Tag Archives: Prototype

18 March 1945

LaVerne Brown, Director of Flight Test, Douglas Aircraft Company, in the cockpit of the first XBT2D-1 Dauntless II prototype, Bu. No. 9085. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
LaVerne Ward Browne, Director of Flight Test, Douglas Aircraft Company, in the cockpit of the first XBT2D-1 Dauntless II prototype, Bu. No. 9085. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

18 March 1945: At the Naval Airplane Factory, El Segundo, California (at the southeast corner of Los Angeles Airport, now best known as LAX), Douglas Aircraft Company Director of Flight Test LaVerne Ward (“Brownie”) Browne took the prototype XBT2D-1 Dauntless II, Bu. No. 9085, for its first flight.

He later commented, “I wish I could tell of some dramatic incident that occurred. There wasn’t any. I just floated around up there for an hour and a half and brought her down. But I did do something that’s unprecedented, I believe, for a first trip. The airplane handled so well that I put it through rolls and Immelmanns to check it for maneuverability.”

The first prototype Douglas XBT2D-1 Dauntless II, Bu. No. 9085. In this photograph the airplane has a propeller spinner. (San Diego Air and Space Museum archive)
The first prototype Douglas XBT2D-1 Dauntless II, Bu. No. 9085. In this photograph the airplane has a propeller spinner. (Douglas Aircraft Company)

The XBT2D-1 would be ordered into production as the Douglas AD-1 Skyraider.

Designed by Douglas’ Chief Engineer, Edward Henry Heinemann, the XBT2D-1 was a single-place, single-engine attack bomber capable of operation from the U.S. Navy’s aircraft carriers. The prototype was 39 feet, 5 inches (12.014 meters) long with a wingspan of 50 feet, ¼ inch (15.246 meters) and overall height of 15 feet, 7½ inches (4.763 meters). The airplane had an empty weight of 10,093 pounds (4,578 kilograms) and maximum weight of 17,500 pounds (7,938 kilograms).

The first four XBT2D-1 prototypes were powered by an air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R3350-8 (Cyclone 18 779C18BB1) twin-row 18-cylinder radial engine rated at 2,100 horsepower at 2,400 r.p.m., and 2,400 horsepower at 2,600 r.p.m., for takeoff. The next 20 airplanes built utilized the R3350-24W (Cyclone 18 825C18BD1) which had a takeoff power rating of 2,500 horsepower at 2,900 r.p.m.

Both engines had a compression ration of 6.5:1 and a propeller drive reduction ratio of 0.4375:1. They differed in external dimensions and weight, with the –24W being both longer and heavier.

Test pilot Brown in teh cockpit of Douglas XBT2D-1 Dauntless II Bu. No. 9085 during a test flight. (Douglas Aircraft Company)
Test pilot LaVerne Brown in the cockpit of Douglas XBT2D-1 Dauntless II Bu. No. 9085 during a test flight. (Douglas Aircraft Company)

The XBT2D-1 had a maximum speed of 375 miles per hour (604 kilometers per hour) at 13,600 feet (4,145 meters) and normal cruise speed of 164 miles per hour (264 kilometers per hour).

The first XBT2D-1, Bu. No. 9085, was sent to NAS Patuxent River, Maryland, for further testing. The second, 9086, went to NACA Ames at Moffet Field, California, where it underwent testing from 11 March 1946 to 4 September 1947.

The second prototype XBT2D-1, Bu. No. 9086, was tested at the NACA Ames Research Center, Moffet Field, California, from 11 March 1946 to 4 September 1947. (NASA)
The second prototype XBT2D-1, Bu. No. 9086, at the NACA Ames Research Center, Moffet Field, California, 18 June 1946. (NASA)

3,180 Skyraiders in 11 variants were built at the Douglas Aircraft Company’s El Segundo, California, plant from 1945 to 1957. The attack bomber was widely used during the Korean War and the Vietnam War. It was utilized for many purposes but is best known for its close support missions during combat rescue operations. After 1962, the AD-series aircraft still in service were redesignated A-1E through A-1J.

