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 he had the aircraft fitted with three inflatable pontoons and on 17 April, 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.

© 2019, Bryan R. Swopes

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 (V_NE) 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.

© 2019, Bryan R. Swopes

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.

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.

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/

² ex-U.S. Army YR-4B, serial number 42-107239

© 2017, Bryan R. Swopes

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

© 2019, Bryan R. Swopes

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/ ]

12 March 1955:  Société nationale des constructions aéronautiques du Sud-Est (SNCASE) Chief Test Pilot Jean Boulet and Flight Test Engineer Henri Petit made the first flight of the SE.3130 Alouette II prototype, F-WHHE, at Buc Airfield, near Paris, France.

Powered by a Societé Anonyme Turboméca Artouste II B1 turboshaft engine, the Alouette II was the first gas turbine powered helicopter to enter series production. SNCASE would become Aérospatiale, later, Eurocopter, and is now Airbus Helicopters.

The Alouette II is a 5-place light helicopter operated by a single pilot. The fuselage is 31 feet, 8.5 inches (9.665 meters) long. The landing skids have a width of 6 feet, 10 inches (2.083 meters). With rotors turning, the overall length of the Alouette II is 39 feet, 6.5 inches (12.052 meters). Its height is 9 feet, 0.25 inches (2.750 meters) to the top of the main rotor mast. (Optional wide-track skids, or installation of an Alouette III three-blade tail rotor will change dimensions slightly.)

The three-bladed fully-articulated main rotor has a diameter of 33 feet, 5.5 inches (10.198 meters). It turns clockwise, as seen from above. (The advancing blade is on the left side of the helicopter.) Normal main rotor speed, NR, is 350–360 r.p.m. In autorotation, the allowable range is 280–420 r.p.m. The two-blade anti-torque rotor is 5 feet, 11.5 inches (1.816 meters) in diameter and turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) The tail rotor turns at 2,020 r.p.m.

The SE.3130 has an empty weight of 1,934 pounds (877 kilograms), depending on installed equipment, and minimum operating weight of 2,050 pounds (930 kilograms). The maximum permissible weight is 3,300 pounds (1,497 kilograms).

The prototype was powered by one Turboméca Artouste II B1 turboshaft engine. The Artouste II B1 is a single-shaft turboshaft engine with a single-stage centrifugal flow compressor section and a three-stage axial-flow turbine. The turbine drives both the compressor and an output drive shaft through reduction gearbox. As installed in the Alouette II, the engine was certified for operation at 33,000–34,000 r.p.m (N1), with transient overspeeds to 35,000 r.p.m. It is capable of producing 400 shaft horsepower, but was derated to 360 shaft horsepower at 5,780 r.p.m. (N2) for installation in the Alouette II.

The helicopter has an economical cruise speed of 92 knots (106 miles per hour/170 kilometers per hour) at 33,000 r.p.m., and a maximum speed (V_NE) of 105 knots (121 miles per hour/194 kilometers per hour) at Sea Level, which decreases with altitude. Sideward or rearward flight (or operation in tailwinds or crosswinds) is limited to 18 knots (20 miles per hour/33 kilometers per hour).

The Allouette II is limited to a maximum operating altitude of 14,800 feet (4,511 meters). At 1,350 kilograms (2,976 pounds) the Alouette II has a hover ceiling in ground effect, HIGE, of 3,400 meters (11,155 feet) and hover ceiling out of ground effect of 1,900 meters (6,234 feet). At 1,500 kilograms the Alouette II’s HIGE is 2,000 meters (6,560 feet) and HOGE is 600 meters (1,968 feet).

The SE.3130 Alouette was in production from 1956 until 1975. It was marketed in the United States by the Republic Aviation Corporation’s Helicopter Division. More than 1,300 of these helicopters were built.

Jean Ernest Boulet was born 16 November 1920, in Brunoy, southeast of Paris, France. He was the son of Charles-Aimé Boulet, an electrical engineer, and Marie-Renée Berruel Boulet.

He graduated from Ecole Polytechnique in 1940 and the Ecole Nationale Supérieure de l’aéronautique In 1942. (One of his classmates was André Edouard Turcat, who would also become one of France’s greatest test pilots.)

