its time, which limited the ASW helicopter to being a carrier-based platform. Smaller ships, such as destroyers, deployed with the the Drone Anti-Submarine Helicopter (DASH) system.

This would change in the early 1970s with the development of LAMPS (Light Airborne Multipurpose System) ASW helicopters. The Light Airborne Multipurpose System combines the SH-60B helicopter with a computer-integrated shipboard system to extend the range and overall capabilities of surface combatants for antisubmarine and antisurface warfare, surface surveillance, and over-the-horizon targeting missions. To enhance littoral warfighting capabilities, the Flight IIA design of the DDG-51 included the capability to support SH-60Bs.

By the late 1990s the F version of the SH-60 was replacing the obsolete carrier-based SH-3H as naval battle groups' inner-zone ASW helicopter system. The SH-60F employed a new, longer-range active dipping sonar to localize and track submarines, particularly in littoral areas. Future plans call for the conversion and reconfiguration of both the SH-60 B and F classes into a common SH-60R model. The SH-60R program includes a service life extension as well as avionics upgrades, such as the addition of an advanced low-frequency sonar and multimode radar. The aircraft also will be outfitted with gun and missile systems, to enhance performance in littoral regions.




Modern ASW Helicopter's

Agusta Westland EH101 Merlin

Merlin HM MK1 (formerly Merlin EH101) is an Anti-Submarine (ASW) variant of the EH101 helicopter. It entered service in December 1998, replacing the ageing ASW Sea King (Mk6). The collaborative program began in 1979 through EH Industries - the company formed by Agusta of Italy and GKN Westland in the UK. Designed in Western Europe, it is the largest collaborative helicopter project in history and the most powerful helicopter in terms of military capability. The mission system is world-leading and the weapons system is a significant force multiplier compared with existing capability.

• Sonar
  • Thomson Marconi Sonar AQS-903 acoustic processor
  • Active/passive sonobuoys
  • Thomson Sintra FLASH dipping sonar array

​

NH-90 NFH

The NH.90 is a medium sized, twin-engine, multi-role military helicopter originally envisioned in 1985 but suffering from both technical and funding problems for more than a decade. The programme was only relaunched in July 2000 when a major order was made by the partner countries. Developed in two main variants: the Tactical Transport Helicopter (TTH) and the NATO Frigate Helicopter (NFH) It has been ordered since then by other 9 nations with deliveries beginning in 2006. NH.90 are manufactured in Cascina Costa (Italy), Marignane (France) and Donauwörth (Germany) whilst local aircraft are also assembled in Patria (Finland) and Brisbane (Australia).

As of January 2013, 529 NH90s have been ordered by 14 nations with 133 already delivered. Together they have logged more than 31,000 flight hours.

​

Sikorsky MH-60MR

The multimission Sikorsky MH-60S Knighthawk helicopter entered service in February 2002. The US Navy is expected to acquire a total of 237 of the MH-60S helicopters, to carry out missions such as vertical replenishment, combat search and rescue, special warfare support and airborne mine countermeasures.

The helicopter began full-rate production in August 2002. As of January 2011 52 MH-60R and 154 MH-60S helicopters were in the service with the US Navy. First deployment of the new helicopter took place on board USS Essex, Wasp Class amphibious assault ship, in January 2003 and a number of MH-60S helicopters were deployed in support of Operation Iraqi Freedom.

The helicopter was originally designated CH-60S, as a replacement for the US Navy's Boeing CH-46D Sea Knight heavy-lift helicopters in the vertical replenishment role. The helicopter was redesignated MH-60S as a result of an expansion in mission requirements to include a range of additional combat support capabilities. Retirement of the US Navy Sea Knights concluded in September 2004.

The MH-60R is designed to combine the features of the SH-60B and SH-60F.[14] Its sensors include the ASE package, MTS-FLIR, the AN/APS-147 multi-mode radar/IFF interrogator,[15] an advanced airborne fleet data link, and a more advanced airborne active sonar. It does not carry the MAD suite. Pilot instrumentation will be based on the MH-60S's glass cockpit, using several digital monitors instead of the complex array of dials and gauges in Bravo and Foxtrot aircraft. Offensive capabilities are improved by the addition of new Mk-54 air-launched torpedoes and Hellfire missiles. All Helicopter Anti-Submarine (HS) and Helicopter Anti-Submarine Light (HSL) squadrons that receive the Romeo will be redesignated Helicopter Maritime Strike (HSM) squadrons.[16]

During a mid-life technology insertion project, the navy will upgrade the radar capability of the MH-60R fleet to the AN/APS-153 Multi-Mode Radar with Automatic Radar Periscope Detection and Discrimination (ARPDD) capability.

