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{{Short description|American military helicopter}}
{{Use dmy dates|date=November 2021}}
{{Use American English|date=November 2021}}
{{Redirect|MH-53|the MH-53E Sea Dragon minesweeper variant|Sikorsky CH-53E Super Stallion}}
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{{Infobox aircraft
 |name= HH-53 "Super Jolly Green Giant" <br/>MH-53 Pave Low
 |image= File:MH-53J Pave Low Mission Descent (altered).jpg
 |caption= A MH-53 Pave Low from the 20th Special Operations Squadron at [[Hurlburt Field]], Florida
 |type= Heavy-lift [[helicopter]]
 |manufacturer= [[Sikorsky Aircraft]]
 |designer=
 |first_flight= 15 March 1967
 |introduction= 1968
 |retired= 30 September 2008
 |status= Retired<ref name="MH-53_fly_final"/>
|primary_user= [[United States Air Force]]
 |more_users=
 |produced= 1967&ndash;1970
 |number_built= 72<ref name="ivory"/>
 |developed_from= [[Sikorsky CH-53 Sea Stallion]]
 |variants =
}}

The '''Sikorsky MH-53 Pave Low''' series is a retired long-range [[special operations]] and [[combat search and rescue]] (CSAR) [[helicopter]] for the [[United States Air Force]].  The series was upgraded from the HH-53B/C, variants of the [[Sikorsky CH-53 Sea Stallion]].  The '''HH-53 "Super Jolly Green Giant"''' was initially developed to replace the [[Sikorsky S-61R|HH-3E "Jolly Green Giant"]].  The U.S. Air Force's MH-53J/M fleet was retired in September 2008.<ref name="MH-53_fly_final">[https://www.af.mil/News/Article-Display/Article/122266/mh-53s-fly-final-combat-missions/ "MH-53s fly final combat missions"]. US Air Force, 1 October 2008.</ref>

==Design and development==
[[File:HH-53C 67th ARRS approaching tanker 1987.JPEG|thumb|left|HH-53C refuels, 1987]]

The US Air Force ordered 72 HH-53B, CH-53C and HH-53C variants for [[Search and Rescue]] and Special Operations units during the [[Vietnam War]], and later developed the MH-53J Pave Low version for all-weather Special Operations missions.

The Pave Low's mission was low-level, long-range, undetected penetration into denied areas, day or night, in adverse weather, for [[infiltration tactics|infiltration]], [[Extraction (military)|exfiltration]] and resupply of [[special operations force]]s. Pave Lows often worked in conjunction with [[MC-130 Combat Talon|MC-130H Combat Talon]] for navigation, communications and combat support,<ref>[https://web.archive.org/web/20030623172743/http://www.af.mil/factsheets/factsheet.asp?fsID=115 MC-130E/H Combat Talon I/II Fact Sheet], US Air Force.</ref> and with [[Lockheed MC-130#MC-130P Combat Shadow|MC-130P Combat Shadow]] for in-flight refueling.<ref>[https://web.archive.org/web/20030623172658/http://www.af.mil/factsheets/factsheet.asp?fsID=116 MC-130P Combat Shadow Fact Sheet], US Air Force.</ref><ref>[http://www.globalsecurity.org/military/systems/aircraft/mh-53j.htm MH-53J page]. Globalsecurity.org</ref>

The large green airframe of the HH-53B earned it the nickname "[[Jolly Green Giant#Pop Culture|Super Jolly Green Giant]]". This name is a reference to the smaller [[Sikorsky S-61R|HH-3E "Jolly Green Giant"]], a stretched variant of the [[H-3 Sea King]], used in the [[Vietnam War]] for combat search-and-rescue (CSAR) operations.

===HH-53B===
The US Air Force regarded their Sikorsky S-61R/HH-3E "Jolly Green Giant" long-range CSAR helicopters favorably and was interested in the more capable S-65/CH-53A. In 1966, the USAF awarded a contract to Sikorsky for development of a CSAR variant of the CH-53A.<ref name="Vectorsite">{{cite web|url=http://www.vectorsite.net/avskbig.html |title=Sikorsky Giant Helicopters: S-64, S-65, & S-80|website=vectorsite.net|access-date=9 February 2019|archive-url=https://web.archive.org/web/20120305081444/http://www.vectorsite.net/avskbig.html |archive-date=5 March 2012 |url-status=usurped}}</ref>

