Tag Archives: First Flight

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

18 January 1906

Graf von Zeppelin's LZ 2 at Lake Constance, 1906. (RAF Museum)
Graf von Zeppelin’s LZ 2 at Lake Constance, 1906. (RAF Museum)

18 January 1906: Ferdinand Adolf Heinrich August Graf von Zeppelin’s second airship, Luftschiff Zeppelin 2, designed by Ludwig Dürr, made its first—and only—flight, at Lake Constance (Bodensee), a large lake at the base of Alps.

Ludwig Dürr (1878–1956)
Ludwig Dürr (1878–1956)

LZ 2 was 127 meters (416 feet, 8 inches) long and 11.70 meters (38 feet, 5 inches) in diameter. It had a volume of 10,400 cubic meters (367,273 cubic feet). The rigid structure was built of triangular-section girders that combined light weight and strength. Hydrogen gas contained in bags inside the airship’s envelope gave it buoyancy.

Ladislas d’Orcy described the airship:

. . . Hull-frame of aluminum-alloy lattice girders, cross-braced by wire stays, and subdivided into compartments for independent gas-cells. No ballonets. Fabric skin. Trim controlled by lifting planes. Cars rigidly connected. Gangway affording passage between the cars.

D’Orcy’s Airship Manual, by Ladislas d’Orcy, M.S.A.E., The Century Company, New York, 1917, at Page 127

The airship was powered by two 85 horsepower Daimler-Motoren-Gesellchaft gasoline-fueled engines designed by Karl Maybach. They turned four three-bladed propellers at 820 r.p.m. It was capable of reaching 40 kilometers per hour (25 miles per hour). The airship’s ceiling was 2,800 feet (853 meters).

L’AÉROPHILE reported:

Une nouvelle sortie—la derniére—eut lieu le jeudi 18 janvier 1906. Parti de son garage et parvenu à 500 mètres environ, le ballon était désemparé, et après avoir passé au-dessus de Raverasburg, Kisslegg et Sommerstadt, venait s’abattre en territoire suisse, à Allgaen. Certains correspondants assurent qu’il était monte par l’inventeur, , des officiers allemands et des hommes d’équipage qui n’eurent pas de mal. Mais, dans la chute, das avaries irréparables se produisirent si bien que le comte Zeppelin, decouragé, ne continuera pas ses essais. ¹

L’AÉROPHILE, 14º Année, Noº 1, Janvier 1906, at Page 32

THE CINCINNATI ENQUIRER reported:

AERONAUT’S ILL LUCK.

CABLE TO THE ENQUIRER AND N. Y. HERALD.

(Copyright, 1906, by N. Y. Herald Company.)

     Berlin, January 18.—Count Zeppelin made a second trial to-day with hi snew airship. Starting from Lake Constance, the airship passed over Ravensberg, Kisslegg and Sommersledat and landed at Allgaen. It was seriously damaged in the storm, and further trials will be impossible at present.

THE CINCINNATI ENQUIRER, Vo. LXIII, No. 10, Friday, 19 January 1906, Page 2. Column 1

An engine failure forced the ship to make an emergency landing close to a small town named Sommersried, Allgäu, in southern Germany, and was so badly damaged by a storm during the night that it had to be scrapped.

Wreckage of LZ 2.
Wreckage of LZ 2.

¹ Google Translation: “A new exit-the last-took place on Thursday, January 18, 1906. From his garage and reached about 500 meters, the balloon was clueless/distraught, and after passing over Raverasburg, Kisslegg and Sommerstadt, came crashing down in Swiss territory, in Allgaen. Some correspondents assert that he was mounted by the inventor, German officers and crewmen who were not hurt. But in the fall, irreparable damage occurred so that Count Zeppelin, discouraged, did not continue his attempts.”

