Tag Archives: Helicopter

13 August 1976

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The prototype Bell 222 hovering in ground effect during its first flight, 13 August 1976. (Bell Helicopter TEXTRON)

13 August 1976: At the Bell Helicopter facility at Arlington, Texas, the prototype Model 222 twin-engine helicopter, registration N9988K, made its first flight. During the 42-minute flight, test pilots Donald Lee Bloom and Louis William Hartwig flew the aircraft through a series of hovering maneuvers and transitions to forward flight. A Bell spokesperson described it as, “One of the most successful prototype flights we’ve ever had.”

The prototype Bell 222 in flight with landing gear retracted, 13 August 1976. (Bell Helicopter TEXTRON)

The Model 222 (“Two Twenty-Two”) was Bell Helicopter’s first completely new helicopter since the Model 206 JetRanger series. Classified as a light twin, the aircraft was originally powered by two Lycoming LTS101-650C-3 turboshaft engines. The two-blade main rotor was similar in design to that used on the AH-1 Cobra attack helicopters. The first four prototypes were built with a T-tail configuration, but problems discovered early in the test program resulted in a change to the arrangement used in the production version.

Bell Model 222 prototypye, N9988K, in flight. Note T-tail configuration. (Bell Helicopter)
Bell Model 222 prototype, N9988K, in flight. Note T-tail configuration. (Bell Helicopter TEXTRON)

The Bell 222 is used as an executive transport, a utility transport and an aeromedical helicopter. It can carry a maximum of ten persons, and is operated with either one or two pilots. The 222 is certified for Instrument Flight Rules. The standard aircraft has retractable tricycle landing gear but the Model 222UT replaces that with a lighter weight skid gear.

The Bell Model 222 is 47 feet, 6.16 inches (14.482 meters) long with rotors turning. The helicopter has a maximum height of 14 feet, 7.25 inches (4.451 meters) with the forward main rotor blade against its droop stop. The height from ground level to the top of the vertical fin is 11 feet, 0.56 inches (3.367 meters). The helicopter’s maximum width is 11 feet, 4.0 inches (3.454 meters). The empty weight is 4,555 pounds (2,066 kilograms), and the maximum gross weight is 7,848 pounds (3,560 kilograms).

The fifth prototype Bell 222, N222BX (c/n 47005), in the 40′ × 80′ (12.2 × 24.4 meters) wind tunnel at the NASA Ames Research Center, Moffett Field, California. The man at the lower left corner of the image shows scale. (NASA)

The 222’s main rotor mast is tilted 5° forward and 1° 15′ to the left. This contributes to a higher forward air speed and counteracts the helicopter’s translating tendency in a hover.

The two-bladed, underslung, semi-rigid main rotor system rotates counter-clockwise as seen from above (the advancing blade is on the right.)and turns 324 r.p.m at 100% NR. The main rotor has a diameter of 39 feet, 9.0 inches (12.116 meters). The blades have a chord of 2 feet, 4.6 inches (7.264 meters) and are pre-coned 3° 30′. The two-bladed tail rotor is positioned on the left side of the tail boom and turns clockwise as seen from the helicopter’s left (the advancing blade is below the axis of rotation). The tail rotor’s diameter is 6 feet, 6.0 inches (1.981 meters). The blades’ chord is 10.0 inches (0.254 meters).

The Bell 222 was originally powered by two Lycoming LTS101-650C-3 engines. The LTS101 is a compact, light weight, turboshaft engine. The 2-stage compressor section has 1 axial-flow stage and 1 centrifugal-flow stage. The turbine section has 1 high-pressure gas generator stage and 1 low-pressure free power stage. The LTS101-650C-3 was has a maximum continuous power rating of 598 shaft horsepower (446 kilowatts at 49,159 r.p.m. (N1) at Sea Level, and 630 shaft horsepower (470 kilowatts) at 49,638 r.p.m. for takeoff (5-minute limit). The output shaft (N2) turns 9,545 r.p.m. With one engine inoperative (OEI), the -650C-3 is rated at 650 shaft horsepower (485 kilowatts) at 50,169 r.p.m. (30-minute limit), and a maximum 675 shaft horsepower at 50,548 r.p.m. N1/9,784 r.p.m. N2 (2½-minute limit). The LTS101-650C-3 is 1 foot, 10.6 inches (0.574 meters) in diameter, 2 feet,7.3 inches (0.795 meters) long, and has a dry weight of 241 pounds (109 kilograms).