[[File:HC-130P refueling HH-53B over North Vietnam.jpg|right|thumb|A HH-53B of the [[40th Aerospace Rescue and Recovery Squadron]] refueling from a [[HC-130P Hercules]] over [[North Vietnam]], 1969–70]]
The '''HH-53B''', as it was designated, featured:
* A retractable in-flight refueling probe on the right side of the nose
* Spindle-shaped jettisonable external tanks with a capacity of {{convert|650|USgal|L|0}}, fitted to the [[sponsons]] and braced by struts attached to the fuselage
* A rescue hoist above the right passenger door, capable of deploying a [[forest penetrator]] on {{convert|250|ft|m|sigfig=2}} of steel cable
* Armament of three pintle-mounted General Electric [[Minigun|GAU-2]]/A 7.62&nbsp;mm (.308 in) six-barreled [[Gatling]]-type machine guns, with one in a forward hatch on each side of the fuselage and one mounted on the tail ramp, with the gunner secured with a harness
* A total of {{convert|1200|lb|kg|sigfig=2}} of armor
* A Doppler navigation radar in the forward belly

Early HH-53Bs featured T64-GE-3 turboshafts with {{convert|3080|shp|kW|0}} each, but these engines were later upgraded to T64-GE-7 turboshafts with {{convert|3925|shp|kW|0}}. Five crew were standard, including a pilot, copilot, crew chief, and two [[United States Air Force Pararescue|pararescuemen]].<ref name="Vectorsite"/>

===HH-53C===
[[File:HH-53C lowers pararescueman June 1970.jpg|thumb|left|An HH-53C lowering a [[United States Air Force Pararescue|PJ]] during a rescue mission, June 1970]]

The HH-53B was essentially an interim type, with production quickly moving on to the modestly improved Air Force '''HH-53C''' CSAR variant. The most visible difference between the HH-53B and HH-53C was that the HH-53C dispensed with the fuel-tank bracing struts. Experience with the HH-53B showed that the original tank was too big, adversely affecting performance when they were fully fueled, and so a smaller {{convert|450|USgal|L|0|abbr=on}} tank was adopted in its place. Other changes included more armor and a more comprehensive suite of radios to improve communications with C-130 tankers, attack aircraft supporting CSAR actions, and aircrews awaiting rescue on the ground. The HH-53C was otherwise much like the HH-53B, with the more powerful T64-GE-7 engines.<ref name="Vectorsite"/>

[[File:HH-53C over Vietnam October 1972.jpg|thumb|A HH-53 seen from the gunner's position of a helicopter over Vietnam in October 1972]]
A total of 44 HH-53Cs were built, with introduction to service in August 1968. Late in the Vietnam War they were fitted with countermeasures pods to deal with heat-seeking missiles. As with the HH-53B, the HH-53C was also used for covert operations and snagging reentry capsules, as well as snagging reconnaissance drones. A few were assigned to support the Apollo space program, standing by to recover an [[Apollo program|Apollo]] [[Apollo Command/Service Module|capsule]] in case of a launchpad abort, though such an accident never happened.<ref name="Vectorsite"/>

In addition to the HH-53Cs, the Air Force obtained 20 '''CH-53C''' helicopters for more general transport work. The CH-53C was apparently very similar to the HH-53C, even retaining the rescue hoist, the most visible difference being that the CH-53C did not have an in-flight refueling probe. Since CH-53Cs were used for covert operations, they were armed and armored like HH-53Cs.<ref name="Vectorsite"/>  A good number of Super Jollies were converted into ''Pave Low'' special-operations helicopters.<ref name="Vectorsite"/>  [[PAVE]] or ''Pave'' is an Air Force code name for a number of weapons systems using advanced electronics.

===HH/MH-53H===
[[File:An air-to-air overhead front view of an MH-53H Pave Low III helicopter - DPLA - 90fe572cad2615b68fdf3bfe365c271b.jpeg|left|thumb|MH-53H Pave Low III]]
[[File:A left front view of a 20th Special Operations Squadron MH-53H PAVELOW helicopter extracting 1723rd Combat Control members with ladder ropes - DPLA - 749e173c49454bfa29149823ae0d4013.jpeg|thumb|right|MH-53H Pave Low on an extraction exercise, 1988]]
The USAF's Super Jollies were essentially daylight / fair weather machines, and downed aircrew were often in trouble at night or in bad weather. A limited night / foul weather sensor system designated "Pave Low I" based on a low-light-level TV (LLLTV) imager was deployed to Southeast Asia in 1969 and combat-evaluated on a Super Jolly, but reliability was not adequate.<ref name="Vectorsite"/>

In 1975, an HH-53B was fitted with the much improved "Pave Low II" system and re-designated YHH-53H. This exercise proved much more satisfactory, and so eight HH-53Cs were given a further improved systems fit and redesignated ''HH-53H Pave Low III'', with the YHH-53H also upgraded to this specification. All were delivered in 1979 and 1980.<ref name="Vectorsite"/>

The HH-53H retained the in-flight refueling probe, external fuel tanks, rescue hoist, and three-gun armament of the HH-53C; armament was typically a [[minigun]] on each side, and a Browning {{convert|.50|in|mm|1|abbr=on}} gun in the tail to provide more reach and a light anti-armor capability. The improvements featured by the HH-53H included:
* A [[Texas Instruments]] AN/AAQ-10 forward-looking infrared (FLIR) imager.
* A Texas Instruments AN/APQ-158 terrain-following radar (TFR), which was a digitized version of the radar used by the A-7. It was further modified to be able to give terrain avoidance and terrain following commands simultaneously (first aircraft capable of this unique feature).{{Citation needed|date=March 2010}}
* A Canadian Marconi Doppler-radar navigation system.
* A Litton or Honeywell inertial guidance system (INS).
* A computerized moving-map display.<ref name="Vectorsite"/>
* A radar-warning receiver (RWR) and chaff-flare dispensers.

