Tag Archives: Bell Helicopter Company

10 January 1966

The prototype Bell Model 206A JetRanger, serial number 1, civil registration N8560F, hovering out of ground effect. (Bell Helicopter Company)
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 OH4A 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% NR). (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, VNE, of 150 miles per hour (241 kilometers per hour) up to 3,000 feet (914 meters). Its best rate of climb, VY, 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)
Three view drawing of the Bell Model 206A/B JetRanger with dimensions. (Bell Helicopter TEXTRON)

© 2018, Bryan R. Swopes

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6 January 1968

Major Patrick Henry Brady, Medical Corps, United States Army.
Major Patrick Henry Brady, Medical Corps, United States Army.

 

The President of the United States in the name of The Congress takes pleasure in presenting the MEDAL OF HONOR to

MAJOR PATRICK HENRY BRADY

Medical Service Corps, United States Army

for service as set forth in the following

Citation:

Major Patrick Henry Brady, Medical Corps, United States Army
Major Patrick Henry Brady, Medical Corps, United States Army

For conspicuous gallantry and intrepidity in action at the risk of his life above and beyond the call of duty, Maj. Brady distinguished himself while serving in the Republic of Vietnam commanding a UH-1H ambulance helicopter, volunteered to rescue wounded men from a site in enemy held territory which was reported to be heavily defended and to be blanketed by fog. To reach the site he descended through heavy fog and smoke and hovered slowly along a valley trail, turning his ship sideward to blow away the fog with the backwash from his rotor blades. Despite the unchallenged, close-range enemy fire, he found the dangerously small site, where he successfully landed and evacuated 2 badly wounded South Vietnamese soldiers. He was then called to another area completely covered by dense fog where American casualties lay only 50 meters from the enemy. Two aircraft had previously been shot down and others had made unsuccessful attempts to reach this site earlier in the day. With unmatched skill and extraordinary courage, Maj. Brady made 4 flights to this embattled landing zone and successfully rescued all the wounded. On his third mission of the day Maj. Brady once again landed at a site surrounded by the enemy. The friendly ground force, pinned down by enemy fire, had been unable to reach and secure the landing zone. Although his aircraft had been badly damaged and his controls partially shot away during his initial entry into this area, he returned minutes later and rescued the remaining injured. Shortly thereafter, obtaining a replacement aircraft, Maj. Brady was requested to land in an enemy minefield where a platoon of American soldiers was trapped. A mine detonated near his helicopter, wounding 2 crewmembers and damaging his ship. In spite of this, he managed to fly 6 severely injured patients to medical aid. Throughout that day Maj. Brady utilized 3 helicopters to evacuate a total of 51 seriously wounded men, many of whom would have perished without prompt medical treatment. Maj. Brady’s bravery was in the highest traditions of the military service and reflects great credit upon himself and the U.S. Army.

// Richard M. Nixon//

President

Call sign, "Dust Off." (U.S. Army)
Call sign, “Dust Off.” (U.S. Army)
Major General Patrick Henry Brady, Medical Corps, United States Army
Major General Patrick Henry Brady, Medical Corps, United States Army

Major General Patrick Henry Brady was born 1 October 1936 at Philip, South Dakota, the son of Michael and LaVona Brady. He graduated from Seattle University with a bachelor’s degree in psychology. As a member of the Reserve Officers Training Corps (ROTC) he received a commission as a second lieutenant in the Medical Service Corps, United States Army. Lieutenant Brady served in Berlin, Germany from 1959 to 1963.

In 1963, Lieutenant Brady was sent to the Army Aviation School at Fort Rucker, Alabama, to be trained as a helicopter pilot. He received his wings in December and the following month was sent to the Republic of South Vietnam, assigned to the 57th Medical Detachment (Helicopter Ambulance).

When the unit’s commanding officer was killed in action, Captain Brady assumed command of the 57th’s Detachment A at Sóc Trăng Airfield. After completing his combat tour, Captain Brady was assigned as a helicopter pilot at Fort Benning, Georgia. In 1967 he was reassigned to the 54th Medical Detachment (Helicopter Ambulance), 67th Medical Group, 44th Medical Brigade, and after the unit completed training, deployed to Chu Lai, Vietnam. It was while serving with this unit that he flew the missions for which he was awarded the Medal of Honor.

