Lieutenant Stewart R. Graham, USCG, in cockpit of Sikorsky HNS-1 near Gander, Newfoundland, September 1946. (U.S. Coast Guard)
April 6, 1949: Lieutenant Stewart Ross Graham, United States Coast Guard, and his crewman, Aviation Metalsmith 2nd Class (AM2) Robert McAuliffe, completed the longest unescorted helicopter flight on record. They flew a Sikorsky HO3S-1G, serial number 51-234, from the Coast Guard Air Station, Elizabeth City, North Carolina, to Coast Guard Air Station Port Angeles, Washington, via San Diego, California, covering a distance of 3,750 miles (6,035 kilometers) in 57.6 flight hours over 11 days.
Lieutenant Graham was the first Coast Guard pilot to fly a helicopter from a ship.¹ On 16 January 1944, he flew a Sikorsky HNS-1, Bu. No. 46445,² from the deck of a British freighter, SS Daghestan, while in convoy from New York to Liverpool. After 30 minutes, he returned to the freighter. He was a pioneer in the use of the helicopter by the Coast Guard and the Navy.
U.S. Coast Guard Sikorsky HO3S-1G 51-232, sister ship of 51-234. (U.S. Coast Guard)
The HO3S (Sikorsky S-51) was a second-generation helicopter, capable of carrying a pilot and up to three passengers. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction.
The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs and covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left.
The helicopter’s fuselage was 41 feet, 7.5 inches (12.687 meters). The main rotor had a diameter of 48 feet (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.2.565 meters) giving the helicopter an overall length of 57 feet, 1 inch (17.399 meters). It was 13 feet, 1.5 inches (4.001 meters) high. The landing gear tread was 12 feet (3.7 meters).
The S-51 had an empty weight of 4,050 pounds (1,837.05 kilograms) and maximum takeoff weight of 5,500 pounds (2,494.76 kilograms). Fuel capacity was 100 gallons (378.5 liters).
The helicopter was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney R-985 AN-5 (Wasp Jr. T1B4) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.
The S-51 had a maximum speed (Vne) of 107 knots (123.1 miles per hour/198.2 kilometers per hour). Range was 275 miles (442.6 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914.4 meters).
Sikorsky built 220 helicopter of the S-51 series.
U.S. Coast Guard HO3S-1G, serial number 51-238, sister ship of Lieutenant Graham’s record-setting helicopter. (USCG/Smithsonian Institution)
¹ On 6 and 7 May 1943, Colonel Hollingsworth Franklin (“Frank”) Gregory, U.S. Army Air Corps, made 23 landings and takeoffs from the tanker SS Bunker Hill in Long Island Sound, flying the Army’s Vought-Sikorsky XR-4, 41-18874. Please see TDiA at: https://www.thisdayinaviation.com/6-7-may-1943/
Sikorsky HH-3E Jolly Green Giant 67-14709 at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio. (U.S. Air Force)
30–31 March 1979: That Others May Live. On a dark and stormy night in the Yellow Sea, between China and the Korean Peninsula, the 160 foot (49 meter), 3,000 ton (2,722 Metric tons) Taiwanese freighter Ta Lai ran aground. As 20 foot (6 meters) waves battered the stranded ship, rocks punched through the hull. It was taking on water and sinking. Her crew of twenty-eight men were in danger.
Major James E. McArdle, Jr., U.S. Air Force. (Airman Magazine)
Detachment 13, 33rd Aerospace Rescue and Recovery Squadron, at Osan Air Base, 40 miles (64 kilometers) south of Seoul, the capital of the Republic of South Korea, answered the distress call.
Major James E. McArdle, Jr., United States Air Force, and his crew of four, flew their helicopter, “Rescue 709,” a Sikorsky HH-3E Jolly Green Giant, serial number 67-14709, through the darkness and gale-force winds to the stranded vessel. These men were just completing there regular 12-hour duty schedule when the distress call came in, but no other crews or helicopters were available.
In addition to Major McArdle, the aircraft commander, the crew consisted of 1st Lieutenant Van J. Leffler, pilot; Sergeant James E. Coker, flight engineer; Staff Sergeant Tony Carlo and Sergeant Mark Zitzow, pararescue jumpers (“PJs”).
