16 July 1983: At 11:10 a.m., a British Airways Sikorsky S-61N-69 Sea King helicopter, c/n 61-770, registration G-BEON, departed Penzance Heliport (PZE) enroute across the Celtic Sea to St. Mary’s Airport, Isles of Scilly. On board were a crew of 3 and 23 passengers. Visibility was poor due to fog. Flying under visual flight rules, the helicopter was at 250 feet (76 meters) while the pilots tried to maintain visual contact with the surface of the calm sea.
Because of the limited visual cues, the crew did not recognize that they were in a slight descent. At approximately 11:35 a.m., the Sikorsky slammed into the ocean at cruise speed. It sank almost immediately. Only six persons survived, including the pilots, Dominic Lawlor and Neil Charleton. The helicopter sank to the sea bed 200 feet (61 meters) below. It was later recovered by the salvage vessel RMAS Seaforth Clansman, along with the bodies of 17 victims.
The official investigation determined that the cause of the accident was pilot error by their failure to recognize and correct the unintentional descent while attempting to fly in conditions not suitable for visual flight. This was the worst helicopter accident in terms of fatalities up to that time.
The Sikorsky S-61N is a civil variant of the United States Navy HSS-2 Sea King. The first S-61N, s/n 61143, first flew 7 August 1962. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. The S-61N fuselage is 4 feet, 2 inches (1.270 meters) longer than that of the HSS-2. The S-61N is 72 feet, 7 inches (22.123 meters) long and 16 feet, 10 inches (5.131 meters) high, with 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 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% r.p.m., the main rotor turns 203 r.p.m. and the tail rotor, 1,244 r.p.m. The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right side.) The tail rotor turns clockwise, as seen from the left side. (The advancing blade is below.)
G-BEON was powered by two General Electric CT58-140-1 turboshaft engines, each of which had maximum power rating of 1,400 shaft horsepower for takeoff and 1,500 SHP for 2½ minutes. 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). The maximum takeoff weight is 20,500 pounds (9,298.6 kilograms).
Between 1958 and 1980, Sikorsky built 794 S-61 series helicopters. 123 were S-61Ns.
12 July 1957: President Dwight D. Eisenhower was the first United States president to fly in a helicopter when a U.S. Air Force H-13J-BF Sioux, serial number 57-2729 (c/n 1576), flown by Major Joseph E. Barrett, USAF, departed the White House lawn for Camp David, the presidential retreat in the Catoctin Mountains of Maryland. Also on board was a U.S. Secret Service special agent. A second H-13J, 57-2728 (c/n 1575), followed, carrying President Eisenhower’s personal physician and a second Secret Service agent.
The helicopter was intended to rapidly move the president from the White House to Andrews Air Force Base where his Lockheed VC-121E Constellation, Columbine III, would be standing by, or to other secure facilities in case of an emergency.
Major Barrett had been selected because of his extensive experience as a combat pilot. During World War II, he had flown the B-17 Flying Fortress four-engine heavy bomber. During the Korean War, Barrett had carried out a helicopter rescue 70 miles (113 kilometers) behind enemy lines, for which he was awarded the Silver Star.
The two helicopters were manufactured by the Bell Helicopter Company at Fort Worth, Texas, and delivered to the Air Force at Wright-Patterson Air Force Base on 29 March 1957. The presidential H-13Js were nearly identical to the commercial Bell Model 47J Ranger. The H-13J differed from the civil Model 47J by the substitution of main rotor blades of all-metal construction in place of the standard laminated wood blades.
Capable of carrying a pilot and up to three passengers, the Ranger was constructed with an enclosed cabin built on a tubular steel framework with all-metal semi-monocoque tail boom. The main rotor diameter was 37 feet, 2.00 inches (11.328 meters) and tail rotor diameter was 5 feet, 10.13 inches (1.781 meters), which gave the helicopter an overall length of 43 feet, 3¾ inches (13.185 meters) with rotors turning. The height (to the top of the centrifugal flapping restraints) was 9 feet, 8 inches (2.946 meters). The helicopter had a maximum gross weight of 2,800 pounds (1,270 kilograms).