SH-60F CV Helo variant
The SH-60F CV Helo variant of the Seahawk is equipped to carry out the anti-submarine warfare role in the noisy inner zone of a carrier battle group. It is equipped with the AQS-13F active dipping sonar system, supplied by L-3 Communications – Ocean Systems, an ASN-150 cockpit management and tactical data processing system.

Super Lynx 300
The Super Lynx 300 ASW/ASuW is the latest generation of the would leading multi role, multi mission maritime and utility aircraft from Agusta Westland. The aircraft is an evolution of the highly successful Lynx helicopter that, for more than 40 years has successfully met the demanding operational needs of 15 nations in both the maritime and land environments. This purpose built military aircraft with fully marinised airframe is designed with small ship operations in mind and benefits from a low centre of gravity, Blade and Tail fold together with excellent cross and tail wind operating envelopes. The superb twin LHTEC CTS800 engines provide excellent hot and high performance and single engine capability, these ruggedized characteristics, optimisation for the harsh maritime environmental and ship-borne operations make it the number one choice when operating from small ships where Flight Deck and Hangar space are at a premium. With its fully Night Vision Goggle (NVG) compatible cockpit, integrated avionics suite, and wide selection of optional equipment, the aircraft delivers a day/night, all weather capability for Tactical (Anti Sub-Marine, Anti Surface), Search And Rescue (SAR) or Utility support missions.

​

Z-9C Anti-submarine warfare (ASW) Helicopter

Chinese Z-9C Anti-submarine warfare (ASW) of the People's Liberation Army Navy Air Force (PLAAF) which is equipped with a pulse-compression radar and low frequency dipping sonar to aid in Anti-submarine warfare (ASW).

ASW variant produced for the Pakistan Naval Air Arm. Configured with pulse-compression radar, low frequency dipping sonar, radar warning receiver and doppler navigation system, it is also armed with torpedoes for use aboardPakistan Navy's F-22P Zulfiquar class frigates.

At present, Z-9C anti-submarine helicopters and British and French naval equipment use a lot of "Lynx" anti-submarine helicopters in the vast majority of performance at the same level, its maximum is not small enough to carry sonar buoys, so that it served as antisubmarine defense mission there a great lack of. As an internal equipped with sonar and amplifiers, antennas and anti-submarine helicopter with a contact acoustic detection equipment, sonar buoys may be in the submarine-infested waters by a certain law into the sea, by setting a good program down to a predetermined depth, in order to actively or passively work, according to the submarine speed, quietness, and sonar buoy the hydrological conditions of work, its detection range of submarines can reach 1.5 to 3 km, and anti-submarine helicopters, communication distance of 15 to 20 km. Passive sonar buoys used for a wide range of sea submarine target detection, you can put 3 to 5 pairs of 300 square kilometers of the vast waters effective detection, but can not accurately determine the distance and direction the submarine, it is generally needed and active sonar buoys (or dipping sonar) used in conjunction in order to determine elements of the submarine campaign, Xie calculate the submarine campaign data, determine the program and select the anti-submarine weapons attack attack.

​

Kamov Ka-27/Ka 28

The Kamov Ka-27 (in Russian : Ка-27, NATO reporting name : Helix-A ) is a military helicopter developed by the company Russian Kamov for the Soviet Navy and currently in service with the Russian Navy in Ukraine and Vietnam . It has also been exported under the name Ka-28 countries such as China , India and Yugoslavia (now in service with Serbia )

China has three Ka-27s and five Ka-28s to operate from their Russian-built Sovremenny destroyers. In addition, nine Ka-28 helicopters were ordered by China, for delivery by end of 2009.

The helicopter is equipped with a radar system for navigation and to detect surfaced submarines and responder beacons. The VGS-3 dipping sonar detects submarines, determines the coordinates of the submarine and transfers the data in semi-automatic mode to data transmission equipment. The mission computer carries out automatic control, stabilisation and guidance of the helicopter to the mission areas to attack targets.