Rescue 709 arrived on scene just before midnight, 30 March. While McArdle and Leffler tried to hold a steady hover over the Ta Lai as it pitched and rolled in the storm, Sergeant Zitzow was lowered 80 feet (24 meters) to the deck. Once there, he assisted the ship’s crew, two at a time, onto the rescue hoist’s jungle penetrator, and after strapping them on, all three were hoisted back to the helicopter. Sergeant Coker, who was controlling the hoist, moved the sailors into the passenger/cargo area of the Jolly Green Giant, and Zitzow was once again lowered to the Ta Lai.
With ten survivors aboard Rescue 709, the helicopter was at its maximum load. Sergeant Zitzow remained aboard Ta Lai. The crew then flew to Kwang-Ju Air Base, 150 miles (241 kilometers) south of Seoul—more than 30 minutes away—to offload the men.
After returning to the rescue scene, Sergeant Zitzow was joined on deck by Sergeant Carlo. While lifting three sailors, the helicopter’s hoist motor overheated and stopped. The sailors were still hanging 50 feet (15 meters) underneath the Jolly Green Giant. The only thing that could be done was to fly to a small island about 2 miles (3.2 kilometers) away and lower them to the ground. 709 then returned to the ship, by which time the hoist was working again. They picked up several more sailors and with Carlo once again on board, made the flight to Kwang-Ju.
On the third trip, the winds, though still high, were blowing from a more advantageous direction, and the final twelve men, including Zitzow, were quickly picked up. Rescue 709 returned to Kwang-Ju and landed at 0415 hours, 31 March 1979.
For this rescue, Major McArdle was awarded the Mackay Trophy by the National Aeronautic Association, for the most “meritorious flight of the year” by an Air Force member, members, or organization. He was also awarded another Distinguished Flying Cross. Lieutenant Leffler and Sergeant Coker were awarded the Air Medal, while both Sergeants Zitzow and Coker received the Airman’s Medal.
Sikorsky HH-3E 67-14709 under restoration at the National Museum of the United States Air Force, 2010. (U.S. Air Force)
67-14709 was built by Sikorsky Aircraft Corporation at Straford, Connecticut as a CH-3E transport helicopter and was later converted to the HH-3E configuration. It served the United States Air Force from 3 July 1968 to 19 February 1991.
During the Vietnam War, 709 operated with the 37th ARRS at Da Nang in the Combat Search and Rescue (CSAR) role. Flying with the call sign “Jolly Green 22,” at least 27 airmen were rescued by this helicopter and its crews.
Jolly Green Giant 67-14709 undergoing restoration at NMUSAF, 2010. (NMUSAF)
During that period, crewmen assigned to 709 were awarded one Air Force Cross,¹ fourteen Silver Stars (three of these had been nominated for the Air Force Cross) and an unknown number of Purple Hearts. On one mission alone, 709 took hits from at least 68 machine gun bullets.
After Operation Desert Storm, 709 was sent to The Boneyard at Davis-Monthan Air Force Base, Tucson, Arizona. After 19 years in the desert, in August 2010, she was pulled from storage and sent to the National Museum of the United States Air Force for a 6-month restoration by Museum staff, as well as technical experts from the 20th Special Operations Squadron at Hurlbert Field, Florida.
67-14709 was repainted in the Southeast Asia camouflage pattern. (NMUSAF)
Sikorsky HH-3E 67-14709 is on display in the Southeast Asia War Gallery of the Museum at Wright-Patterson Air Force Base, Ohio. Colonel McArdle, her pilot during the 1979 rescue mission, was present at 709’s Museum debut, 14 December 2010.
Mackay Trophy winner Colonel James E. McCardle, U.S. Air Force (Retired) speaks at the NMUSAF. His Jolly Green Giant, 67-14709, is behind him. (U.S. Air Force)
Colonel James E. McArdle, Jr., was born at LaCrosse, Wisconsin, 2 March 1943. He attended Marquette University High School in Milwaukee, where he competed on the Swimming Team and worked on the student newspaper. He entered the United States Air Force Academy as a cadet in 1961, majoring in engineering management. Upon graduating from the Academy, 9 June 1965, he was presented the Secretary of the Air Force Award for Behavorial Sciences. McArdle was commissioned as a Second Lieutenant, United States Air Force.
2nd Lieutenant McArdle trained as a helicopter pilot at Randolph Air Force Base, Texas, finishing at the top of his class. After finishing advanced helicopter training at Sheppard AFB, Texas, McArdle was assigned to the 20th Helicopter Squadron, 14th Air Commando Wing, operating in Southeast Asia, where he flew the Sikorsky CH-3C transport helicopter. He was awarded the Distinguished Flying Cross, four Air Medals and the Air Force Commendation Medal.
