Tag Archives: Sikorsky Aircraft Corporation

21 May 1949

Captain Hubert D. Gaddis, USAAF with teh Sikorsky S-51-1. NAA representatives check baraographs. (Sikorsky Archives)
Captain Hubert D. Gaddis, United States Army, with the Sikorsky S-52-1 NX92824. NAA representatives Walter Goddard and Charles Logsdon check the barographs. (Sikorsky Archives)

21 May 1949: Captain Hubert Dale Gaddis, Field Artillery, United States Army, flew a prototype Sikorsky S-52-1 helicopter, serial number 52003, registration NX92824, to a Fédération Aéronautique Internationale (FAI) World Record for Altitude Without Payload of 6,468 meters (21,220 feet) over Bridgeport, Connecticut. ¹ The flight was observed by National Aeronautic Association representatives Walter Goddard and Charles Logsdon.

The Sikorsky S-52-1 was a completely new design based on the company’s experience with the earlier R-4 and R-5/S-51 models. It was a two-place light helicopter of all metal monocoque construction, using primarily aluminum and magnesium. With Sikorsky test pilot Harold Eugene (“Tommy”) Thompson at the controls, the prototype made its first flight 4 May 1948.

The three-bladed fully-articulated articulated main and two-bladed tail rotor were also of all metal construction. The main rotor had a diameter of 33 feet (10.058 meters) and rotated counter-clockwise as seen from above. (The advancing blade is on the right side of the helicopter.) It had an extruded aluminum spar, covered with sheet duralumin, riveted and glued in place. The blade used a NACA 0012 airfoil with -6° twist. The two-bladed semi-rigid tail rotor was mounted on the left side of the tail boom in a pusher configuration. It had a diameter of 6 feet, 4 inches (1.930 meters) and rotated counter clockwise, as seen from the helicopter’s left. (The advancing blade is at the top of the tail rotor arc.)

The S-52-1 was powered by an air-cooled, normally-aspirated, 425.29-cubic-inch-displacement (6.97 liter) Franklin Engine Company 6V6-245-B16F (O-425-1) vertically-opposed 6-cylinder overhead valve engine. The engine was rated at 245 horsepower at 3,275 r.p.m.

On 27 April 1949 Tommy Thompson flew the same helicopter to an FAI speed record of 208.49 kilometers per hour (129.55 miles per hour) over a 3 kilometer straight course at Cleveland, Ohio, ² and on 6 May, to 197.54 kilometers per hour (122.75 miles per hour) over a 100-kilometer course between Milford and Westbrook, Connecticut. ³

Sikorsky S-52-1 NX92824 (FAI)
Sikorsky S-52-1 NX92824 (FAI)
Hubert Gaddis.(Tom Tom 1938)

Hubert Dale Gaddis was born in Jasper County, Missouri, 9 September 1920, the first of two children of Hubert E. Gaddis, a utility company purchasing agent, and Beatrice Mae Cook Gaddis.

The family trelocated to Tulsa, Oklahoma, where Hubert attended Central High School. While there, he developed an interest in radio. Gaddis graduated in 1938.

Gaddis married Martha Tucker in 1950. They would have three children,Cheryl, Sandra and Dale.

Captain Hubert D. Gaddis, Artillery, United States Army. (FAI)

Gaddis enlisted in the United States Army in Oklahoma, 24 September 1942. He had brown hair and hazel eyes, was 5 feet, 6 inches (1.68 meters) tall and weighed 133 pounds (60.3 kilograms).

Gaddis was commissioned a second lieutenant, Army of the United States (AUS), 18 February 1944. He remained in the Army following World War II as an officer in the Field Artillery (Regular Army). In 1956, he graduated of the Army Command and General Staff College.

On September 8 1966, Gaddis was promoted to the rank of colonel (temporary). The rank became permanent 1 July 1971. He was released from military service 28 February 1974. During his career, Colonel Gaddis had been awarded the Distinguished Flying Cross, the Bronze Star Medal, and the Air Medal with 14 oak leaf clusters (15 awards).

