Tag Archives: General Electric TF34-GE-2

21 January 1972

Lockheed YS-3A Viking Bu. No. 157992 (394A-1001) during a test flight. (U.S. Navy/Wikipedia)

21 January 1972: At Palmdale, California, Lockheed test pilots John Jean (“Chris”) Christiansen and Lyle Howard Schaefer took the first Lockheed YS-3A Viking, Bu. No. 157992 (Lockheed serial number 394A-1001), for its first flight. The duration of the flight was 1 hour, 42 minutes.

When interviewed afterward, Christiansen said, “The aircraft handled beautifully. It was exceptionally stable and very responsive to the controls. I think it will do everything the Navy expects of it.”

The aircraft was a response to the U.S. Navy’s need to counter the Soviet Union’s massive submarine fleet. By 1972, the USSR had 340 submarines in service, 100 of which were nuclear powered. It was adding new submarines at a rate of 15 per year. The S-3A was needed to replace the aging Grumman S-2 Tracker.

In 1969, the Navy issued a $494,000,000 development contact to Lockheed for the first four YS-3A pre-production aircraft. A second lot of four YS-3As were also built. The total production for the Viking came to 187 aircraft.

Lockheed YS-3A Viking Bu. No. 157992 during first flight, 21 January 1972. (Lockheed Martin)

The Lockheed S-3A Viking is a twin-engine anti-submarine warfare aircraft designed to operate from Essex-class or larger aircraft carriers. It carries a four-man crew consisting of a pilot, co-pilot, tactical coordinator and sensor operator. It is a high-wing aircraft with retractable tricycle landing gear. The S-3A had an extensive electronics suite, and a retractable MAD (Magnetic Anomaly Detector) boom. The vertical fin and wings could be folded for storage.

Lockheed YS-3A Viking Bu. No. 157992 at Hollywood-Burbank Airport (BUR), Burbank, California, 1971. (Lockheed Martin)

The S-3A is 53 feet, 4 inches (16.256 meters) long, with a wingspan of 68 feet, 8 inches (20.930 meters) and overall height of 22 feet 9 inches (6.934 meters). The total wing area is 598 square feet (55.6 square meters). With the wings and vertical fin folded for storage, the airplane’s length is reduced to 49 feet, 5 inches (15.062 meters), span 29 feet, 6 inches (8.992 meters) and height of 15 feet, 3 inches (14.648 meters). The S-3A has an empty weight of 26,581 pounds (12,057 kilograms), and a maximum takeoff weight (MTOW) of 52,539 pounds (23,831 kilograms).

The S-3A is powered by two General Electric TF34-GE-2 turbofan engines mounted under the wings on pylons. The TF34-GE-2 is a two-spool, axial-flow, high-bypass turbofan. It has a single fan stage, a 14 stage compressor, annular combustion chamber and six stage turbine (2 high-pressure stages a 4 low-pressure stages). It has a maximum continuous power rating of 7,513 pounds of thrust (33.420 kilonewtons) at 6,690 r.p.m, N1 (17,130 r.p.m., N2); 8,159 pounds (36.293 kilonewtons) at 6,930 r.p.m., N1 (17,340 r.p.m., N2) for 30 minutes; and a maximum of 9,275 pounds of thrust (41.257 kilonewtons) at 7,365 r.p.m., N1 (17,900 r.p.m., N2), for five minutes. The TF34-GE-2 is 8 feet, 4 inches (2.54 meters) long and 4 feet, 4.4 inches (1.331 meters) in diameter. It weighs 1,421 pounds (664.6 kilograms).

A Lockheed S-3A Viking, Bu. No. 159755, with its MAD boom extended, 6 May 1982. (W.M. Welch, U.S. Navy/VIRIN DN-ST-84-05128)

The cruise speed of the S-3A Viking is 348 knots (400 miles per hour/644 kilometers per hour). Its maximum speed is 429 knots (494 miles per hour/795 kilometers per hour) at Sea Level, or 447 knots (514 miles per hour/828 kilometers per hour) at 20,000 feet (6,096 meters). It can climb at 4,450 feet per minute (22.61 meters per second) and its service ceiling is 40,900 feet (12,466 meters).

The S-3A’s fuel capacity is 2,533 gallons (9,588 liters) usable fuel in three tanks. Its combat range is 2,765 nautical miles (3,182 statute miles/5,121 kilometers). It could also carry two 300 gallon (1,136 liter) drop tanks on the underwing hard points. The maximum ferry range is 3,368 nautical miles (3,875 statute miles/6,238 kilometers).

The S-3A could carry up to 60 sonobuoys. It was normally armed with four Mark 46 homing torpedoes carried in an internal bomb bay. Alternatively, it could carry four Mark 53 mines or Mark 54 depth bombs. It was also capable of carrying two Mark 57 Mod. 0 five-kiloton nuclear depth bombs. Three low drag Mark 82 bombs could be carried on each of the underwing hard points. After conversion to the S-3B configuration, it could carry two AGM-84 Harpoon anti-ship missiles.