U.S. Air Force Sikorsky CH-3C, 20th Special Operations Squadron, 14th Air Commando Wing. This aircraft is not equipped with a rescue hoist or refueling boom. (U.S. Air Force)
In 1970, McArdle was retrained as a Northrop T-38A Talon pilot and spent the next four years as an instructor and check pilot at Williams Air Force Base, Arizona.
Major McArdle was assigned to the Air Force Reserve Officer Training Corps from 1974 to 1978. Next, he became the operations officer for Detachment 13, 33rd Aerospace Rescue and Recovery Squadron, Osan Air Base, Korea. During a 12-month period, the detachment saved 80 lives, including those rescued from the Ta Lai.
From 1979 to 1981 Lieutenant Colonel McArdle served at headquarters, Aerospace Rescue and Recovery Service, Scott Air Force Base, Illinois. While there he developed combat rescue tactics and helped develop the MH-53J Pave Low and MH-60G Pave Hawk special operations helicopters.
Compare this Sikorsky HH-3E to the CH-3C in the photograph above. The HH-3E has a rescue hoist and spotlight over the door, a refueling boom and external fuel tanks. (U.S. Air Force)
As operations officer of the 67th Aerospace Rescue and Recovery Squadron at RAF Woodbridge, Suffolk, England, McArdle supervised three detachments. Next, Lieutenant Colonel McArdle assumed command of the 41st ARRS at McClellan Air Force Base, Sacramento, California, 7 August 1984. At that time, unit’s primary assignment was special operations support, the only helicopter squadron so assigned in the U.S. Air Force.
Colonel McArdle’s final assignment was as Inspector General at McLellan Air Force Base. He retired from the U.S. Air Force on 1 August 1991 after thirty years of service.
An HH-3E of the 129th Aerospace Rescue and Recovery Group, California Air National Guard, hoists two PJs from the Pacific Ocean, 13 April 1977. (TSgt. Richard M. Diaz, U.S. Air Force)
The SH-3A Sea King (Sikorsky S-61) first flew 11 March 1959, designed as an anti-submarine helicopter for the U.S. Navy. The prototype was designated XHSS-2 Sea King. In 1962, the HSS-2 was redesignated SH-3A Sea King. Many early production aircraft were upgraded through SH-3D, SH-3G, etc. In addition to the original ASW role, the Sea Kings have been widely used for Combat Search and Rescue operations. Marine One, the call sign for the helicopters assigned to the President of the United States, are VH-3D Sea Kings.
The Sikorsky HH-3E (Sikorsky S-61R) is a development of the SH-3A. It earned the nickname Jolly Green Giant during the Vietnam War. It is a dedicated Combat Search and Rescue (CSAR) helicopter flown by the U.S. Air Force, based on the CH-3C transport helicopter. The aircraft is flown by two pilots and the crew includes a flight mechanic and gunner. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. It has retractable tricycle landing gear and a rear cargo ramp. The rear landing gear retracts into a stub wing on the aft fuselage. The helicopter has an extendable inflight refueling boom.
A Sikorsky HH-3E Jolly Green Giant refuels in flight from a Lockheed HC-130P Combat King. (U.S. Air Force)
The HH-3E is 72 feet, 7 inches (22.123 meters) long and 18 feet, 10 inches (5.740 meters) high with all rotors turning. The main rotor has five blades and a diameter of 62 feet (18.898 meters). Each blade has a chord of 1 foot, 6.25 inches (0.464 meters). The main rotor turns at 203 r.p.m., counter-clockwise, as seen from above. (The advancing blade is on the right.) The tail rotor also has five blades and has a diameter of 10 feet, 4 inches (3.150 meters). The blades have a chord of 7–11/32 inches (0.187 meters). The tail rotor turns clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.) The tail rotor turns 1,244 r.p.m.
HH-3E three-view illustration (Sikorsky Historical Archives)Beginning in 1928, an American food company began using a cartoon figure to advertise its “Green Giant” brand of canned peas. Eventually the mascot represented The Green Giant Company’s other canned and frozen vegetables. The character is now owned by General Mills.
The HH-3E has an empty weight of 13,341 pounds (6,051 kilograms). The maximum gross weight is 22,050 pounds (10,002 kilograms).
