Sikorsky SH-60 Seahawk
The Sikorsky SH-60/MH-60 Seahawk is a twin turboshaft engine, multi-mission United States Navy helicopter based on the United States Army UH-60 Black Hawk and a member of the Sikorsky S-70 family. The most significant modifications are the folding main rotor blades and a hinged tail to reduce its footprint aboard ships.
The U.S. Navy acquired H-60 helicopters under the model designations SH-60B, SH-60F, HH-60H, MH-60R, and MH-60S. Able to deploy aboard any air-capable frigate, destroyer, cruiser, fast combat support ship, expeditionary transfer dock, amphibious assault ship, littoral combat ship or aircraft carrier, the Seahawk can handle anti-submarine warfare, anti-surface warfare, naval special warfare insertion, search and rescue, combat search and rescue, vertical replenishment, and medical evacuation. When entering service, the SH-60B was too large to operate from some of the smaller vessels in service, so it served along with the Kaman SH-2F and SH-2G models until 2001.
Early model Seahawks began to be retired in the 2010s and 2020s, with the last B model leaving U.S. Navy service in 2015, after over three decades, then the F and H models followed in 2016. These were replaced by the upgraded MH-60R and S models.
Design and development
Origins
In the 1970s, the U.S. Navy began looking for a new helicopter to replace the Kaman SH-2 Seasprite. The SH-2 Seasprite was used by the Navy as its platform for the Light Airborne Multi-Purpose System Mark I avionics suite for maritime warfare and a secondary search and rescue capability. Advances in sensor and avionic technology lead to the LAMPS Mk II suite being developed by the Naval Air Development Center. In 1974, the Navy conducted a competition to develop the Lamps MK III concept, which would integrate both the aircraft and shipboard systems. The Navy selected IBM Federal Systems as the Prime systems integrator for the Lamps MK III concept.Since the SH-2 was not large enough to carry the Navy's required equipment, a new airframe was required. In the mid-1970s, the Army evaluated the Sikorsky YUH-60 and Boeing Vertol YUH-61 for its Utility Tactical Transport Aircraft System competition. The Navy based its requirements on the Army's UTTAS specification, to decrease costs from commonality as the new airframe to carry the Lamps MK III avionics. In April 1977, Sikorsky and Boeing-Vertol submitted proposals for Navy variants of their Army UTTAS helicopters for review. The Navy also looked at helicopters being produced by Bell, Kaman, Westland and MBB, but these were too small for the mission. In early 1978, the Navy selected Sikorsky's S-70B design, which was designated "SH-60B Seahawk".
SH-60B Seahawk
IBM was the prime systems integrator for the Lamps MK III with Sikorsky as the airframe manufacturer. The SH-60B maintained 83% commonality with the UH-60A. The main changes were corrosion protection, more powerful T700 engines, single-stage oleo main landing gear, removal of the left side door, adding two weapon pylons, and shifting the tail landing gear forward to reduce the footprint for shipboard landing. Other changes included larger fuel cells, an electric blade folding system, folding horizontal stabilators for storage, and adding a 25-tube pneumatic sonobuoy launcher on the left side.An emergency flotation system was originally installed in the stub wing fairings of the main landing gear. It was found to be impractical and possibly impeded emergency egress, and was removed. Five YSH-60B Seahawk LAMPS III prototypes were ordered. The first YSH-60B flight occurred on 12 December 1979. The first production SH-60B made its first flight on 11 February 1983. The SH-60B entered operational service in 1984, with its first operational deployment in 1985.
The SH-60B is deployed primarily aboard frigates, destroyers, and cruisers. The primary missions of the SH-60B are surface warfare and anti-submarine warfare. It carries a complex system of sensors, including a towed magnetic anomaly detector and air-launched sonobuoys. Other sensors include the APS-124 search radar, ALQ-142 ESM system and optional nose-mounted forward looking infrared turret. Munitions carried include the Mk 46, Mk 50, or Mark 54 Lightweight Torpedo, AGM-114 Hellfire missile, and a single cabin-door-mounted M60D/M240 7.62 mm machine gun, or GAU-16.50 in machine gun.
A standard crew for a SH-60B is one pilot, one ATO/Co-Pilot, and an enlisted aviation warfare systems operator. The U.S. Navy operated the SH-60B in Helicopter Anti-Submarine Squadron, Light squadrons. All HSL squadrons were redesignated Helicopter Maritime Strike squadrons, and transitioned to the MH-60R between 2006 and 2015.
The SH-60J is based on the SH-60B airframe for the Japan Maritime Self-Defense Force without IBM avionics. The SH-60K is a modified variant of the SH-60J. The SH-60J and SH-60K are built under license by Mitsubishi in Japan.