The Bell 222 has a maximum speed of 130 knots. Its hover ceiling is approximately 9,000 feet (2,743 meters). The service ceiling is 12,800 feet (3,901 meters). The maximum range is 324 nautical miles (373 statute miles/600 kilometers).

During early production, problems were experienced with the LTS101 engines, which were also used on the Sikorsky S-76 and the Aérospatiale AS-350D A-Star. This seriously hurt the reputation and sales of all three helicopters. Bell Helicopter’s parent corporation, Textron, bought the Lycoming factory and modernized it in order to improve the engine. (The engine is now owned by Honeywell Aerospace.) Operators began to replace the two Lycoming engines with a pair of Allison 250-C30 turboshafts, and eventually Bell Helicopter modified the aircraft, marketing it as the Model 230. A four-bladed variant with a longer cabin is called the Model 430.

After the test program was completed, the first prototype, N9988K, was used as a static prop on the popular television series, “Airwolf.”

Bell 222 N34NR, an aeromedical helicopter operated by Air Angels, Inc., Bolingbrooke, Illinois. (Photograph courtesy of Chris Hargreaves)
Donald Lee Bloom

Donald Lee Bloom was born in Tulsa, Oklahoma, 23 April 1932. He was the son of Fred Miles Bloom, a telegraph operator for the Standard Oil Company, and Georgia Randolph Bloom.

Don Bloom attended the University of Houston as a Naval Reserve Officers Training Corps (NROTC) midshipman. He graduated in 1955. Bloom was commissioned as a second lieutenant, United States Marine Corps, 15 September 1955. He was assigned to pilot training at NAS Pensacola, Florida.

Lieutenant Bloom was promoted to the rank of first lieutenant, 15 March 1957. He married Miss Anne Marie Carruthers in Los Angeles, California, 5 September 1958. They would have four children, Susan, Stacy, Robert and Todd.

Lieutenant Bloom was released from active duty in 1960, and joined the Kaman Aircraft Corporation as a test pilot. In 1961, began his 29-year career as an experimental test pilot with the Bell Helicopter Company.

The first production Bell OH-58A-BF Kiowa, 68-16687. Don Bloom flight-tested this type in his investigation of Loss of Tail Rotor Effectiveness. (U.S. Army)

In 1984 the Society of Experimental Test Pilots gave its Iven C. Kincheloe Award to Don Bloom for his experimental research into the Loss of Tail Rotor Effectiveness (LTE).

After flying as a test pilot on 187 projects, Don Bloom retired from the Bell Helicopter Corporation in 1990 as Senior Experimental Test Pilot. He then worked for the Federal Aviation Administration Southwest Region as its Designated Engineering Representative Flight Test Pilot, testing aircraft for government certification. During his aviation career, Bloom flew over 14,000 hours in 102 different aircraft.

In 2011, the Federal Aviation Administration presented its Wright Brothers Master Pilot Award to Don Bloom.

Donald Lee Bloom died 18 July 2017 at Grapevine, Texas. He was buried at the Dallas-Fort Worth National Cemetery, Dallas, Texas.

Don Bloom was a project development test pilot for the Bell AH-1G Cobra. (U.S. Army)

Louis William Hartwig was born at Sherman, Iowa, 26 July 1922. He was the son of Lawrence C. Harwig and Alta May Gaughey Hartwig. He attended Bowie High Schoo in Bowie, Texas.

Lou Hartwig enlisted in the United States Army 8 September 1942. (s/n 17119277) He was assigned to the 304th and 902nd Field Artillery Battalions, 77th Infantry Division.

Lou Hartwig married Miss Katherine Elizabeth Healzer, a school teacher, at Rustburg, Virginia, 19 February 1944. They would have a son, Ronald.

Piper L-4 Grasshopper. (Harry S. Truman Library & Museum)

Hartwig was deployed to the Pacific theater of operations, 24 March 1944. He flew a Piper L-4 Grasshopper as an artillery spotter at Guam and Okinawa. He was discharged from his enlistment 18 June 1944, and commissioned a second lieutenant, 19 June 1944 (s/n O-1821011). Lieutenant Hartwig returned to the United States on 21 November 1945. He was released from active duty 24 January 1946.

