SIKORSKY PRODUCT CHARTS:

Please click on any of the coded models listed on the pages below to learn more about its background and why it came into being, its special features, its specifications and its production history. The following lineage charts are organized in groups:


S-65/H-53A/D Sea Stallion/ H-53E Super Stallion

s-65 1 
U.S. Marine Corps CH-53A heavy lift helicopter

Background

In January 1961, The Department of Defense issued a Request for Proposals for the Tri-Service Assault Transport Program, a medium sized Vertical Take Off and Landing (VTOL) aircraft.  This project was initiated to provide a replacement forSikorsky S-56 (HR2S-1) helicopter and the competition was won by the Ling Tempco Vought (LTV) XC-142A VTOL Transport.  The Marine Corps was concerned with the XC-142A prop-rotor downwash which was considerably higher than the HR2S-1 (S-56), decided it was unsuitable for shipboard operations, and decided to make their own request for a new heavy lift helicopter.

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LTV XC-142Atilt wing VTOL transport

On March 7, 1962, the Bureau of Naval Weapons (BuWeps) issued a Request for Proposals for a ship based helicopter able to lift an 8,000 pounds (3630 kg) payload over a radius of 100 nm (115 miles, 185 km) at a speed of 150 knots (172 mph, 278 km/h).  Its mission was ship-to-shore transport, downed aircraft recovery, personnel transport, and Medical Evacuation.  Three proposals were submitted to BuWeps: Vertol proposed a version of the HC-1B (CH-47A Chinook), Kaman proposed a development of the British-designed Fairey Rotodyne, and Sikorsky proposed the S-65.  In July 1962 Sikorsky was chosen as a result of technical, production capability, and cost considerations.  However, insufficient funds prevented a contract award. Sikorsky negotiated to lower theResearch and Development (R&D) costs and reduce the number of prototype helicopters to two instead of the original four prototype helicopters.  On September24, 1962Sikorsky was awarded a contract to design and develop a mock up, a static test airframe, and two YCH-53A prototype helicopters for $9,965,635. First flight of the YCH-53A occurred on October 14, 1964

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YCH-53A first flight on October 14, 1964 

The S-65 helicopters featured a 72 foot 6 bladed fully articulated main rotor and a 4 bladed tail rotor powered by two 2,850 shp General ElectricT-64-6 free turbine turboshaft engines.  All fuel was carried in external sponsons.  With a crew of 3,it was capable of carrying 38 fully-equipped troops or 24 litter patients and 4 medical attendants.  Internally 8,000 pounds of cargo could be carried or 13,000 pounds externally.

The S-65 helicopter design was based on previous designs. The S-56 and S-64 models contributed the basis for dynamic components and the S-61R provided a basic shape for the S-65

In January 1965,a MarineCH-53A flew at speeds as high as 170 knots (196 mph) at gross weights of up to 35,000 lbs. making it the free world’s fastest production helicopter.

S-65 Model Designations

 

Customer

Model No.

Nickname

Mission

Two Engine Models

 

 

 

US Marine Corps

CH-53A/D

Sea Stallion

Utility Transport

US Navy

RH-53A/D

Sea Stallion

Airborne Minesweeping

US Air Force

HH-53B/C

Super Jolly Green Giant

Combat Search and Rescue

US Air Force

CH-53C

 

General Transport Work

US Air Force

HH/MH-53H/J/M

Pave Low I,II,III,IV

CSAR with low light TV

German Army/Air Force

CH-53G/GS/GE/GA

License built CH-53D

Utility Transport

Israeli Air Force

S-65C-3

Yas’ur/ Yas’ur 2000/ Yas’ur 2025

Utility Transport

Three Engine Model

 

 

 

US Marine Corps

CH-53E

Super Stallion

Heavy Lift Transport

US Navy

MH-53E

Sea Dragon

Airborne Minesweeping

 

 

 

 

 

 

S-65 Development Timeline

  • September 24, 1962. Contract award for two YCH-53A helicopters
  • October 14, 1964. First Flight of the YCH-53A helicopter
  • November 13, 1964.  First flight “Over the Fence”, a half hour flight over Stratford, Shelton, and Milford, by Sikorsky pilots Lloyd (Opie) Blanchard and Robert Decker.
  • November 19, 1964.CH-53A is introduced to the public.

 

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November 19, 1964 the YCH-53A BuNo 151614 is introduced to the public

  • May 1966.  CH-53A BIS (Board of Inspection and Survey) trials commence at the Naval Air Test Center, Patuxent River Maryland
  • September 12, 1966.  First CH-53Ahelicopters delivered to an operational unit.  Five CH-53A helicopters weredelivered to Marine helicopter squadron HMH-463 and flown to MCAS Santa Anta California for the Fleet Introduction Team (FIT).

