Tag Archives: Helicopter

10 January 1966

January 10, 2025AviationAllison 250-C18, Allison 250-C20, Allison 250-C20B, Allison Division of General Motors, B06, Bell Helicopter Company, Bell Model 206A JetRanger, First Flight, Helicopter, N8560F, Turboshaft EngineBryan Swopes

The prototype Bell Model 206A JetRanger, serial number 1, civil registration N8560F, hovering out of ground effect. (Bell Helicopter Company)

10 January 1966: The prototype Bell Model 206A JetRanger serial number 1, N8560F, made its first flight at at the Bell Helicopter Company plant at Hurst, Texas. This aircraft would be in production for almost 45 years. The final JetRanger to be built, Bell 206B-3 serial number 4690, was delivered in December 2010 and production came to an end.

During early production of the Model 206A, cabin sections were built by Beechcraft and Agusta then shipped to Bell at Fort Worth. (The vertical seam just to the rear of the fuel cap distinguished the two.) Oil pressure and temperature gauges for the engine and transmission, the loadmeter and fuel quantity indicator were provided by Cessna.

The Bell JetRanger is a 5-place, single-engine light civil helicopter based on the Bell Helicopter’s unsuccessful OH-4 entrant for the U.S. Army’s Light Observation Helicopter (LOH, or “loach”) contract. It is flown by a single pilot in the right front seat. Dual flight controls can be installed for a second pilot. The helicopter was certified for VFR flight, but could be modified for instrument flight.

The industrial design firm of Charles Wilfred Butler

“. . . was responsible for the complete redesign of the Bell OH-4A prototype army helicopter (1961) into the Bell Jet Ranger (1965). He and his designers restyled the machine inside and out in the manner of automotive design, creating in the process one of the world’s most successful and beautiful helicopters.”

—Encyclopedia Britannica.

The JetRanger is 38 feet, 9.5 inches (11.824 meters) long, overall. On standard skid landing gear the overall height is 9 feet, 4 inches (2.845 meters). The Bell 206A has an empty weight of approximately 1,700 pounds (771 kilograms), depending on installed equipment. The maximum gross weight is 3,200 pounds (1,451.5 kilograms). With an external load suspended from the cargo hook, the maximum gross weight is increased to 3,350 pounds (1,519.5 kilograms).

The two-bladed main rotor is semi-rigid and under-slung, a common feature of Bell’s main rotor design. It has a diameter of 33 feet, 4.0 inches (10.160 meters) and turns counter-clockwise (seen from above) at 394 r.p.m. (100% N_R). (The advancing blade is on the helicopter’s right side.) The rotor blade has a chord of 1 foot, 1.0 inches (0.330 meter) and 10° negative twist. The airfoil is symmetrical. The cyclic and collective pitch controls are hydraulically-boosted.

The first Bell 206B JetRanger (Bell Helicopter Co.) — The first Bell 206A JetRanger, N8560F. (Bell Helicopter Co.)

The two-bladed tail rotor assembly is also semi-rigid and is positioned on the left side of the tail boom in a pusher configuration. It turns at 2,550 r.p.m., clockwise, as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.) The tail rotor diameter is 5 feet, 6.0 inches (1.676 meters).

The turboshaft engine is mounted above the roof of the fuselage, to the rear of the main transmission. Output shafts lead forward to the transmission and aft to the tail rotor 90° gear box. The transmission and rotor mast are mounted tilting slightly forward and to the left. This assists in the helicopter’s lift off to a hover, helps to offset its translating tendency, and keeps the passenger cabin in a near-level attitude during cruise flight.

A vertical fin is attached at the aft end of the tail boom. The fin is offset 4° to the right to unload the tail rotor in cruise flight. Fixed horizontal stabilizers with an inverted asymmetric airfoil are attached to the tail boom. In cruise flight, these provide a downward force that keeps the passenger cabin in a near-level attitude.

The 206A was powered by an Allison 250-C18 turboshaft engine (T63-A-700) which produced a maximum of 317 shaft horsepower at 104% N₁, 53,164 r.pm. The improved Model 206B JetRanger and 206B-2 JetRanger II used a 370 horsepower 250–C20 engine, and the Model 206B-3 JetRanger III had 250-C20B, -C20J or -C20R engines installed, rated at 420 shaft horsepower at 105% N₁, (53,519 r.p.m.). Many 206As were upgraded to 206Bs and they are sometimes referred to as a “206A/B.” The Allison 250-C20B has a 7-stage compressor section with 6-stage axial-flow stages, and 1 centrifugal-flow stage. The 4-stage axial-flow turbine has a 2-stage gas producer (N₁) and 2-stage power turbine (N₂). These were very light weight engines, ranging from just 141 to 173 pounds (64.0 to 78.5 kilograms).

