Tag Archives: Sikorsky Aircraft Division of United Aircraft Corporation

1 June 1961

June 1, 2024AviationGeneral Electric CT58-110-1, Mervin Frances ("Mike") Bagan, N323Y, N978, s/n 62009, s/n 62014, San Francisco-Oakland Helicopter Airlines, SFO Helicopter Airlines, Sikorsky Aircraft Division of United Aircraft Corporation, Sikorsky S-62ABryan Swopes

A Sikorsky S-62, N323Y, at the SFO heliport adjacent to the Ferry Building in downtown San Francisco. (Vertical Flight Society)

1 June 1961: San Francisco-Oakland Helicopter Airlines (also known as SFO Helicopter Airlines) begins operating scheduled passenger service between San Francisco International Airport (SFO), Oakland Metropolitan Airport (OAK), and the cities of Berkeley, San Francisco, Oakland and Palo Alto, in the San Francisco Bay Area of California. The company initially used two Sikorsky S-62A helicopters.

Passenger fares ranged from $4.00 to $8.50.

One of the helistops was in the parking lot adjacent to the Ferry Building in downtown San Francisco. The noise of the helicopters generated many complaints.

On 13 July, the San Francisco Port Authority warned the airline that it had 30 days to “abate” the noise of the helicopters taking off and landing at the Ferry Building “or to find another location.” After the airline notified the Port Authority that it would acquire quieter, twin-engine Sikorsky S-61N helicopters, the Authority rescinded its removal order on 9 August.

The Palo Alto Times reported:

‘Copter passenger service under way

San Francisco-Oakland today became the fourth metropolitan area in the United States to get scheduled helicopter passenger service.

The new San Francisco and Oakland Helicopter Airlines, Inc., this morning inaugurated regular flights linking the San Francisco and Oakland airports with downtown heliports in both cities.

Approximately 30 daily flights are scheduled between the hours of 6:30 a.m. and 10:30 p.m.

Flights to Palo Alto, San Jose, Berkeley and Sacramento will be added in the near future.

Initially the line is flying two turbine-powered Sikorsky S-62 amphibious helicopters. Each helicopter is capable of carrying 10 passengers, plus baggage, at speeds of 100 miles per hour.

The downtown San Francisco heliport is located on a new site just north of the Ferry Building and adjacent to the World Trade center. The Oakland heliport is near Lake Merritt on 10th Street, next to the Oakland Auditorium and the Exposition Building

An airlines spokesman said the firm has applied to the Civil Aeronautics Board for authority to carry passengers and cargo between any points within a 100-mile radius of the San Francisco and Oakland airports.

The firm has plans to acquire a third helicopter which would carry 28 passengers as soon as the traffic load increases, the spokesman said.

The new service makes the trip between downtown San Francisco and the San Francisco International Airport in eight minutes. Fares for the service range from $4 to $8.50.

Other cities which already have helicopter passenger service are Los Angeles, New York and Chicago.

—Palo Alto Times, Vol. 69, No.130, 1 June 1961, Page 10, Columns 6–8

The president of the new company, Mervyn Frances (“Mike”) Bagan, was formerly an attorney for the Civil Aeronautics Board, and vice president of Los Angeles Airways. He also served as the Director of Research for Central Airlines.

San Francisco-Oakland Helicopter Airlines’ Sikorsky S-62A N978 takes of from the main terminal at San Francisco International Airport. (Vertical Flight Society)

SFO Helicopter Airline’s S-62As could carry 10 passengers. (Vertical Flight Society)

Left to right: Captain Bruce F. DeHaas, Vice President-Operations; John J. Cunningham, Vice President; Mervyn F. Bagan, President; Roger E. Hall, Director of Traffic and Sales; Chester M. Schmidt, Director of Maintenance. (Vertical Flight Society)

The S-62A was manufactured by the Sikorsky Aircraft Division of the United Technologies Corporation at Stratford, Connecticut. It is a medium helicopter, flown by two pilots. It could carry ten passengers. The helicopter was powered by a single turboshaft engine. It used the dynamic components of the earlier Sikoprsky S-55 model (main rotor head, main rotor blades, intermediate gear box, tail gear box tail rotor head and blades). The main transmission was modified to bring the turboshaft engine’s r.p.m. to an acceptable speed (85.839:1 gear reduction). Tail rotor drive is 12.274:1 The fuselage features a “boat hull” for water landings.

The helicopter’s main landing gear is retractable into sponsons. The tail wheel is fixed.