 

  • s 65 5
    MH-463 CH-53A helicopters depart for MCAS Santa Anna California 
  • November 12, 1967.  First HH-53B Combat Search and Rescue (CSAR) helicopter delivered to US Air Force.
  • June 28, 1968.  First HH-53C CSAR helicopter delivered to the US Air Force.
  • October 23, 1968. A CH-53A helicopter flown by Marine Lt.Col. Robert Guay and Sikorsky pilot Byron Graham performed a series of loops and rolls over Long Island Sound. A link to a video of that event is provided below:
    http://www.youtube.com/watch?v=VC2E8RJE3Jo
  • March 6, 1969.  First CH-53D helicopter delivered to the US Marine Corps.
  • September 26, 1969.  Two Sikorsky built CH-53G helicopters delivered to the German Government. Kits were provide for the next 20 CH-53G helicopters were provided to Germany which then built 90 helicopters under license by VFW/Fokker in Speyer, Germany.
  • October2, 1969.  First S-65C-3 (CH-53D) helicopters of an order for 7 helicopters delivered to the Government of Israel.  Thirty Fivemore were delivered under subsequent orders.
  • August 15–August 24, 1970.  The first Trans-Pacific helicopter flight by two HH-53C helicopters. The historic flight was from Eglin AFB Florida and with several enroute stops to DaNang South Vietnam.
    The flight shortened the delivery time toVietnam by about 75% and demonstrated the long-range capability of helicopters refueled in the air.
  • Late 1971. DOD approved prototype development of the CH-53E and authorization to build two YCH-53E helicopters.
  • October 31, 1972.  First RH-53D minesweeper delivered to the U.S. Navy.
  • March 1, 1974.  First Flight of the three engine YCH-53E helicopter.

 

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First flight YCH-53E on March 1, 1974

  • Early 1975.  Authorization to build two additional CH-53E production prototype helicopters and a static test article. 
  • December 1975.  First flight of production prototype CH-53E.
  • August 1976.  Two CH-53E production prototype helicopters delivered to the Naval Air Test Center for Testing
  • February 27, 1978. Production contract for six CH-53E helicopters received.
  • June 1978. First production CH-53E delivered to Marine Helicopter Squadron HMH-464, MCAS New River, North Carolina.
  • February 1982. First CH-53E delivered to Marine Helicopter Squadron HMH-465, MCAS Tustin, California

S-65 Two Engine Models

Configuration Features

CH-53A

U.S Marine Corps heavy lift helicopter featured a six blade 72 foot main rotor and a 4 bladed 16 foot anti torque tail rotor.  The fuselage was watertight allowing water landings in an emergency.

 

RH-53A

Fifteen CH-53A helicopters modified for the U. S. Navy airborne minesweeping mission.

 

HH-53B

U.S. Air Force modelbased on the CH-53A helicopter modified for the Combat Search and Rescue (CSAR) mission.  Air-to-Air Refueling capability and jettisonable external auxiliary fuel tanks, a rescue hoist above the crew door were added.  The engines were upgraded to T64-GE-3 engines (3,080 shp). 

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U.S. Air Force HH-53B Combat SAR helicopter
  

HH-53C

U.S. Air Force follow-on to the HH-53B CSAR helicopters with increased engine power (T64-GE-7 engines 3,435 shp).and cantilevered external auxiliary fuel tank mounts.  

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U.S Air Force HH-53C Super Jolly Green Giant
 

CH-53D

A follow-on to the CH-53A for the Marines with many improvements including more powerful engines (T64-GE-412 engines 3,925 shp) with Engine Air Particle Separators (EAPS) which eliminated ingestion of dust and foreign objects and an uprated transmission.Internal cargo carrying ability was increased to 14,000 pounds for 200 nautical miles.  The CH-53D was retired by the Marines in February 2012 after completing 43 years of service andtheir final deploymentssupporting Operation Enduring Freedom in Afghanistan. 