The helicopter also has a magnetic anomaly detector (MAD) and an airborne receiver to detect and guide the helicopter towards sonar buoy radio transmissions. The export version Ka-28 also has an IFF (interrogation friend or foe) system.

Weapons systems
The helicopter is armed with one homing torpedo, one torpedo rocket, ten PLAB 250-120 bombs and two OMAB bombs. It is fitted with a heated torpedo bay, ensuring the reliability of weapons in low-temperature weather conditions.

​

Kaman SH-2G Super Seasprite

The SH-2G Super Seasprite, manufactured by Kaman Aerospace, was the US Navy's front-line intermediate-weight helicopter. 16 SH-2G helicopters were operational in two US Navy squadrons, HSL-94 and HSL-84. First flight of the SH-2G was in 1985 and it entered service with the US Navy in 1993. The SH-2G Super Seasprite was retired from service with the US Navy Air Reserve in May 2001.

The Super Seasprite SH-2G can be equipped for anti-submarine warfare (ASW), anti-surface warfare (ASuW), over-the-horizon-targeting airborne mine countermeasures (AMCM), surveillance, search and rescue (SAR) and covert operations.

SH-2G(E) is equipped with L-3 Communications AN/AQS-18A active dipping sonar and digital hover coupler.

​

​

 

[jaibi]

Sir, can not UAVs do the same role? I read somewhere that the USN is looking in to adopt them for anti-sub warfare, can we not do the same?

Anti-Submarine Warfare Helicopters

An ASW helicopter will traditionally team with a surface ship to prosecute an underwater target. The helicopter will deploy multiple sonobuoys and then utilize tactical sensor systems installed on both the surface ship and the helicopter in order to localize the target. The helicopter's crew can track and, if necessary, attack a submarine with torpedoes.

The ASW mission requires a helicopter crew to track submarines using sonobuoys. Sonobuoys are passive or active sonars that can localize a sound source. Sonobuoys are placed in patterns and provide the direction from which a sound is emanating underwater.Typical sonobuoys used by the Navy include Low Frequency and Ranging (LOFAR) and Directional Frequency and Ranging (DIFAR). Bathythermograph sonobuoys create a profile of water temperature versus depth. ASW aircraft are predominantly equipped with sonobuoy launcher systems which utilize cartridge-activated devices, such as pyrotechnic squibs or high-pressure gas bottles, as the energy source for ejecting the sonobuoys. Gas is discharged at high pressure for high reactive loads at low volume entailing very sophisticated breech and firing mechanisms within separate metal, plastic or filament-wound fiberglass sonobuoy launch containers.



Dipping sonar allows the helicopter to listen for and transmit underwater electronic signals while in a "hover" or stationary mode. The aircraft typically hovers at an altitude of 50 to 300 feet above sea level and lowers the transducer into the water using a powered reel system similar to a fishing reel. The transducer can be lowered to depths ranging from the water's surface to 2,500 ft. Once lowered to the selected depth, the transducer is activated, generating sound signals and receiving echoes from submerged objects. These echoes can then be processed to identify and locate potential underwater threats.

During the early part of World War II, the Navy Department initially visualized the helicopter as an aid in combating German submarines which were seriously menacing United States and Allied shipping. Original plans called for the helicopters, piloted by Coast Guard flyers, to accompany ocean convoys and operate as scout aircraft from platforms constructed on the merchant ships. The Navy accepted delivery of its first helicopter, the R-4 (HNX-1), on 16 October 1943 and assigned it to the United States Coast Guard, Coast Guard Air Station, Floyd Bennett Field, Brooklyn, New York.Testing of the helicopter's suitability as an antisubmarine weapon began the following month.

The helicopter could carry a MK IX 200-pound, fast-sinking-type depth charge and drop it after surface contact had been made. The helicopters could be based on destroyers and could be directed by radio to the subs. Then, by hovering until a sonar signature was obtained, they could drop a depth charge and be rearmed by the destroyer. The one thing that had not been considered was that if the helicopter was rushed into mass production, it would inevitably interfere to some degree with airplane production. Thus, the actual value of the helicopter had to be weighed before a production program could be approved. Production scheduling, however, was already a potential problem.