Douglas XBT2D-1 Skyraider Bu. No. 9086 at NACA Ames Research Center, 18 June 1946. (NASA)

The most numerous Skyraider variant was the AD-6 (A-1H), of which 713 were produced by Douglas. The AD-6 was 38 feet, 10 inches (11.836 meters) long with a wingspan of 50 feet, 9 inches (15.469 meters) and overall height of 15 feet, 8¼ inches (4.782 meters). Its empty weight was 11,968 pounds (5,429 kilograms) and gross weight was 18,106 pounds (8,213 kilograms). The maximum takeoff weight (MTOW) for the AD-6 was 25,000 pounds (11,340 kilograms).

Douglas AD-4 Skyraider of VA-195 taking off from USS Princeton (CV-37) circa 1950–52 (U.S. Navy)
Douglas AD-4 Skyraider of VA-195 taking off from USS Princeton (CV-37) circa 1950–52 (U.S. Navy)

The Douglas AD-6 was powered by an air-cooled, supercharged, direct-fuel-injected, 3,347.662-cubic-inch-displacement (54.858 liter), Wright Aeronautical Division R-3350-26WA (Cyclone 18 836C18CA1) twin-row 18-cylinder radial engine, with water/alcohol injection. This engine has a compression ratio of 6.71:1. The R-3350-26W has a Normal Power rating of  2,300 horsepower at 2,600 r.p.m., and a Takeoff/Military Power rating of 2,700 horsepower at 2,900 r.p.m., using 115/145 aviation gasoline. The engine drives a four-bladed Aeroproducts constant-speed propeller with a diameter of 13 feet, 6 inch (4.115 meters) through a 0.4375:1 gear reduction. The engine is 4 feet, 7.62 inches (1.413 meters) in diameter and 6 feet, 6.81 inches (2.002 meters) long. It weighs 2,848 pounds (1,292 kilograms), dry.

The AD-6/A-1H Skyraider had a cruise speed of 198 miles per hour (319 kilometers per hour) and a maximum speed of 322 miles per hour (518 kilometers per hour). The ceiling was 29,400 feet (8,961 meters) and its combat radius carrying 2,000 pounds (907 kilograms) of ordnance was 275 miles (443 kilometers).

A U.S. Marine Corps Douglas AD-2 Skyraider of VMF-121 parked at airfield K-6, Pyongtaek, South Korea, 1952. The hard points under the wings are fully loaded with bombs.
A U.S. Marine Corps Douglas AD-4 Skyraider, Bu. No. 127874, of VMF-121 is parked at airfield K-6, Pyongtaek, South Korea, 1952. The hard points under the wings are fully loaded with bombs. The aircraft is painted overall glossy sea blue. (Navy Pilot Overseas)
Douglas AH-1H Skyraider 52-137593 (U.S. Air Force)
Douglas AH-1H Skyraider 52-137593 of the 602nd Special Operations Squadron. (U.S. Air Force)

The AD-6 Skyraider was armed with four 20mm AN-M2 autocannons, with two in each wing, and 200 rounds of ammunition per gun. The guns fired explosive projectiles with a muzzle velocity of 2,850 feet per second (869 meters per second), and had a rate of fire of 600–700 rounds per minute. The AD-6 could carry 8,000 pounds (3,629 kilograms) of bombs, rockets, gun pods and external fuel tanks from the 15 hard points and pylons under the wings and fuselage.

A Douglas A-1H Skyraider of the 6th Special Operations Squadron dive bombing a target during a close air support mission, Vietnam, 1968. (U.S. Air Force)
A Douglas A-1J Skyraider, 52-142016, of the 6th Special Operations Squadron, dive bombing a target during a close air support mission, Vietnam, 1968. (U.S. Air Force)

Many United States Navy and Marine Corps Skyraiders were transferred to the U.S. Air Force. The Air Force retained the Navy’s Bureau of Aeronautics serial numbers (“Bu. No.”) but added two digits corresponding to the fiscal year in which each airplane was originally contracted. This resulted in serial numbers similar, though longer, than customary in the Air Force and Army numbering system.

The oldest Skyraider in existence is XBT2D-1 Bu. No. 9102. Formerly on display at NAS Oceana, Virginia Beach, Virginia, the airplane was transferred to The Intrepid Sea, Air & Space Museum in New York City for restoration and preservation.