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U.S. Marine Corps CH-53D lands in Grenada, October 1983

RH-53D

36 U.S. Navy Minesweeping helicopters ( 6 sold to Iran by U.S Government as a Foreign Military Sale (FMS)).  The RH-53D helicopters featured an improved fully redundant four axis (pitch, roll, yaw, collective) AFCS (Automatic Flight Control System), larger external fuel tanks, and specialized AMCM equipment.  The AMCM equipment included a tow boom attached under the main gearbox, adjustable rear view mirrors on the nose , tow tension and cable angle instruments in the cockpit. Guard rails were installed on the rear ramp to prevent the tow cable from contacting the airframe.  Internal winches deployed the tow cable and a fuel system allowed the power units on the towed sled to be refueled under tow.  The RH-53D was capable of flying with 15,000 pounds of cable tension while towing at 15 knots. 

s 65 10
U.S. Navy RH-53D minesweeper
 

S-65C-1 (CH-53G/GS/GE/GA)

CH-53D helicopters builtin a Co-Production Program for the German Army(Heersflieger) by VFW/Fokker in Speyer, Germany.  The German Government has modernized the fleet of helicopters over the years and they remain in service 44 years, as of 2013, after the first delivery.  The latest upgrade to the CH-53GA configuration equips the helicopters for an operational lifetime lasting beyond 2030.  In January 2013, all CH-53 helicopters were transferred from the German Army (Heersflieger) to the German Air Force (Luftwaffe). 

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German Army (Heersflieger) S-65C-1 (CH-53G)
 

S-65C-2

Two S-65C-2 (CH-53D) helicopters were delivered to Austria. Although they performed well in high altitude operations, high operating costs eventually lead to the sale of the 2 helicopters to Israel. 

s 65 12
S-65C-2 (CH-53D) Austrian Air Force
 

S-65C-3 CH-53 Yasur (Petrel)

Forty two CH-53D helicopters sold to the Government of Israel.  Israel also acquired additional used H-53 helicopters from Austria and the U.S. Government.  They have been upgraded several times and are projected to remain in service until at least 2025.

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Israeli Air Force S-65C-3 (CH-53D) Yasur
 

VH-53F

Six VH-53F helicopters were ordered for the Presidential support program.  Trial landings at the White House revealed that the downwash from the H-53 rotor system was not compatible with the White House shrubbery.  The plan was cancelled by the White House groundskeeper.  Two CH-53D helicopters modified with Glossy “Marine Green” paint and more comfortable interiorswere assigned to VX-1 as VH-53D helicopters to carry the press corps and spare parts in support of the Executive Transport mission.

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Artist conception of the VH-53F helicopter
 

MH-53H/J/M
U.S. Air Force Special Operations helicopters with sophisticated equipment for the CSAR and Special Forces insertion and extraction. They were retired in October 2008 after final service in Iraq.

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U.S.Air Force MH-53M departs Eglin AFB, Floridaheading into retirement

Design Features

The CH-53A helicopters featured extensive use of Titanium which at the time was considered an exotic metal with limited applications.  

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The CH-53 pioneered the use of Titanium in a helicopter design.

 

The S-65 fuselage was constructed of an aluminum structure with aluminum skins and composite removable panels.  The sharp break in the fuselage for the rear ramp caused significant drag.  The engineering solution to this problem was to add strakes, known as “Elephant Ears”, to the fuselage at the ramp.

s 65 17
S-65 fuselage drag reduction elephant ears.
 

Stabilizer

The fixed stabilizer was located on top of the tail rotor pylon on the right side.  This 24.5 sq. ft. stabilizer had 10 degrees of dihedral and a zero degree angle of incidence.

 

Main Rotor Assembly

 

Oil Lubricated.

A 6 bladed fully articulated oil lubricated main rotor head was installed on the S-65 helicopter. The 72 foot 2.7 inch diameter main rotor was controlled by a 2 stage hydraulicirreversible servo control system.

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CH-53A oil lubricated (Wet Head) main rotor head
 

Elastomeric Bearings

A Government funded design program was initiated to greatly reduce maintenance of the main rotor head while increasing reliability.  All lubrication requirements were eliminated to solve a persistent oil leakage problem  The elastomeric head went through extensive bench and whirl stand testing and achieved first flight in early 1972.  A retrofit program for the CH-53D fleet replaced the oil lubricated main rotor with a lower maintenance elastomeric rotor head.  It featured a cone-shaped spherical bearing for pitch, flap, lead and lag changes. The elastomeric bearing was constructed of a sandwich of rubber and metal laminates with no lubrication required.


s 65 19
CH-53D Elastomeric main rotor head

 

Main Rotor Blades (Aluminum Spar)

The all metal main rotor blades were constructed of aluminum alloy except for titanium cuffs.  The main rotor blade was constructed of a hollow extruded aluminum spar pressurized with nitrogen (Blade Inspection System(BIM)) to detect cracks withhoneycomb filled, aluminum skinned pockets bonded to the spar. A cockpit warning system advised the flight crew if spar pressure was depleted.The H-53 fleet was retrofitted by the U.S. Government with the IBIS (Inflight Blade Inspection System) which used radioactive Strontium 90 to detect a loss of pressure in the blade spar.  A detector assembly picked up the radiation signal which sent a signal to a signal processor.  The signal processor picked up the message which illuminated the caution lights in the cockpit.