The Jolly Green Giant is powered by two General Electric T58-GE-5 turboshaft engines, which have a Maximum Continuous Power rating of 1,400 shaft horsepower, each, and Military Power rating of 1,500 shaft horsepower. The main transmission is rated for 2,500 horsepower, maximum.
The HH-3E has a cruise speed of 154 miles per hour (248 kilometers per hour) at Sea Level, and a maximum speed of 177 miles per hour (285 kilometers per hour), also at Sea Level. The service ceiling is 14,000 feet (4,267 meters). The HH-3E had a maximum range of 779 miles (1,254 kilometers) with external fuel tanks.
The Jolly Green Giant can be armed with two M60 7.62 mm machine guns.
Sikorsky built 14 HH-3Es. Many CH-3Cs and CH-3Es were upgraded to the HH-3E configuration. Sikorsky built a total of 173 of the S-61R series.
The restored Sikorsky HH-3E Jolly Green Giant, 67-14709, on display at the National Museum of the United States Air Force. (NMUSAF)
¹ Sergeant Dennis Martin Richardson, United States Air Force
The first Super Jolly Green Giant, Sikorsky HH-53B 66-14428, now upgraded to an MH-53J Pave Low IIIE Enhanced, assigned to the 551st Special Operations Squadron, 58th Special Operations Wing, in flight near Kirtland Air Force Base, New Mexico, 24 March 2000. (Master Sergeant Dave Dolan, U.S. Air Force)
24 March 2000: In flight near Kirtland AFB, New Mexico, is this Sikorsky MH-53J Pave Low IIIE, a “Super Jolly Green Giant” special operations helicopter assigned to the 551st Special Operations Squadron. This helicopter, serial number 66-14428, was the very first HH-53B built. [A photograph of its first flight is posted on TDiA at “15 March 1967” https://www.thisdayinaviation.com/15-march-1967/ ]
66-14428 was sent to The Boneyard at Davis-Monthan AFB, 7 January 2007, after 40 years of service.
Sikorsky HH-53B 66-14428, Super Jolly Green Giant, first flight at Stratford, Connecticut, 15 March 1967. (Sikorsky Historical Archives)
15 March 1967: The first Sikorsky HH-53B, 66-14428, made its maiden flight at Stratford, Connecticut. In the cockpit were Sikorsky test pilots James R. (“Dick”) Wright and Patrick A. Guinn. The helicopter would be called the “Super Jolly Green Giant.”
A variant of the United States Navy/Marine Corps CH-53A Sea Stallion, the Super Jolly Green Giant was the largest, most powerful, and fastest helicopter in the United States Air Force inventory. Configured for combat search and rescue (CSAR) and special operations, the HH-53B was equipped for inflight refueling and was armed with three General Electric GAU/2A 7.62 mm miniguns or .50-caliber Browning machine guns. The HH-53B can be visually distinguished from other H-53s by the two diagonal sponson support struts on each side of the fuselage.
U.S. Air Force Sikorsky HH-53B Super Jolly Green Giant in flight near the Sikorsky plant at Stratford, Connecticut. (Sikorsky Historical Archives)
The HH-53B Super Jolly Green Giant was flown by two pilots and was crewed by a flight engineer/gunner, two additional gunners, and one or two pararescue jumpers (“PJs”). It has an overall length of 88 feet, 2.4 inches (26.833 meters) with rotors turning. With the refueling boom extended the total length of the helicopter is 91 feet, 11.34 inches (28.025 meters). The fuselage is 67 feet, 2.4 inches (20.483 meters) long and 8 feet (2.438 meters) wide. The height to the top of the main rotor pylon is 17 feet, 1.68 inches (5.224 meters). The maximum height (rotors turning) is 24 feet, 10.88 inches (7.592 meters).
A flight engineer looks over a General Electric GAU-2/A minigun while his helicopter flies formation with a Sikorsky HH-53C Super Jolly Green Giant of the 40th Aerospace Rescue and Recovery Squadron, Vietnam, October 1972. (Ken Hackman, U.S. Air Force)
The HH-53B’s fully-articulated 6-blade main rotor has a diameter of 72 feet, 2.7 inches (22.014 meters). The main rotor turns counter-clockwise at 185 r.p.m. (100% Nr), as seen from above. (The advancing blade is on the helicopter’s right.) The main rotor blades are built with titanium spars and have -16° of twist. The semi-articulated four-blade tail rotor has a diameter of 16 feet, 0 inches (4.877 meters) and is positioned on the left side of the tail pylon. It turns clockwise at 792 r.p.m., as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) The gap between rotor arcs is just 4.437 inches (11.270 centimeters).