This is the Douglas A-1H Skyraider flown by LCOL Jones, 1 September 1968. Though it was extensively damaged by anti-aircraft gunfire and the subsequent fire, 52-139738 was repaired and returned to service. On 22 September 1972, -738 was shot down over Laos. It was the last Skyraider shot down during the Vietnam War.
Douglas A-1H Skyraider 52-139738, 1st Special Operations Squadron. Lieutenant Colonel William A. Jones III, commanding the 602nd Special Operations Squadron, flew this airplane on 1 September 1968 during a Combat Search and Rescue mission for which he was awarded the Medal of Honor. On 22 September 1972, -738 was shot down over Laos. It was the last Skyraider shot down during the Vietnam War. (U.S. Air Force)

LaVerne Ward Browne was born at Orange, California, 9 December 1906. He was the third child of Edwin J. Brown, a farm worker, and Phebe Alice Proctor Brown. He studied law at the University of Southern California (USC).

“Mystery Plane” poster. (Monogram Pictures Corporation)

In 1928, Brown learned to fly at the Hancock College of Aeronautics, Santa Maria, California. He then worked as a pilot for Transcontinental and Western Airways, flying the Douglas DC-2. He was also commissioned as a second lieutenant in the United States Army Air Corps Reserve.

Browne married Miss Dorothy Leonore Bach at Los Angeles, California, 28 January 1926. They had a daughter, Barbara May Browne, born 6 December 1926, but later divorced. One 12 June 1933, Browne married Harriette Fitzgerald Dodson at Norfolk, Virginia.

From 1931 to 1941, under the pseudonym “John Trent,” Browne performed in sixteen Hollywood movies, including “I Wanted Wings,” with William Holden, Ray Milland and Veronica Lake. He played the character “Tailspin Tommy Tompkins” in four: “Danger Flight,” “Sky Patrol,” “Stunt Pilot,” and “Mystery Plane.”

Browne worked for Douglas Aircraft Company from 1942 to 1957. He died 12 May 1966 at Palos Verdes, California, at the age of 59 years.

“John Trent” (LaVerne Ward Browne) portrayed “Tailspin Tommy Tompkins” in four Hollywood movies. (Monogram Pictures Corporation via IMDb)

© 2017, Bryan R. Swopes

17 March 1969

SNCASE SA 315A 001 (Airbus Helicopters)

17 March 1969: First flight, Société nationale des constructions aéronautiques du Sud-Est test pilot Roland Coffignot and flight engineer Gérard Boutin made the first flight of the prototype SA 315A Lama, serial number 315-001. The new helicopter combined the airframe of the SNCASE Alouette II with the drive train and rotors of the Alouette III.

The helicopter was built to meet the specific needs of the Indian Air Force for operations in the Himalayan Mountains. It was required to take off and land at an altitude of 6,000 meters (19,685 feet) while carrying a pilot, one passenger and 200 kilograms (441 pounds) of cargo. The SA 315A was able to exceed this, landing and taking off in the Karakoram Mountains at 6,858 meters (22,500 feet).

315-001 was later upgraded to the SA 315 B configuration. It was registered F-BPXS. On 19 June 1972, Aérospatiale Chief Test Pilot Jean Boulet with Gérard Boutin set a Fédération Aéronautique Internationale (FAI) World Record for Altitude Without Payload at 10,836 meters (35,551 feet).¹ Three days later, 21 June, Boulet set another three World Records by flying 315-001 to an altitude of 12,442 meters (40,820 feet).²

SNCASE SA 315 B 001. (Airbus Helicopters)

The SA 315 B Lama is a 5-place light helicopter powered by a turboshaft engine. It is operated by a single pilot. The fuselage is 10.236 meters (33 feet, 7.0 inches) long. With rotors turning, the helicopter has an overall length of 12.919 meters (42 feet, 4.6 inches) and height of 3.090 meters (10 feet, 1.7 inches). The SA 315 B has an empty weight of 1,021 kilograms (2,251 pounds) and a maximum gross weight of 1,950 kilograms (4,300 pounds). With an external load carried on its cargo hook, the allowable maximum gross weight is 2,300 kilograms (5,070 pounds).