The helicopter’s main transmission is limited to a maximum input of 317 shaft horsepower (100% Torque, 5-minute limit). The engine’s accessory gear unit reduces the output shaft speed to 6,016 r.p.m. N₂, which is further reduced by the transmission’s planetary gears, and the tail rotor 90° gear box.

The JetRanger has a maximum speed, V_NE, of 150 miles per hour (241 kilometers per hour) up to 3,000 feet (914 meters). Its best rate of climb, V_Y, is at 60 miles per hour (97 kilometers per hour) and best speed in autorotation (minimum rate of descent and maximum distance) is at 80 miles per hour (129 kilometers per hour), resulting in a glide ratio of about 4:1. The service ceiling is 13,500 feet (4,145 meters) with the helicopter’s gross weight above 3,000 pounds (1,361 kilograms), and 20,000 feet (6,096 meters) when below 3,000 pounds. The helicopter has a maximum range of 430 miles (692 kilometers).

After being used as a factory demonstrator and development aircraft, N8560F was retired from flight status and used as a maintenance ground training device at Bell’s training school at Hurst.

Note: The Model 206A-1 was adopted by the U.S. Army as the OH-58A Kiowa. Though very similar in appearance to the Model 206A and 206B, the OH-58A differs significantly. Few of the parts are interchangeable between the types.

Three view drawing of the Bell Model 206A/B JetRanger with dimensions. (Bell Helicopter TEXTRON)

7 January 1967

January 7, 2025Aviation10th Calvary Regiment, 1st Squadron, Bell UH-1B Iroquois, D Troop, Helicopter, Helicopter Pilot, Huey, John Steinbeck, Pleiku, Vietnam WarBryan Swopes

During 1966–1967, author John Steinbeck was in Vietnam. He wrote a series of dispatches to Newsday which have recently been published as a book, Steinbeck In Vietnam: Dispatches From the War, edited by Thomas E. Barden. University of Virginia Press, 224 pp., $29.95.

On 7 January 1967, Steinbeck was at Pleiku, where he flew aboard a UH-1 Huey helicopter with D Troop, 1st Squadron, 10th Cavalry. He wrote the following about the helicopter pilots:

“I wish I could tell you about these pilots. They make me sick with envy. They ride their vehicles the way a man controls a fine, well-trained quarter horse. They weave along stream beds, rise like swallows to clear trees, they turn and twist and dip like swifts in the evening. I watch their hands and feet on the controls, the delicacy of the coordination reminds me of the sure and seeming slow hands of (Pablo) Casals on the cello. They are truly musicians’ hands and they play their controls like music and they dance them like ballerinas and they make me jealous because I want so much to do it. Remember your child night dream of perfect flight free and wonderful? It’s like that, and sadly I know I never can. My hands are too old and forgetful to take orders from the command center, which speaks of updrafts and side winds, of drift and shift, or ground fire indicated by a tiny puff or flash, or a hit and all these commands must be obeyed by the musicians hands instantly and automatically. I must take my longing out in admiration and the joy of seeing it. Sorry about that leak of ecstasy, Alicia, but I had to get it out or burst.”

Bell UH-1B Iroquois gunship of D Troop, 1st Squadron, 10th Cavalry Regiment, U.S. Army. Vietnam ca. 1966–1967. (U.S. Army) — Bell UH-1B Iroquois gunship of D Troop, 1st Squadron, 10th Cavalry Regiment, U.S. Army. Vietnam, ca. 1966–1967. (U.S. Army)

Author John Steinbeck observes the Vietnam War from a U.S. Army UH-1B "Huey" helicopter. A gunner mans an M60 7.62mm machine gun. (Associated Press) — Author John Steinbeck observes the Vietnam War from a U.S. Army UH-1B “Huey” helicopter. A gunner mans an M60B 7.62 mm machine gun. (Associated Press)