Following the collapse of the Soviet Union, the submarine threat was believed to be considerably reduced. 122 S-3As had their antisubmarine suite removed and were converted to the S-3B configuration. Another 16 were converted to ES-3A Shadow electronics intelligence aircraft. YS-3A Bu. No. 157996 was converted to a prototype KS-3A aerial tanker. It and five other YS-3As were later converted to US-3A Carrier Onboard Delivery (“COD”) transport aircraft.

The last S-3s were withdrawn from U.S. Navy service on 30 January 2009. Four S-3Bs were transferred to the NASA John H. Glenn Research Center at Lewis Field, Cleveland, Ohio. The last one was retired 13 July 2021.

Lockheed YS-3A Viking Bu. No. 157992 launches an AGM-84 Harpoon anti-ship missile, 4 January 1983. (U.S. Navy)

The first YS-3A was rolled out at the Lockheed California Company plant, Burbank, California, on 8 November 1971. It was then transported to the Lockheed plant at Palmdale, California.

Lockheed YS-3A Viking Bu. No. 157992, is rolled out at the Lockheed California Company plant at Burbank, California, 8 November 1971. (Lockheed Martin)

Additional testing of Bu. No. 157992 was carried out at NATC Patuxent River, Maryland.

Lockheed YS-3A Viking, Bu. No. 157992, at NATC Patuxent River, Maryland. (U.S. Navy/Flickr)

According to Rick Pospisil’s “Hoover History,” the first YS-3A, Bu. No. 157992, was damaged at NATF Lakehurst, New Jersey, during barrier arrest trials. It was stricken from the Navy’s active inventory on 20 January 1976, having accumulated just 184.8 flight hours. The damaged aircraft was then stored at the Naval Aircraft Depot (NADEP) at Alameda, California. In 1991, the fuselage was transported to the Navy Avionics Center (NAC) at Indianapolis, Indiana, for modifications. It was later scrapped.

John Christiansen
John Christiansen, 1942. (The 1942 Log)

John Jean (“Chris”) Christiansen was born 1 May 1923, at Oslo, Norway. He was the second of three children of John Christiansen, a painter, and Ruth Floby Christiansen. After the family immigrated to the United States, he grew up in St. Paul, Minnesota. He became a naturalized U.S. citizen.

Christiansen attended Woodrow Wilson High School in Saint Paul, graduating in 1942. He played football and was a member of the W Club.

In June 1942, he was employed by Hayden Motor Service in St. Paul. When he registered for the draft (conscription), he was described as being 5 feet, 10 inches (1.778 meters) tall, 160 pounds (72.6 kilograms), with a ruddy complexion, blonde hair and blue eyes.

Alice Phoebe Zeis, 1942.

John Christiansen married Miss Alice Phoebe Zeis, who had been a fellow student at Woodrow Wilson High School. They had one son. Christiansen was later married to Diane S. Schindler.

Christiansen served in the United States Navy during World War II and the Korean War.

John Christiansen joined the Lockheed Aircraft Corporation as an experimental test pilot in 1953. During his career with Lockheed, he made the first flights of the prototype YP3V-1 (P-3 Orion), 25 November 1958, and the YS-3A Viking, 21 January 1972. He retired from Lockheed in 1983.

John Christiansen with his family and a Lockheed P-3C orion, circa 1984

John Christiansen died at Lake Havasu, Arizona, 6 September 1998, at the age of 75 years.

Lyle Howard Shaefer

Lyle Howard Schaefer, was born 18 Dec 1939 at Union, Nebraska. he was the first of two children of Russell H. Schaefer, a farmer, and Marcella L. McQuin Schaefer. He grew up in Meade, Colorado.

Following his graduation from the University of Colorado, Schaefer entered the United States Navy, 8 June 1962.

Ensign Shaefer was promoted to the rank of lieutenant (junior grade), 6 December 1963.

Serving during the Vietnam War, Lieutenent Schaefer was awarded the Air Medal, 5 October 1968 for meritorious action during a strike mission.

Lieutenant Schaefer was promoted to the rank of lieutenant commander 1 September 1969.

A graduate of the U.S. Navy’s test pilot school, Lieutenant Commander Schaefer resigned in 1972 to join Lockheed.

Lyle Schaefer married Virginia (“Ginny”) Maude Greenlee 29 June 1974, in Los Angeles County

Schaefer later earned a masters degree in business administration (MBA) from California State University Northridge (CSUN).

As Lockheed’s chief experimental test pilot, Schaefer is credited with having set 26 Fédération Aéronautique Internationale (FAI) world records for altitude and time to altitude while flying a Lockheed C-130J Hercules, 20 April and 14 May 1999. He was inducted into the Society of Experimental Test Pilots in 2011.