Colonel Hubert Dale Gaddis, United States Army (Retired) died 24 February 1976 at the age of 55 years. He was buried at Woodlawn Memorial Gardens, Ozark, Alabama.

¹ FAI Record File Number 2181

² FAI Record File Number 13097

³ FAI Record File Number 13146

© 2019, Bryan R. Swopes

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16 May 1977

Sikorsky S-61L N619PA
New York Airways’ Sikorsky S-61L, N916PA. (Photograph by Stefan Sjögren, used with permission.)

16 May 1977: At approximately 5:32 p.m. Eastern Standard Time, New York Airways Flight 971, a Sikorsky S-61L helicopter, landed at the Pan Am Building rooftop heliport (JPB) in New York City. Flight 971 had originated at John F. Kennedy International Airport (JFK) and carried 20 passengers and a crew of three. The helipad was 855.23 feet (260.67 meters) above Sea Level.

In the cockpit’s right seat was Captain Lee G. Richmond. Captain Richmond had 11,721 total flight hours with over 9,000 in helicopters and approximately 2,200 in the Sikorsky S-61. He had worked for New York Airways since 1964. The co-pilot was First Officer John F. Flanagan had worked for NYA for about five weeks. He had 1,768.4 flight hours with 1,339.2 hours in helicopters. Both pilots had flown 3 hours, 33 minutes on 16 May. Flight Attendant Lammie Chevalier had been employed by NYA for four years.

A Sikorsky S-61L hovers over the Pan Am Building heliport. (Unattributed)
A New York Airways Sikorsky S-61L hovers over the Pan Am Building heliport. (Pan Am)

Captain Richmond taxied the S-61 into position on the 131-foot × 131-foot (39.9 × 39.9 meters) concrete helipad. While parked at the gate, Richmond kept the rotors turning at 100%, keeping the cyclic control centered and the collective full down (negative pitch). The Automatic Flight Control System (AFCS) was engaged. Flanagan kept his left knee against the collective pitch lever to ensure that it remained full down. Flight Attendant Chevalier stood inside the passenger cabin, supervising departing and boarding passengers.

The return flight to JFK was designated Flight 972.

Aerial photo of the wreck of Flight 972 atop the Pan Am Building, 16 May 1977. (Neal Boenzi/The New York Times)
Aerial photo of the wreck of Flight 972 atop the Pan Am Building, 16 May 1977. (Neal Boenzi/The New York Times)

2 minutes, 21 seconds after touch down, at approximately 5:35 p.m., the right main landing gear of the helicopter failed and the S-61 rolled over to the right. All main rotor blades struck the concrete helipad. Four passengers who were waiting to board were struck by the blades and killed. One of the blades, 28 feet, 10 inches (8.787 meters) long and weighing 209.3 pounds (94.9 kilograms) flew out over the building’s railing and fell alongside the building before crashing through an office window on the 36th floor. The main rotor blade broke into two segments, one of which fell to the street below, striking a pedestrian and killing him. Additional pieces of the main rotor blades were found up to four blocks north of the Pan Am Building.

Wreck of S-61L N619PA at the Pan Am Building rooftop heliport, 16 May 1977. (Unattributed)
Wreck of S-61L N619PA at the Pan Am Building rooftop heliport, 16 May 1977. The Chrysler Building is in the background. (Unattributed)

The helicopter assigned to Flight 971/972 was a Sikorsky S-61L, s/n 61427, registered N619PA. At the time of the accident, the helicopter had a total of 6,913:15 hours on the airframe. Just 7 hours, 22 minutes had elapsed since the last major inspection.

The National Transportation Safety Board (NTSB) investigation determined that the probable cause of the accident was: “. . . the fatigue failure of the upper right forward fitting of the right main landing gear tube assembly. Fatigue originated from a small surface pit of undetermined source. All fatalities were caused by the operating rotor blades as a result of the collapse of the landing gear.”