© 2019, Bryan R. Swopes

14 January 1953

Convair XF2Y-1 Sea Dart Bu. No. 137634 during high-speed taxi on San Diego Bay (National Naval Aviation Museum)

14 January 1953: During a high-speed taxi test on San Diego Bay, Convair Chief Test Pilot Ellis Dent (“Sam”) Shannon inadvertently made the first flight of the prototype XF2Y-1 Sea Dart, Bu. No. 137634. The airplane flew approximately 1,000 feet (305 meters) across the bay.

Sam Shannon with the Convair XF2Y-1 Sea Dart. (Image courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

The Sea Dart was a prototype single-seat, twin-engine, delta-winged fighter designed and built by the Convair Division of General Dynamics Corporation at San Diego, California. It was equipped with retractable skis in place of ordinary landing gear to allow it to take off and land on water, snow or sand.

The XF2Y-1 was 52 feet, 7 inches (16.027 meters) long with a wingspan of  33 feet, 8 inches (10.262 meters) and height of 16 feet, 2 inches (4.928 meters) with the skis retracted. The airplane had an empty weight of 12,625 pounds (5,727 kilograms) and maximum takeoff weight of 21,500 pounds (9,752 kilograms).

Convair XF2Y-1 Sea Dart Bu. No. 137634 in flight over San Diego, California. (National Naval Aviation Museum)

The prototype XF2Y-1 was powered by two Westinghouse J34-WE-32 single-shaft axial-flow turbojet engines. The engine used an 11-stage compressor and 2-stage turbine. It was rated at 3,370 pounds (14.99 kilonewtons) of thrust, and 4,900 pounds (21.80 kilonewtons) with afterburner. The J34-WE-32 was 15 feet, 4.0 inches (4.674 meters) long, 2 feet, 1.6 inches (0.650 meters) in diameter, and weighed 1,698 pounds (770.2 kilograms).

The YF2Y-1 service test prototypes that followed were powered by Westinghouse XJ46-WE-2 engines. The J46 was also a single-shaft axial-flow turbojet, but had a 12-stage compressor and 2-stage turbine. These were rated at 4,080 pounds of thrust  (18.15 kilonewtons), and 6,100 pounds (27.13 kilonewtons) with afterburner. The J46-WE-2 was 15 feet, 11.7 inches (4.869 meters) long, 2 feet, 5.0 inches (0.737 meters) in diameter and weighed 1,863 pounds (845 kilograms).

The YF2Y-1 service test aircraft had a maximum speed of 695 miles per hour (1,118 kilometers per hour) at 8,000 feet (2,438 meters), and 825 miles per hour (1,328 kilometers per hour)—Mach 1.25— at 36,000 feet (10,973 meters). The service ceiling was estimated at 54,800 feet (16,073 meters), and the range was 513 miles (826 kilometers).

There was one XF2Y-1 and four YF2Y-1 aircraft built, but only two of the service test aircraft ever flew. The XF2Y-1 prototype is in storage at the Smithsonian Institution National Air and Space Museum’s restoration facility. One YF2Y-1, Bu No. 135763, is displayed at the San Diego Air and Space Museum, and another, Bu. No. 135764, is in the collection of the Harold F. Pitcairn Wings of Freedom Aviation Museum at Horsham, Pennsylvania, about 30 minutes north of Philadelphia.

Convair XF2Y-1 Sea Dart Bu. No. 137634 taxis to the seaplane ramp at the north end of San Diego Bay. (National Naval Aviation Museum)

Ellis Dent Shannon was born at Andalusia, Alabama, 7 February 1908. He was the third of five children of John William and Lucy Ellen Barnes Shannon.

He was commissioned as a second lieutenant the Alabama National Guard (Troop C, 55th Machine Gun Squadron, Cavalry) 21 May 1926. He transferred to the Air Corps, United States Army, in 1929. In 1930, he was stationed at Brooks Army Airfield, Texas.

Lieutenant Ellis Dent Shannon, Air Corps, United States Army

In 1932 Shannon was was assigned as a flight instructor and an aviation advisor to the government of China.

On 24 December 1932, Shannon married Miss Martha Elizabeth Reid at Shanghai, China. They had son, Ellis Reid Shannon, born at Shanghai, 24 August 1934, and a daughter, Ann N. Shannon, born at Baltimore, Maryland, in 1940.

