9 December 1959: At Bloomfield, Connecticut, U.S. Air Force Captain Walter J. Hodgson test pilot and Major William J. Davis flew a Kaman H-43B-KA Huskie, 58-1848, to an altitude of 9,097 meters (29,845.8 feet), setting a Fédération Aéronautique Internationale (FAI) World Record for Altitude Without Payload.¹
The helicopter lifted off at 9:12 a.m., after a 1 hour, 12 minute weather delay, and reached its peak altitude at 10:30½. It landed back at Bloomfield after a flight of 1 hour, 53 minutes. 58-1848 was described as being in “mission configuration,” carrying all equipment for a normal operational flight. 58-1848 weighed 5,443 pounds (2,469 kilograms) at takeoff.
It was reported that this was the first altitude record for helicopters accomplished with two pilots on board.
Davis and Hodgson were presented with the Frederick L. Feinberg Award in 1960, for “demonstrating outstanding skills or achievement,” by the American Helicopter Society.
The Kaman Aircraft Corporation H-43 Huskie was a single-engine helicopter using a unique arrangement of counter-rotating and intermeshing rotors. The two rotors turning in opposite directions counteracted the torque effect, eliminating the need for a anti-torque tail rotor. In helicopters using a tail rotor, as much as 30% of the total engine power is used to drive the tail rotor. By eliminating that requirement, the total engine power could be used to produce lift. The Huskie could lift more weight and climb higher than a similar size helicopter with the same engine. Also, retreating blade stall was significantly reduced.
The Kaman Huskie was designed by German inventor Anton Flettner. He had designed and built the Flettner Fl 282 Kolibri. He was brought to the United States at the end of World War II under Operation Paperclip, and went to work at Kaman Aircraft Corporation, Bloomfield, Connecticut.
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-43 was 25.0 feet (7.62 meters) long. Each rotor had a diameter of 47.0 feet (14.33 meters). The overall height was 15 feet, 6 inches (4.724 meters).
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 maximum speed was 107 miles per hour (172 kilometers per hour). Its hover ceiling in ground effect (HIGE) was 20,000 feet (6,096 meters) and it had a range of 250 miles (402 kilometers).
Kaman H-43B-KA Huskie 58-1848 was reclassified as HH-43B in 1962. It was retired to The Boneyard at Davis-Monthan Air Force Base, Tucson, Arizona, in 1972, and was scrapped in 1977.
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.
6 June 1955: Société nationale des constructions aéronautiques du Sud-Est (SNCASE) Chief Test Pilot Jean Boulet set two Fédération Aéronautique Internationale (FAI) World Records for Altitude Without Payload when he flew the number two prototype SE.3130 Alouette II to an altitude of 8,209 meters (26,932 feet) near Buc, France.¹
FLIGHT and Aircraft Engineer briefly mentioned the flight:
“. . . On the same day S.N.C.A.S.E. claimed the world’s helicopter height record when the Alouette II, powered by a Turboméca Artouste, reached 27,100ft. The machine took off from Buc, near Paris, climbed for 42 min and landed at Montesson. The pilot was M. Jean Boulet.”
—FLIGHT and AIRCRAFT ENGINEER, No. 2420 Vol. 67. Friday, 10 June 1955, at Page 784
Powered by a Turboméca Artouste IIB1 turboshaft engine, the Alouette II was the first gas turbine 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 9.66 meters (31 feet, 9 inches) long. The three-bladed fully-articulated main rotor has a diameter of 10.20 meters (33 feet, 6 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 two-blade anti-torque rotor is 1.81 meters (9 feet, 11.25 inches) in diameter and turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the helicopter.) It turns at 2,020 r.p.m.
The SE.3130 has an empty weight of 895 kilograms (1,973 pounds) and a maximum takeoff weight (MTOW) of 1,600 kilograms (3,527 pounds). The prototype was powered by one Turboméca Artouste IIB1 turboshaft engine which produced 400 horsepower, but was derated to 360 horsepower for installation in the Alouette II.
The helicopter has a cruise speed 175 kilometers per hour (109 miles per hour) at Sea Level, and a maximum speed of 185 kilometers per hour (115 miles per hour) at Sea Level. VNE is 195 kilometers per hour (121 miles per hour.)
The service ceiling is 4,000 meters (13,123 feet) at 1,500 kilograms (3,307 pounds) gross weight. The absolute ceiling is 4,500 meters (14,764 feet). 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. More than 1,300 of these helicopters were built.
Jean Boulet was born 16 November 1920, in Brunoy, southeast of Paris, France. He graduated from Ecole Polytechnique in 1940 and the Ecole Nationale Supérieure de l’aéronautique In 1942. As an officer of the Armée de l’Air (French Air Force) he was sent to the United States for training as a fighter pilot, and later as a helicopter pilot. In 1947 he joined Société nationale des constructions aéronautiques du Sud-Est (SNCASE) as an engineer and test pilot. As a test pilot he made the first flight in every helicopter produced by SNCASE, which would become Sud-Aviation and later Aérospatiale (then, Eurocopter, and now, Airbus Helicopters). He set 24 Fédération Aéronautique Internationale world records for speed, distance and altitude. While flying a SE 530 Mistral fighter, 23 January 1953, he entered an unrecoverable spin and became the first French pilot to escape from an aircraft by ejection seat during an actual emergency. Médaille de l’Aéronautique. In 1972 he was appointed Officier de la Légion d’honneur. He had more than 9,000 flight hours with over 8,000 hours in helicopters.