The NTSB determined that the flight crew had performed correctly, and that the aircraft was properly certified, maintained and operated. The Board speculated that the four boarding passengers would have been killed by the helicopter rolling over, even if the engines had been shut down and rotors stopped.

Sikorsky S-61L N619PA lies on its right side at the Pam Am Building heliport, May 1977. The Empire State Building is in the background. (Unattributed)
Sikorsky S-61L N619PA lies on its right side at the Pam Am Building heliport, May 1977. The Empire State Building is in the background. (Unattributed)

A similar accident had occurred when a Los Angeles Helicopters Sikorsky S-61L suffered a fatigue fracture of its right landing gear and rolled over at Los Angeles International Airport (LAX) in 1963. This accident had resulted in a change in the material used to manufacture the parts.

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 axis of rotation.)

N619PA was powered by two General Electric CT58-140-2 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. 13 were S-61Ls. As of May 2017, two remained in service.

© 2019, Bryan R. Swopes

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9 May 1962

Sikorsky S-64 Skycrane N325Y, s/n 64001. (John Daniel)

9 May 1962: The Sikorsky S-64 Skycrane, N325Y, prototype of a heavy-lift helicopter, made its first flight at Stratford, Connecticut. The Skycrane was a turbine-powered evolution of the piston-engined S-60. The United States Army bought six S-64s for evaluation, and then ordered 54 production aircraft, designated CH-54A Tarhe, and 35 CH-54Bs. Sikorsky produced 12 S-64E and Fs for the commercial helicopter market.

The Sikorsky CH-54A Tarhe is a large single-main-rotor/tail rotor helicopter, specifically designed to carry large external loads. In U.S. Army service, it had a crew of five: pilot, co-pilot, third pilot and two mechanics. The third pilot was in a rear-facing cockpit position and flew the helicopter while it was hovering to pick up or position an external load.

FAI record-setting Sikorsky CH-54A Tarhe (FAI)

The CH-54A is 88 feet, 5.9 inches (26.972 meters) long and 25 feet, 4.7 inches (7.739 meters) high. The main rotor has six blades and turns counter-clockwise, seen from above. (The advancing blade is on the helicopter’s right side.) The main rotor has a diameter of 72 feet (21.946 meters). The main rotor blades have a chord of 1.97 feet (0.601 meters) and incorporate a twist of -13°. The tail rotor has four blades and is placed on the left side of a vertical pylon in a pusher configuration. The tail rotor turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) The diameter of the tail rotor is 16 feet (4.877 meters). The chord of the tail rotor blade is 1.28 feet (0.390 meters).

The helicopter has an empty weight of 19,120 pounds (8,673 kilograms) a design gross weight of 38,000 pounds (17,237 kilograms) and overload gross weight of 42,000 pounds (19,051 kilograms).

The prototype S-64A Skycrane, N325Y, lifts an  M-113 armored personnel carrier during a demonstration at Fort Benning, Georgia. (NASM-84-8161)

The CH-54A is powered by two Pratt & Whitney JFTD12A-4A (T73-P-1) turboshaft engines, each rated at 4,000 shaft horsepower at 9,000 r.p.m. (N2) maximum continuous power at Sea Level, and 4,500 shaft horsepower at 9,500 r.p.m. (N2) for takeoff, 5-minute limit, or 30 minutes, with one engine inoperative (OEI). The maximum gas generator speed (N1) is 16,700 r.p.m. The T73-P-1 is an axial-flow free-turbine turboshaft engine with a 9-stage compressor section, 8 combustion chambers and a 4-stage turbine section (2-stage gas generator and 2-stage free turbine). It is 107.0 inches (2.718 meters) long, 30.0 inches (0.762 meters) in diameter, and weighs 966 pounds (438 kilograms). The helicopter’s main transmission is limited to a maximum 6,600 horsepower.