Lou Hartwig was one of the early students of the Bell Aircraft Corporation’s helicopter flight school at Niagara Falls Airport, New York. The school was for experienced pilots only, and required 10–15 days to complete. Each student received a minimum 22½ flight hours in a Bell Model 47. The cost of the course was $600. Hartwig was then employed as an agriculture “crop dusting” pilot in California.

While spraying insecticide in a field near Sacramento, California, Hartwig was overcome by the poisonous chemicals and lost consciousness. The helicopter struck power lines and crashed. Hartwig was thrown from the cockpit. Crash investigators described the accident as “unsurvivable.” He spent the next 11 months in hospital.

Lou Hartwig was a test pilot for the U.S. Navy’s Bell HSL-1 ASW helicopter. (Bell Aircraft Corporation)

The Bell Helicopter Company hired Hartwig as a test pilot on 15 February 1955. One of his first projects was flight testing the Model 61, the only tandem rotor helicopter ever produced by Bell. It was used as an anti-submarine warfare helicopter by the U.S. Navy, designated HSL-1.

On 31 January 1961, Hartwig set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a Closed Circuit of 100 Kilometers Without Payload, when he flew a Bell Model 47J Ranger at an average speed of 168.36 kilometer per hour (104.61 miles per hour).¹

On 2 February 1961, Lou Hartwig flew a Bell Model 47G, N967B, to set three more FAI world records: Distance in a Closed Circuit Without Landing, 1,016.20 kilometers (631.44 miles); ² Speed Over a Closed Circuit of 500 Kilometers Without Payload, averaging 119.07 kilometers per hour (73.99 miles per hour); ³ and Speed Over a Closed Circuit of 1,000 Kilometers, 118.06 kilometers per hour (73.36 miles per hour.⁴ The Model 47G had been modified with an additional fuel tank from the earlier Model 47D-1, and curved landing skids from the Model 47J.

The Bell 533, 56-6723, in one of its many configurations. It was flown with two- and four-bladed main rotors, with and without wings, and with and without turbojet engines. (Bell Helicopter Corporation)

Lou Hartwig worked on the U.S. Army’s High Performance Helicopter project. A pre-production YH-40 Iroquois, serial number 56-6723, was modified into a winged and compound helicopter configuration, designated Model 533. Hartwig flew the helicopter to a speed of 274.6 knots (316.00 statute miles per hour/508.56 kilometers per hour). In 1971, the Vertical Flight Society gave its Frederick L. Feinberg Award to Hartwig.

Mrs. Hartwig died 10 February 1989, in San Diego, California. Lou Hartwig married his second wife, Joanne Dunning, in 1990.

Louis William Hartwig died 12 April 2016, at the age of 93 years. He was buried at the Dearborn Memorial Park, Poway, California.

¹ FAI Record File Number 986

² FAI Record File Number 983

³ FAI Record File Number 989

⁴ FAI Record File Number 990

© 2018, Bryan R. Swopes

11 August 1986: The World’s Fastest Helicopter

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Westland Lynx AH.1 G-LYNX.

11 August 1986: A modified factory demonstration Westland Lynx AH.1 helicopter, civil registration G-LYNX, piloted by Chief Test Pilot John Trevor Egginton and Flight Test Engineer Derek J. Clews, set a Fédération Aéronautique Internationale (FAI) Absolute Record for Speed for helicopters over a straight 15/25 km course with an average speed of 400.87 kilometers per hour (249.09 miles per hour) over a measured 15 kilometer (9.32 miles) course near Glastonbury on the Somerset Levels and Moors, Southwest England.¹ ² ³

Westland WG.13 Lynx G-LYNX, c/n 102. (Vertipedia)

The helicopter was equipped with experimental BERP main rotor blades and two Rolls Royce Gem 60 turboshaft engines with digital electronic fuel control and water-methanol injection, producing 1,345 shaft horsepower, each. The engines’ exhausts were modified to provide 600 pounds of thrust (2,669 Newtons). The horizontal tail plane and vertical fins from a Westland WG.30 were used to increase longitudinal stability and to unload the tail rotor in forward flight. In an effort to reduce aerodynamic drag, items such as steps, antennas and windshield wipers were removed.