Sikorsky S-62 three-view illustration with dimensions. (Sikorsky)

The S-62 has an overall length of 62 feet, 3 inches (18.974 meters) with rotors turning. The fuselage is 45 feet, 5.5 inches (13,856 meters) long and 5 feet, 10 inches (1.778 meters) wide. The three-blade main rotor diameter is 53 feet, 0 inches (16.154 meters), and tail rotor diameter, 8 feet, 9 inches (2.667 meters). It has a maximum height of 15 feet, 11.8 inches (4.872 meters). As is common with American single main rotor helicopters, the main rotor turns counterclockwise as seen from above. (The advancing blade is on the right side of the helicopter.) The two-blade tail rotor, which is mounted on the left side of the tail boom, turns clockwise, as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.) The S-62A has an empty weight of 5,083 pounds (2,306 kilograms), and maximum gross weight of 8,300 pounds (3,765 kilograms).

The Sikorsky S-62A is powered by one General Electric CT58-110-1 turboshaft engine, offset to the left of the aircraft centerline. The engine has a 10-stage axial-flow compressor, an annular combustion chamber, 2-stage gas producer turbine, a single-stage power turbine. The CT58-110-1’s maximum continuous power rating is 1,050 shaft horsepower (783 kilowatts). The engine is derated to 670 shaft horsepower (500 kilowatts) as installed. This engine is 1 foot, 4 inches (0.406 meters) in diameter and 4 feet, 7 inches (1.397 meters) long. Without the reduction gear box, it weighs 285 pounds (129 kilograms).

The helicopter has two fuel tanks with a total capacity of 325.0 U.S. gallons (1,230.26 liters). The unusable fuel is 1.07 gallons (4.050 liters).

The S-62’s normal cruise speed 85 knots (98 miles per hour/157 kilometers per hour), while its maximum allowable speed (V_NE) is 109 knots (125 miles per hour/202 kilometers per hour) with the gross weight below 6,500 pounds (2,948 kilograms). Sideward flight is limited to 25 knots (29 miles per hour/46 kilometers per hour), and rearward, 20 knots (23 miles per hour/37 kilometers per hour). The maximum range is 400 nautical miles (460 statute miles/741 kilometers), and the service ceiling is 11,200 feet (3,414 meters).

A total of 151 Sikorsky S-62s were built. The United States Coast Guard purchased 99 S-62Cs, designated HH-52A. These differed from the commercial variant by having three axis automatic stabilization equipment, LORAN navigation, and a rescue hoist, and a General Electric T58-GE-8 engines rated at 1,250 shaft horsepower (919 kilowatts), derated to 730 shaft horsepower (553 kilowatts). Mitsubishi Heavy Industries built the S-62J variant under license. The HH-52 was in service with the USCG from 1963 until 1989. According to Sikorsky, the HH-52 series has rescued more than 15,000 people while in service with the Coast Guard, far more than any other helicopter type up to that time.

Two S-62As were operated by San Francisco-Oakland Helicopter Airlines. Sikorsky S-62 N978 (serial number 62009) was manufactured in 1960. Its FAA registration was cancelled 18 September 2009. N323Y (serial number 62014) was manufactured in 1961. It was destroyed and its FAA registration cancelled 18 November 1980.

18 December 1953

December 18, 2023AviationBu. No. 133732, Dimitry D. Viner, Fédération Aéronautique Internationale, First Flight, James Edward Chudars, Major Roy Lee Anderson USMC, Pratt & Whitney R-2800-54, Prototype, Robert Stewart Decker, Sikorsky Aircraft Division of United Aircraft Corporation, Sikorsky H-37 Mohave, Sikorsky Model S-56, Sikorsky XHR2S-1Bryan Swopes

Sikorsky XHR2S-1, Bu. No. 133732, the first Model S-56, hovers at Sikorsky Aircraft, Bridgeport, Connecticut. (Sikorsky Historical Archives)

18 December 1953: At Bridgeport, Connecticut, Sikorsky chief test pilot Dimitry D. (“Jimmy”) Viner and co-pilot James Edward Chudars made the first flight of the Sikorsky XHR2S-1 (Sikorsky Model S-56). The XHR2S-1 was a prototype assault and heavy-lift helicopter for the United States Navy and Marine Corps. It was later adopted by the U.S. Army as the H-37 Mohave.

The S-56 was a large twin-engine helicopter, following the single main rotor/tail (anti-torque) rotor configuration pioneered by Sikorsky with the Vought-Sikorsky VS-300 in 1939. The helicopter was designed to be flown by two pilots in a cockpit located above the main cabin. The two engines were placed in nacelles outboard of the stub wings which also housed the helicopter’s retractable main landing gear. Two large clam shell cargo doors and loading ramp were placed in the nose. The HR2S-1 incorporated a stability system and an automatic torque compensating tail rotor.

The S-56 series was the largest and fastest helicopter built up to that time, and remains the largest reciprocating engine helicopter ever built.