11 December 1951

December 11, 2024AviationBoeing 502-2E, Boeing YT-50-BO-2, Bu. No. 125477, Gas Turbine, Helicopter, Kaman Aircraft Company, Kaman K-225, Test Pilot, William R. MurrayBryan Swopes

Test pilot William R. Murray at the control of Kaman K-225, Bu. No. 125477, with a Boeing 502-2 gas turbine engine installed. (U.S. Navy)

11 December 1951: The first helicopter powered by a gas turbine engine made its first flight at the Kaman Aircraft Company plant at Bloomfield, Connecticut. Using a K-225 tandem rotor helicopter delivered to the U.S. Navy in 1949, Bureau of Aeronautics serial number (“Bu. No.”) 125477, Kaman replaced the 220 horsepower Lycoming O-435-A2 reciprocating engine with a Boeing 502-2E turboshaft engine. This engine could produce 175 continuous horsepower at 2,900 r.p.m. at Sea Level, less than the piston engine it replaced, but it also weighed considerably less.

K-225 Bu. No. 125477 was the first helicopter to perform an intentional loop, when it was delivered to the Navy at NATC Patuxent River by factory test pilot William R. Murray. It was placed in storage at Bradley Field, Windsor Locks, Connecticut until 1957. The gas turbine had been removed. When the helicopter was transferred to the Smithsonian Institution in 1957, a similar-appearing Boeing YT-50-BO-2 gas turbine engine was installed.

The K-225 was a two-place, single-engine helicopter using Kaman’s unique system of counter-rotating, intermeshing rotors (“synchropter”). Each rotor cancelled the torque reaction of the other, eliminating the need for a tail rotor. In a conventional single-rotor helicopter, up to 30% of the engine power is required to drive the tail rotor. With the counter-rotating design, the total engine power is available for lift and thrust.

K-225 Bu. No. 125477 is 22 feet, 5 inches (6.83 meters) long. Each rotor has a diameter of 38 feet (11.58 meters). It stands 11 feet, 6 inches (3.51 meters) high. The helicopter has an empty weight of 1,800 pounds (816 kilograms) and a maximum gross weight of 2,700 pounds (1,225 kilograms). It is a slow helicopter, with a never-exceed (V_NE) limit of 70 miles per hour (112.7 kilometers per hour). This historic helicopter is on display at the Smithsonian Institution National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Kaman K-225, Bu. No. 125477, the first gas turbine-powered helicopter, at the Vertical Flight Gallery, Steven F. Udvar-Hazy Center, Smithsonian Institution National Air and Space Museum, Chantilly, Virginia. (NASM)

9 December 1959

December 9, 2024Aviation58-1848, FAI, Fédération Aéronautique Internationale, Helicopter, Kaman Aircraft Corporation, Kaman H-43B-KA Huskie, Lycoming T53-L-1B, Lycoming Turbine Engine Division, Walter J. Hodgson, William J. Davis, World Record for Altitude Without PayloadBryan Swopes

Captain Walter J. Hodgson (1924–1978) and Major William J. Davis, U.S. Air Force, with the world record-setting Kaman H-43B Huskie, 58-1848. (FAI)

9 December 1959: At Bloomfield, Connecticut, U.S. Air Force Captain Walter J. Hodgson 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.

Anton Flettner, 1885–1961. (Library of Congress)

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.

Kaman H-43B-KA Huskie 58-1848 at Bloomfield, Connecticut, 9 December 1959. (FAI)

¹ FAI Record File Number 1869

8 December 1945

December 8, 2024AviationArthur M. Young, Bell 47, Bell Aircraft Corporation, Bell Helicopter Company, Bell Model 47, C.A.A., Civil Aviation Administration, First Flight, Floyd Carlson, Floyd William Carlson, Franklin 6V4-175-B3, Helicopter, NC1H, NX41962, Prototype, Rollout, s/n 1Bryan Swopes

Prototype of the Bell Model 47. (Niagara Aerospace Museum)

8 December 1945: At the Bell Aircraft Corporation Wheatfield Plant, Niagara Falls, New York, the first Model 47 helicopter, NX41962, was rolled out. Designed by Arthur M. Young, the Model 47 was based on Young’s earlier Model 30. The new helicopter made its first flight on the same day.

The Civil Aviation Administration (C.A.A.), predecessor of the Federal Aviation Administration, had never certified a helicopter, so Bell worked with government officials to develop civil certification standards. The Bell 47 received the C.A.A. Type Certificate H-1 on 8 March 1946 and the first helicopter’s registration was changed to NC1H.