Following his graduation, Boulet joined the Armée de l’Air (French Air Force)and was commissioned a sous-lieutenant. He took his first flight lesson in October. After the surrender of France in the Nazi invaders, Boulet’s military career slowed. He applied to l’Ecole Nationale Supérieure de l’Aéronautique in Toulouse for post-graduate aeronautical engineering. He completed a master’s degree in 1943.

During this time, Boulet joined two brothers with La Resistance savoyarde, fighting against the German invaders as well as French collaborators.

In 1943, Jean Boulet married Mlle Josette Rouquet. They had two sons, Jean-Pierre and Olivier.

In February 1945, Sous-lieutenant Boulet was sent to the United States for training as a pilot. After basic and advanced flight training, Boulet began training as a fighter pilot, completing the course in a Republic P-47D Thunderbolt. He was then sent back to France along with the other successful students.

On 1 February 1947 Jean Boulet joined Société nationale des constructions aéronautiques du Sud-Est (SNCASE) as an engineer and test pilot. He returned to the United States to transition to helicopters. Initially, Boulet and another SNCASE pilot were sent to Helicopter Air Transport at Camden Central Airport,  Camden, New Jersey, for transition training in the Sikorsky S-51. An over-enthusiastic instructor attempted to demonstrate the Sikorsky to Boulet, but lost control and crashed. Fortunately, neither pilot was injured. Boulet decided to go to Bell Aircraft at Niagara Falls, New York, where he trained on the Bell Model 47. He was awarded a helicopter pilot certificate by the U.S. Federal Aviation Administration, 23 February 1948.

As a test pilot Boulet made the first flight in every helicopter produced by SNCASE, which would become Sud-Aviation and later, Aérospatiale (then, Eurocopter, and now, Airbus Helicopters).

While flying a SE 530 Mistral fighter, 23 January 1953, Boulet entered an unrecoverable spin and became the first French pilot to escape from an aircraft by ejection seat during an actual emergency. He was awarded the Médaille de l’Aéronautique.

Jean Boulet was appointed Chevalier de la légion d’honneur in 1956, and in 1973, promoted to Officier de la Légion d’honneur.

Jean Boulet had more than 9,000 flight hours, with over 8,000 hours in helicopters. He set 24 Fédération Aéronautique Internationale world records for speed, distance and altitude. Four of these are current.

Jean Boulet wrote L’Histoire de l’Helicoptere: Racontée par ses Pionniers 1907–1956, published in 1982 by Éditions France-Empire, 13, Rue Le Sueuer, 75116 Paris.

Jean Ernest Boulet died at Aix-en-Provence, in southern France, 15 February 2011, at the age of 90 years.

© 2019, Bryan R. Swopes

11 March 1959: At Stratford, Connecticut, the prototype Sikorsky XHSS-2 Sea King, U.S. Navy Bureau of Aeronautics serial number (Bu. No.) 147137, company serial number 61001, makes its first flight. Sikorsky’s Assistant Chief Test Pilot Robert Stewart Decker is at the controls.

The Sikorsky SH-3A Sea King was the first of the S-61 series of military and civil helicopters, designated as HSS-2 until 1962. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. The fuselage is designed to allow landing on water. The helicopter was originally used as an anti-submarine helicopter.

The HSS-2 is 72 feet, 6 inches (22.098 meters) long and 16 feet, 10 inches (5.131 meters) high with all rotors turning. The helicopter’s width, across the sponsons, is 16 feet. The main rotors and tail can be folded for more compact storage aboard aircraft carriers, shortening the aircraft to 46 feet, 6 inches (14.173 meters). The empty weight of the HSS-2 is 10,814 pounds (4,905 kilograms). The overload gross weight is 19,000 pounds (8,618 kilograms).

The main rotor has five blades and a diameter of 62 feet, 0 inches (18.898 meters). Each blade has a chord of 1 foot, 6¼ inches (0.464 meters). The rotor blade airfoil was the NACA 0012, which was common for helicopters of that time. The total blade area is 222.5 square feet (20.671 square meters), and the disc area is 3,019 square feet (280.474 square meters). The tail rotor also has five blades and a diameter of 10 feet, 4 inches (3.150 meters). They each have a chord of 7–11/32 inches (0.187 meters). At 100% NR, the main rotor turns 203 r.p.m. and the tail rotor, 1,244 r.p.m.