The FLIR and TFR were mounted on a distinctive "chin" mount. The HH-53H could be fitted with 27 seats for troops or 14 litters. The upgrades were performed by the Navy in Pensacola, reflecting the fact that the Navy handled high-level maintenance on Air Force S-65s. In 1986, the surviving HH-53Hs were given an upgrade under the ''CONSTANT GREEN'' program, featuring incremental improvements such as a cockpit with blue-green lighting compatible with [[night vision goggle]]s (NVGs). They were then reclassified as "special operations" machines and accordingly given a new designation of ''MH-53H''.<ref name="Vectorsite"/>
[[File:MH-53J Pave Low III.jpg|thumb|A MH-53J Pave Low IIIE of the [[551st Special Operations Squadron]], [[58th Special Operations Wing]], flying a training mission]]
The HH-53H proved itself and the Air Force decided to order more, coming up with an ''MH-53J Pave Low III Enhanced'' configuration. The general configuration of the MH-53J is similar to that of the HH-53J, the major change being fit of twin T64-GE-415 turboshafts with 4,380 shp (3,265&nbsp;kW) each, as well as more armor, giving a total armor weight of 1,000&nbsp;lb (450&nbsp;kg). There were some avionics upgrades as well, including fit of a modern [[Global Positioning System]] (GPS) satellite navigation receiver. A total of 31 HH-53Bs, HH-53Cs, and CH-53Cs were upgraded to the MH-53J configuration from 1986 through 1990, with all MH-53Hs upgraded as well, providing a total of 41 MH-53Js.<ref name="Vectorsite"/>

===MH-53J/M===
[[File:An MH-53M Pave Low IV helicopter approaches the refueling basket of an MC-130P Combat Shadow.jpg|thumb|left|A MH-53M Pave Low IV of the [[21st Special Operations Squadron]] approaches the refueling basket of an [[Lockheed MC-130#MC-130P Combat Shadow|MC-130P Combat Shadow]] for in-flight refueling during the [[2000 Mozambique flood]].]]

The '''MH-53J Pave Low III''' helicopter was the largest, most powerful and technologically advanced transport helicopter in the [[united states air force|US Air Force]] inventory. The [[terrain-following radar|terrain-following]] and terrain-avoidance [[radar]], [[forward looking infrared]] sensor, [[inertial navigation]] system with Global Positioning System, along with a projected map display enable the crew to follow terrain contours and avoid obstacles, making low-level penetration possible.

Under the Pave Low III program, the Air Force modified nine MH-53Hs and 32 HH-53s for night and adverse weather operations. Modifications included AN/AAQ-18 forward-looking infrared, inertial navigation system, global positioning system, [[Doppler radar|Doppler]] navigation systems, APQ-158 terrain-following and terrain-avoidance radar, an on-board mission computer, enhanced navigation system, and integrated avionics to enable precise [[navigation]] to and from target areas. The Air Force designated these modified versions as MH-53J.

The MH-53J's main mission was to drop off, supply, and pick up special operations forces behind enemy lines. It also can engage in combat search and rescue missions. Low-level penetration was made possible by a state-of-the-art terrain following radar, as well as infrared sensors that allow the helicopter to operate in bad weather.  It was equipped with armor plating. It could transport 38 troops at a time and sling up to 20,000 pounds (9,000&nbsp;kg) of cargo with its external hook. It was capable of a top speed of 165&nbsp;mph (266&nbsp;km/h) and had a ceiling of 16,000 feet (4,900&nbsp;m).
[[File:Four MH-53 Pave Lows from 20th SOS fly over Hurlburt Field.jpg|thumb|Four MH-53M Pave Low IV, 2008]]
The '''MH-53M Pave Low IV''' was modified from the MH-53J configuration with the addition of Interactive Defensive Avionics System/Multi-Mission Advanced Tactical Terminal or IDAS/MATT. The system enhanced the defensive capabilities of the Pave Low. It provided instant access to the total battlefield situation, through near real-time Electronic Order of Battle updates. It also provided a new level of detection avoidance with [[near real-time]] threat broadcasts [[over-the-horizon]], so crews can avoid and defeat threats, and replan en route if necessary.