A U.S. Air Force Sikorsky HH-53C Super Jolly Green Giant hovers to hoist a pararescueman with one downed pilot, while a second waits on the ground. The blade tip vortices are visible because of the high humidity. (National Archives at College Park)
The HH-53B had an empty weight of 26,500 pounds (12,020 kilograms). Its maximum takeoff weight was 42,000 pounds (19,051 kilograms).
The HH-53B was originally equipped with two General Electric T64-GE-3 turboshaft engines, producing 3,080-shaft horsepower, each. The T64 is an axial flow free-turbine turboshaft engine. It has a 14-stage compressor and 4-stage turbine (2 high-pressure and 2 low pressure). The turbine shaft is coaxial with the compressor shaft and delivers power forward.
The helicopter had a cruise speed of 150 knots (173 miles per hour/278 kilometers per hour), and a maximum speed of 170 nautical miles per hour (196 miles per hour/315 kilometers per hour). The service ceiling was 20,400 feet (6,218 meters). Its range is 600 nautical miles (690 statute miles/1,111 kilometers), and it is capable of inflight refueling.
A Sikorsky HH-53B Super Jolly Green Giant refuels from a Lockheed HC-130P Combat King over Vietnam, circa 1970. (U.S. Air Force)
The Air Force ordered eight HH-53Bs, followed by 58 improved HH-53C Super Jolly Green Giants.¹ The first HH-53B, 66-14428, was delivered to the Air Force Air Rescue and Recovery Service at the Sikorsky plant in June 1967. It was flown to Eglin Air Force Base, Florida by Lieutenant Colonel James Dixon and Captain Fredric Donohue of Detachment 2, 37th Air Rescue and Recovery Squadron. For the next two months ARRS crews trained with it at Eglin.
The first Sikorsky HH-53Bs arrive in Vietnam, 1967. (U.S. Air Force)
Along with the second HH-53B, the new helicopter was then shipped to Vũng Tàu, Republic of Vietnam, aboard the former U.S. Navy escort carrier, USNS Card (T-AKV-40) for assignment to the 37th Aerospace Rescue and Recovery Squadron at Udorn Royal Thai Air Force Base. They were soon joined by four more HH-53Bs.
As upgraded HH-53Cs became available, the six -53Bs were returned to the United States, where some were used as trainers, and others as test aircraft for the development of the Pave Imp and Pave Low systems. 4428 was one of five HH-53Bs modified to the initial Pave Low configuration. This was followed by the HH-53H Pave Low II configuration.
In 1988, all HH-53 and CH-53 helicopters in the U.S. Air Force inventory began to be modified to the MH-53J Pave Low III Enhanced special operations configuration. The modifications, along with incorporation of a Service Life Extension Program (SLEP) were performed by Naval Air Rework Facility (NARF) at NAS Pensacola, Florida, or by the Marine Corps aviation depot at MCAS Cherry Point, North Carolina.
After nearly 40 years of service, 66-14428 was sent to The Boneyard at Davis-Monthan Air Force Base, Tucson, Arizona, 7 January 2007. By September 2008, all U.S. Air Force Pave Low helicopters had been withdrawn from service.
Super Jolly Green Giant 66-14428, now upgraded to an MH-53J Pave Low IIIE, assigned to the 551st Special Operations Squadron, 58th Special Operations Wing, in flight near Kirtland Air Force Base, New Mexico, 24 March 2000. The diagonal struts above each outboard fuel tank show its HH-53B origin. This was the first Super Jolly Green Giant. (Master Sergeant Dave Dolan, U.S. Air Force)
Highly recommended: On A Steel Horse I Ride: A History of the MH-53 Pave Low Helicopters in War and Peace, by Darrel D. Whitcomb, Air University Press, 2012
¹ By the time the United States withdrew from the Vietnam War, Sikorsky had produced 52 HH-53B and -53C Search and rescue helicopters, and 20 CH-53C transports. Of these, 9 HH-53s and 7 CH-53s were destroyed in combat, and 2 HH-53s and 1 CH-53 were lost in accidents in the United States.
The number 2 Sikorsky S-76 prototype, s/n 76002, makes the type’s first flight, 13 March 1977. (Sikorsky Historical Archives)
13 March 1977: The protoype Sikorsky S-76A Spirit made its first flight at the company’s Development Flight Center, West Palm Beach, Florida (06FA). This was the number two aircraft, serial number 76002, registered N762SA. Sikorky’s chief pilot, John Dixson, and S-76 program test pilot Nicholas D. Lappos were in the cockpit.