SH-60F
After the SH-60B entered service, the Navy conducted a competition to replace the Sikorsky SH-3 Sea King. The competitors were Sikorsky, Kaman and IBM. Sikorsky began development of this variant in March 1985. In January 1986, seven SH-60Fs were ordered including two prototypes. The first example flew on 19 March 1987. The SH-60F was based on the SH-60B airframe, but with upgraded SH-3H avionics.The SH-60F primarily served as the carrier battle group's primary anti-submarine warfare aircraft. The helicopter hunted submarines with its AQS-13F dipping sonar, and carried a six-tube sonobuoy launcher. The SH-60F is unofficially named "Oceanhawk". The SH-60F can carry Mk 46, Mk 50, or Mk 54 torpedoes for its offensive weapons, and it has a choice of fuselage-mounted machine guns, including the M60D, M240D, and GAU-16 for self-defense. The standard aircrew is one pilot, one co-pilot, one tactical sensor operator, and one acoustic sensor operator. The SH-60F was operated by the U.S. Navy's Helicopter Antisubmarine squadrons, until they were redesignated Helicopter Sea Combat squadrons and transitioned to the MH-60S. The last HS squadron completed its transition in 2016.
HH-60H
The HH-60H was developed in conjunction with the US Coast Guard's HH-60J, beginning in September 1986 with a contract for the first five helicopters with Sikorsky as the prime contractor. The variant's first flight occurred on 17 August 1988. Deliveries of the HH-60H began in 1989. The variant earned initial operating capability in April 1990 and was deployed to Desert Storm with HCS-4 and HCS-5 in 1991. The HH-60H's official DoD and Sikorsky name is Seahawk, though it has been called "Rescue Hawk".Based on the SH-60F, the HH-60H is the primary combat search and rescue, naval special warfare and anti-surface warfare helicopter. It carries various defensive and offensive sensors. These include a FLIR turret with laser designator, and the Aircraft Survival Equipment package including the ALQ-144 Infrared Jammer, AVR-2 Laser Detectors, APR-392 Radar Detectors, AAR-47 Missile Launch Detectors and ALE-47 chaff/flare dispensers. Engine exhaust deflectors provide infrared thermal reduction, reducing the threat of heat-seeking missiles. The HH-60H can carry up to four AGM-114 Hellfire missiles on an extended wing using the M299 launcher, and a variety of mountable guns including M60D, M240, GAU-16 and GAU-17/A machine guns.
The HH-60H's standard crew is a pilot, a copilot, an enlisted crew chief, and two door gunners or one rescue swimmer. Originally operated by HCS-5 and HCS-4, these two special USNR squadrons were established with the primary mission of Naval Special Warfare and Combat Search and Rescue. Due to SOCOM budget issues, the squadrons were deactivated in 2006 and 2016 respectively. The HH-60H was also operated by Helicopter Antisubmarine squadrons, with a standard dispersal of six F-models and two or three H-models, before the transition of HS squadrons to HSC squadrons equipped with the MH-60S, the last of which completed its transition in 2016. The only squadron equipped with the HH-60H as of 2016 is HSC-85, one of only two remaining USNR helicopter squadrons, the other being HSM-60 equipped with the MH-60R. In Iraq, HH-60Hs were used by the Navy, assisting the Army, for MEDEVAC purposes and special operations missions.
MH-60R
The MH-60R "Romeo" was originally known as "LAMPS Mark III Block II Upgrade" when development began in 1993 with Lockheed Martin, formerly IBM/Loral. Two SH-60Bs were converted by Sikorsky, the first of which made its maiden flight on 22 December 1999. Designated YSH-60R, they were delivered to NAS Patuxent River in 2001 for flight testing. The production variant was redesignated MH-60R to match its multi-mission capability. The MH-60R was deployed by the US Navy in 2006.The MH-60R is designed to combine the features of the SH-60B and SH-60F. Its avionics includes dual controls and instead of the complex array of dials and gauges in Bravo and Foxtrot aircraft, 4 fully integrated 8" x 10" night vision goggle-compatible and sunlight-readable color multi-function displays, all part of the glass cockpit produced by Owego Helo Systems division of Lockheed Martin. Onboard sensors include: AAR-47 Missile Approach Warning System by ATK, Raytheon AAS-44 electro-optical system that integrates FLIR and laser rangefinder, ALE-39 decoy dispenser and ALQ-144 infrared jammer by BAE Systems, ALQ-210 electronic support measures system by Lockheed Martin, APS-147 multi-mode radar/IFF interrogator, which during a mid-life technology insertion project is replaced by APS-153 Multi-Mode Radar with Automatic Radar Periscope Detection and Discrimination capability.
Both radars were developed by Telephonics, a more advanced AN/AQS-22 advanced airborne low-frequency sonar jointly developed by Raytheon & Thales, an ARC-210 voice radio by Rockwell Collins, an advanced airborne fleet data link SRQ-4 Hawklink with radio terminal set ARQ-59 radio terminal, both by L3Harris, and LN-100G dual-embedded global positioning system and inertial navigation system by Northrop Grumman Litton division. Beginning in 2020, CAE's MAD-XR were fielded on MH-60Rs, providing it with a magnetic anomaly detector.
Offensive capabilities are improved by the addition of new Mk-54 air-launched torpedoes and Hellfire missiles. All Helicopter Anti-Submarine Light squadrons that receive the MH-60R are redesignated Helicopter Maritime Strike squadrons.