During the speed runs, the main rotor blade tips reached a speed of 0.97 Mach.

Four passes over the course were made at an altitude of 500 feet (150 meters). The results of the two best successive passes were averaged. This set records for helicopters; helicopters in the 3,000–4,500 kilogram weight class; and an Absolute World Record for Rotorcraft. Thirty-two years later, these official speed records still stand.

Westland Lynx AH.1, G-LYNX. This is the World's Fastest Helicopter. (Westland)
Westland Lynx AH.1, G-LYNX. This is the World’s Fastest Helicopter. (Westland)

Another Westland AH.1 Lynx, flown by then Westland Chief Pilot Leonard Roy Moxham and Michael Ball, had set two FAI World Records for Speed, 20 and 22 June 1972. Flying over a straight 15/25 kilometer course, the Lynx averaged 321.74 kilometers per hour (199.92 miles per hour).⁴ Two days later, the Lynx flew a closed 100 kilometer circuit at an average speed of 318.50 kilometers per hour (197.91 miles per hour).⁵ Both of these records were for helicopters in the 3,000–4,500 kilogram weight class.

Westland WG.13 c/n 102 made its first flight in May 1979. After setting the speed record, G-LYNX was used as a demonstrator and as a test platform, before finally being retired in 1992. Beginning in 2007, AgustaWestland restored the Lynx to its speed record configuration, withe more than 25,000 man hours expended on the project.

G-LYNX was unveiled on 11 August 2011, the 25th anniversary of the world record flight. Today, it is on display at The Helicopter Museum, Weston-super-Mare, Somerset, South West England.

On 25 September 2014, the Institution of Mechanical Engineers bestowed its Engineering Heritage Award on G-LYNX. John Wood, chairman of the Institution said,

“The G-Lynx helicopter is a remarkable example of British engineering and vision. It is a testament to the cutting-edge modifications made to the helicopter, that the world speed record still stands 28 years later.

“This award is in recognition of all the people in making the 1986 record possible, but also to the AgustaWestland apprentices who restored the helicopter in 2011 and the Helicopter Museum who continue to maintain the craft in such excellent condition.”

The Engineering Heritage Award was accepted by Elfan Ap Rees, founder of the Helicopter Museum, and John Trevor Egginton, pilot of the world record helicopter.

John Trevor Egginton, O.B.E., A.F.C., FRAeS. Chief Test Pilot, Westland Helicopters. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight test Engineers)

John Trevor Egginton was born in Birmingham, England, 14 March 1933. He was the second child of Alfred T. Egginton and Emma Hammond Egginton. John attended the George Dixon Grammar School at Edgbaston, a suburb of Birmingham.

In 1951, Egginton joined the Royal Air Force. On 7 May 1952, he was appointed a cadet pilot, with date of service from 2 January 1952. He was sent to the United States for flight training, and returned to England aboard RMS Queen Elizabeth, arriving at Southampton, 17 November 1953. He flew the Canadair CL-13 Sabre Mk.4 with No. 67 Squadron and the Hawker Hunter with Nos. 222 and 63 Squadrons.

In December 1956, Pilot Officer Egginton married Miss Joan Mary Wheeler at Bromsgrove, near Birmingham. They would have three children, Jane, Michael and Frazer.

Pilot Officer Egginton was promoted to the rank of Flight Lieutenant, 2 October 1957. His commission was made permanent, 31 August 1961.

Following an overseas tour of duty in the Colony of Aden, Flight Lieutenant Egginton transitioned to helicopters, training in the Bristol Sycamore. He was then assigned to No. 22 Squadron at RAF Chivenor, on the north coast of Devon, as a search and rescue pilot. The squadron was equipped with the Westland Whirlwind HAR.2, a licensed variant of the Sikorsky S-55. In August 1962, the unit upgraded to the turboshaft-powered Whirlwind HAR.10.

On the night of 2–3 November 1962, the French fishing trawler Jeanne Gougy, with a crew of 18 men, went aground at Land’s End, Cornwall. A Royal Air Force helicopter from RAF Chivenor and a lifeboat from the Sennen Cove life boat station went to the scene. The lifeboat was unable to approach the wreck because of the heavy weather, but recovered two dead fishermen offshore. The helicopter also recovered a body. No other sailors were seen, the the two rescue craft returned to there bases with the remains.