Test pilot Nick Lappos is congratulated by His Majesty King Hussein bin Talal of Jordan following the first flight of the Sikorsky S-76, 13 March 1977. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
The prototype was rolled out 11 January 1977.
The Sikorsky S-76 is a twin-engine medium helicopter designed to carry up to 12 passengers 400 nautical miles (460.3 statute miles, 740.8 kilometers) for the offshore oil industry. It is flown by two pilots and is certified for instrument flight. The helicopter can be configured to carry up to thirteen passengers.
The S-76 is used as a passenger transport, executive or VIP aircraft, and in law enforcement, search and rescue, or military service. It is also widely used as a medical transport helicopter.
Prototype Sikorsky S-76A rollout, 11 January 1977. (Sikorsky Historical Archives)
In 1979, Sikorsky proposed the new helicopter for consideration as the U.S. Coast Guard Short Range Recovery Helicopter, along with competitors Aérospatiale and Bell Helicopter. The S-76 was considered to be the most suitable of the three but the company made a business decision to withdraw before any contract was awarded. The Aérospatiale SA-365 Dauphin variant was finally selected and became the MH-65 Dolphin.
Air Logistics accepted the first Sikorsky S-76A production helicopter, 27 February 1979. (Sikorsky, a Lockheed Martin Company)
The S-76A has an overall length of 52 feet, 6 inches (16.002 meters) with rotors turning, and overall height of 14 feet, 6 inches (4.420 meters). It had an empty weight of 7,132 pounds (3,235 kilograms) and a maximum gross weight of 10,500 pounds (4,763 kilograms).
The four-bladed, fully-articulated main rotor has a diameter of 44 feet, 0 inches (13.411 meters). The main rotor hub is constructed of forged aluminum and uses elastomeric bearings to allow for blade flapping and lead-lag. The blades are made of composite materials formed around a hollow titanium spar. The blade tips are swept to reduce the formation of blade tip vortices. Each blade is 19 feet, 11¾ inches long (6.090 meters). The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the right.) At 107% NR, the maximum speed with power on, the rotor turns 313 r.p.m.
A four-bladed tail rotor with a diameter of 8 feet, 0 inches (2.438 meters) is mounted on the left side of a pylon in a pusher configuration. The tail rotor turns clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)
A Turboméca-powered Sikorsky S-76C in flight over the City of New York. (Sikorsky, a Lockheed Martin Company)
The S-76A was originally powered by two Allison 250-C30 turboshaft engines mounted side-by-side, behind the main transmission. The engines were rated at 557 shaft horsepower (maximum continuous power). 100% torque is 564 foot-pounds. Later production models have used Turboméca and Pratt & Whitney Canada engines.
The S-76A has a cruise speed and maximum speed (VNE) of 155 knots (178 miles per hour/287 kilometers per hour). (The helicopter’s cruise speed is the same as its maximum.) The service ceiling is 15,000 feet (4,572 meters). The maximum altitude for takeoff and landing is 6,900 feet (2,103 meters).
Over a five-day period, 4–9 February 1982, Sikorsky test pilots Nicholas D. Lappos, William Frederick Kramer, Byron Graham, Jr., David R. Wright, and Thomas F. Doyle, Jr., set a series of twelve Fédération Aéronautique Internationale (FAI) speed, time-to-climb and sustained altitude world records while flying a Sikorsky S-76A helicopter, N5445J, at Palm Beach, Florida. These included an absolute world speed record for helicopters (186.69 knots/214.83 miles per hour/345,74 kilometers per hour). Nine of these records remain current.¹
In April 2020, new FAA regulations requiring crash-resistant fuel tanks for new-production aircraft took effect. Lockheed Martin decided not to invest in the engineering required to update the S-76. As such, the helicopter was no longer allowed to be sold in the United States. New Sikorsky S-76Ds continued to be sold to overseas customers. Later in the year, though, production came to an end.
876 Sikorsky S-76 were built. There were 307 S-76A and S-76A+ variants produced, followed by the S-76B, S-76C, -C+ and -C++. The final production model was the S-76D.
Sikorsky S-76D N7621Y, c/n 761021. (Sikorsky, a Lockheed Martin Company)
¹ See “This Day in Aviation” https://www.thisdayinaviation.com/4-february-1982/