The main rotor, in common to all American-designed helicopters, rotates counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right.) The anti-torque (tail) rotor is mounted to the right side of an angled tail boom extension, in a tractor configuration, and rotates counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.)
The main rotor is a two-bladed, under-slung, semi-rigid assembly that would be a characteristic of helicopters built by Bell for decades. The main rotor system incorporates a stabilizer bar, positioned below and at right angles to the main rotor blades. Teardrop-shaped weights are placed at each end of the bar, on 100-inch (2.540 meters) centers. The outside diameter of the stabilizer bar is 8 feet, 6.781 inches (2.611 meters). (A similar system is used on the larger Bell 204/205/212 helicopters.)
The H-13J was powered by an air-cooled, normally-aspirated 433.972-cubic-inch-displacement (7.112 liter) AVCO Lycoming VO-435-A1B (O-435-21) vertically-opposed 6-cylinder direct-drive engine. The VO-435 had a compression ration of 7.3:1. It was rated at 220 horsepower at 3,200 r.p.m., maximum continuous power, and 260 horsepower at 3,200 r.p.m. for takeoff. The VO-435-A1B weighed 393.00 pounds (178.262 kilograms).
Engine torque is sent through a centrifugal clutch to a 9:1 gear-reduction transmission, which drives the main rotor through a two-stage planetary gear system. The transmission also drives the tail rotor drive shaft, and through a vee-belt/pulley system, a large fan to provide cooling air for the engine.
Fuel was carried in two gravity-feed tanks, mounted above and on each side of the engine. The total fuel capacity was 34.0 gallons (128.7 liters)
Cruise speed for the H-13J was 87–98 miles per hour (140–158 kilometers per hour), depending on gross weight, and its maximum speed was 105 miles per hour (169 kilometers per hour). The helicopter had a hover ceiling in ground effect (HIGE) of 8,100 feet (2,469 meters). The service ceiling was 15,000 feet (4,572 meters).
Both H-13J Sioux served as presidential aircraft until 1962. They were redesignated UH-13J and continued in use for VIP transportation until 1967.
Bell UH-13J-BF Sioux 57-2729 is in the collection of the Smithsonian Institution National Museum National Air and Space Museum, Steven V. Udvar-Hazy Center, while its sister ship, 57-2728, is at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio, along with Columbine III.
8 July 1953: America’s first helicopter airline, New York Airways, began scheduled passenger service, operating flights between the three area airports—La Guardia, Idlewild and Newark. There were 16 flights per day at 90-minute intervals.
The first aircraft used was the Sikorsky S-55, a commercial variant of the military H-19 Chickasaw. It carried 8 passengers and a cargo of U.S. Mail. The mail contract actually was the source of 75% of NYA’s revenue.
As its popularity increased, New York Airways shifted to larger helicopters when they became available, adding three Sikorsky S-58s in 1956. In 1958, the fleet was changed to the Vertol V-44 tandem-rotor helicopter, a commercial model of the Piasecki H-21 Shawnee. In 1962 the turbine-powered Boeing Vertol BV 107-II replaced the earlier helicopters. NYA’s final aircraft was the twin-turbine Sikorsky S-61.
On 16 May 1977, the landing gear of a S-61L failed while on the roof top heliport of the Pan Am building in Manhattan. The helicopter rolled over and spinning rotor blades killed four waiting passengers. Broken blades then fell to the street, fifty-nine stories below, killing a pedestrian and injuring several others.
With its reputation severely damaged and fuel prices escalating, New York Airways filed for bankruptcy in 1979. It’s surviving helicopters are operated today by Columbia Helicopters, Inc., Aurora, Oregon.
5 July 1962: Captain Chester R. Radcliffe, Jr., United States Air Force, flew Kaman HH-43B-KA Huskie 60-0263 from Hill Air Force Base, Utah, to Springfield, Minnesota, a distance of 1,429.80 kilometers (888.44 miles). This established a new Fédération Aéronautique Internationale (FAI) World Record for Distance Without Landing.¹
This same helicopter, flown by Captain Richard H. Coan, set a World Record for Distance Over a Closed Circuit Without Landing, 13 June 1962 at Mono Lake, California.²
A turboshaft engine drove a unique system of counter-rotating and intermeshing rotors to provide lift, thrust and directional control. The counter-rotation cancelled the torque effect so no anti-torque, or tail, rotor was necessary. This allowed all of the engine’s power to drive the main rotor system.