Jean Boulet died at Aix-en-Provence, 15 February 2011, at the age of 90.
21 May 1949: Captain Hubert Dale Gaddis, Field Artillery, United States Army, flew a prototype Sikorsky S-52-1 helicopter, serial number 52003, registration NX92824, to a Fédération Aéronautique Internationale (FAI) World Record for Altitude Without Payload of 6,468 meters (21,220 feet) at Bridgeport, Connecticut.¹
The Sikorsky S-52-1 was an completely new design helicopter based on the company’s experience with the earlier R-4 and R-5/S-51 models. It was of all metal monocoque construction, using primarily aluminum and magnesium.
The three-bladed fully-articulated articulated main and two-bladed tail rotor were also of all metal construction. The main rotor had a diameter of 33 feet (10.058 meters) and rotated counter-clockwise as seen from above. (The advancing blade is on the right side of the helicopter.) The semi-rigid tail rotor was mounted on the left side of the tail boom in a pusher configuration. It had a diameter of 6 feet, 4 inches (1.930 meters) and rotated counter clockwise, as seen from the helicopter’s left. (The advancing blade is at the top of the tail rotor arc.)
The S-52-1 was powered by an air-cooled, normally-aspirated, 425.29-cubic-inch-displacement (6.97 liter) Franklin Engine Company 6V6-245-B16F (O-425-1) vertically-opposed 6-cylinder overhead valve engine. The engine was rated at 245 horsepower at 3,275 r.p.m.
On 27 April 1949 Sikorsky test pilot Harold E. “Tommy” Thompson flew the same helicopter to an FAI speed record of 208.49 kilometers per hour (129.55 miles per hour) over a 3 kilometer straight course (Record File Number 13097), and on 6 May, to 197.54 kilometers per hour (122.75 miles per hour) over a 100-kilometer closed circuit (Record File Number 13146). ²
Hubert Dale Gaddis was born in Jasper County, Missouri, 9 September 1920, the first of two children of Hubert E. Gaddis, a utility company purchasing agent, and Beatrice Mae Cook Gaddis.
The family trelocated to Tulsa, Oklahoma, where Hubert attended Central High School. While there, he developed an interest in radio. Gaddis graduated in 1938.
Gaddis married Martha Tucker in 1950. They would have three children,Cheryl, Sandra and Dale.
Gaddis enlisted in the United States Army in Oklahoma, 24 September 1942. He had brown hair and hazel eyes, was 5 feet, 6 inches (1.68 meters) tall and weighed 133 pounds (60.3 kilograms).
Gaddis was commissioned a second lieutenant, Army of the United States (AUS), 18 February 1944. He remained in the Army following World War II as an officer in the Field Artillery (Regular Army). In 1956, he graduated of the Army Command and General Staff College.
On September 8 1966, Gaddis was promoted to the rank of colonel (temporary). The rank became permanent 1 July 1971. He was released from military service 28 February 1974. During his career, Colonel Gaddis had been awarded the Distinguished Flying Cross, the Bronze Star Medal, and the Air Medal with 14 oak leaf clusters (15 awards).
Colonel Hubert Dale Gaddis, United States Army (Retired) died 24 February 1976 at the age of 55 years. He was buried at Woodlawn Memorial Gardens, Ozark, Alabama.
14 April 1953: Dmitry Konstantinovich Efremov, chief test pilot for the Kamov Design Bureau, made the first flight of the prototype Kamov Ka-15 helicopter.
The Ka-15 was a single-engine, two-place, light helicopter, flown by a single pilot. It used two fully-articulated, three-bladed, counter-rotating coaxial rotors. The helicopter had two vertical fins mounted at the ends of a horizontal stabilizer, and four-wheeled fixed landing gear.
The fuselage of the Ka-15 was 6.26 meters (20 feet, 6.5 inches) long. The main rotors’ diameter was 9.96 meters (32 feet, 8.1 inches), and the overall height of the the helicopter was 3.35 meters (10 feet, 11.9 inches). The span of the horizontal stabilizer and vertical fins were 2.85 meters (9 feet, 4.2 inches). The Ka-15 had an empty weight of 996 kilograms (2,196 pounds), normal takeoff weight of 1,360 kilograms (2,998 pounds), and maximum takeoff weight (MTOW) of 1,460 kilograms (3,219 pounds).
The rotors turn at 333 r.p.m. The upper rotor turned clockwise, as seen from above. (The advancing blade is on the left), and the lower blades turn counter-clockwise (their advancing blades are on the right). The area of the main rotor disc was 155.83 square meters (1,677.29 square feet) with a solidity ratio of 3% per rotor. (This is the lowest coefficient of disc area of any helicopter.) Each main rotor blade was trapezoidal, with a theoretical chord at the axis of rotation of 300 millimeters (11.8 inches), narrowing to 100 millimeters (3.9 inches) at the blade tip. The blades incorporated 12° of negative twist.