Shannon and his family returned to the United States in 1935 aboard SS Bremen, arriving at New York.

He was employed by the Glenn L. Martin Co., Baltimore, Maryland, in 1936 as a test and demonstration pilot. He traveled throughout Latin America, demonstrating the company’s aircraft. As a test pilot, he flew the Martin Model 187 Baltimore, the B-26 Marauder, PBM Mariner and the Martin JRM Mars.

In February 1943, Shannon started working as a Chief of Flight Research for the Consolidated Aircraft Company at San Diego, California. While there, made the first flights of the Consolidated XB-24K, a variant of the Liberator bomber with a single vertical tail fin; the XR2Y-1, a prototype commercial airliner based on the B-24 Liberator bomber; the XB-46 jet-powered medium bomber; the XP5Y-1 Tradewind, a large flying boat powered by four-turboprop-engines; the Convair 340 Metropolitan airliner; and the XF-92A, a delta-winged proof-of-concept prototype. Shannon also participated in the flight test program of the YF-102A Delta Dart.

After retiring from Convair in 1956, Ellis and Martha Shannon remained in the San Diego area.

Ellis Dent Shannon died at San Diego, California, 8 April 1982 at the age of 74 years.

Ellis Dent Shannon, Convair Chief Test Pilot, circa 1953. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

© 2018 Bryan R. Swopes

14 January 1950

This is the second Mikoyan Gurevich I 330 prototype, SI 02.
This is the second Mikoyan Gurevich I 330 prototype, SI 02.

14 January 1950: The Mikoyan Gurevich prototype fighter I 330 SI made its first flight with test pilot Ivan Ivashchenko. It would be developed into the MiG 17.

The MiG 17 was an improved version of the earlier MiG 15. It was a single-seat, single engine fighter armed with cannon, and capable of high subsonic and transonic speed.

Mikoyan Gurevich MiG 17.
Mikoyan Gurevich MiG 17.

The prototype’s wings were very thin and this allowed them to flex. The aircraft suffered from “aileron reversal,” in that the forces created by applying aileron to roll the aircraft about its longitudinal axis were sufficient to bend the wings and that caused the airplane to roll in the opposite direction.

The first prototype I 330 SI developed “flutter” while on a test flight, 17 March 1950. This was a common problem during the era, as designers and engineers learned how to build an airplane that could smoothly transition through the “sound barrier.” The rapidly changing aerodynamic forces caused the structure to fail and the horizontal tail surfaces were torn off. The prototype went into an unrecoverable spin. Test pilot Ivashchenko was killed.

Two more prototypes, SI 02 and SI 03, were built. The aircraft was approved for production in 1951.

More than 10,000 MiG 17 fighters were built in the Soviet Union, Poland and China. The type remains in service with North Korea.

A MiG 17 in flight.
A MiG 17 in flight.
Иван Т. Иващенко летчик-испытатель
Иван Т. Иващенко летчик-испытатель

Ива́н Тимофе́евич Ива́щенко (Ivan T. Ivashchenko) was born at Ust-Labinsk, Krasnodar Krai, Russia, 16 October 1905. He served in the Red Army from 1927 to 1930. He graduated from the Kuban State University in 1932.

Ivashchenko was trained as a pilot at the Lugansk Military Aviation School at Voroshilovgrad, and a year later graduated from the Kachin Military Aviation College at Volgograd.

In 1939, he fought in The Winter War. During the Great Patriotic War, Ivan Ivashchenko flew with a fighter squadron in the defense of Moscow.

From 1940 to 1945, Ivan Ivashchenko was a test pilot. He trained at the M.M. Gromov Flight Research Institute at Zhokovsky, southeast of Moscow, in 1941. He was assigned to Aircraft Factory No. 18 at Kuibyshev (Samara) from 1941 to 1943. Ivashchenko flew the Ilyushin Il-2 Sturmovik fighter bomber extensively. From 1943 to 1945 he was a test pilot for Lavochkin OKB at Factory 301 in Khimki, northwest of Moscow.