During two combat tours in Vietnam, Major Brady flew more than 2,000 combat missions and rescued as many as 5,000 wounded soldiers.

Patrick Brady served in the United States Army for thirty-four years, rising to the rank of Major General. Major General Brady has been awarded the Medal of Honor, Distinguished Service Cross, Distinguished Service Medal with oak leaf cluster (two awards), Defense Superior Service Medal, Legion of Merit, Distinguished Flying Cross with silver oak leaf cluster (six awards), Bronze Star with one oak leaf cluster (two awards, with “V” Device (“participation in acts of heroism involving conflict with an armed enemy”), Purple Heart, Meritorious Service Medal with two oak leaf clusters (three awards), Air Medal with V-Device (52 awards), and Army Commendation Medal with oak leaf cluster (two awards).

Major General Brady retired in 1983 and lives in Sumner, just south of Auburn, Washington, with his wife, Nancy, whom he met in high school. They have six children. Two are graduates of the U.S. Military Academy, West Point, New York. A daughter, Meghan Brady, who also graduated from the ROTC unit at Seattle University, served as an officer in the Medical Service Corps with duty in Kosovo and the invasion of Iraq. Captain Brady was awarded the Bronze Star.

Major General Brady and Captain Brady are co-authors of Dead Men Flying: Victory in Vietnam (WND Books, 2012).

Major General Patrick Henry Brady, U.S. Army (retired) with Senator John Cornyn of Texas, as they announce The Dust Off Crews of the Vietnam War Congressional Gold Medal Act, at Fort Sam Houston, Texas, 11 November 2015. (U.S Army)
Major General Patrick Henry Brady, U.S. Army (retired) with Senator John Cornyn of Texas, as they announce The Dust Off Crews of the Vietnam War Congressional Gold Medal Act, at Fort Sam Houston, Texas, 11 November 2015. (U.S Army)

The Bell Helicopter Co. UH-1H Iroquois (Model 205A-1) is an improved variant of the UH-1D (Model 205), which was itself derived from the UH-1B (Model 204). The type’s initial military designation was HU-1, and this resulted in the helicopter being universally known as the “Huey.”

The UH-1H is a single main rotor/tail rotor medium helicopter powered by a turboshaft engine. It can be flown by a single pilot, but is commonly flown by two pilots in military service. The helicopter has an overall length of 57 feet, 0.67 inches (17.375 meters) with rotors turning. The fuselage is 41 feet, 5 inches (12.624 meters) long. The two blade semi-rigid, under-slung main rotor has a diameter of 48 feet, 3.2 inches (14.712 meters), and turns counter clockwise when viewed from above. (The advancing blade is on the helicopter’s right.) At 100% NR, the main rotor turns 324 r.p.m. The two blade tail rotor assembly has a diameter of 8 feet, 6 inches (2.591 meters). It is on the left side of the pylon in a pusher configuration and turns counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.) The helicopter has a height of 13 feet, 7.4 inches (4.150 meters), measured to the top of the mast.

A Bell UH-1H helicopter ambulance, Vietnam, 1969.
A Bell UH-1H helicopter ambulance, Vietnam, 1968. (John Metcalf, “Dustoff 68,” via dustoff.net)

The UH-1H is powered by a Lycoming LTC1K-4 (T53-L-13) turboshaft engine rated at 1,400 shaft horsepower, though it is derated to the helicopter’s transmission limit. The T53-L-13 is a two-shaft free turbine with a 6-stage compressor (5 axial-flow stages, 1 centrifugal-flow stage) and a 4-stage axial-flow turbine (2 high-pressure stages, 2 low-pressure power turbine stages). The T53-L-13 is 3 feet, 11.9 inches (1.217 meters) long, 1 foot, 11.0 inches (0.584 meters) in diameter and weighs 549 pounds (249 kilograms).