==Operational history==
[[File:An MH-53 Pave Low helicopter.jpg|thumb|left|Special forces depart a MH-53 Pave Low]]
While waiting for delivery of the HH-53Bs, the Air Force obtained two [[United States Marine Corps|Marine]] CH-53As for evaluation and training. The first of eight HH-53Bs performed its initial flight on 15 March 1967, and the type was performing CSAR missions with the USAF Aerospace Rescue & Recovery Service in Southeast Asia by the end of the year. The Air Force called the HH-53B the "Super Jolly". It was used for CSAR, covert combat operations, and "snagging" reentry capsules from [[KH-8|photo]]-[[reconnaissance satellite]]s.<ref name="Vectorsite"/>

The Air Force lost 17 Super Jollies during the Southeast Asia conflict, with 14 lost in combat – including one that was shot down by a North Vietnamese [[Mikoyan-Gurevich MiG-21|MiG-21]] on 28 January 1970 while on a CSAR mission over [[Laos]] – and three lost in accidents.<ref name="Vectorsite"/>  The Super Jollies made headlines in November 1970 in the unsuccessful [[Operation Ivory Coast|raid into North Vietnam to rescue prisoners-of-war]] from the [[Son Tay]] prison camp, as well as in the operation to rescue the crew of the freighter [[SS Mayagüez|SS ''Mayagüez'']] from [[Cambodia]]n [[Khmer Rouge]] fighters in May 1975. 
[[File:A US Air Force (USAF) AIRMAN assigned to the 21st Special Operations Squadron (SOS) mans the tail gunner position aboard a USAF MH-53M Pave Low IV helicopter, during a training flig - DPLA - 0f89cbff8775c4ef60ce2549bd22f334.jpeg|thumb|View out of MH-53M Pave Low IV in 2002, with its ramp open]]
The HH-53B, HH-53C, and CH-53C remained in Air Force service into the late 1980s. Super Jollies operating in front-line service were painted in various camouflage color schemes, while those in stateside rescue service were painted in an overall gray scheme with a yellow tailband.<ref name="Vectorsite"/>

The first nine HH-53H Pave Lows became operational on 1 July 1980, and were transferred from the [[Military Airlift Command]], where they were to have been CSAR assets, to the [[1st Special Operations Wing]] in the aftermath of the ''[[Operation Eagle Claw]]'' disaster. Two of the HH-53Hs were lost in training accidents in 1984, and so two CH-53Cs were brought up to HH-53H standard as replacements.<ref name="Vectorsite"/>

Five MH-53Js of the [[20th Special Operations Squadron]] deployed to [[Panama]] as part of [[Operation Just Cause]] in December 1989. During the operation, MH-53Js conducted missions including reconnaissance, small team insertion, medivac, logistics, and fire support. The MH-53's terrain-following and terrain-avoidance radar, along with GPS, enabled the helicopters to reach objectives other helicopters could not; in one case, an MH-53 used its precision navigation capability to lead a SEAL team on [[MH-6 Little Bird]] helicopters to their remote objective. 20th SOS crews flew 193 sorties during the operation, totaling 406.1 hours of flying time.<ref>{{Cite book|url=https://www.afsoc.af.mil/Portals/86/documents/history/AFD-131112-025.pdf|title=On a Steel Horse I Ride: A History of the MH-53 Pave Low Helicopters in War and Peace|last=Whitcomb|first=Darrel D.|publisher=Air University Press|year=2012|isbn=978-1-58566-220-3|location=Montgomery, Alabama|pages=265–274}}</ref>

The MH-53 Pave Low's last mission was on 27 September 2008, when the remaining six helicopters flew in support of special operations forces in Southwest Asia. These MH-53Ms were retired shortly thereafter and replaced with the [[V-22 Osprey]].<ref name="MH-53_fly_final"/><ref>Whitcomb, D.D. (2012). ''[https://purl.fdlp.gov/GPO/gpo32414 On a Steel Horse I Ride: A History of the MH-53 Pave Low Helicopters in War and Peace.]'' Maxwell Air Force Base, AL: Air University Press, Air Force Research Institute.</ref><ref>{{Cite web|url=https://www.military.com/defensetech/2008/10/08/bye-bye-pave-low-hello-osprey|title=Bye-Bye Pave Low, Hello Osprey|date=October 8, 2008|website=Military.com}}</ref>