Later that morning, observers from the shore saw several men inside the Jeanne Gougy‘s pilot house. A helicopter and the Penlee lifeboat, Soloman Brown, hurried to the scene, but conditions were still too extreme for the lifeboat to approach the trawler.

The Westland Whirlwind, flown by Flight Lieutenants John Lorimer Neville Canham, D.F.C., and John Trevor Egginton, hovered over the capsized fishing trawler while the winch operator, Sergeant Eric Charles Smith, was lowered to the ship’s pilot house. A rescue line was also rigged to the nearby rocks. Sergeant Smith rigged two men for hoisting to the hovering helicopter and continued searching for additional survivors. Four sailors were rescued by the line to the shore. 12 of the fishermen did not survive.

Westland Whirlwind HAR.10, No. 22 Squadron, hoists a man from the fishing trawler Jeanne Gougy at Armoured Knight Rock, Land’s End, Cornwall, England, 3 November 1962. (RNLI Penlee Lifeboat Station)
Sergeant Eric Smith, RAF, is lowered to the wreck of Jeanne Gougy, 3 November 1962. (BFI)

For his bravery during the rescue, Sergeant Smith was awarded the George Medal by Queen Elizabeth II. He was also awarded the Silver Medal of the Société des Hospitalers Sauveteurts Bretons.

The President of the French Republic, Charles de Gaulle, conferred the honor of Chevalier du Mérite Maritime on Flight Lieutenant Canham, Flight Lieutenant Egginton, and Sergeant Smith. On 13 June 1964, Egginton was awarded the Air Force Cross.

In 1965, Flight Lieutenant Egginton attended the Empire Test Pilots’ School at RAF Boscombe Down. On graduation, he was assigned as a helicopter test pilot with D Squadron (now the Rotary Wing Test and Evaluation Squadron, or RWTES). In 1969, Egginton returned to the Test Pilots’ School as a helicopter flight instructor.

Squadron Leader Egginton retired from the Royal Air Force in 1973. He was awarded the Queen’s Commendation for Valuable Service in the Air, 2 June 1973. (London Gazette No. 45984 at Page 6463)

Egginton joined Westland Helicopters at Yeovil as deputy chief test pilot, and later became the company’s chief test pilot. He from Westland retired after 15 years.

In the 1989 New Year’s Honours List, Squadron Leader Egginton was appointed an Officer of the Most Excellent Order of the British Empire (O.B.E.):

Squadron Leader John Trevor Egginton, O.B.E., A.F.C., F.R.Ae.S., Q.C.V.S.A., Chevalier du Mérite Maritime, died at his home in Yeovil, 23 November 2014. He was 81 years of age.

In April 2013, Trevor Egginton spoke to members of the Empire Test Pilots’ School at The Helicopter Museum, Weston-super-Mare. In this photograph, Mr. Egginton is seated in the World Record Helicopter’s pilot seat. (The Helicopter Museum)

¹ FAI Record File Number 11659: Rotorcraft, Absolute Record for Speed Over a 15–25 Kilometer Straight Course

² FAI Record File Number 1842: Rotorcraft, Helicopters, Subclass E-1e, 3,000–4,500 kilograms (6,613.9–9,920.8 pounds), takeoff weight

³ FAI Record File Number 1843: Rotorcraft, Helicopters, Subclass E-1

⁴ FAI Record File Number 1826: Rotorcraft, Helicopters, Subclass E-1e

⁵ FAI Record File Number 1853: Rotorcraft, Helicopters, Subclass E-1e

Westland Lynx G-LYNX.

© 2018, Bryan R. Swopes

4 August 1950

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A U.S. Air Force Sikorsky H-5F lifts off during the Korean War. (U.S. Air Force)

4 August 1950: During the Battle of the Pusan Perimeter, wounded soldiers were evacuated from the battlefield by helicopter for the first time when a Sikorsky H-5F of Detachment F, 3rd Emergency Rescue Squadron,¹ Air Rescue Service, United States Air Force, flew Private 1st Class Claude C. Crest, Jr., U.S. Army, from the Sengdang-ni area to an Army hospital. By the end of combat in 1953, 21,212 soldiers had been medevaced by helicopters.