 

Improved Main Rotor Blades (Titanium Spar)

In May ,1970 Sikorsky initiated a company funded Research and Development (R&D) project prior to receiving Government funding to increase the CH-53D helicopter lift and performance with a titanium spar main rotor blade identified as the Improved Rotor Blade (IRB).  Titanium was the metal of choice due to its strength and light weight.  In order to economically produce the 33 foot titanium spars new manufacturing techniques were developed.  The spars were constructed of a long and narrow sheet of titanium.  The sheets were cold formed in a four step process using a 40 foot long 2,000 ton hydraulic press into a round shape with the gap closed by plasma arc welding.  The titanium root attachment was inertially bonded to the end of the spar.  The assembly was then placed in heated dies and creep formed into the final oval shape. The Nomex honeycomb pockets were bonded to the spar and the entire assembly wrapped in fiberglass epoxy to produce the complete blade.  . The IRB, with a larger chord, improved SC1095 airfoils and a higher 16 degree twist, allowed a gross weight increase from 36,693 to 42,000 pounds.  The first flight of a CH-53D with the IRB installed was September 29, 1971.  The same blades were used on the CH/MH-53E helicopter with 3 foot extenders to increase the main rotor diameter.  Blades of similar construction were used for both the S-70 and S-76 model helicopters.

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CH-53D Improved Rotor Blade (IRB)

Cruise Guide Indicators

The cruise guide indicators, one for the pilot and one for the copilot were mounted on the instrument panel to assist the pilot in obtaining optimum performance from the helicopter by providing a direct indication of the degree of main rotor blade stall..  This was accomplished by a transducer mounted within the piston of the aft lateral main rotor servo which measured the vibratory loads imposed on the stationary swashplate.  Thevibratory loads on the stationary swashplate were influenced by varying conditions of main rotor speed, gross weight, altitude, temperature, load factor, airspeed, andcenter-of-gravity position.  These loads were a direct indication of the onset of blade stall or the degree of blade stall encountered during a flight.The indicators were graduated in percent, from 0 to 100 percent.  Normal operation was between 0 and 30 percent with a maximum of 70 percent. Transient operations between 30 and 70 percent were permitted.  If one indicator failed, the other indicator would read double.

 

Transmission System

The transmission system consists of two nose gearboxes, a main gearbox, accessory gearbox, intermediate gearbox and the tail rotor gearbox.

 

Nose Gearbox

The nose gearbox rotates the output of the engine 135 degrees to align with the main gearbox inputs and reduces engine rpm from 13,600 rpm to 6,023 rpm through high speed bevel gears

 

Main Gearbox

The main gearbox couples the two nose gearboxes and provides output power for the main rotor, tail rotor, and accessory gearboxes.  The main gearbox bevel gears and a two stage planetary reduction to reduce main rotor speed to 185 rpm and the tail drive shaft speed to 3,011 rpm.  The main gearbox also drives the main gearbox oil cooler (7,070 rpm), the main gearbox oil pump, freewheeling units, No. 1 generator, main rotor tachometer-generator, first-stage hydraulic pump, and the accessory gearbox (6,144 rpm) when it is not being driven by the Auxiliary Power Plant (APP).

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T. Englehart and W. Glover from the gearbox supplier, Indiana Gear Works, with the CH-53A Main Gearbox

Accessory Gearbox

The accessory gearbox drives the No. 2 generator, second-stage servo hydraulic pump, winch hydraulic pump, and the accessory gearbox oil pump.  The accessory gearbox is driven by the main gearbox when the main rotor is turning and the APP when the main rotor is stopped.

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CH-53A/D Transmission System

Tail Rotor Assembly

A 4 bladed 16foot diameter all metal semi-articulated tail rotor was installed.  The tail rotor pitch change was accomplished by a 2 stage hydraulic servo.