==Variants and modification/upgrade programs==
[[File:MH53 night.jpg|thumb|right|MH-53 Pave Lows fly over Iraq on their last combat missions in September 2008, before their retirement.]]Variants :
* '''CH-53A''' – the original transport version of the H-53 was procured in the mid-1960's by the United States Marine Corps. 20 examples were obtained second-hand over the years by the Air Force, in four distinct batches
** 2 were loaned by the USMC to the USAF from December 1966 until September 1967 to initiate aircrew training by the Eglin AFB based 48th Air Rescue and Recovery Squadron (Training);
** 2 were obtained in January 1988 and reconfigured as NCH-53A's for drone recovery operations by the 6514th Test Squadron at Hill AFB
** 16 were obtained in two separate batches in July 1988 (6) and May 1990 (10), of which six entered service as aircrew trainers, in order to free up HH-53C airframes for MH-53J conversion (see below) while the other ten remained in storage.
* '''NCH-53A''' – two CH-53A's converted for drone recovery operations and later used as aircrew trainers
* '''TH-53A''' – six of the 20 ex-USMC CH-53A's converted as aircrew trainers
* '''HH-53B''' – [[CH-53 Sea Stallion|CH-53A]] type for USAF search and rescue (SAR), featuring an aerial refueling probe. Eight were procured, which are recognizable from later HH-53C's by the stiffening struts between the sponsons and the fuselage. All helicopters modified with an experimental Limited Night Recovery System (LNRS).<ref>Project CHECO South East Asia Report - USAF Search and Rescue November 1967 to June 1969. HQ PACAF Directorate, Tactical Evaluation CHECO Division. July 30, 1969</ref> Some modified to Pave Imp LNRS-standard.<ref>On a Steel Horse I ride - A History of the MH-53 Pave Low Helicopters in War and Peace - Darrel D. Whitcomb - Air University Press. Air Force Research Institute. Maxwell Air Force Base, Alabama 2012</ref> One HH-53B serial number 66-14433 converted to Pave Low I Test Bed at Edwards Air Force Base in 1972.<ref>Pave Low - Evaluation of a Terrain Following Radar System for the HH-53 Helicopter. Technical Report No. 73-11 March 1973. Air Force Flight Test Center. Edwards Air Force Base, California, Air Force Systems Command, United States Air Force</ref> HH-53B 66-14433 consequently became the YHH-53H Black Knight.<ref>On a Steel Horse I ride - A History of the MH-53 Pave Low Helicopters in War and Peace - Darrel D. Whitcomb - Air University Press. Air Force Research Institute. Maxwell Air Force Base, Alabama 2012</ref> The four survivors were converted to MH-53J standards in 1987-1988.
* '''CH-53C''' – heavy-lift version for USAF, 20 built. 2 were converted to MH-53H standards in 1985-1986 and the eight survivors followed suit as MH-53J's in 1989-1991.
* '''HH-53C''' – "Super Jolly Green Giant", improved HH-53B for USAF. Some fitted with Pave Imp LNRS.<ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref> 44 built. The 21 survivors were converted to MH-53J standards in 1989-1991
* '''YHH-53H Black Knight''' – HH-53B 66-14433 Test Bed for Pave Low II and Pave Low III systems. Became Pave Low III prototype. Later brought up to Pave Low III production standard.<ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref>
* '''HH-53H''' – Production standard "Pave Low II" variant. Eight HH-53C's converted to this standard in 1979-1980 at the Naval Air Rework Facility in Naval Air Station (NAS) Pensacola, Florida.<ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref>. The six survivors were converted to MH-53H standards in 1985-1986.
* '''MH-53H''' – Improved version of the HH-53H for special operations in conjunction with its original combat SAR role. Nine were converted in 1985-1986 from the sole YHH-53H, two CH-53C's and the six surviving HH-53H's. The eight survivors were converted to MH-53J in 1988-1990.
* '''MH-53J''' – "Pave Low III" Upgraded MH-53H. Improved variant with integrated digital avionics, an upgraded transmission, more powerful engines, and various enhanced mission and defensive systems. All survivors of the H-53's acquired by the USAF were converted in 1988-1991 by NARF Pensacola, totaling 41 airframes : 4 HH-53B's, 8 CH-53C's, 21 HH-53C's and 8 MH-53H's.
* '''MH-53M''' – "Pave Low IIIE" aka "Pave Low IV" upgraded MH-53Js. 28 of the surviving MH-53J's converted.
For non-USAF H-53 variants, see [[CH-53 Sea Stallion]], [[CH-53E Super Stallion]] and [[CH-53K King Stallion]].