Lyle Howard Schaefer died 1 June 2017 at Marietta, Georgia. His remains were interred at the Georgia National Cemetery, Canton, Georgia.

Full Disclosure: TDiA’s father, Bart Robert Swopes (1925–1995) was Lockheed’s Configuration Manager for both the S-3A Viking and the CP-140 Aurora.

© 2024, Bryan R. Swopes

12 October 1976

Sikorsky S-72 RSRA 72001 in initial configuration. (Sikorsky, a Lockheed Martin Company)

12 October 1976: The Sikorsky S-72 Rotor Systems Research Aircraft (RSRA) made its first flight at Stratford, Connecticut. The S-72 was a hybrid aircraft built for the United States Army and the National Aeronautics and Space Administration. Its purpose was to serve as a flight test vehicle for various helicopter rotor configurations.

The S-72 was three-place, four-engine, single main rotor/tail rotor compound helicopter with retractable main landing gear. The flight crew consisted of two test pilots in a side-by-side cockpit, and a flight test engineer in the cabin. The left pilot’s position was equipped with “fly-by-wire” flight controls, while the right seat used conventional mechanical controls as a safety back up. The S-72 had a crew escape system, which blew the main rotor blades off, allowing the crew to land the aircraft in its airplane mode, or to be extracted by rockets.

The aircraft was built with a low-drag fuselage capable of reaching 340 knots (391 miles per hour/630 kilometers per hour) and used the rotors and drive train of the S-61 Sea King. A wing and two turbofan engines allowed the aircraft to fly as an airplane.

Sikorsky S-72 N740NA in flight near Edwards Air Force Base, California, without a main rotor, circa 1984. (NASA)

The S-72 had an overall length with rotors turning, of 75 feet, 11 inches (23.139 meters). The fuselage had a length of 63 feet, 8 inches (19.406 meters), and maximum width of 8 feet, 4 inches (2.642 meters). The RSRA had an overall height of 15 feet, 6 inches (4.724 meters). The variable incidence wing has a span of 45 feet, 1.2 inches (13.746 meters). The angle of incidence could be varied in flight from +15° to -9°. The span of the horizontal stabilizer is 20 feet, 10 inches (6.350 meters). The S-72 compound helicopter had an empty weight of 20,812 pounds (9,440 kilograms) and gross weight of 26,392 pounds (11,971 kilograms). When stripped to a pure helicopter configuration, the empty weight was reduced to 14,490 pounds (6.573 kilograms).

The S-72 was first flown using the rotors from the S-61. These were later to be replaced with experimental rotor systems. The S-61 main rotor has five blades and a diameter of 62 feet, 0 inches (18.898 meters). Each blade has a chord of 1 foot, 6.25 inches (0.464 meters). The main rotor turns at 203 r.p.m., counter-clockwise, as seen from above. (The advancing blade is on the right.) The S-72’s tail rotor also has five blades and has a diameter of 10 feet, 7.25 inches (3.232 meters). The blades have a chord of 7–11/32 inches (0.187 meters). The tail rotor turns clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.) The tail rotor turns 1,244 r.p.m.

General arrangement with dimensions. (Sikorsky Historical Archives)

The S-72 was powered by two General Electric T58-GE-5 turboshaft engines, driving the rotor system, and two General Electric TF34-GE-2 turbofan engines providing thrust for flight in the airplane or compound helicopter configuration.

The T58-GE-5 turboshaft engines are the same engines that powered the HH-3E Jolly Green Giant combat search and rescue helicopters. They are a free-turbine turboshaft with a 10-stage axial-flow compressor section a 2-stage gas generator turbine (N1) and 1-stage free power turbine (N2). The T58-GE-5 has a Maximum Continuous Power rating of 1,400 shaft horsepower, each, and Military Power rating of 1,500 shaft horsepower. The engine is 59.0 inches (1.499 meters) long, 20.9 inches (0.531 meters) in diameter, and weighs 335 pounds (152 kilograms).

The TF34-GE-2 turbofan was developed for the U.S. Navy’s Lockheed S-3A Viking anti-submarine aircraft. It was a two-spool axial-flow jet engine with a single-stage fan section, 14-stage compressor, and 6-stage turbine section (2 high- and 4 low-pressure stages). The TF34-GE-2 was rated at 9,275 pounds of thrust (41.26 kilonewtons).

The S-72 had a maximum speed in level flight of 300 knots (345 miles per hour/556 kilometers per hour), and 340 knots (391 miles per hour/630 kilometers per hour) in a dive.

Two RSRAs were built. After Sikorsky’s flight test program was completed in 1979, the two RSRA aircraft were delivered to NASA Ames. The Aircraft received civil registrations N740NA (72001) and N741NA (72002).

The stripped airframe of the first Sikorsky S-72, 72001, sits behind a chain link fence at Fort Rucker, Alabama.

© 2020, Bryan R. Swopes