The UH-1H has a maximum gross weight of 9,500 pounds (4,309.1 kilograms). Its maximum speed, Vne, is 124 knots (143 miles per hour, 230 kilometers per hour). With full fuel, 206.5 gallons (781.7 liters), the helicopter has a maximum endurance of three hours.

5,345 UH-1H Hueys were built, and many of the earlier UH-1Ds were upgraded to the UH-1H standard.

A Bell UH-1H medevac helicopter returns to its base, while ground personnel standby to offload the injured. (U.S. Army)
A Bell UH-1H medevac helicopter landing while ground personnel standby to offload the injured. (Free Republic)

© 2018, Bryan R. Swopes

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26 December 2015

Deputy Sheriff Jim Miller Dalton, flies Copter 7 over the Solimar Fires, northwest of the City of Ventura just after sunrise, 26 Decmber 2015. Jim has been flying all night. (KABC)
Deputy Sheriff Jim Miller Dalton flies Copter 7 over the Solimar Fire, west of the City of Ventura, at sunrise, 26 December 2015. Jim has been flying all night. (Ventura County Sheriff’s Department Air Unit)

26 December 2015: Shortly before midnight, Christmas Day, a wind-driven fire threatened the tiny coastal community of Solimar Beach, just west of the City of Ventura, California. Low humidity and gusty winds whipped the fire out of control and emergency evacuations were ordered. Winds were clocked at 42 miles per hour (19 meters per second). Highway 1, California’s famous Pacific Coast Highway (or just “PCH”) was closed to traffic in both directions.

Jim Dalton makes a water drop over the Solimar Fire during the night of 25–26 December 2015.
Jim Dalton makes a water drop over the Solimar Fire during the night of 25–26 December 2015. (Cal Fire)

Almost immediately, Copter 7 flew from the Ventura County Sheriff’s Department Air Unit base at nearby Camarillo Airport (CMA). The pilot of the helicopter was Deputy Sheriff Jim Miller Dalton, a 45-year-veteran helicopter pilot who has served with the Air Unit for more than twenty years.

The Solimar Fire, looking west from the City of Ventura, 26 December 2015. (Austi V. Campbell)
The Solimar Fire, looking west from the City of Ventura, 26 December 2015. (Austi V. Campbell)

Copter 7 is a 1970 Bell HH-1H Iroquois, originally a U.S. Air Force rescue helicopter, serial number 70-2472, and now carrying the FAA registration N205SD. The HH-1H was a variant of the U.S. Army UH-1H transport helicopter.

The Bell Helicopter Co. UH-1H Iroquois (Model 205A-1) is an improved variant of the UH-1D (Model 205), which was itself derived from the UH-1B (Model 204). The type’s initial military designation was HU-1, and this resulted in the helicopter being universally known as the “Huey.”

The UH-1H is a single main rotor/tail rotor medium helicopter powered by a turboshaft engine. It can be flown by a single pilot, but is commonly flown by two pilots in military service. The helicopter has an overall length of 57 feet, 0.67 inches (17.375 meters) with rotors turning. The fuselage is 41 feet, 5 inches (12.624 meters) long. The two blade semi-rigid, under-slung main rotor has a diameter of 48 feet, 3.2 inches (14.712 meters), and turns counter clockwise when viewed from above. (The advancing blade is on the helicopter’s right.) At 100% NR, the main rotor turns 324 r.p.m. The two blade tail rotor assembly has a diameter of 8 feet, 6 inches (2.591 meters). It is on the left side of the pylon in a pusher configuration and turns counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.) The helicopter has a height of 13 feet, 7.4 inches (4.150 meters), measured to the top of the mast.

The UH-1H is powered by a Lycoming LTC1K-4 (T53-L-13) turboshaft engine rated at 1,400 shaft horsepower, though it is derated to the helicopter’s transmission limit. The T53-L-13 is a two-shaft free turbine with a 6-stage compressor (5 axial-flow stages, 1 centrifugal-flow stage) and a 4-stage axial-flow turbine (2 high-pressure stages, 2 low-pressure power turbine stages). The T53-L-13 is 3 feet, 11.9 inches (1.217 meters) long, 1 foot, 11.0 inches (0.584 meters) in diameter and weighs 549 pounds (249 kilograms).