Description of the upgrade programmes :
* '''Pave Star''' - Program designed to address shortcomings of LNRS and deliver an improved night infiltration and rescue capability. Cancelled due to multiple technical issues and cost overruns<ref>On a Steel Horse I ride - A History of the MH-53 Pave Low Helicopters in War and Peace - Darrel D. Whitcomb - Air University Press. Air Force Research Institute. Maxwell Air Force Base, Alabama 2012</ref><ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref>
* '''Pave Imp''' - LNRS developed by USAF Air Force Systems Command. Replaced Pave Star. Some HH-53B and C's converted. Used in action during the Vietnam War<ref>On a Steel Horse I ride - A History of the MH-53 Pave Low Helicopters in War and Peace - Darrel D. Whitcomb - Air University Press. Air Force Research Institute. Maxwell Air Force Base, Alabama 2012</ref><ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref>
* '''Pave Low I''' - Program built on lessons learned from Pave Star, Pave Imp and LNRS. A proof-of-concept test program with the objective of developing a true night and all-weather capability for the HH-53. The main difference from earlier programs centred around the evaluation of a modified Norden AN/APQ-141 Terrain Following/Terrain Avoidance radar along with associated instrumentation, and modifications to existing systems.<ref>Pave Low - Evaluation of a Terrain Following Radar System for the HH-53 Helicopter. Technical Report No. 73-11 March 1973. Air Force Flight Test Center. Edwards Air Force Base, California, Air Force Systems Command, United States Air Force</ref>
* '''Pave Low II''' - Program which aimed to address three distinct limitations identified in previous programs; the inability to avoid terrain and exposure to hostile radar/sensor-directed threats at low level; insufficient accuracy in the navigation system to reach the rescue area at low level; and inability to precisely locate the survivor(s) and hold a hover over his/her position.<ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref>
* '''Pave Low III''' - Follow-on program to Pave Low II, but with the LNRS-vintage Low Level Light Television (LLLTV) system replaced with the more capable AN/AAQ-10 Forward-looking Infrared (FLIR) sensor, along with the installation of the AN/APQ-158 Terrain Following/Terrain Avoidance Radar and an Inertial Navigation System. Other equipment additions included a central avionics computer and a projected map display system<ref>MH-53J/M Pave Low III/IV Systems Engineering Case Study by W. Albery Ph.D, Raymond L. Robb & Lt. Col. Lee Anderson (2010). Air Force Institute of Technology. Air Force Center for Systems Engineering</ref><ref>On a Steel Horse I ride - A History of the MH-53 Pave Low Helicopters in War and Peace - Darrel D. Whitcomb - Air University Press. Air Force Research Institute. Maxwell Air Force Base, Alabama 2012</ref>
[[File:70-1630 an 352 SOG 21 SOS MH-53M (3113878224).jpg|thumb|MH-53M in May 2007]]
*

==Operator==
;{{USA}}
*[[United States Air Force]]<ref>{{cite web|url= http://www.helis.com/database/modelorg/489/|title= USAF|publisher= helis.com|access-date=5 January 2013}}</ref>