Despite the mounting threat to shipping, the development of helicopters slowed for a year, due to differences between the Army and Navy. The Army felt that it was not its function to develop the helicopter for anti-submarine warfare. The Navy, on the other hand, felt that the Army had been given the job of developing the helicopter and that until this was done, the Navy should not butt in. The Navy based its limited interest in rotary-wing aircraft on the thesis that a helicopter could never be built large enough to carry a sufficient load to be of any value.

To expedite the evaluation of the helicopter in antisubmarine operations, In May 1943 the Commander in Chief, U.S. Fleet directed that a "joint board" be formed with representatives of the Commander in Chief, U.S. Fleet; the Bureau of Aeronautics; the Coast Guard; the British Admiralty and the Royal Air Forces. The resulting Combined Board for the Evaluation of the Ship-Based Helicopter in Anti-Submarine Warfare was later expanded to include representatives of the Army Air Forces, the War Shipping Administration and the National Advisory Committee for Aeronautics. Navy representatives witnessed landing trials of the XR-4 helicopter aboard the merchant tanker Bunker Hill in a demonstration sponsored by the Maritime Commission and conducted in Long Island Sound. The pilot, Colonel R. F. Gregory, AAF, made about 15 flights, and in some of these flights he landed on the water before returning to the platform on the deck of the ship.

In an attempt to make helicopters more proficient in the role of a submarine hunter, a project began in April 1944 to equip them with a "dipping sonar" similar to what blimps carried. The major concern was the noise transmitted to the water by the wash from the helicopter's rotors. Working off the Cobb, it was found that the noise level was insignificant and did not interfere with equipment operation. During flight operations, it was discovered that the HNS-1 helicopter was extremely helpful when used as a target for the alignment of fire-control radar, anti-aircraft radar and loran testing. This use was so helpful, in fact, that it later became the chief operational function during the war.

Had the submarine menace increased rather than declined in 1942, more resources might have been poured by the United States into the development of the helicopter as an anti-submarine-warfare weapon. The allies eventually solved the problem of the air-gap in the Atlantic Ocean with long-range bombers and escort carriers. Planes from the escort carriers in particular played the role that had originally been envisioned for the helicopter. Rotary-winged aircraft appeared on the scene about two years before the helicopter could be adapted for any type of active anti-submarine warfare role.

As it was, helicopters remained largely untested and undeveloped and thus never played the role that many envisioned for them during the war. Given the declining submarine threat, those that wanted to develop the helicopter found it difficult to shift national policy. Perhaps more important was the fact that technology is evolutionary rather than revolutionary. The helicopter could not be developed fast enough to be effectively used and, so it sat out the war.

In 1946 the Anti-Submarine Helicopter Dipping Sonar program was run by the Naval Research Laboratory in Washington, DC. Helicopters were used during the successful testing of a special "dipping" sonar, a device that is still in use today by Navy ASW helicopter squadrons.

Beginning in the 1950s, the carrier-based air ASW community was one of the driving forces behind helicopter development, and within the HUK groups, HS squadrons deploying active, dipping sonars became a key new addition to the combined arms ASW team. HS squadrons gave the HUK group an active sonar platform with the speed and mobility of an aircraft. The original attraction of an airborne dipping sonar was in cooperative operations with radar-equipped aircraft in operations against snorkelers. The latter would often detect a snorkel, but the submarine would submerge and be lost when it went on battery because no destroyers were within range to hold the contact with active sonar. The ASW helicopter with a dipping sonar filled this gap by holding the contact until destroyers with the endurance to hold the submarine down until its batteries were exhausted arrived.

As ASW against nuclear submarines became more important, HS squadrons also were useful because they could operate in noisy environments where passive acoustics were much less effective, but where screening forces were still necessary, as in the inner screen of a carrier battle group or within a convoy.

Lightweight torpedoes became the weapon of choice for the air ASW community, while heavyweight torpedoes were developed for submarines. Surface ships initially carried both, but came to rely mostly on "thrown" (ASROC) or air-delivered (DASH, LAMPS) lightweight torpedoes.

The culmination of this first phase of the helicopter's use as an ASW platform was the SH-3 Sea King. The Sea King was too big to be deployed on all but the largest surface combatants of its time, which limited the ASW helicopter to being a carrier-based platform. Smaller ships, such as destroyers, deployed with the the Drone Anti-Submarine Helicopter (DASH) system.