The Ka-15 was powered by a single air-cooled, supercharged 10.131 liter (618.234 cubic inches) Ivchenko AI-14V nine-cylinder radial engine with a compression ratio of 5.9:1. The engine was rated at 188 kilowatts (252 horsepower). It weighed approximately 200 kilograms (441 pounds).
The helicopter could carry a single passenger or 364 kilograms (802 pounds) of cargo. (Interestingly, the contemporary single main rotor/tail rotor Mil Mi-1 helicopter required 575 horsepower to lift the same payload as the Ka-15.)
The Ka-15 had a cruise speed 120 kilometers per hour (75 miles per hour) and maximum speed 155 kilometers per hour (96 miles per hour). The service ceiling was 3,500 meters (11,483 feet). It could hover out of ground effect (HOGE) at 600 meters (1,969 feet). The helicopter had a normal range of 278 kilometers (173 miles) and maximum range of 520 kilometers (323 miles).
The performance of the Ka-15 was better than had been predicted. After several years of testing, the Ka-15 entered production in 1956. It was the first mass-produced coaxial helicopter, with approximately 375 being built by Aircraft Factory No. 99 at Ulan-Ude, the capitol city of the Buryat-Mongolian Autonomous Soviet Socialist Republic.
In a coaxial rotor system, one rotor is placed above the other, with the drive shaft for the upper rotor inside the hollow drive shaft of the lower. As in tandem rotor helicopters, each counter-rotating rotor counteracts the torque effect of the other. There is no anti-torque rotor (tail rotor) required. In helicopters using a tail rotor, as much as 30% of engine power is required to drive the tail rotor. With counter-rotating rotors, all of the engine’s power can be used to provide lift and thrust.
A second benefit of a coaxial rotor is that the dissymetry of lift of each rotor is also canceled out. There is no translating tendency while in a hover, and higher forward speeds are possible because retreating blade stall is reduced. A helicopter with coaxial rotors is more compact than a similar helicopter with tandem rotors. This makes it useful for operations in confined areas or aboard ships.
Nikolai Ilich Kamov was previously known for his autogyro designs, which were first produced in 1929. These included the Tsentralniy Aerogidrodinamicheskiy Institut (Central Aero-Hydrodynamic Institute) TsAGI A-7, which was the first armed autogyro. The Kamov Design Bureau was established 7 October 1948 at Lyubertsy, near Moscow, Russia.
Ефремов Дмитрий Константинович (Dmitry Konstantinovich Efremov) was born at Moscow, in the Russian Socialist Federative Soviet Republic, 30 October 1920.
In 1941, Efremov was a cadet at the Bauman Aero Club. He entered the Red Army the same year and was sent to the Saratov Military Aviation Gliding School, at Samara, Kuybyshev, Russia, U.S.S.R., for training as a military glider pilot. During the Great Patriotic War, Efremov flew gliders behind enemy lines. He was next assigned to an experimental test squadron of of the Airborne Forces, and then as a pilot instructor at the aviation school of the Airborne Forces in Slavogorod, Altai Krai, Russia, U.S.S.R.
Efremov contracted tuberculosis and in January 1948, was discharged from the Red Army. He was employed as a senior technician at TsAGI, and in November of that year went to work as a mechanic at Kamov OKB. He made the first flight of the Kamov Ka-10, and was then sent to test pilot school.
Efremov returned to Kamov OKB after completing test pilot school and was soon promoted the the design bureau’s chief pilot. He made the first flights of the Ka-15, Ka-18 and Ka-25 helicopters.
After transitioning to the Antonov An-8 and Ilyushin Il-18 turboprop transports to gain flight experience in larger transport airplanes, Efremov made the first flight of the Kamov Ka-22 gyrodyne prototype, 15 August 1959. On 7 October 1961, with V.V. Gromov, he flew the Ka-22 to a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 15km/25km Straight Course of 356.3 kilometers per hour (221.4 miles per hour),¹ and on 24 November 1961, set seven world records for payload to altitude.²
On 28 February 1962, Efremov and a flight test crew were conducting a long-distance test flight of a Kamov Ka-22M gyrodyne prototype, 01-01, 63972, from Tashkent, Uzbekistan, to Kzyl-Orda, Kazakhstan. During an intermediate refueling stop in Turkestan, mechanics found a loose or missing retaining nut for the left support of the synchronizing shaft. The problem was repaired and the flight continued.
While on approach to the main runway at the Dzhusaly airport, the gyrodyne suddenly banked left, entered a left spiraling turn, and, in an inverted dive, crashed on the runway. The Ka-22 exploded and burned. Dmitry Konstantinovich Efremov and seven men of his flight test crew were killed.
TdiA would like to thank regular reader Mike for suggesting this topic.
¹ FAI Record File Number 13226
² FAI Record File Numbers 13221, 13222, 13223, 13224, 13227 and 13228