Tag Archives: Helicopter

14 August 1968

Aviation, , , , , , , , , , , , , , , ,
Sikorsky S-61L N300Y, Los Angeles Airways, at Disneyland Heliport, Anaheim, California. (Robert Boser)
Sikorsky S-61L N300Y, Los Angeles Airways, at Disneyland Heliport, Anaheim, California. (Robert Boser)

14 August 1968: At 10:28:15 a.m., Pacific Daylight Time, Los Angeles Airways Flight 417, a Sikorsky S-61L helicopter, departed Los Angles International Airport (LAX) on a regularly-scheduled passenger flight to Disneyland, Anaheim, California. On board were a crew of three and eighteen passengers. The aircraft commander, Captain Kenneth L. Waggoner, held an Airline Transport Pilot certificate and was type-rated in the Sikorsky S-55, S-58 and S-61L. He had a total of 5,877:23 flight hours, with 4,300:27 hours in the S-61L. Co-pilot F. Charles Fracker, Jr. had 1,661:18 flight hours, of which 634:18 were in the S-61L. Flight Attendant James A. Black had been employed with LAA for nearly ten years.

At approximately 10:35 a.m., while flying at an estimated altitude of 1,200–1,500 feet (370–460 meters) above the ground, one of the helicopter’s five main rotor blades separated from the aircraft which immediately went out of control, started to break up, and crashed in a recreational park in Compton. All twenty-one persons on board, including the 13-year-old grandson of the airlines’ founder and CEO, were killed.

The Sikorsky S-61 was registered N300Y.  It had been the prototype S-61L, serial number 61031. Los Angeles Airways was the first civil operator of the S-61, purchasing them at a cost of $650,000 each. As of the morning of 14 August 1968, 61031 had accumulated a total of 11,863.64 hours flight time on the airframe (TTAF). It flew an estimated 3.17 hours on the morning of the accident.

The Sikorsky S-61L was a civil variant of the United States Navy HSS-2 Sea King, and was the first helicopter specifically built for airline use. The prototype, N300Y, first flew 2 November 1961. It is a large twin-engine helicopter with a single main rotor/tail rotor configuration. Although HSS-2 fuselage is designed to allow landing on water, the S-61L is not amphibious, having standard fixed landing gear rather than the sponsons of the HSS-2 (and civil S-61N). The S-61L fuselage is 4 feet, 2 inches (1.270 meters) longer than that of the HSS-2. The S-61L 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.)

The S-61L was powered by two General Electric CT58-140-1 turboshaft engines, each of which was rated for 1,400 shaft horsepower for takeoff and maximum power of 1,500 shaft horsepower 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). 61031 had a maximum takeoff weight (MTOW) of 19,000 pounds (8,618.3 kilograms).

Between 1958 and 1980, Sikorsky built 794 S-61 series helicopters. 13 were S-61Ls.

The National Transportation Safety Board investigation found that most of the helicopter was contained with a small area of Leuders Park. One main rotor blade, however, was located approximately 0.25 miles (0.40 kilometers) west of the main wreckage. This blade is referred to as the “yellow” blade. (The main rotor blades marked with colored paint for simplicity, red, black, white, yellow, and blue.) Analysis found that this blade’s spindle, where it attached to the main rotor hub assembly, had failed due to a fatigue fracture. It was believed that the fracture began in an area of substandard hardness which was present in the original ingot from which the part was forged, and that inadequate shot-peening of the part during the overhaul process further weakened the spindle.

Diagram of fractured main rotor spindle. (NTSB)
Diagram of fractured main rotor spindle. (NTSB)

Los Angeles Airways had experienced a similar accident only three months earlier which had resulted in the deaths of all 23 persons on board. (Flight 841, 22 May 1968). L.A. Airways never recovered and ceased all operations by 1971.

© 2016, Bryan R. Swopes

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13 August 1976

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The prototype Bell 222 hovering during its first flight, 13 August 1983. (Bell Helicopter)
The prototype Bell 222 hovering during its first flight, 13 August 1976. (Bell Helicopter)

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 Bloom and Lou 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 Model 222 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 LTS101-650C3 turboshaft engines producing 592 horsepower, each. 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)

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.

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 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 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)

© 2017, Bryan R. Swopes

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11 August 1986

Aviation, , , , , , , , , , , , , , , , ,
John Trevor Egginton, Chief Pilot, Westland Helicopters. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight test Engineers)
John Trevor Egginton, Chief Pilot, Westland Helicopters. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

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

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. The horizontal tail plane and vertical fins from a Westland WG.30 were used to increase longitudinal stability and unload the tail rotor. In an effort to reduce aerodynamic drag, items such as steps, antennas and windshield wipers were removed.