The HSS-2 was powered by two General Electric T58-GE-6 turboshaft engines, which had a Normal Power rating of 900 horsepower, and Military Power rating of 1,050 horsepower; both ratings at 19,555 r.p.m. at Sea Level. The main transmission was rated for 2,000 horsepower, maximum. (Later models were built with more powerful T58-GE-8 engines. Early aircraft were retrofitted.)

The HSS-2 has a cruise speed of 125 knots (144 miles per hour/232 kilometers per hour) at Sea Level, and a maximum speed of 133 knots (153 miles per hour/246 kilometers per hour) at Sea Level. The service ceiling is 12,100 feet (3,688 meters). The hover ceiling at normal gross weight is 5,200 feet (1,585 meters), out of ground effect (HOGE), and 7,250 feet (2,210 meters), in ground effect (HIGE). The HSS-2 had a combat endurance of 4 hours and a maximum range of 500 nautical miles (575 statute miles/926 kilometers).

The Sea King was primarily an anti-submarine aircraft. It could be armed with up to four MK 43 or MK 44 torpedoes and one MK 101 nuclear-armed depth bomb. Other weapons loads included four MK 14 depth charges and four MK 54 air depth bombs.

In 1962, the HSS-2 was redesignated SH-3A Sea King. Many early production aircraft have remained in service and have been 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.

Sikorsky produced the last S-61 helicopter in 1980, having built 794. Production has been licensed to manufacturers in England, Italy, Canada and Japan. They have produced an additional 679 Sea Kings.

© 2019, Bryan R. Swopes

6 March 1965: A U.S. Navy Sikorsky SH-3A Sea King helicopter named Dawdling Dromedary, Bu. No. 152104, piloted by Commander James R. Williford and Lieutenant David A. Beil, with Aviation Machinist Mate 1st Class Paul J. Bert, took off from the aircraft carrier USS Hornet (CVS-12), alongside NAS North Island, San Diego, California, at 4:18 a.m., Pacific Standard Time, (12:18 UTC) and flew non-stop, without refueling, to land aboard another aircraft carrier, USS Franklin D. Roosevelt (CVA-42), off Mayport, Florida, at 11:10 p.m. Eastern Standard Time (04:10 UTC). The distance flown was 3,388.70 kilometers (2,105.64 miles) with an elapsed time of 16 hours, 52 minutes, and set a Fédération Aéronautique Internationale (FAI) World Record for Distance Without Landing.¹ This exceeded the previous record distance by more than 750 miles (1,207 kilometers).²

The SH-3A averaged 200.91 kilometers per hour (124.84 miles per hour/108.42 knots.)

On takeoff, Dawdling Dromedary had a gross weight of 23,000 pounds (10,433 kilograms), about 4,000 pounds (1,814 kilograms over its normal operating weight. Its fuel load was 1,690 gallons (6,397 liters) and it had only 60 gallons (227 liters) remaining on landing.

After clearing Guadalupe Pass between Carlsbad, New Mexico, and El Paso, Texas, (5,414 feet, 1650 meters) the crew shut down one the the SH-3A’s two turboshaft engines in an effort to reduce fuel consumption. They flew on a single engine for 9½ hours, restarting the second engine as they descended through 5,000 feet (1,524 meters) over Jacksonville, Florida.

Commander Williford, head of the Rotary Wing Branch, Flight Test Division, at the Naval Air Test Center, NAS Patuxent River, Maryland, was quoted in Naval Aviation News for the May 1965 issue:

“Since weight counted, the heater had been removed. We therefore wore rubber boots, long underwear, etc., but still were thoroughly chilled upon arrival. The temperature at 15,000 feet [4,572 meters] was -11° [-23.9 °C.] that night.

“The C-131 chase aircraft crew was amazed at our accuracy of navigation with a lone omni. Actually, it was such a clear day it was the old type of piloting, that is, ‘just north of that reservoir’ or ‘one mile south of that city,’ etc. We flew through mountain passes until Guadalupe, thence great circle route to Mayport.

“For the trip, +10 knots [18.5 kilometers per hour] tailwind average was needed, and it appeared we weren’t going to make it for the first 8–9 hours because we were behind in our time vs. distance plot. But as we climbed higher—climbing being limited by retreating blade stall—we gained stronger and more favorable winds. By the time we reached Valdosta, Georgia, we had about 35 knots [64.8 kilometers per hour] pushing us. That was a nice feature because the Okefenokee Swamp at night is no place for an autorotation with empty fuel tanks.”