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CH-53A/D Tail Rotor
 

Engine
TwoGeneral Electric T-64GE-6, 2,850 shp (2,130 kw) free turbine turboshaft engines were installed on the CH-53A.  More powerful models of the T-64 engines were used by various models culminating with the CH-53D using the 3,925 shp (2,927 kw) T64-GE-413 engine

s 65 24
General Electric T-64 free turbine turboshaft engine 

Engine Air Particle Separators (EAPS)

To extend engine life in hostile environments based on experience in Vietnam, EAPS was installed on most H-53 model helicopters.  The engine air particle separators were designed to remove visible moisture, sand, dust, and other foreign particles from the engine inlet air.Each EAPS unit contained 759 STRATA tubes.  As the inlet air traveled through the STRATA tube it traveled in a cyclonic motion which caused foreign particles to migrate towards the walls of the tube and pass into the scavenge ducting. The clean air continued into the engine and the scavenge blowers exhausted the particle laden air overboard.  The EAPS units were hinged to swing away to allow normal access to the engine inlet and servicing of the nose gearbox.  Bypass doors opened in the event of EAPS clogging and at airspeeds above 60 knots. The electric power for the EAPS was provided by the power normally used for the nose gearbox fairing anti-ice controllers.

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H-53 Engine Air Particle Separators

Auxiliary Power Plant (APP)
The S-65 helicopters were equipped with a Solar T-62T-27 Gas Turbine APP mounted on the top forward section of theupper deck of the helicopter which powered the accessory gearbox to provide hydraulic and electrical power to the helicopter. The APP weighed 83 pounds and was rated at 100 shp.  The APP turbine turned at 61,248 rpm was reduced to 8,380 rpm through a reduction gear system.  The APP was started by hydraulic pressure from accumulator (s)

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H-53 T-62T-27 APP

Fuel System

Main Fuel Tanks S-65 helicopters were equipped two 319 gallon main fuel tanks in sponsons attached to the cabin.  Each tank consisted of a single bladder type fuel cell with the bottom third of each cell being self-sealing.  No boost pumps were installed in the tanks. Fuel was sucked from tanks using a “Soda Straw” technique by boost pumps above the cabin.  A crashworthy fuel system could be installed by a modification kit which included self-sealing breakaway valves where fuel lines passed through the fuel cell wall.  Contamination traps were installed in the vent lines to remove sand and other contaminates.

Internal Range Extension Tanks S-65 helicopters modified with a retrofit kit could install up to seven 285 gallon tanks in the cabin. For safety, these tanks were filled with reticulated foam to prevent an explosive fuel/air mixture from forming in an empty or partially filled tank.  Internal tanks contained fuel transfer pumps to transfer fuel to the main tanks.  Each empty tank including tiedown chains, electrical harness, and hoses weighed 340 pounds.

External Auxiliary Fuel Tanks Jettisonable 650 gallon external tanks were installed on a pylon attached to the sponsons on CH-53D and HH-53C helicopters. Theses tanks were fabricated by winding a fiberglass-composite filament over a thin aluminum shell.  For cg (center of gravity) control the tanks contained two compartments. During fueling the forward compartment filled first and then the aft compartment.  Engine compressor bleed air was used to force fuel from the auxiliary fuel tanks to the main tanks. 

General Arrangement Drawing

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CH/HH-53A/C/D (Two Engine) 3-view Drawing

General Characteristics and Performance S-65(CH-53D)

PERFORMANCE
Standard Day, Sea Level


Maximum speed (Vne) CH-53D Elastomeric Head

130 kts           241 km/hr

Range with maximum payload

540  miles       1,000 km

Service ceiling

16,750ft            5,106 m

Rate of Climb

2,460 ft/min      12.5 m/s


WEIGHTS

Maximum takeoff gross weight

42,000 lbs 19,050.9kg

Weight empty

26,500 lbs 12,020.2kg

Maximum fuel load – Main Tanks

638 gal        2,415.1 ltr

Maximum fuel load – External Drop Tanks

1,300gal        4,921 ltr

Maximum fuel load - Cabin Range Extension Tanks (7)

1,995 gal     7,551.9 ltr

Useful Load

15,500lbs   7,030.7 kg

Maximum External Load ( Cargo Hook)

20,000lbs   9,071.8 kg


GENERAL DATA

Crew seating capacity

2

Seating capacity

Up to 29 passengers.
47 with center seats


POWERPLANT RATINGS

Standard Day at Sea Level

CH-53A  General Electric T-64-6

2,850 shp  2,130 kw

CH-53D  General Electric T64-GE-413

3,925 shp 2,927 kw


AIRCRAFT DIMENSIONS

Main rotor diameter (blade tip circle)

72’ 2.7”        21.95 m

Tail rotor diameter (blade tip circle)