==Aircraft on display==
[[File:MH-53 Pave Low IV Maxwell.jpg|thumb|An MH-53M on display at [[Maxwell Air Force Base|Maxwell AFB]]]]
[[File:16 19 181 MH 53.jpg|thumb|MH-53 displayed in a museum]]
*MH-53M Pave Low IV, AF serial number 68-10928, was retired 29 July 2007 and placed on display at Air Commando Park, [[Hurlburt Field]], Florida on 3 December 2007.  This helicopter took part in the May 1975 [[Mayagüez incident]] rescue operation and sustained major battle damage to the engine, rotor blades, and instrument panel.  The aircraft flew in combat during the [[War in Afghanistan (2001–2021)|War in Afghanistan]] and the [[Iraq War|War in Iraq]] for its last seven years of service, completing its last combat mission in Iraq during the summer 2007.<ref>Hurlburt Field, [http://www.hurlburt.af.mil/library/factsheets/factsheet.asp?id=10952 MH-53 Pave Low] {{webarchive|url=https://web.archive.org/web/20110728104919/http://www.hurlburt.af.mil/library/factsheets/factsheet.asp?id=10952 |date=2011-07-28 }}, Fact Sheet, retrieved 24 March 2012</ref>
*MH-53M Pave Low IV, AF serial number 68-10357, was retired in March 2008 and placed on display at the [[National Museum of the United States Air Force|National Museum of the US Air Force]] at [[Wright-Patterson Air Force Base|Wright-Patterson AFB]], Ohio on 8 July 2008. This MH-53 carried the command element during [[Operation Ivory Coast]], the mission to rescue American prisoners of war from the [[Son Tay]] North Vietnamese prison camp in 1970.<ref name="ivory">Bardua, Rob. [http://www.nationalmuseum.af.mil/news/story.asp?id=123105770 "New MH-53M helicopter exhibit opens at the National Museum of the U.S. Air Force"] {{webarchive|url=https://web.archive.org/web/20080723155648/http://www.nationalmuseum.af.mil/news/story.asp?id=123105770 |date=2008-07-23 }}. USAF National Museum, 8 July 2008.</ref>
*MH-53M Pave Low IV, AF serial number 70-1626, was retired 11 August 2008 and will be placed on display at the [[Museum of Aviation (Warner Robins)|Museum of Aviation]], [[Robins Air Force Base|Robins AFB]], Georgia.<ref>Purser, Becky. [http://www.macon.com/197/story/429474.html "Celebrated combat search and rescue helicopter finds new home at Robins"]{{dead link|date=February 2018 |bot=InternetArchiveBot |fix-attempted=yes }}. macon.com</ref>
*MH-53M Pave Low IV, AF serial number 68-8284, was retired on 30 September 2008 and arrived at the Cold War Exhibition at the Royal Air Force Museum, [[DCAE Cosford|RAF Cosford]], UK on 17 December 2008.<ref>Willetts, Richard. [http://www.airshows.co.uk/feature-reports/2008/raf-cosford-mh-53-delivery.html "RAF Cosford MH-53 Delivery Feature Report, 17 December 2008"] {{webarchive|url=https://web.archive.org/web/20090617071414/http://www.airshows.co.uk/feature-reports/2008/raf-cosford-mh-53-delivery.html |date=17 June 2009 }}</ref>
*MH-53M Pave Low IV, AF serial number 73-1652, was retired 5 September 2008 and placed on display at the [[Air Force Armament Museum]] next to [[Eglin Air Force Base|Eglin AFB]].  This MH-53M was involved in operations shortly after the [[Jonestown Massacre]].<ref>Getlin, Noel, [http://www.rotorheadsrus.us/documents/Last%20flight%20for%20the%20Pave%20Low%20near%20Shalimar.pdf Hurlburt MH-53 flies last mission to where it is displayed at the Air Force Armament Museum] 5 September 2008, Eglin Dispatch</ref>
*MH-53M Pave Low IV, AF serial number 73-1649.  It was retired and intended for a museum when it erroneously ended up in the "Boneyard" of the [[309th Aerospace Maintenance and Regeneration Group]]. Its last dedicated Crew Chief discovered it and "rescued" it.  It is on display at the [[Pima Air & Space Museum]].<ref>{{cite web|url=http://www.pimaair.org/aircraft-by-name/item/sikorsky-mh-53m-pave-low-iv|title=PAVE LOW IV|website=www.pimaair.org|access-date=9 February 2019|archive-date=9 October 2016|archive-url=https://web.archive.org/web/20161009214229/http://www.pimaair.org/aircraft-by-name/item/sikorsky-mh-53m-pave-low-iv|url-status=dead}}</ref><ref>{{Cite web|url=http://www.dm.af.mil/news/story.asp?id=123248537|archive-url=https://web.archive.org/web/20131216174530/http://www.dm.af.mil/news/story.asp?id=123248537|url-status=dead|title="Restoration of a Jolly Green, Davis-Monthan Air Force Base News"|archive-date=December 16, 2013}}</ref>
*MH-53M Pave Low IV, AF serial number 69-5785, on display at [[Maxwell Air Force Base|Maxwell AFB]].  It was dedicated on June 8, 2009, and is in the base's Air Park.<ref name="Maxwell MH-53">{{cite web|last=Berquist|first=Carl|title=Maxwell dedicates veteran MH-53 to Air Park|url=http://www.aetc.af.mil/news/story.asp?id=123154042|archive-url=https://archive.today/20140422012030/http://www.aetc.af.mil/news/story.asp?id=123154042|url-status=dead|archive-date=22 April 2014|publisher=Air University|access-date=22 April 2014}}</ref>
*MH-53J Pave Low III, AF serial number 66-14433, on display at [[Kirtland Air Force Base|Kirtland AFB]]. This aircraft was the prototype for the Pave Low III configuration. It was the first H-53 to reach 10,000 flight hours.<ref>{{cite web|last=McCune|first=Christopher|title=Kirtland AFB's MH-53J Pave Low - a historic pioneer|date=2 September 2010 |url=https://www.kirtland.af.mil/News/Article-Display/Article/389987/kirtland-afbs-mh-53j-pave-low-a-historic-pioneer/|access-date=19 Jan 2017}}</ref>
*MH-53M Pave Low IV, AF serial number 68-10369, was retired in September 2008 and is now on display at [[Hill Aerospace Museum]].<ref name="HillAerospace">{{cite web|url= https://aerospaceutah.org/museum/our-collections/aircraft-collection/mh-53m-pave-low-iv/|title= MH-53M Pave Low IV|access-date= 16 April 2021|author= Hill Aerospace Museum|author-link= Hill Aerospace Museum|work= aerospaceutah.org|year= 2021|archive-url= https://archive.today/20210416180224/https://aerospaceutah.org/museum/our-collections/aircraft-collection/mh-53m-pave-low-iv/|archive-date= 16 April 2021|url-status= live}}</ref>
*MH-53M Pave Low IV, AF serial number 68-10357, is on display at Cannon AFB, NM.