This would change in the early 1970s with the development of LAMPS (Light Airborne Multipurpose System) ASW helicopters. The Light Airborne Multipurpose System combines the SH-60B helicopter with a computer-integrated shipboard system to extend the range and overall capabilities of surface combatants for antisubmarine and antisurface warfare, surface surveillance, and over-the-horizon targeting missions. To enhance littoral warfighting capabilities, the Flight IIA design of the DDG-51 included the capability to support SH-60Bs.

By the late 1990s the F version of the SH-60 was replacing the obsolete carrier-based SH-3H as naval battle groups' inner-zone ASW helicopter system. The SH-60F employed a new, longer-range active dipping sonar to localize and track submarines, particularly in littoral areas. Future plans call for the conversion and reconfiguration of both the SH-60 B and F classes into a common SH-60R model. The SH-60R program includes a service life extension as well as avionics upgrades, such as the addition of an advanced low-frequency sonar and multimode radar. The aircraft also will be outfitted with gun and missile systems, to enhance performance in littoral regions.




Modern ASW Helicopter's

Agusta Westland EH101 Merlin

Merlin HM MK1 (formerly Merlin EH101) is an Anti-Submarine (ASW) variant of the EH101 helicopter. It entered service in December 1998, replacing the ageing ASW Sea King (Mk6). The collaborative program began in 1979 through EH Industries - the company formed by Agusta of Italy and GKN Westland in the UK. Designed in Western Europe, it is the largest collaborative helicopter project in history and the most powerful helicopter in terms of military capability. The mission system is world-leading and the weapons system is a significant force multiplier compared with existing capability.

• Sonar
  • Thomson Marconi Sonar AQS-903 acoustic processor
  • Active/passive sonobuoys
  • Thomson Sintra FLASH dipping sonar array

​

NH-90 NFH

The NH.90 is a medium sized, twin-engine, multi-role military helicopter originally envisioned in 1985 but suffering from both technical and funding problems for more than a decade. The programme was only relaunched in July 2000 when a major order was made by the partner countries. Developed in two main variants: the Tactical Transport Helicopter (TTH) and the NATO Frigate Helicopter (NFH) It has been ordered since then by other 9 nations with deliveries beginning in 2006. NH.90 are manufactured in Cascina Costa (Italy), Marignane (France) and Donauwörth (Germany) whilst local aircraft are also assembled in Patria (Finland) and Brisbane (Australia).

As of January 2013, 529 NH90s have been ordered by 14 nations with 133 already delivered. Together they have logged more than 31,000 flight hours.

​

Sikorsky MH-60MR

The multimission Sikorsky MH-60S Knighthawk helicopter entered service in February 2002. The US Navy is expected to acquire a total of 237 of the MH-60S helicopters, to carry out missions such as vertical replenishment, combat search and rescue, special warfare support and airborne mine countermeasures.

The helicopter began full-rate production in August 2002. As of January 2011 52 MH-60R and 154 MH-60S helicopters were in the service with the US Navy. First deployment of the new helicopter took place on board USS Essex, Wasp Class amphibious assault ship, in January 2003 and a number of MH-60S helicopters were deployed in support of Operation Iraqi Freedom.

The helicopter was originally designated CH-60S, as a replacement for the US Navy's Boeing CH-46D Sea Knight heavy-lift helicopters in the vertical replenishment role. The helicopter was redesignated MH-60S as a result of an expansion in mission requirements to include a range of additional combat support capabilities. Retirement of the US Navy Sea Knights concluded in September 2004.

The MH-60R is designed to combine the features of the SH-60B and SH-60F.[14] Its sensors include the ASE package, MTS-FLIR, the AN/APS-147 multi-mode radar/IFF interrogator,[15] an advanced airborne fleet data link, and a more advanced airborne active sonar. It does not carry the MAD suite. Pilot instrumentation will be based on the MH-60S's glass cockpit, using several digital monitors instead of the complex array of dials and gauges in Bravo and Foxtrot aircraft. Offensive capabilities are improved by the addition of new Mk-54 air-launched torpedoes and Hellfire missiles. All Helicopter Anti-Submarine (HS) and Helicopter Anti-Submarine Light (HSL) squadrons that receive the Romeo will be redesignated Helicopter Maritime Strike (HSM) squadrons.[16]

During a mid-life technology insertion project, the navy will upgrade the radar capability of the MH-60R fleet to the AN/APS-153 Multi-Mode Radar with Automatic Radar Periscope Detection and Discrimination (ARPDD) capability.