It has a useful load of 22,880 pounds (10,342 kilograms) and can carry a payload of 20,000 pounds (9,072 kilograms) from a single point cargo hoist.

The CH-54A has a maximum cruise speed of 115 knots (132 miles per hour, 213 kilometers per hour). It’s range is 217 nautical miles (250 miles,  402 kilometers). The CH-54A has a hover ceiling in ground effect (HIGE) of 10,600 feet (3,231 meters) and its service ceiling is 13,000 feet (3,962 meters).

The United States Army has a tradition of using Native American names for its aircraft. Tarhe (pronounced tar-HAY) was a famous chief, or sachem, of the Wyandot People of North America, who lived from 1742–1818. He was very tall and the French settlers called him “The Crane.”

Sikorsky CH-54A Tarhe 68-18448, Nevada National Guard, 16 November 1989. (Mike Freer/Wikipedia)

N325Y, the prototype Sikorsky S-64, was damaged beyond repair in an accident near Arboles, California, 19 August 1968. The FAA registration was cancelled.

© 2019, Bryan R. Swopes

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12 April 1972

BG Charles A. Lindbergh USAFR and MAJ Bruce Ware USAF, 31st ARRS, with Jolly 36, HH-3E 66-13289, 12 April 1972. (U.S. Air Force)
Brigadier General  Charles A. Lindbergh, USAFR (Ret.), and Major Bruce Ware USAF, 31st ARRS, with Jolly 36, HH-3E 66-13289, 12 April 1972. (U.S. Air Force)

12 April 1972: Famed pioneer aviator Charles A. Lindbergh, Brigadier General, United States Air Force Reserve, with a television news team investigating reports of a “lost tribe” in the Tasaday mountains of Mindanao, Republic of the Philippines, were stranded on a 3,000-foot (915 meter) jungle ridge line when their support helicopter developed mechanical trouble. Faced with a three-day walk through difficult terrain, the 70-year-old pilot was in trouble. The 31st Aerospace Rescue and Recovery Squadron at Clark Air Base on the Island of Luzon, was called in.

Major Bruce Ware and his crew, co-pilot Lieutenant Colonel Dick Smith, flight engineer Staff Sergeant Bob Baldwin, and pararescueman Airman 1st Class Kim Robinson, flew their Sikorsky HH-3E Jolly Green Giant, 66-13289, over 600 miles (965 kilometers) to the rescue location. The helicopter, call sign “Jolly 36,” was supported by a Lockheed HC-130N Combat King for aerial refueling, navigation and communications.

A Sikorsky HH-3E Jolly Green Giant refuels in flight from a Lockheed HC-130 Combat King. (U.S. Air Force)
A Sikorsky HH-3E Jolly Green Giant refuels in flight from a Lockheed HC-130 Combat King. (U.S. Air Force)

The pick-up point was a knife-edge ridge. Trees had been cut for clearance, but landing the Sikorsky was impossible. Major Gray had to hover with the nose wheel on one side of the ridge, and the main wheels on the other, with the boarding steps a few feet over the ridge top. The very high temperature and humidity created a density altitude equivalent to more than 6,000 feet (1,830 meters). Hovering the helicopter out of ground effect (OGE) was difficult under these conditions and fuel had to be dumped to lighten the load. Even so, only a few persons could be carried at a time. Eight trips to a drop point 15 minutes away were required. Lindbergh was on the second load. On clearing the ridge, Major Ware rendezvoused with the HC-130N to take on fuel. They partially refueled twice during the ridge line operation. Lindbergh commented that although he had helped to develop inflight refueling, he had never been aboard an aircraft while it was taking place.

After all persons—a total of 46—had been removed from the mountain, Jolly 36 and the Combat King flew back to Clark Air Base. The total elapsed time for the mission was 12 hours, 20 minutes, with 11 hours, 30 minutes actual flight time. Major Ware had to just sit in the cockpit for a few minutes before he could leave the helicopter, but General Lindbergh refused to leave until Ware was ready.