U.S. Marine Corps HR2S-1 Bu. No. 138423, the seventh production S-56 helicopter (Sikorsky Historical Archives)

The S-56 was equipped with a five blade articulated main rotor. This allowed increased lift and higher forward air speed before encountering retreating blade stall than earlier three and four blade systems. A six blade rotor system was tested, which showed further improvements, but was not adopted. The main rotor diameter was initially 68 feet (20.726 meters), but later increased to 72 feet (21.946 meters). The main rotor blades had a chord of 1 foot, 9.5 inches (0.546 meters) and used the symmetrical NACA 0012 airfoil, which was standard with American helicopters up to that time. Later in the program, the blades were lengthened and the chord increased to 1 foot, 11.65 inches (0.601 meters). The airfoil was changed to the NACA 0010.9 airfoil. These changes resulted in increased lift and higher speed. The four blade tail rotor had a diameter of 15 feet (4.572 meters). The individual blades had a chord of 1 foot, 1.5 inches (0.343 meters). As is common with American helicopters, the main rotor system turned counter-clockwise as seen from above. (The advancing blade is on the right.) The tail rotor turned counter-clockwise when viewed from the helicopter’s left side. (The advancing blade is above the axis of rotation.)

Sikorsky S-56 three-view illustration with dimensions. (Sikorsky Historical Archives)

With the longer blades installed, the helicopter’s length with rotors turning was 88 feet (26.822 meters). The fuselage had a length of 64 feet, 10.69 inches (19.779 meters), and the height was 17 feet, 2 inches (5.232 meters). The HR2S-1 had an empty weight of 21,502 pounds (9,753 kilograms), and maximum weight (overload) of 31,000 pounds (14,061 kilograms). Its fuel capacity was 1,000 U.S. gallons (3,785 liters) carried in 6 tanks located in the nacelles, wings and fuselage. It could carry 20 fully-equipped troops, or 16 litters. Its maximum cargo capacity was 10,000 pounds (4,536 kilograms).

The HR2S-1 had an automatic main rotor blade folding system, and its tail rotor pylon could be folded alongside the fuselage, reducing the length to 55 feet, 8 inches (16.967 meters) and width to 27 feet, 4 inches (8.331 meters). This allowed the helicopter to use aircraft carrier elevators and reduced storage space on the hangar deck.

Early S-56 models were powered by two air-cooled, supercharged 2,804.461 cubic inch displacement (45.957 liters) Pratt & Whitney Double Wasp R-2800-50 two-row, 18-cylinder radial engines rated at 1,900 horsepower at 2,500 r.p.m. These were upgraded in later models to R-2800-54s. These were direct drive engines with a compression ratio of 6.75:1. The R-2800-54 was rated at 2,100 horsepower at 2,700 r.p.m. to 5,000 feet (1,524 meters) for takeoff; with a normal power rating of 1,900 horsepower at 2,600 r.p.m. to 7,000 feet (2,134 meters). It required 115/145 octane aviation gasoline. Each engine was supplied with 13.3 gallons (50.35 liters) of lubricating oil. The R-2800-54 was 6 feet, 9.00 inches long (2.057 meters), 4 feet, 5.00 inches (1.346 meters) in diameter, and weighed 2,300 pounds (1,043 kilograms).

The helicopter’s engines were installed at an 80° angle to the aircraft center line, with a 12.5° upward angle to align with the main transmission input. The front of the engines faced inboard. According to Sikorsky, this unusual installation resulted in high oil consumption, and because the engines were operated at continuous high r.p.m., the time interval between engine overhauls was reduced from the normal 2,000 hours to just 350 hours.

Two U.S. Marine Corps HR2S-1 Mohave assault helicopters of Marine Helicopter Transport Squadron (HMR) 462 at Camp Pendelton, California, late 1950s. (Naval History and Heritage Command)

The production HR2S-1 had a cruise speed of 100 knots (115 miles per hour/185 kilometers per hour), and a maximum speed of 121 knots (139 miles per hour/224 kilometers per hour) at Sea Level. The helicopter’s service ceiling was 13,800 feet (4,206 meters), and its absolute hover ceiling was 5,400 feet (1,646 meters). It had a maximum rate of climb of 1,580 feet per minute (8.03 meters per second) at Sea Level, and a vertical rate of climb 950 feet per minute (4.83 meters per second), also at Sea Level. The combat radius of the HR2S-1 was 100 nautical miles (115 statute miles/185 kilometers) at 100 knots (115 miles per hour/185 kilometers per hour.)

55 HR2S-1s were delivered to the U.S. Marine Corps. The U.S. Army purchased 94 S-56s in the H-37A Mohave configuration. 90 of these were later returned to Sikorsky to be upgraded to H-37Bs. This added the automatic stabilization system of the HR2S-1, changed the variable incidence horizontal stabilizers on both side of the fuselage to a single stabilizer on top of the tail rotor pylon. Engine oil capacity was increased to 30 gallons (113.6 liters) per engine.