==Specifications (MH-53J)==
[[File:Sikorsky MH-53J Pave Low Line Drawing.svg|right|400px]]
[[File:Final Combat Mission of MH-53 Pave Low, Sept. 27, 2008, Iraq.jpg|right|thumb|MH-53 Pave Lows prepare to take off for their final combat mission on 27 September 2008, in Iraq.]]
{{Aircraft specs
|ref=USAF MH-53J/M,<ref name=USAF_fact_sht>[https://archive.today/20121212212244/http://www.af.mil/information/factsheets/factsheet.asp?id=117 MH-53J/M PAVE LOW fact sheet]. US Air Force, October 2007.</ref> International Directory,<ref name="Frawley Military">Frawley, Gerard: ''The International Directory of Military Aircraft'', p. 152. Aerospace Publications Pty Ltd, 2002. {{ISBN|1-875671-55-2}}.</ref> Vectorsite<ref name="Vector_MH-53">{{usurped|1=[https://web.archive.org/web/20040608234615/http://www.vectorsite.net/avskbig.html#m5 USAF PAVE LOW: HH-53H / MH-53H, MH-53J, MH-53M, TH-53A]}}. Vectorsite.net, 1 April 2009.</ref>
|prime units?=kts
<!--    General characteristics
-->
|crew=6 (two pilots, two flight engineers and two aerial gunners)
|capacity=37 troops (55 in alternate configuration)
|length ft=88
|length in=
|length note=
|width ft=<!-- if applicable -->
|width in=<!-- if applicable -->
|width note=
|height ft=25
|height in=
|height note=
|empty weight lb=32000
|empty weight note=
|gross weight lb=
|gross weight note=
|max takeoff weight lb=46000
|max takeoff weight note=normal
::::{{cvt|50000|lb}} fortime emergency
|fuel capacity=
|more general=
<!--    Powerplant
-->
|eng1 number=2
|eng1 name=[[General Electric T64-GE-100]]
|eng1 type=[[turboshaft]] engines
|eng1 shp=4330
|eng1 note=

|rot number=1
|rot dia m=<!-- helicopters -->
|rot dia ft=72
|rot dia in=0
|rot area sqft=<!-- helicopters -->
|rot area note=<!--'''root:''' [[NACA airfoil|NACA ]]; '''tip:''' [[NACA airfoil|NACA ]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>-->
<!--    Performance
-->
|max speed kts=170
|max speed note=
|cruise speed kts=150
|cruise speed note=
|never exceed speed kts=
|never exceed speed note=
|range nmi=600
|range note=can be extended with [[in-flight refueling]]
|combat range nmi=
|combat range note=
|ferry range nmi=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=16000
|ceiling note=
|g limits=<!-- aerobatic -->
|climb rate ftmin=
|climb rate note=
|time to altitude=
|disk loading lb/sqft=
|disk loading note=
|fuel consumption lb/mi=
|power/mass=
|more performance=
<!--    Armament
-->
|guns=
* Any combination of three [[7.62×51mm NATO]] [[M134 Minigun]]s and/or [[12.7×99mm NATO]] (.50 BMG) [[M2 Browning machine gun]]s mounted on left and right sides (immediately behind flight deck) and ramp
|bombs= 
|rockets= 
|missiles= 
|hardpoints=
|hardpoint capacity=
|hardpoint rockets=
|hardpoint missiles=
|hardpoint bombs=
|hardpoint other=

|avionics=
}}

==Notable appearances in media==
<!-- All content about the aircraft in fictional and gaming use has been moved to [[Aircraft in fiction, please see [[WP:AIRPOP]] -->
{{Main article|Aircraft in fiction#Sikorsky H-53 series}}

==See also==
[[File:MH-53 Pave Low 73-1649.JPG|thumb|MH-53M Pave Low IV]]
{{aircontent
|see also=

|related=
* [[CH-53 Sea Stallion]]
* [[CH-53E Super Stallion]]
* [[Sikorsky S-61R|HH-3E "Jolly Green Giant"]]
|similar aircraft=
* [[CH-47 Chinook|MH-47 Chinook]]
* [[Sikorsky HH-60 Pave Hawk]]
|lists=
* [[List of active United States military aircraft]]
* [[List of rotorcraft]]
* [[List of military electronics of the United States]]
}}

==References==
{{reflist|2}}

==External links==
{{Commons category|HH-53/MH-53 (US Air Force)}}
{{vectorsite}}
* [https://archive.today/20121212212244/http://www.af.mil/information/factsheets/factsheet.asp?id=117 USAF MH-53 page (archived)]
* [https://pavelow.us USAF MH-53 PAVE LOW site]
* [http://www.globalsecurity.org/military/systems/aircraft/hh-53.htm HH-53], [http://www.globalsecurity.org/military/systems/aircraft/mh-53j.htm MH-53J Pave Low III], and [http://www.globalsecurity.org/military/systems/aircraft/mh-53m.htm MH-53M Pave Low IV pages on GlobalSecurity.org]

{{Sikorsky Aircraft}}
{{US helicopters}}
{{PAVE US}}
{{USAF system codes}}

{{DEFAULTSORT:MH-53 PAVE LOW}}
[[Category:United States military helicopters|Sikorsky MH-53 Pave Low]]
[[Category:Sikorsky aircraft|H-053, M]]
[[Category:1960s United States helicopters]]
[[Category:Twin-turbine helicopters]]
[[Category:Aircraft first flown in 1967]]
[[Category:Sikorsky H-53]]