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

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 both a record for helicopters in the 3,000 to 4,500 kilogram weight class, and the absolute record for helicopters in general. Thirty-one years later, these official speed records still stand.

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).³ 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).⁴ Both of these records were for helicopters in the 3,000–4,500 kilogram weight class.

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)

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.

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 helicopter's pilot seat. (The Helicopter Museum)
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 1842 (Helicopters with takeoff weight 3,000–4,000 kg)

² FAI Record File Number 1843 (Helicopters, General) [Absolute Record]

³ FAI Record File Number 1826

⁴ FAI Record File Number 1853

© 2017, Bryan R. Swopes

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6 August 1969

Aviation, , , , , , , , , , , , ,
One of the two Mil Design Bureau V-12 heavy lift helicopter prototypes, 1971. (Groningen Airport-Eelde)

6 August 1969: The largest helicopter ever built, the four-engine, transverse tandem rotor Mil V-12, registration CCCP-21142, lifted a payload of 88,636 pounds (44,205 kilograms) to an altitude of 7,400 feet (2,255 meters). This weight record has never been broken by any helicopter.

FAI Record File Num #9916 [Direct Link]
Status: ratified – current record
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1 (Helicopters)
Category: General
Group: 2 : turbine
Type of record: Altitude with 35 000 kg payload
Performance: 2 255 m
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV, V.P. BARTCHENKOV, S.G. RIBALKO, A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

FAI Record File Num #9917 [Direct Link]
Status: ratified – current record
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1 (Helicopters)
Category: General
Group: 2 : turbine
Type of record: Altitude with 40 000 kg payload
Performance: 2 255 m
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV, V.P. BARTCHENKOV, S.G. RIBALKO, A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

FAI Record File Num #9937 [Direct Link]
Status: ratified – superseded since approved
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1e (Helicopters: take off weight 3000 to 4500 kg)
Category: General
Group: 2 : turbine
Type of record: Greatest mass carried to height of 2 000 m
Performance: 40 204.5 kg
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV,V.P. BARTCHENKO,S.G. RIBALKO,A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

This was the first of two prototypes built by the Mil Design Bureau. (Both had the same registration number: 21142.) It was intended to transport intercontinental ballistic missiles and load them directly into underground silos where there were no existing roads. The V-12 used two main rotor, transmission and twin engine systems from the single rotor Mil-6 helicopter. With counter-rotating main rotors, the torque created by each rotor system is cancelled out, eliminating the need for a tail, or anti-torque, rotor. This makes the total power produced available for lift. Each rotor had a diameter of 114 feet, 10 inches (35 meters). The four Soloviev D-25VF turboshaft engines combined to produce 26,000 horsepower. The aircraft was operated by a six-man crew. It’s maximum takeoff weight was 231,500 pounds (105,000 kilograms). It had a range of 310 miles (500 kilometers). Maximum speed of the V-12 was 140 knots (260 kilometers per hour) and the service ceiling was 11,500 feet (3,500 meters).

The helicopter was not put into series production. The record-setting first prototype is at the Mikhail Leontyevich Mil helicopter factory at Panki-Tomilino, near Moscow.

World Record Mil Mi-12 at Tomolino.
World Record holding Mil Mi-12 at Tomolino. (Yuriy Lapitskyi)

© 2015, Bryan R. Swopes

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4 August 1950

Aviation, , , , , , , , , , , , , , ,
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 Air Rescue Squadron, United States Air Force, flew out 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 civil Sikorsky S-51 helicopters had been purchased 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 and 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.) 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.)

The helicopter’s fuselage was 41 feet, 7.5 inches (12.687 meters). The main rotor had a diameter of 48 feet (14.630 meters) and tail rotor diameter was 8 feet, 5 inches (2.2.565 meters), giving the helicopter an overall length of 57 feet, 1 inch (17.399 meters). It was 13 feet, 1.5 inches (4.001 meters) high. The landing gear tread was 12 feet (3.7 meters). The S-51 had an empty weight of 4,050 pounds (1,837 kilograms) and maximum takeoff weight of 5,500 pounds (2,495 kilograms). Fuel capacity was 100 gallons (378.5 liters).

The H-5F was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney Wasp Jr. T1B4 (R-985 AN-5) direct-drive, nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine 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 (442.6 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)

© 2016, Bryan R. Swopes

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