A total of 154 S-56s were built between 1953 and 1960.

U.S. Marines exit the front cargo doors of a Sikorsky XHR2S-1 helicopter during a demonstration at Bridgeport, Connecticut, circa 1953. The leading Marine is carrying an M1918 .30-caliber Browning Automatic Rifle (commonly known as the “B-A-R”), while those following are armed with the M1 “Garand” .30-caliber semi-automatic rifle. Note the cinematographer behind the starboard cargo door. (National Archives and Records Administration, NAID: 74241875)

From 9 through 11 November 1956, a U.S. Marine Corps HR2S-1 flown by Major Roy Lee Anderson, USMC, and Sikorsky test pilot Robert S. Decker at Windsor Locks, Connecticut, set three Fédération Aéronautique Internationale (FAI) world records for speed and payload:

On 9 November, the helicopter reached an altitude of 3,722 meters (12,211 feet) with a payload of 5,000 kilograms (11,023 pounds).¹ The following day, 10 November, it set a record for the greatest mass carried to a height of 2,000 meters (6562 feet): 6,010 kilograms (13,250 feet).² Then on 11 November, the HR2S-1 reached a speed of 261.91 kilometers per hour (162.74 mph) over a 3-kilometer (1.86 miles) course.³ For these flights, Major Anderson was awarded a third gold star in lieu of a fourth award of the Distinguished Flying Cross.

Major Roy Lee Anderson, USMC, (left) and Sikorsky test pilot Robert Stewart Decker. (Fédération Aéronautique Internationale)

The world-record-setting Sikorsky HR2S-1. Note the dorsal filet. (Fédération Aéronautique Internationale)

¹ FAI Record File Number 13129

² FAI Record File Number 13124

³ FAI Record File Number 13098

9–11 November 1956

November 9, 2023AviationFédération Aéronautique Internationale, Major Roy Lee Anderson USMC, National Aeronautic Association, Robert Stewart Decker, Sikorsky Aircraft Division of United Aircraft Corporation, Sikorsky HR2S-1, World Record for Altitude with a 5000 Kilogram Payload, World Record for Greatest Mass Carried to a Height of 2000 Meters, World Record for Speed Over a 3 Kilometer CourseBryan Swopes

Major Roy Lee Anderson, USMC (left), and Sikorsky test pilot Robert Stewart Decker. (FAI)

9–11 November 1956: Over a three-day period at Windsor Locks, Connecticut, a Sikorsky HR2S-1 heavy-lift helicopter, flown by Major Roy Lee Anderson, United States Marine Corps, and Sikorsky test pilot Robert Stewart Decker, set three Fédération Aéronautique Internationale (FAI) world records for payload and speed.

On 9 November 1956, the HR2S-1 carried a payload of 5,000 kilograms (11,023 pounds) payload to an altitude of 3,722 meters (12,211 feet). ¹

The following day, 10 November, it set a record for the Greatest Mass Carried to a Height of 2,000 Meters (6562 feet), with a payload of 6,010 kilograms (13,250 pounds). ²

On 11 November, the third day, Anderson and Decker flew the helicopter to a speed of 261,91 kilometers per hour (162.74 miles per hour) over a 3-kilometer (1.86 statute miles) course .³

For these flights, Major Anderson was awarded a third gold star in lieu of a fourth award of the Distinguished Flying Cross.

The world-record-setting Sikorsky HR2S-1. (Fédération Aéronautique Internationale)

United Press reported:

US Helicopter Sets Altitude, Speed Records

STRATFORD, Conn.—UP—A twin-engine Marine helicopter has established two international records for speed and altitude.

The Sikorsky division of United Aircraft Corporation said one of its S56 helicopters reached 162.7 miles per hour during a recent trial. The old record, set two years ago by another Sikorsky model, was 156 miles per hour.

Tops Russian Craft

The S56 flew more than 12,000 feet high while carrying 11,050 pounds. With the payload increased to 13,250 pounds it reached 7,000 feet, far outstripping the previous mark set by a Russian craft of 8,820 pounds to 6,560 feet.

The altitude trials were conducted from Sikorsky’s field in Stratford. Major Roy L. Anderson was pilot and Robert S. Decker copilot.

The records are subject to confirmation by the Federation Aeronautique Internationale. The trials were conducted under the auspices of the National Aeronautics [sic] Association.

—The Modesto Bee, Vol 79, No. 272, Tuesday, 13 November 1956, Page 12, Column 2

The Sikorsky HR2S-1 was an assault and heavy-lift helicopter produced for the United States Navy and Marine Corps. It was later adopted by the U.S. Army as the H-37 Mohave.