—Commander James R. Williford, United States Navy, Naval Aviation News, May 1965, NavWeps No. 00-75R-3, at Pages 8–9.

[Co-pilot David A. Beil was killed 12 March 1969 while testing a Lockheed AH-56 Cheyenne compound helicopter. See TDiA at: https://www.thisdayinaviation.com/12-march-1969/ ]

Dawdling Dromedary is the same Sikorsky SH-3A, Bu. No. 152104, that set a Fédération Aéronautique Internationale (FAI) world speed record for helicopters of 339 kilometers per hour (210.6 miles per hour), 5 February 1962, flown by Lieutenant Robert W. Crafton, USN, and Captain Louis K. Keck, USMC.³

The Sikorsky SH-3A Sea King was the first of the S-61 series of military and civil helicopters, designated as HSS-2 until 1962. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. The fuselage is designed to allow landing on water. The XHSS-2 made its first flight 11 March 1959. The helicopter was originally used as an anti-submarine helicopter.

The SH-3A is 72 feet, 7 inches (22.123 meters) long and 16 feet, 10 inches (5.131 meters) high with all rotors turning. The main rotors and tail can be folded for more compact storage aboard aircraft carriers, shortening the aircraft to 46 feet, 6 inches (14.173 meters). 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 tail rotor also has five blades and a diameter of 10 feet, 4 inches (3.150 meters). They each have a chord of 7–11/32 inches (0.187 meters). At 100% NR, the main rotor turns 203 r.p.m. and the tail rotor, 1,244 r.p.m.

The SH-3A was powered by two General Electric T58-GE-6 turboshaft engines, which had a Normal Power rating of 900 horsepower, and Military Power rating of 1,050 horsepower. The main transmission was rated for 2,300 horsepower, maximum. (Later models were built with more powerful T58-GE-8 engines. Early aircraft were retrofitted.)

The SH-3A has a cruise speed of 125 knots (144 kilometers per hour) at Sea Level, and a maximum speed of 135 knots (155 kilometers per hour) at Sea Level. The service ceiling is 14,000 feet (4,267 meters). The design maximum gross weight is 16,237 pounds (7,365 kilograms). The SH-3A had a combat endurance of 4 hours.

In 1962, the HSS-2 was redesignated SH-3A Sea King. Many early production aircraft have remained in service and have been 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.

Sikorsky produced the last S-61 helicopter in 1980, having built 794. Production has been licensed to manufacturers in England, Italy, Canada and Japan. They have produced an additional 679 Sea Kings.

¹ FAI Record File Number 2179

² FAI Record File Number 2180: 2,170.70 kilometers (1,348.81 miles), set by Captain Michael N. Antoniou, U.S. Army, flying a Bell YUH-1D Iroquois, 60-6029, from Edwards Air Force Base, California, to Rogers, Arkansas, 27 September 1964.

³ FAI Record File Number 13121. (See TDiA, 5 February 1962.)

© 2020, Bryan R. Swopes

1 March 1962: Los Angeles Airways inaugurated scheduled passenger service utilizing twin-engine, turbine-powered helicopters.

Shown in the photograph above is LAA’s Sikorsky S-61L, FAA registration N300Y, at the Disneyland Heliport, Anaheim, California. LAA was the first civil operator of the S-61, purchasing them at a cost of $650,000, each. N300Y was the prototype S-61L, serial number 61031. On 14 August 1968, N300Y suffered a catastrophic main rotor spindle failure and crashed at Leuders Park, Compton, California. All 21 persons aboard were killed.

Los Angeles Airways began operations in 1947 and continued until 1971. It flew Sikorsky S-51, S-55 and S-61L helicopters.

The Sikorsky S-61L was a civil variant of the United States Navy HSS-2 Sea King and was the first helicopter specifically built for airline use. The prototype, N300Y, first flew 2 November 1961. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. Although HSS-2 fuselage is designed to allow landing on water, the S-61L is not amphibious, having standard landing gear rather than the sponsons of the HSS-2 (and civil S-61N).

