17 April 1941: Igor Sikorsky’s Vought-Sikorsky VS-300 helicopter went through various rotor configurations during development as he searched for a combination that would give stability, anti-torque control, as well as lateral and yaw control. By April 1941, the VS-300 was configured with a single main rotor for lift and three smaller tail rotors to provide anti-torque and directional control.
This was not the ultimate solution, but on 17 April, he had the aircraft fitted with three inflatable pontoons and made a successful water landing, demonstrating that the helicopter could be a practical amphibious aircraft. During a lecture to the Rotating Wing Section of the Tenth Annual Meeting of the Institute of Aeronautical Sciences, Igor Sikorsky gave a brief description of the flight:
“On April 17 the helicopter, mounted on rubber floats, was repeatedly taken off from water and landed on water and then landed on ground, demonstrating for the first time a direct lift aircraft with excellent amphibian characteristics on which no adjustments whatsoever are needed when going from water to land and vice versa.”
The VS-300 had a welded tubular steel airframe and used a 28-foot (5.34 meters) diameter, fully-articulated, three-bladed main rotor, which turned clockwise (as seen from above) at 260 r.p.m. (The advancing blade was on the left. This would later be reversed.) The main rotor had collective pitch control for vertical control, but cyclic pitch (Sikorsky referred to this as “sectional control”) for directional control would not be developed for another several months.
The tail “propellers” (what we now consider to be rotors—one vertical and two horizontal) each had two blades with a diameter of 7 feet, 8 inches (2.337 meters) and turned approximately 1,300 r.p.m. The vertical rotor provided “torque compensation” (anti-torque) and the blade pitch was fully reversible. The horizontal rotors were mounted on 10-foot (3.048 meters) outriggers at the aft end of the fuselage. For lateral control, the pitch on one rotor was increased and the other decreased. For longitudinal control, the pitch of both rotors was increased or decreased together.
The VS-300 was originally equipped with an air-cooled, normally-aspirated 144.489-cubic-inch-displacement (2.368 liter) Lycoming O-145C-3 four-cylinder horizontally-opposed engine which was rated at 75 horsepower at 3,100 r.p.m. According to Mr. Sikorsky, “early in 1941,” the Lycoming engine was replaced by an air-cooled, normally-aspirated 198.608 cubic inch (3.255 liter) Franklin 4AC-199-E, a four-cylinder horizontally-opposed overhead valve (OHV) direct-drive engine with a compression ratio of 7:1, rated at 90 horsepower at 2,500 r.p.m. It is not known if this change was made prior to 17 April.
11 April 1952: At the Piasecki Helicopter Corporation factory at Morton Grove, Pennsylvania, the first YH-21 tandem-rotor helicopter, serial number 50-1231, made it’s first flight. The test pilots were Leonard Joseph (“Len”) LaVassar and Martin P. (“Marty”) Johnson, both former U.S. Navy aviators.
The Piasecki Helicopter Corporation built 18 pre-production YH-21-PH helicopters, followed by three production variants, the H-21A, H-21B and H-21C.
The U.S. Air Force immediately ordered 32 H-21A helicopters for Search and Rescue operations. The Workhorse was well suited to cold weather operations and it was widely used in Alaska, Canada, and the Antarctic. Another 163 H-21B models were ordered as a troop transports. The U.S. Army ordered a similar H-21C variant.
The YH-21 was a single-engine, tandem-rotor transport helicopter. It was normally operated by two pilots, with a flight mechanic (crew chief), and could carry up to 20 soldiers under ideal conditions.
With rotors turning, the YH-21’s overall length was 86 feet, 5 inches (26.340 meters). The fuselage was 52 feet, 6 inches (16.002 meters) long, and the helicopter had an overall height of 16 feet, 0 inches (4.877 meters). The rotors were 44 feet, 0 inches (13.411 meters) in diameter. The YH-21’s empty weight was approximately 8,117 pounds (3,682 kilograms) and maximum gross weight was 14,500 pounds (6,577 kilograms).
The forward rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) The rear rotor turns the opposite direction. Normal operating speed for the main rotors was 233 to 258 r.p.m. (233–270 r.p.m. in autorotation.) The counter-rotating rotors cancelled out engine torque, eliminating any need for a tail rotor. The angle in the fuselage was intended to provide adequate vertical clearance between the intermeshing fore and aft rotor assemblies. (Later tandem rotor helicopters use raised pylons.)
The H-21 was powered by a single air-cooled, supercharged, 1,823.129-cubic-inch-displacement (29.875 liter) Wright Aeronautical Division Cyclone 9 863C9WD1 (R-1820-103) nine-cylinder radial, mounted inside the fuselage at midship, and drove the front and rear rotors in opposite directions through drive shafts and gear boxes. The Wright R-1820-103 engine was rated at 1,275 horsepower at 2,500 r.p.m., and 1,425 horsepower at 2,700 r.p.m., for takeoff. This direct-drive engine had a compression ratio of 6.80:1 and required 100/130 aviation gasoline. The engine was 4 feet, 0.50 inches (1.232 meters) long, 4 feet, 6.95 inches (1.396 meters) in diameter, and weighed 1,350 pounds (612 kilograms). Wright built 971 R-1820-103s from November 1950 through 1957.
The YH-21 could reach a maximum speed in level flight of 131 knots (151 miles per hour/243 kilometers per hour). Its Never Exceed limit (VNE) was 151 knots (174 miles per hour /280 kilometers per hour) (diving). The maximum Sea Level range was 397 nautical miles (457 statute miles/735 kilometers) at 125 knots (144 miles per hour/232 kilometers per hour). Its service ceiling was 19,200 feet (5,852 meters).
In 1955, Piasecki became Vertol and eventually Boeing Vertol. The company would continue to produce tandem rotor helicopters such as the H-46 Sea Knight and the CH-47 Chinook, which is still in production.
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 pilot to fly a helicopter from a ship. On 16 January 1944, he flew a Sikorsky YR-4B, serial number 46445, 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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
¹ Sergeant Dennis Martin Richardson, United States 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”]
66-14428 was sent to The Boneyard at Davis-Monthan AFB, 7 January 2007, after 40 years of service.