The Huskie was used by the U.S. Air Force, U.S. Navy and Marine Corps, primarily for short range rescue operations. It was operated by two pilots and two rescue crewmen.
The fuselage of the H-43B was 25 feet, 2 inches (7.671 meters) long. Each rotor had a diameter of 47 feet, 0 inches (14.326 meters). It’s height was 15 feet, 6½ inches (4.737 meters). The helicopter’s empty weight was 4,470 pounds (2,028 kilograms) and its maximum gross weight was 8,800 pounds (3,992 kilograms).
The H-43B was powered by one Lycoming T53-L-1B turboshaft engine, rated at 860 shaft horsepower at 21,510 r.p.m. The engine uses a 5-stage axial-flow, 1 stage centrifugal-flow, compressor with a single stage gas producer turbine and single-stage power turbine. A reverse-flow combustion section allows significant reduction in the the engine’s total length. The power turbine drives the output shaft through a 3.22:1 gear reduction. The T53-L-1 is 3 feet, 11.8 inches (1.214 meters) long and 1 foot, 11.0 inches (0.584 meters) in diameter. It weighs 460 pounds (209 kilograms).
The Huskie’s economical cruise speed was 98 miles per hour (158 kilometers per hour), and the maximum speed was 120 miles per hour (193 kilometers per hour). Its hover ceiling out of ground effect (HOGE) was 18,000 feet (5,486 meters), and in ground effect (HIGE) was 20,000 feet (6,096 meters) and it had a range of 235 miles (378 kilometers).
With the call sign Pedro, the HH-43 was a rescue helicopter that served in combat during the Vietnam War.
The record-setting Kaman HH-43B Huskie 60-0263 was last assigned to Detachment 3, 42nd Aerospace Rescue and Recovery Squadron, Kirtland Air Force Base, New Mexico. It is in the collection of the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio. Its distance record still stands.
21 June 1972: Aérospatiale Chief Test Pilot Jean Boulet set a Fédération Aéronautique Internationale (FAI) Absolute World Record for helicopters by flying the first Aérospatiale SA 315 Lama, serial number 315-001, to an altitude of 12,442 meters (40,820 feet) from Aérodrome d’Istres, northwest of Marseille, France.¹ He also set two class and sub-class world records.² These records remain current.
The SA 315B Lama was designed to perform at the very high altitudes and temperatures necessary for service with the Indian Army. It combined an SE.3130 Alouette II airframe with a much more powerful Turboméca Astazou IIIB turboshaft engine—derated to 550 shaft horsepower—and the rotor system, transmission and gearboxes from the larger 7-place Alouette III.
The record-setting helicopter was modified by removing all equipment that was not needed for the record flight attempt. Various instruments and the co-pilot and passengers seats were taken out of the cockpit, as well as the helicopter’s synchronized horizontal stabilizer and tail rotor guard. The standard fuel tank was replaced with a very small tank holding just 70 kilograms (approximately 22.7 gallons) of jet fuel. Turboméca modified the engine to increase the output shaft r.p.m. by 6%. After Jean Boulet started the turbine engine, mechanics removed the battery and starter motor to decrease the weight even further.
In just 12 minutes, the Lama had climbed to 11,000 meters (36,089 feet). As he approached the peak altitude, the forward indicated airspeed had to be reduced to 30 knots (34.5 miles per hour, 55.6 kilometers per hour) to prevent the advancing main rotor blade tip from reaching its Critical Mach Number in the thin air, which would have resulted in the blade stalling. At the same time, the helicopter was approaching Retreating Blade Stall.