SH-60F CV Helo variant
The SH-60F CV Helo variant of the Seahawk is equipped to carry out the anti-submarine warfare role in the noisy inner zone of a carrier battle group. It is equipped with the AQS-13F active dipping sonar system, supplied by L-3 Communications – Ocean Systems, an ASN-150 cockpit management and tactical data processing system.

Super Lynx 300
The Super Lynx 300 ASW/ASuW is the latest generation of the would leading multi role, multi mission maritime and utility aircraft from Agusta Westland. The aircraft is an evolution of the highly successful Lynx helicopter that, for more than 40 years has successfully met the demanding operational needs of 15 nations in both the maritime and land environments. This purpose built military aircraft with fully marinised airframe is designed with small ship operations in mind and benefits from a low centre of gravity, Blade and Tail fold together with excellent cross and tail wind operating envelopes. The superb twin LHTEC CTS800 engines provide excellent hot and high performance and single engine capability, these ruggedized characteristics, optimisation for the harsh maritime environmental and ship-borne operations make it the number one choice when operating from small ships where Flight Deck and Hangar space are at a premium. With its fully Night Vision Goggle (NVG) compatible cockpit, integrated avionics suite, and wide selection of optional equipment, the aircraft delivers a day/night, all weather capability for Tactical (Anti Sub-Marine, Anti Surface), Search And Rescue (SAR) or Utility support missions.

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Z-9C Anti-submarine warfare (ASW) Helicopter

Chinese Z-9C Anti-submarine warfare (ASW) of the People's Liberation Army Navy Air Force (PLAAF) which is equipped with a pulse-compression radar and low frequency dipping sonar to aid in Anti-submarine warfare (ASW).

ASW variant produced for the Pakistan Naval Air Arm. Configured with pulse-compression radar, low frequency dipping sonar, radar warning receiver and doppler navigation system, it is also armed with torpedoes for use aboardPakistan Navy's F-22P Zulfiquar class frigates.

At present, Z-9C anti-submarine helicopters and British and French naval equipment use a lot of "Lynx" anti-submarine helicopters in the vast majority of performance at the same level, its maximum is not small enough to carry sonar buoys, so that it served as antisubmarine defense mission there a great lack of. As an internal equipped with sonar and amplifiers, antennas and anti-submarine helicopter with a contact acoustic detection equipment, sonar buoys may be in the submarine-infested waters by a certain law into the sea, by setting a good program down to a predetermined depth, in order to actively or passively work, according to the submarine speed, quietness, and sonar buoy the hydrological conditions of work, its detection range of submarines can reach 1.5 to 3 km, and anti-submarine helicopters, communication distance of 15 to 20 km. Passive sonar buoys used for a wide range of sea submarine target detection, you can put 3 to 5 pairs of 300 square kilometers of the vast waters effective detection, but can not accurately determine the distance and direction the submarine, it is generally needed and active sonar buoys (or dipping sonar) used in conjunction in order to determine elements of the submarine campaign, Xie calculate the submarine campaign data, determine the program and select the anti-submarine weapons attack attack.

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Kamov Ka-27/Ka 28

The Kamov Ka-27 (in Russian : Ка-27, NATO reporting name : Helix-A ) is a military helicopter developed by the company Russian Kamov for the Soviet Navy and currently in service with the Russian Navy in Ukraine and Vietnam . It has also been exported under the name Ka-28 countries such as China , India and Yugoslavia (now in service with Serbia )

China has three Ka-27s and five Ka-28s to operate from their Russian-built Sovremenny destroyers. In addition, nine Ka-28 helicopters were ordered by China, for delivery by end of 2009.

The helicopter is equipped with a radar system for navigation and to detect surfaced submarines and responder beacons. The VGS-3 dipping sonar detects submarines, determines the coordinates of the submarine and transfers the data in semi-automatic mode to data transmission equipment. The mission computer carries out automatic control, stabilisation and guidance of the helicopter to the mission areas to attack targets.

The helicopter also has a magnetic anomaly detector (MAD) and an airborne receiver to detect and guide the helicopter towards sonar buoy radio transmissions. The export version Ka-28 also has an IFF (interrogation friend or foe) system.