Only the second military helicopter, the H-5 was frequently flown overloaded and outside of its center of gravity limits. The helicopter was not armed, though the pilot normally carried an M1911 .45-caliber semi-automatic pistol, and the crewman, a .30-caliber M1 Carbine.

Eleven commercial Sikorsky S-51 helicopters had been purchased by the Air Force in 1947 and designated R-5F. This was later changed to H-5F. It was a four-place, single-engine helicopter, operated by one pilot. The cabin was built of aluminum with Plexiglas windows. The fuselage was built of plastic-impregnated plywood, and the tail boom was wood monocoque construction. The main rotor consisted of three fully-articulated blades built of metal spars and plywood ribs, covered with two layers of fabric. (All metal blades soon became available.) The three bladed semi-articulated tail rotor was built of laminated wood. The main rotor turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) Its normal operating range was 175–195 r.p.m. The tail rotor was mounted on the helicopter’s left side in a pusher configuration. It turned clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)

Sikorsky S-51 three-view drawing with dimensions. (Sikorsky Historical Archives)

The helicopter’s fuselage was 41 feet, 1¾ inches (12.541 meters) long. The main rotor had a diameter of 48 feet, 0 inches (14.630 meters) and the tail rotor diameter was 8 feet, 5 inches (2.565 meters),² giving the helicopter an overall length of 57 feet, ½ inch (17.386 meters) with rotors turning. It was 12 feet, 11–3/8 inches (3.947 meters) high. The tricycle landing gear had a wheel base of 10 feet, 1 inch (3.073 and the tread was 12 feet, 0 inches (3.658 meters). The S-51 had an empty weight of 4,050 pounds (1,837 kilograms) and maximum gross weight of 5,300 pounds (2,404 kilograms) below 1,000 feet (305 meters) MSL.³ Fuel capacity was 100 gallons (379 liters).

The H-5F was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney R-985 AN-5 (Wasp Jr. T1B4 ) which was placed in the fuselage behind the crew compartment with the crankshaft vertical. The R-985-AN-5 was a direct-drive, nine-cylinder radial engine with a compression ratio of 6:1. It required 91-octane aviation gasoline and was rated at 450 horsepower at 2,300 r.p.m., Standard Day at Sea Level. The R-985 AN-5 was 48.00 inches (1.219 meters) long, 46.25 inches (1.175 meters) in diameter and weighed 684 pounds (310.3 kilograms) with a magnesium crankcase.

The H-5F had a maximum speed (VNE) of 107 knots (123 miles per hour/198 kilometers per hour). Range was 275 miles (443 kilometers). The service ceiling was 14,800 feet (4,511 meters). The absolute hover ceiling was 3,000 feet (914 meters).

Sikorsky H-5, Korea. (U.S. Air Force)
Sikorsky H-5, Korea. (U.S. Air Force)

¹ Reorganized as the 3rd Air Rescue Squadron 10 August 1950.

² An 8 foot, 9 inch (2.667 meter) all-metal two-blade tail rotor assembly became standard with the H-5G, and was available to retrofit earlier helicopters.

³ The maximum gross weight had to be reduced 150 pounds (68 kilograms) for each additional 1,000 feet of altitude.

© 2018, Bryan R. Swopes

18 July 1967

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18 July 1967: For the first time, a U.S. Air Force Sikorsky HH-3E Jolly Green Giant combat search and rescue helicopter refueled in flight from a Lockheed HC-130P Combat King command and control aircraft during an actual rescue mission in Southeast Asia.

A Lockheed HC-130P Combat King refuels a Sikorsky HH-3E Jolly Green Giant, with escorting Douglas A-1E and A-1H Skyraiders, Southeast Asia, 1968. (U.S. Air Force)

© 2015, Bryan R. Swopes

16 July 1983

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British Airways’ Sikorsky S-61N Mark II, G-BEON, at Newquay Cornwall Airport, 21 July 1982. (Carl Ford)

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.

Great Circle route from Penzance Heliport, Cornwall, to St. Mary’s Airport, Iles of Scilly, 33 nautical miles (37 statute miles/60 kilometers) away. (Great Circle Mapper)

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 wreck of British Airways S-61N Sea King G-BEON on board RMAS Seaforth Clansman. Isles of Scilly, 1983. (Andrew Besley/cornishmemory.com)

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.

© 2018, Bryan R. Swopes