The S-61L fuselage is 4 feet, 2 inches (1.270 meters) longer than that of the HSS-2. The S-61L is 72 feet, 7 inches (22.123 meters) long and 16 feet, 10 inches (5.131 meters) high, with rotors turning. The fully-articulated 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 tail rotor also has five blades and a diameter of 10 feet, 4 inches (3.149 meters). They each have a chord of 7–11/32 inches (0.187 meters). At 100% NR, the main rotor turns 203 r.p.m. and the tail rotor, 1,244 r.p.m.

The S-61L was powered by two General Electric CT58-110 turboshaft engines, each of which had a continuous power rating of 1,050 shaft horsepower and maximum power of 1,250 shaft horsepower. The main transmission was rated for 2,300 horsepower, maximum.

The S-61 has a cruise speed of  166 miles per hour (267 kilometers per hour). The service ceiling is 12,500 feet (3,810 meters). Its maximum takeoff weight is 20,500 pounds (9,298.6 kilograms).

Between 1958 and 1980, Sikorsky built 794 S-61-series helicopters. 13 were S-61Ls.

© 2019, Bryan R. Swopes

18 February 1973: Aérospatiale company pilots Daniel Bouchart and Didier Potelle land their SA 319B Alouette III helicopter, similar to the one in the photograph above, at the summit of Mount Kilimanjaro, an elevation of 5,895 meters (19,341 feet). The air temperature was -6 °C. (+22 °F.) On takeoff from the summit, the gross weight of the helicopter was 1,560 kilograms (3,439 pounds). Three days later, Bouchart and Potelle landed atop Mount Kenya, the second highest mountain in Africa at 5,199 meters (17,057 feet).

This helicopter is extremely effective at high altitudes and is widely used in the Alps, the Canadian Rockies and the Himalayas. The SA 319B is a development of the previous SA 316B. It is a single-engine, seven-place, light helicopter, operated by one or two pilots.

The helicopter’s fuselage is 10.175 meters (33 feet, 4.6 inches) long, with a main rotor diameter of 11.020 meters (36 feet, 1.9 inches). It has a height of 3.000 meters (9 feet, 10.1 inches).

The three-bladed articulated main rotor follows the French practice of turning clockwise as seen from above. (The advancing blade is on the helicopter’s left side.) Main rotor speed is 353.2 r.p.m. at 100% NR.  In autorotation, it may operate in a range from 270 to 420 r.p.m. A three-bladed tail rotor is mounted on the right side of the tail boom in a pusher configuration. It turns clockwise as seen from the helicopter’s left side. (The advancing blade is below the tail boom.) The tail rotor has a diameter of 1.912 meters (6 feet, 3.228 inches). The tail rotor speed is 2,001 r.p.m.

The Alouette III has an approximate empty weight of 1,122 kilograms (2,474 pounds), depending on installed equipment, and the maximum certificated takeoff weight is 2,200 kilograms (4,850 pounds).

The SA 319B is powered by a Turboméca Astazou XIV turboshaft engine, capable of producing 870 shaft horsepower, but derated to 660 shaft horsepower. This provides a power rating of 90 horsepower more than the earlier helicopter’s Artouste IIIB engine. The engine turns 33,500 r.p.m at 100% N1.

At its maximum gross weight the SA 316B Allouette III has a cruising speed of 185 kilometers per hour (100 knots, or 115 miles per hour), and a maximum speed (V_NE) of 210 kilometers per hour (113 knots, 130 miles per hour), both at Sea Level. Its range is 470 kilometers (254 nautical miles, 292 statute miles), and the service ceiling is 6,000 meters (19,685 feet).

As with all helicopters, the Alouette III’s Hover Ceiling varies with its weight. At maximum gross weight, the Hover Ceiling in Ground Effect (HIGE) is 1,650 meters (5,413 feet), and out of Ground Effect (HOGE), just 100 meters (328 feet), MSL. At a reduced gross weight of 1,750 kilograms (3,858 pounds), HIGE increases to 5,550 meters (18,045 feet), and HOGE, 1,650 meters (5,413 feet). With the same weights, the helicopter’s rate of climb varies from 4.3 meters per second to 8.7 meters per second (846–1,713 feet per minute).

Kilimanjaro is an extinct stratovolcano in Africa. It is the tallest free-standing mountain in the world. Mount Kenya is also an extinct volcano. Its peak is the volcanic plug of a stratovolcano that was likely once taller that Mount Kilimanjaro.

© 2019, Bryan R. Swopes