Weapons systems
The helicopter is armed with one homing torpedo, one torpedo rocket, ten PLAB 250-120 bombs and two OMAB bombs. It is fitted with a heated torpedo bay, ensuring the reliability of weapons in low-temperature weather conditions.

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Kaman SH-2G Super Seasprite

The SH-2G Super Seasprite, manufactured by Kaman Aerospace, was the US Navy's front-line intermediate-weight helicopter. 16 SH-2G helicopters were operational in two US Navy squadrons, HSL-94 and HSL-84. First flight of the SH-2G was in 1985 and it entered service with the US Navy in 1993. The SH-2G Super Seasprite was retired from service with the US Navy Air Reserve in May 2001.

The Super Seasprite SH-2G can be equipped for anti-submarine warfare (ASW), anti-surface warfare (ASuW), over-the-horizon-targeting airborne mine countermeasures (AMCM), surveillance, search and rescue (SAR) and covert operations.

SH-2G(E) is equipped with L-3 Communications AN/AQS-18A active dipping sonar and digital hover coupler.

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[Rashid Mahmood]

Sir, can not UAVs do the same role? I read somewhere that the USN is looking in to adopt them for anti-sub warfare, can we not do the same?

Yes it is under trials, but it will take a long time for actual integration into a ASW scenario.
Helicopters are multi-role/multi task platforms, so there importance will never be undermined.

ADCOM Systems unveiled the first fixed wing UAV for anti-submarine warfare



At the Dubai Airshow 2013, which was held in November, UAE based company ADCOM Systems which specializes in Unmanned Aerial Vehicles (UAV) unveiled its “NAVY UAV”. This new UAV project is designed specifically for Anti-Submarine Warfare (ASW). This makes it the world’s first fixed wing UAV project dedicated to ASW missions. According to ADCOM, the Navy UAV would detect submarines through the use of sonobuoys. The ASW UAV is expected to carry a maximum of two torpedoes and would detect and attack submarines autonomously or with live control from an operator depending on the mission and flight plan.

 

[Rashid Mahmood]

in continuation of ASW Helicopters;

Another addition is the CH-148 Cyclone Maritime Helicopter, specifically designed by Sikorsky for the Canadian Forces Air Command.

Sikorsky CH-148 Cyclone

The Sikorsky CH-148 Cyclone is a twin-engine, multi-role maritime helicopter manufactured by Sikorsky Aircraft Corporation for the Canadian Forces. CH-148 is to replace Canada's main ship-borne maritime helicopter, the CH-124 Sea King.

The CH-148 will be operated by the Canadian Forces Air Command. It can conduct anti-submarine warfare (ASW), anti-surface warfare, surveillance and control, search and rescue (SAR) missions. It will also provide tactical transport for national and international security missions.

The helicopter has been developed under the Canadian Forces' Maritime Helicopter Project (MHP). The project provides scope for the acquisition of 28 new, fully-equipped CH-148 Cyclone helicopters along with a long-term in-service support program. It will also provide 12 C-RAST helicopter haul-down systems for Halifax class (HFX) ships to accommodate the CH-148 Cyclone.

CH-148 is a military variant of the Sikorsky S-92 helicopter. It features a composite aluminium airframe with lightning-strike and high-intensity radio frequency pulse protection. It incorporates a wider four-bladed articulated composite main rotor blade in comparison with the S-70 Blackhawk. The tapered blade tip is angled downward to cut down noise and increase lift.

The helicopter can operate with modern high-tech naval frigates and is equipped with numerous safety features. Flaw tolerance, bird strike capability and engine burst containment are integrated into the design.

Avionics
CH-148 is equipped with APS-143B radar, the SAFIRE III EO System, L-3 HELRAS sonar and Lockheed Martin AN/ALQ-210 electronic support measure (ESM) system. Its aircraft management system (CMA-2082MH) is provided by CMC Electronics.

General Dynamics Canada was contracted in 2004 to provide the mission systems for the entire fleet of 28 helicopters. These mission systems include radar, ESM, acoustics, self-defence, navigation and communication systems.

Armament
Armaments include door-arm mounted GP machine guns and two MK 46 torpedoes on BRU-14/A weapon or stores rack mounted in folding weapons pylons.

Countermeasures
The helicopter is fitted with sensor equipment to search and locate submarines during ASW missions. A modern countermeasures suite is incorporated to defend the helicopter against incoming missiles.