Bell Model 47 NX41962, Serial Number 1, at Bell’s Wheatfield Plant, early 1946. (Niagara Aerospace Museum)

The Bell 47 series was constructed of a welded tubular steel airframe with a sheet metal cockpit and a characteristic plexiglas bubble. In the original configuration, it had a four-point wheeled landing gear, but this was soon replaced with a tubular skid arrangement. It was a two-place aircraft with dual flight controls.

The first Bell Model 47 had an overall length (with rotors turning) of 39 feet, 7½ inches (12.078 meters). The main rotor diameter was 33 feet, 7 inches (10.236 meters). The length of the fuselage, from the front of the plexiglass bubble canopy to the trailing edge of the tail rotor disc, was 29 feet, 3½ inches (8.928 meters). The tail rotor had a diameter of 5 feet, 5 inches (1.676 meters). The helicopter’s height, to the top of the main rotor mast, was 9 feet, 2-7/16 inches (2.805 meters).

NC1H had an empty weight of 1,393 pounds (632 kilograms). Its gross weight was 2,100 pounds (953 kilograms).

Bell Aircraft Corp. test pilot Floyd W. Carlson demonstrates the stability of the Model 47 by taking his hands off of the flight controls during a hover. (Bell Helicopter)

The Bell 47’s main rotor is a two-bladed, under-slung, semi-rigid assembly that would be a characteristic of helicopters built by Bell for decades. The blades were constructed of laminated wood, and covered with fabric. A stabilizer bar was placed below the hub and linked to the flight controls through hydraulic dampers. This made for a very stable aircraft. The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the right.) The tail rotor is positioned on the right side of the tail boom in a tractor configuration. It rotates counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.)

Floyd Carlson, chief Test Pilot for the Bell Aircraft Corporation, hovers the world’s first civil-certified helicopter, NC1H, Serial Number One. (Niagara Aerospace Museum)

Power was supplied by an air-cooled, normally-aspirated, 333.991-cubic-inch-displacement (5.473 liter) Franklin Engine Company 6V4-178-B3 vertically-opposed six cylinder engine, serial number 17008, rated at 178 horsepower at 3,000 r.p.m. Power was sent through a centrifugal clutch to a transmission which turned the main rotor through a two-stage planetary gear reduction system with a ratio of 9:1. The transmission also drove the tail rotor drive shaft, and through a vee-belt/pulley system, a large fan to provide cooling air for the engine.

The new helicopter had a cruise speed of 75 miles per hour (121 kilometers per hour) and a maximum speed (V_NE) of 80 miles per hour (129 kilometers per hour). NC1H had a service ceiling of 11,400 feet (3,475 meters).

The Bell 47 gained fame during the Korean War as a rescue helicopter, transferring wounded soldiers directly to Mobile Army Surgical Hospitals placed near the front lines. Here, a wounded soldier is offloaded from an H-13D-1 Sioux. (U.S. Army)

The manufacturer's data plate for Bell Model 47, Serial Number 1. (Niagara Museum of Aeronautics) — The manufacturer’s data plate for Bell Model 47, Serial Number 1. (Niagara Museum of Aeronautics)

The Bell 47 was produced at the plant in New York, and later at Fort Worth, Texas. It was steadily improved and remained in production until 1974. In military service the Model 47 was designated H-13 Sioux, (Army and Air Force), HTL (Navy) and HUG (Coast Guard). The helicopter was also built under license by Agusta, Kawasaki and Westland. More than 7,000 were built worldwide and it is believed that about 10% of those remain in service.

In 2010, the type certificates for all Bell 47 models was transferred to Scott’s Helicopter Service, Le Sueur, Minnesota, which continues to manufacture parts and complete helicopters.

After certification testing and demonstrations, NC1H was one of two Bell 47s used for flight training. The first Bell 47, s/n 1, crashed at Niagara Falls Airport, 3 April 1946.

While hovering out of ground effect, a student inadvertently oversped the main rotor by decreasing collective pitch when he had intended to increase it. The main rotor hub separated and the helicopter dropped to the ground. Both the student and instructor were injured. Damage to NC1H was extensive and the helicopter was scrapped. The registration, NC1H, was reassigned to Bell 47 s/n 11.

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