In 1945 Ivashchenko was reassigned to OKB Mikoyan, where he worked on the development of the MiG 15 and MiG 17 fighters. He participated in testing ejection seat systems and in supersonic flight.

Ivan T. Ivashchenko was a Hero of the Soviet Union, and was awarded the Order of Lenin, Order of the Red Banner (two awards) and Order of the Patriotic War. Killed in the MiG 17 crash at the age of 44 years, he was buried at the Novodevichy Cemetery in Moscow.

© 2017, Bryan R. Swopes

14 January 1942

Les Morris at the controls of the Vought-Sikorsky VS-316A (XR-4, serial number 41-18874) on its first flight at Stratford, Connecticut, 13 January 1942. (SikorskyHistorical Archives)
Les Morris at the controls of the Vought-Sikorsky VS-316A (XR-4, serial number 41-18874) on its first flight at Stratford, Connecticut, 14 January 1942. (Sikorsky Historical Archives)

14 January 1942: Chief Test Pilot Charles Lester (“Les”) Morris (1908–1991) made the first flight of the Vought-Sikorsky VS-316A at Stratford, Connecticut. The first flight lasted approximately 3 minutes, and by the end of the day, Morris had made 6 flights totaling 25 minutes duration.

“One-half left front close-up head-and-shoulders view of test pilot Charles L. “Les” Morris posed seated in the cockpit of the Sikorsky VS-300 helicopter (r/n NX28996), March 29, 1943.” (Hans Groenhoff Photographic Collection, Smithsonian Institution National Air and Space Museum NASM-HGC-1408)

The VS-316A (which was designated XR-4 by the U.S. Army Air Corps and assigned serial number 41-18874), established the single main rotor/anti-torque tail rotor configuration. It was a two-place helicopter with side-by-side seating and dual flight controls.

The fabric-covered three-blade main rotor was 38 feet (11.582 meters) in diameter and turned counter-clockwise as seen from above. (The advancing blade is on the helicopter’s right.) The tail rotor was mounted to the aft end of the tail boom in a tractor configuration, and rotated counter-clockwise when seen from the helicopter’s right side.

The VS-316A was 33 feet, 11.5 inches (10.351 meters) long and 12 feet, 5 inches (3.785 meters) high. It weighed 2,010 pounds (911.7 kilograms) empty and the maximum gross weight was 2,540 pounds (1,152.1 kilograms).

The original engine installed in the VS-316A was an air-cooled, normally-aspirated, 499.805-cubic-inch-displacement (8.190 liter) Warner Aircraft Corporation Scarab SS-50 seven-cylinder radial  engine with a compression ratio of 5.55:1. The SS-50 was a direct-drive engine, with a maximum continuous power rating of 109 horsepower at 1,865 r.p.m., and 145 horsepower at 2,050 r.p.m. at Sea Level for takeoff. 73-octane gasoline was required. The SS50 was 2 feet, 5 inches (0.737 meters) long, 3 feet, 0-9/16 inches (0.929 meters) in diameter and weighed 306 pounds (139 kilograms).

gor Ivanovich Sikorsky and Charles Lester Morris with the XR-4 at Wright Field, Ohio, May 1942. (Sikorsky Historical Archives)
Orville Wright and Igor Ivanovich Sikorsky with the XR-4 at Wright Field, Ohio, May 1942. (Sikorsky Historical Archives)

Numerous modifications were made, including lengthening the main rotor blades, covering them with metal, and upgrading the engine to a 200 horsepower Warner R-550-1 Super Scarab. The XR-4 was redesignated XR-4C. This would be the world’s first production helicopter. It is at the Steven F. Udvar-Hazy Center of the Smithsonian National Air and Space Museum.

Sikorsky XR-4C 41-18874 at the National Air and Space Museum. (NASM)
Sikorsky XR-4C 41-18874 at the National Air and Space Museum. (NASM)

© 2019, Bryan R. Swopes