16’                   4.9 m

Fuselage length

67’ 2.4”        20.42 m

Length over-all (including rotors)

88’ 2.4”        26.82 m

Height over-all

17’ 1.68”        5.18 m

Main landing gear tread

15' 6"               4.7 m

 

S-65 Three Engine Models

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Two CH-53E helicopters refueling from HC-130P while carrying a 26,000 lb sling load

CH-53E Super Stallion

The CH-53E design was a combination of a company funded S-64B three engine Super Skycrane and the RH-53D helicopter.  The S-64B was envisioned as an 18 ton heavy lifter.  To reduce development costs, it was based on CH-53D components.  Three T-64 engines were used and extenders were used to increase main rotor diameter without designing new blades.  Significant development was done on the S-64B including wind tunnel testing and a Power System Test Bed (PSTB) which was used for endurance testing of the CH-53E powertrain.

S 65-29
Artist’s conception of a three engine S-64B Super Skycane

In order to avoid a full scale competition for a heavy lift helicopter, the CH-53E was procured as an Engineering Change Proposal (ECP) to the RH-53D helicopter to add a third engine and a seventh main rotor blade to double the external lift capability (CH-53A, 16,000 lbs. vs. 32,000 lbs.).  During the design phase one system after another required major modification with the final result being essentially a new helicopter.  Six feet were added to the main rotor diameter by adding 3 foot extensions to the main rotor spindles. This created a 79 foot main rotor diameter while allowing use of the CH-53D Improved Rotor Blades (IRB) already in the inventory.

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CH-53E main rotor blade extenders

The tail rotor was increased to 20 foot diameter canted 20 degrees to the left to provide lift as well as anti-torque functions.  The fuselage was extended 6 feet 2 inches to accommodate the third engine.

The CH-53E prototype helicopter, the western world’s most powerful helicopter, during testing at the Naval Air Test Center Patuxent River, Maryland

 
  • Lifted a payload of 37,000 pounds
  • Flew at a gross weight of 75,000 pounds
  • Flew at a Maximum Forward Speed of 182 knots
  • Exceeded a rate of climb of 6,000 feet per minute
  • Demonstrated hovering at 70,000 pounds with one engine inoperative

The design goal of doubling the lift capability of the helicopter was accomplished with only a 10% increase in size of the helicopter.

CH/MH-53E Transmission System
The transmission system consists of two nose gearboxes, a main gearbox, an accessory gearbox, an intermediate gearbox, and a tail rotor gearbox.  The freewheeling units can disangage the engines during autorotaion, or one or two engine for single or dual engine operation, or any time engine rpm decreases below rotor rpm.

Main Gearbox
The 13,140 hp main gearbox couples the three engine inputs and provides output power for the main rotor, tail rotor, and accessory gearboxes.  The main gearbox bevel gears and a two stage planetary reduction reduce main rotor to 179 rpm(100% Nr) and the tail drive shaft to 4,271 rpm.  The main gearbox also drives the main gearbox accessory section which reduces the No. 2 engine input and drives the main gearbox oil cooler, the main gearbox oil pump, No. 2 generator, main rotor tachometer-generator, first-stage hydraulic pump, and the accessory gearbox (6,144 rpm) when it is not being driven by the Auxiliary Power Plant (APP).  The main rotor shaft was tilted 5 degrees forward to provide a level fuselage at cruise speeds.

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CH/MH-53E Main Gearbox

Nose Gearbox
The nose gearboxes forward of the No. 1 and No. 3 engines contain high spees bevel gears which reduceengine rpm from 14,280 rpm  to 6,323 rpm for input to the main gearbox.  The No. 2 engine input is directly into the main gearbox accessory section.

Accessory Gearbox
The accessory gearbox drives the No. 1 and No. 3 generators, second-stage servo hydraulic pump, engine start hydraulic pump, hydraulic system pump utility, and the accessory gearbox oil pump.  The APP is connected to the accessory gearbox through a clutch and shaft. The APP will drive the accessory gearbox until the main gearbox rpm exceeds APP rpm.

Intermediate Gearbox
The intermediate gearbox changes the angle of drive and provides an reduction of rpm from 4,271 to 2,628 rpm.

Tail Rotor Gearbox
The tail rotor gearbox provides power transmission at a right angle and a reduction in rpm from 2,628 to 699 rpm for the tail rotor.