When the helicopter could climb no higher, Boulet reduced power and decreased collective pitch. The Turboméca engine, not calibrated for the very high altitude and cold temperature, -62 °C. (-80 °F.), flamed out. With no battery and starter, a re-start was impossible. Boulet put the Lama into autorotation for his nearly eight mile descent. Entering multiple cloud layers, the Plexiglas bubble iced over. Because of the ice and clouds, the test pilot had no outside visibility. Attitude instruments had been removed to lighten the helicopter. Boulet looked up through the canopy at the light spot in the clouds created by the sun, and used that for his only visual reference until he broke out of the clouds.
Still in autorotation, the SA 315 missed touching down exactly on its takeoff point, but was close enough that FAI requirements were met.
Two days earlier, 19 June 1972, Boulet and fellow test pilot Gérard Boutin had set another FAI World Record for Altitude Without Payload, when they flew the Lama to 10,856 meters (35,617 feet).³ This record also still stands.
The SA 315B Lama is a 5-place light turboshaft-powered helicopter which is operated by a single pilot. The helicopter was built to meet the specific needs of the Indian Air Force for operations in the Himalayan Mountains. It was required to take off an land at an altitude of 6,000 meters (19,685 feet) while carrying a pilot, one passenger and 200 kilograms (441 pounds) of cargo.
The fuselage is 10.26 meters (33 feet, 7.9 inches) long. With all rotors turning, the helicopter has an overall length of 12.92 meters (42 feet, 4.7 inches) and height of 3.09 meters (10 feet, 1.7 inches). The SA 315B has an empty weight of 1,021 kilograms (2,251 pounds) and a maximum gross weight of 1,950 kilograms (4,299 pounds). With an external load carried on its cargo hook, the maximum gross weight is 5,070 pounds (2,300 kilograms).
The three-bladed, fully-articulated main rotor has a diameter of 11.02 meters (36 feet, 1.9 inches). 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. The three-bladed anti-torque tail rotor is 1.91 meters (6 feet, 3.2 inches) in diameter and turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) It turns at 2,020 r.p.m.
The Lama was initially powered by a Turboméca Artouste IIIB (later aircraft, Artouste IIIB1) turbo-moteur. This is a turboshaft engine with a two-stage compressor section (1 axial-flow, 1 centrifugal-flow stages), and a three-stage axial-flow turbine. The engine turns 33,500 r.p.m. and the output drive shaft turns 5,773 r.p.m. The Artouste IIIB1 produces a maximum 870 horsepower, but is derated to 570 horsepower for installation in the Lama. The engine is 1.815 meters (5 feet, 11.5 inches) long, 0.667 meters (2 feet, 2.3 inches) high and 0.520 meters (1 foot, 8.5 inches) wide. It weighs 178 kilograms (392 pounds).
The helicopter has a cruise speed 103 knots (191 kilometers per hour, 119 miles per hour) and a maximum speed of 113 knots (209 kilometers per hour, 130 miles per hour) at Sea Level. The service ceiling is 5,400 meters (17,717 feet). At 1,950 kilograms (4,299 pounds), the Lama has a hover ceiling in ground effect (HIGE) of 5,050 meters (16,568 feet), and out of ground effect (HOGE), 4,600 meters (15,092 feet).
Société nationale des constructions aéronautiques du Sud-Est became Aérospatiale in 1970. The company produced the SA 315B Lama beginning in 1971. It was also built under license by Hundustan Aeronautics in India and Helibras in Brazil.
The total number of SA 315Bs and its variants built is uncertain. In 2010, Eurocopter, the successor to Aérospatiale, announced that it will withdraw the Lama’s Type Certificate in 2020.
After setting the world altitude record, 315-001 was returned to the standard configuration and assigned registration F-BPXS. It crashed at Flaine, a ski resort in the French Alps, 23 February 1985.
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 LaResistance 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, Bouelt 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 Jen 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.
¹ FAI Record File Number 11657: Class: E (Rotorcraft): Sub-Class: E-Absolute (Absolute Record of class E)
² FAI Record File Number 753: Altitude Without Payload: Sub-Class: E-1b (Helicopters: take off weight 500 to 1000 kg). FAI Record File Number 754: Altitude Without Payload: Sub-Class: E-1 (Helicopters).
³ FAI Record File Number 788: Altitude Without Payload: Sub-Class E-1c.