 |
| Download Papercraft |
The Sikorsky MH-53 Pave Low
series is a long-range 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 HH-3 "Jolly Green
Giant". The helicopters later transitioned to Special Operations missions.
The U.S. Air Force's MH-53J/M fleet was retired in September 2008.[1]
Design and development
The
US Air Force ordered HH-53B and HH-53C variants for Search and Rescue units,
and developed the MH-53J Pave Low version for 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, exfiltration
and resupply of special operations forces. Pave Lows often work in conjunction
with MC-130H Combat Talon for navigation, communications and combat support,[4]
and with MC-130P Combat Shadow for in-flight refueling.[5][6]
The
large green airframe of the HH-53B earned it the nickname "Super Jolly
Green Giant". This name is a reference to the smaller 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 combat search and rescue (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.[7]
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 650 US gallons (2,461 L), 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 250 feet (76 m) of steel cable.
- Armament of three pintle-mounted General Electric GAU-2/A 7.62 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 1,200 pounds (540 kg) of armor.
- A Doppler navigation radar in the forward belly.
Early
HH-53Bs featured T64-GE-3 turboshafts with 3,080 shaft horsepower (2,297 kW)
each, but these engines were later upgraded to T64-GE-7 turboshafts with 3,925
shaft horsepower (2,927 kW). Five crew were standard, including a pilot,
copilot, crew chief, and two pararescuemen.[7]
HH-53C
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 450 US gal (1,703 L) 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.[7]
A
total of 44 HH-53Cs were built, with introduction to service in August 1968.
Late in the 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 capsule in case of a launchpad abort, though such an accident
never happened.[7]
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.[7]
A good number of Super Jollies were converted into Pave Low special-operations
helicopters.[7] PAVE or Pave is an Air Force code name for a
number of weapons systems using advanced electronics.
HH/MH-53H
The
USAF's Super Jollies were useful helicopters, but they 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.[7]
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.[7]
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 .50cal (12.7mm) 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]
- A Canadian Marconi Doppler-radar navigation system.
- A Litton or Honeywell inertial guidance system (INS).
- A computerized moving-map display.[7]
- 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 goggles (NVGs). They were then reclassified as "special
operations" machines and accordingly given a new designation of MH-53H.[7]
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 kW) each, as well as more
armor, giving a total armor weight of 1,000 lb (450 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.[7]
MH-53J/M
The
MH-53J Pave Low III helicopter was the largest, most powerful and
technologically advanced transport helicopter in the US Air Force inventory.
The 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 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-53Js.
The
MH-53J's main mission was to drop off, supply, and pick up special 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 kg) of cargo with its external
hook. It was capable of a top speed of 165 mph (266 km/h) and had a
ceiling of 16,000 feet (4,900 m).
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
While
waiting for delivery of the HH-53Bs, the Air Force obtained two 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 photo-reconnaissance satellites.[7]
The
Super Jollies made headlines in November 1970 in the unsuccessful 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 from
Cambodian Khmer Rouge fighters in May 1975. The Air Force lost 17 Super Jollies
in the conflict, with 14 lost in combat – including one that was shot down by a
North Vietnamese MiG-21 on 28 January 1970 while on a CSAR mission over Laos –
and three lost in accidents.[7]
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.[7]
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.[7]
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.[1][8]
Variants
- TH-53A - training version used by US Air Force (USAF)
- HH-53B - CH-53A type for USAF search and rescue (SAR)
- CH-53C - heavy-lift version for USAF, 22 built
- HH-53C - "Super Jolly Green Giant", improved HH-53B for USAF
- S-65C-2 (S-65o) - export version for Austria, later to Israel
- S-65-C3 - export version for Israel
- YHH-53H - prototype Pave Low I aircraft
- HH-53H - Pave Low II night infiltrator
- MH-53H - redesignation of HH-53H
- MH-53J - "Pave Low III" special operations conversions of HH-53B, HH-53C, and HH-53H.
- MH-53M - "Pave Low IV" upgraded MH-53Js
No comments:
Post a Comment