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CH/MH-53E Transmission System

Tail Rotor Pylon
Adding a third engine and increasing the main rotor diameter to the H-53 helicopter aggravated an aft cg problem since the third engine was aft of the main gearbox.  To solve this engineering challenge the tail rotor was increased in size from 16 to 20 feet in diameter and the pylon was canted 20 degrees to the left to provide lift (2,000 pounds) for the tail as well as anti-torque power.  Blade folding requirements required a “Gull Wing” horizontal stabilizer on the Right side of the tail rotor pylon.

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A rear view of the CH-53E shows the unique tail rotor design

CH-53E Fuel System
The CH-53E main fuel system was contained in the extended length sponsons. Fuel for the No. 1 and No. 3 engines was supplied by a self sealing bladder fuel cell in the sponson.  Fuel for the third engine (No. 2) was supplied by an additional self-sealing fuel cell in both the left and right sponsons.

External Cargo Hooks
The CH-53E was equipped with a single point 36,000 pound capacity hook or a two pointsystem with two 21,600 pound cargo hooks which are limited to a combined load of 36,000 pounds.  The 2 point system limited the swing of the load compared to the single point system.

General Arrangement Drawing

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CH-53E (Three Engine) 3-view drawing

MH-53E Sea Dragon
The MH-53E was derived from the CH-53E for the U.S Navy Airborne Mine CounterMeasures (AMCM) mission.  It was heavier with a greater fuel capacity carried in very large sponsons.  The MH-53E was capable of carrying up to 55 troops or a 16 ton payload 50 nautical miles.  The fuel capacity of the MH-53E was increased to 3,196 gallons in large sponsons to increase tow mission time.  The MH-53E was capable of towing a variety of mine sweeping/countermeasures systems including the Magnet Mine Sweeping System (Mk-105/Edo ALQ-166), the Mk 103 mechanical mine sweeping system, the AQS-20A underwater towed body which contains a high resolution, side-looking sonar system used for minehunting along the ocean bottom, and the Airborne Mine Neutralization System (AMNS- Sea Fox) (AN/ALQ-232).

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MH-53E differences from the CH-53E helicopter.

As the number of H-53E airframes available has diminished due to attrition and requirements have increased, a number of MH-53E helicopters have been modified to a utility configuration and attached to Marine squadrons for combat assault duties.

General Characteristics and Performance S-65 (CH-53E)

PERFORMANCE
Standard Day, Sea Level


Maximum speed (Vne)CH-53E

170 kts           315 km/hr

Range with maximum payload

540 miles         1,000 km

Service ceiling

18,500 ft           5,640 m

Rate of Climb

2,500ft/min        1  3 m/s


WEIGHTS

Maximum takeoff gross weight

73,500 lbs    33,300 kg

Weight empty

33,226 lbs    15,070kg

Maximum fuel load  internally

977 gal         3,698.4ltr

Maximum fuel load externally

1300 gal         4,921 ltr

Useful Load

40,234 lbs 18,249.8 kg

Maximum External Load ( Cargo Hook)

32,000lbs     14,515 kg


GENERAL DATA

Crew seating capacity

2

Seating capacity

Up to 36 passengers
55 with center seats


POWERPLANT RATINGS

Standard Day at Sea Level

General Electric T-64-GE-416  (3)

4,380 shp  3,270 kw


AIRCRAFT DIMENSIONS

Main rotor diameter (blade tip circle)

72’ 2.7”            22 m

Tail rotor diameter (blade tip circle)

20’                   6.1 m

Fuselage length

73’ 3.92”     22.35 m

Length over-all (including rotors)

99’ 0.5””       30.2 m

Height over-all

17’2”               5.2 m

Main landing gear tread

15' 6"               5.8 m

 

Production History

Sikorsky Aircraft S-65 production consisted of 737 helicopters.

  •  2 U.S. Marine Corps YCH-53A prototype helicopters
  • 139 U.S Marine Corps CH-53Ahelicopters (15 modified to RH-53A minesweeping configuration).
  • 18 U.S. Air ForceHH-53B CSAR helicopters
  • 40 U.S. Air Force HH-53C CSAR helicopters (modified by customer to MH-53H/J/H configurations)
  • 126 U.S. Marine Corps CH-53D
  • 36 U.S. Navy RH-53D Minesweeping helicopters( 6 sold to Iran by U.S Government FMS)
  • 112 S-65C-1 (CH-53G) helicopters built in a Co-Production Program for the German Army (Heersflieger) by VFW/Fokker in Speyer, Germany. CH-53G German Army helicopters were modified by customer to GA/GE/GS configurations.  The first 2 CH-53G helicopters were built by Sikorsky Aircraft followed by 18 kits of structural components and 2 kits of detailed parts which were assembled in Germany. The remaining CH-53G helicopter airframes were complete German products with dynamic components provided by Sikorsky Aircraft.
  • 2 S-65C-2 (CH-53D) Austrian Army helicopters (sold to Israel).
  • 35 S65C-3 Yasur (CH-53D) Israeli Air Force helicopters (modified by customer to Yasur 2000 and Yasur 2025 configurations)
  • 2 YCH-53E Prototype helicopters
  • 178 CH-53E U.S. Marine Corps helicopters
  • 47 M-53E U.S. Navy Minesweeping helicopters