The UH-1H has a maximum gross weight of 9,500 pounds (4,309.1 kilograms). Its maximum speed, Vne, is 124 knots (143 miles per hour, 230 kilometers per hour). With full fuel, 206.5 gallons (781.7 liters), the helicopter has a maximum endurance of three hours.

5,345 UH-1H Hueys were built, and many of the earlier UH-1Ds were upgraded to the UH-1H standard.

Copter 7, the Ventura County Sheriff’s Department HH-1H helicopter, was rebuilt and upgraded to Bell’s Huey II configuration in 1998. The revised aircraft features the driveline and rotors of the more powerful Model 212. The tail rotor has been moved to the right side of the tail rotor pylon in a tractor configuration, reversing its direction of rotation to clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) The original 1,400 shaft horsepower Lycoming T53-L-13 has been replaced with a T53-L-703, rated at 1,800 shaft horsepower (de-rated to the transmission limit). This engine is more durable, more fuel-efficent and increases the Huey’s maximum gross weight to 10,500 pounds (4,763 kilograms). The overhaul interval (TBO) increases from 2,400 hours, to 5,000 hours. The Huey II is optimized for “hot and high” operation, with increased hover ceilings, both in (HIGE) and out (HOGE) of ground effect.

Copter 7 also uses the BLR Aerospace FastFin for improved tail rotor performance. Water is dropped from a Simplex Aerospace Model 304 Fire Attack System which can carry 369 gallons (1,397 liters) of water, and is equipped with a snorkel to allow the helicopter to take on water while hovering over a source.

Dalton’s helicopter was soon joined by Copter 16, a Sikorsky S-70A Fire Hawk of the Los Angeles County Fire Department. Mutual aid between agencies is critical with limited air attack resources available.

Copter 16, a Sikorsky S-70 Fire Hawk operated by the Los Angeles County Fire Department, makes a water drop on the Solimar Fire, early on the morning 26 December 2015. (Cal Fire)
Copter 16, a Sikorsky S-70 Fire Hawk operated by the Los Angeles County Fire Department, makes a water drop on the Solimar Fire, early on the morning 26 December 2015. (Cal Fire)

After sunrise, Copters 7 and 16 were joined by two more Huey air attack helicopters from the Santa Barbara County Air Support Unit and Cal Fire, along with four fixed-wing air tankers. More than 600 firefighters fought the flames from the ground. Two of them were injured.

By early afternoon on the 26th, the Solimar Fire was contained after burning 1,236 acres (500 hectares). Traffic was restored and residents were allowed to return to their homes.

The fire was caused by arcing power lines.

The Ventura County Sheriff’s Department also operates a Bell 206L-1 LongRanger II (Copter 3), Bell 205A-1 (Copter 8), and a Bell 212 (Copter 9).

© 2016, Bryan R. Swopes

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8 December 1962

Bell YOH-4 N73999 (U.S. Army serial number 62-4202. (U.S. Army)
Bell Model 206 N73999 (U.S. Army YOH-4-BF 62-4202) at the Bell Helicopter Company plant, Hurst, Texas. (Bell Helicopter Co.)
Bell YHO-4-BF. (U.S. Army)
Bell YHO-4. (Bell Helicopter Co.)

8 December 1962: At the Bell Helicopter Company plant at Hurst, Texas, the first Model D-250, N73999 (YHO-4-BF 62-4202) made its first flight.

The United States military had requested proposals from 25 aircraft manufacturers for a Light Observation Helicopter (LOH) to be powered by a gas turbine engine. Eventually, helicopters proposed by three companies were selected for flight testing. These were the Bell YHO-4, the Fairchild Hiller FH-1100, designated as YHO-5, and the Hughes Aircraft Company Model 369, designated YHO-6.