Distinguished Flying Cross

Major Ware was awarded the Distinguished Flying Cross. The other crew members of Jolly 36 and all those aboard the Combat King received the Air Medal. Ware retired from the Air Force in July 1989, after 29 years of service.

Sikorsky HH-3E 66-13289 (c/n 61-588) was delivered to the U.S. Air Force 8 December 1967 as a CH-3E. By July it was in South East Asia, operating as Jolly Green 03. The helicopter was later modified to the HH-3E combat rescue configuration. It was lost in the South China Sea in 1972, following a rescue from a freighter west of Luzon, Philippine Islands.

Notified by the accompanying HC-130 that the helicopter was trailing smoke, the aircraft commander, Lieutenant Colonel James (“Bud”) Green, made an emergency landing at sea. It was determined that the main transmission had cracked and was leaking oil.

A U.S. Navy helicopter hoisted the Air Force crew and the rescued man aboard, while a tug boat had been dispatched to recover 66-13289. Unfortunately the Jolly Green Giant overturned during a squall and sank in 12,900 feet (3,932 meters) of water.

Sikorsky CH-3E Jolly Green Giant 66-13289, hovering over the deck of a U.S. Navy guided missile frigate, USS William V. Pratt (DLG-13), August 1967. (U.S. Navy)

© 2017, Bryan R. Swopes

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11 March–6 April 1949

Lieutenant Stewart R. Graham, USCG, in cockpit of Sikorsky HNS-1 near Gander, Newfoundland, September 1946. (U.S. Coast Guard)
Lieutenant Stewart R. Graham, USCG, in cockpit of Sikorsky HNS-1 near Gander, Newfoundland, September 1946. (U.S. Coast Guard)

April 6, 1949: Lieutenant Stewart Ross Graham, United States Coast Guard, and his crewman, Aviation Metalsmith 2nd Class (AM2) Robert McAuliffe, completed the longest unescorted helicopter flight on record. They flew a Sikorsky HO3S-1G, serial number 51-234, from the Coast Guard Air Station, Elizabeth, New Jersey, to Coast Guard Air Station Port Angeles, Washington, via San Diego, California, covering a distance of 3,750 miles (6,035 kilometers) in 57.6 flight hours over 11 days.

Lieutenant Graham was the first pilot to fly a helicopter from a ship. On 16 January 1944, he flew a Sikorsky YR-4B, serial number 46445, from the deck of a British freighter, SS Daghestan, while in convoy from New York to Liverpool. After 30 minutes, he returned to the freighter. He was a pioneer in the use of the helicopter by the Coast Guard and the Navy.

U.S. Coast Guard Sikorsky HO3S-1G 51-232. (U.S. Coast Guard)
U.S. Coast Guard Sikorsky HO3S-1G 51-232, sister ship of 51-234. (U.S. Coast Guard)

The HO3S (Sikorsky S-51) was a second-generation helicopter, capable of carrying a pilot and up to three passengers. 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 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 (1,837.05 kilograms) and maximum takeoff weight of 5,500 pounds (2,494.76 kilograms). Fuel capacity was 100 gallons (378.5 liters).

The helicopter was powered by an air-cooled, supercharged, 986.749-cubic-inch-displacement (16.170 liter) Pratt & Whitney R-985 AN-5 (Wasp Jr. T1B4) direct-drive,  nine-cylinder radial engine which was placed vertically in the fuselage behind the crew compartment. This engine had a compression ratio of 6:1 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 S-51 had a maximum speed (Vne) of 107 knots (123.1 miles per hour/198.2 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 (914.4 meters).

Sikorsky built 220 helicopter of the S-51 series.

U.S. Coast Guard HO3S-1G, serial number 51-238, sister ship of Lieutenant Graham’s record-setting helicopter. (USCG/Smithsonian Institution)

© 2017, Bryan R. Swopes

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