 

CH-53K

s 65 36
Artist’s rendering of the CH-53K

The replacement for the CH-53E is presently (2013) in development. In April, 2006 a $3.6 billion contract was awarded by the Naval Air Systems Command to design and develop the CH-53K Heavy Lift helicopter for the USMC.  The contract provided for one Ground Test Vehicle (GTV) and four flight articles designated as Engineering Development Models (EDM). In addition, 2 additional GTV helicopters were built for laboratory structural testing, one static test article and one fatigue test article.  The design goals for the CH-53K were to increase the lifting ability to three times the CH-53E (27,000 pounds) with a 110 mile radius under USMC hot and high conditions while maintaining the same “footprint” as the CH-53E for shipboard operations. Other design parameters are a 23% reduction in maintenance man-hours, increased survivability, and a 20% reduction in fuel consumption.

The CH-53K is powered by three GE38-1B 7,500 shp (5,600 kw) turbo shaft engines. The flight control system is a fly-by-wire system.  The main gearbox features a split torque design to more evenly distribute engine power.  The seven blade elastomeric folding main rotor features a reduced maintenance design.  The four bladed bearingless tail rotor is a design similar to the Sikorsky H-60 series helicopters   The fourth generation all composite main rotor blades have an advanced airfoil section and an anhedral tip for enhanced lift.  The hybrid composite cabin structure provides lighter weight and lower vibration levels than aluminum.


CH-53K 3-view drawing

The Rockwell Collins Avionics Management System (AMS) advanced cockpit incorporates fully integrated flight and navigational displays.

s 65 38
CH-53K Rockwell Collins AMS digital cockpit

On December 4, 2012 the CH-53K GTV was rolled out at the Sikorsky Florida Assembly and Flight Operations (FAFO) facility in West Palm Beach Florida and delivered to the Sikorsky flight test team.

s 65 39
The CH-53K Ground Test Vehicle roll out

On June 6, 2013 Sikorsky Aircraft Corp. received a $435 million U.S. Navy contract amendment to build four production-representative CH-53K heavy lift helicopters for the U.S. Marine Corps. Designated as System Demonstration Test Articles (SDTA), the four aircraft will enable the Marines to conduct operational evaluation of the new helicopter system in support of Initial Operational Capability scheduled for 2019. 

Additional Information:

Restored S-65 helicopters are on display at:

 

National Museum of Naval Aviation, Pensacola, FL

CH-53A USMC BuNo 153715

Combat Air Museum, Forbes Field, Topeka, KS

NCH-53A Navy BuNo 152399

Air Commando Park, Hurlburt Field, Florida

MH-53M Pave Low IV, AF Serial No. 68-10928

National Museum of the USAF, Wright-Patterson AFB,OH

MH-53M Pave Low IV, AF Serial No. 68-10357

Hill AFB Museum,  Ogden, Utah

MH-53M Pave Low IV, AF Serial No. 68-10369

Museum of Aviation, Robbins AFB, GA

MH-53M Pave Low IV, AF Serial No. 70-1626

Royal Air Force Museum, RAF Cosford, UK

MH-53M Pave Low IV, AF Serial No.68-8284

Air Force Armament Museum next to Eglin AFB, FL

MH-53M Pave Low IV, AF Serial No.73-1652

Pacific Aviation Museum, Ford Island, Oahu, HI

CH-53DUSMC BuNo157173

Naval Air Museum, Barbers Point, Oahu, HI

CH-53D USMC BuNo156964

Air Victory Museum, Medford, NJ

RH-53D Navy BuNo 158690

 

Sikorsky Archives News October 2007 “S-65”
http://www.sikorskyarchives.com/pdf/News_Oct_2007.pdf
Skycrane – Igor Sikorsky’s Vision of the Perfect External Lift Aircraft
http://www.sikorskyarchives.com/pdf/news%202013/Newsletter%2013%20July%202013.pdf

 

Prepared by Vinny Devine
July 2013


 

 

LAST UPDATE SEPTEMBER 4, 2013