In 1962, U.S. military aircraft designations were standardized between services, and the three helicopters were redesignated YOH-4, YOH-5 and YOH-6. Bell Helicopter had also changed its internal company designation for their proposal from D-250 to Model 206. All three were powered by an Allison T63-A-5 turboshaft engine rated at 250 shaft horsepower (Allison 250-C18).

Bell 206 N73999 (YHO-4-BF-62-4202). (U.S. Army)
Bell 206 N73999 (YHO-4-BF 62-4202). Note the stabilizer bar. (U.S. Army)
A prototype Bell YOH-4 Light Observation Helicopter hovers in ground effect. The vertical fin has been changed from the original ventral configuration. (U.S. Army)

After the fly-off, the Hughes OH-6A Cayuse was selected for production. With the LOH classification, the OH-6 earned the nickname “Loach.”  Modern variants of the OH-6, now the AH-6 and MH-6 “Little Bird,” remain in service with United States special operations forces.

Bell Helicopter tried to market their Model 206 as a light civil aircraft, but its utilitarian appearance made it a hard sell. The helicopter was redesigned as the Model 206A and given the name JetRanger. This became one of the most successful aircraft ever built and it remained in production until 2011.

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

As the Vietnam War escalated, the need for helicopters increased. Hughes Aircraft had limited production capacity so the U.S. Army ordered a version of the redesigned Bell YOH-4 as the OH-58A Kiowa (Bell Model 206A-1). Though similar in appearance to the civil Bell 206A JetRanger, the OH-58A has significant differences and few parts are interchangeable between models. The Kiowa’s main rotor blades and tail boom are longer than the JetRanger’s. The rotor system turns at a slower r.p.m. Landing skids are mounted differently. The OH-58A has a lower maximum gross weight. There are internal differences as well, for example, the main transmission of the OH-58A has only three planetary gears while the 206B uses four, giving it a greater torque capacity.

The OH-58 Kiowa was continuously upgraded to the OH-58D Kiowa Warrior, with advanced targeting and communications capabilities. The D model uses a composite four-bladed “soft-in-plane” main rotor. Military variants of the civil Bell 206B-3 JetRanger III have been used as training helicopters for the U.S. Navy (TH-57 Sea Ranger) and U.S. Army (TH-67 Creek). The U.S. Army has now retired all of its OH-58s. The final flight of an OH-58D Kiowa Warrior took place in September 2017.

The first production Bell OH-58A-BF Kiowa, 68-16687. (U.S. Army)
The first production Bell OH-58A-BF Kiowa, 68-16687. (Bell Helicopter Co.)

The YOH-4A prototype is in storage at the U.S. Army Aviation Museum, Fort Rucker, Alabama. Because of an error is assigning serial numbers, this aircraft carries a manufacturer’s data plate with the military serial number 62-4201,¹ however, the correct serial number, 62-4202, is painted on the airframe exterior.

A flight of Bell OH-58D Kiowa Warriors scouting in a war zone. (U.S. Army)
A flight of Bell OH-58D Kiowa Warriors scouting in a war zone. (U.S. Army)

¹ Serial number 62-4201 had already been assigned to a Lockheed C-140B-LM JetStar.

© 2017, Bryan R. Swopes

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8 December 1945

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)
Floyd William Carlson, Chief Test Pilot, Bell Aircraft Corporation, hovers the world’s first civil-certified helicopter, NC1H, Serial Number One. (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 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 assigned changed to NC1H.

Bell Model 47 NX41962, Serial Number 1, at Bell’s Wheatfield Plant, early 1946. (Bell Helicopter via “Floyd W. Carlson, Helicopter Pioneer”)

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.)

Power was supplied by an air-cooled, normally-aspirated, 333.99-cubic-inch-displacement (5.473 liter) Franklin Engine Company 6V4-175-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 gear reduction transmission which turned the main rotor through a two-stage planetary gear system. 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 (Vne) 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 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 produced under license by Agusta, Kawasaki and Westland. More than 7,000 were built worldwide and it is believed that about 10% of thoe 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. 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.

Wreck of Bell Model 47 NC1H, s/n 1. (Niagara Aerospace Museum)

© 2018, Bryan R. Swopes

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