Aérospatiale SA 315 B Lama three-view illustration with dimensions. (Aérospatiale Hélicoptères)

The three-bladed, fully-articulated main rotor has a diameter of 11.020 meters (36 feet, 1.9 inches). It turns clockwise, as seen from above. (The advancing blade is on the left side of the helicopter.) Normal main rotor speed, NR, is 350–360 r.p.m. The range in autorotation ins 270–420 r.p.m. The three-bladed anti-torque tail rotor is mounted on the left side of the tail boom in pusher configuration. It is 1.912 meters (6 feet, 3.3 inches) in diameter and turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) It turns at 2,020 r.p.m.

Aérospatiale SA 315 B Lama F-BPXS, s/n 315-001, lifting an external load on its cargo hook, 1980. (Kenneth Swartz)

The Lama was initially powered by a Societé Anonyme Turboméca Artouste III B (later aircraft, Artouste III B1) turboshaft engine. This is a single-shaft engine with a single-stage axial-flow, single-stage centrifugal flow, compressor section and a three-stage turbine. The engine turns 33,500 r.p.m. and the output drive shaft turns 5,773 r.p.m. The Artouste III B1 produces a maximum 870 horsepower, but is derated to 570 horsepower for installation in the Lama. The engine is 1.815 meters (5 feet, 11.5 inches) long, 0.667 meters (2 feet, 2.3 inches) high and 0.520 meters (1 foot, 8.5 inches) wide. It weighs 178 kilograms (392 pounds).

The helicopter has a cruise speed 98 knots (113 miles per hour/181 kilometers per hour) and a maximum speed (VNE) of 113 knots (130 miles per hour/209 kilometers per hour) at Sea Level. Sideward or rearward flight (or operations in crosswinds or tailwinds) are restricted to 18 knots. The maximum operating altitude is 7,000 meters (22,966 feet). At 1,950 kilograms (4,299 pounds), the Lama has a hover ceiling in ground effect (HIGE) of 5,050 meters (16,568 feet), and out of ground effect (HOGE), 4,600 meters (15,092 feet).

Société nationale des constructions aéronautiques du Sud-Est became Societe nationale industrielle aérospatiale (SNIAS) in 1970. The company produced the SA 315 B Lama beginning in 1971. It was also built under license by Hindustan Aeronautics in India and Helibras in Brazil.

The total number of SA 315 Bs and its variants built is uncertain. In 2010, Eurocopter, the successor to Aérospatiale, announced that it will withdraw the Lama’s Type Certificate in 2020.

An Aérospatiale SA 315 B Lama “On Top of the World” ( © Phillipe Fragnol)

¹ FAI Record File Number 788.

² FAI Record File Numbers 753, 754 and 11657.

© 2019 Bryan R. Swopes

17 March 1947

North American Aviation XB-45 45-59479 in flight. (U.S. Air Force)

17 March 1947: The prototype of the United States’ first jet-powered bomber, the North American Aviation XB-45 Tornado, 45-59479, made a one-hour first flight at Muroc Army Air Field (later known as Edwards Air Force Base) with company test pilot George William Krebs at the controls.

The photographs below show the XB-45 parked on Muroc Dry Lake. Notice that the windows over the bombardier’s compartment in the nose are painted on.

The North American Aviation XB-45 Tornado was a four-engine prototype bomber. It had a high-mounted straight wing and tricycle landing gear. It was 74 feet, 0 inches (22.555 meters) long with a wingspan of 89 feet, 6 inches (27.279 meters) and overall height of 25 feet, 2 inches (7.671 meters). It had an empty weight of 41,876 pounds (18,995kilograms) and maximum takeoff weight of 82,600 pounds (37,467 kilograms).

North American Aviation XB-45 Tornado 45-59479 parked on the dry lake bed at Muroc Army Airfield, California. (U.S. Air Force)
North American Aviation XB-45 Tornado 45-59479 parked on Muroc Dry Lake. (U.S. Air Force)
North American Aviation XB-45 45-59479 makes a low pass over the runway. (U.S. Air Force)

The three prototypes were powered by four Allison-built General Electric J35-A-4 turbojet engines, installed in nacelles which were flush with the bottom of the wings. The J35 was a single-shaft engine with an 11-stage axial-flow compressor section and a single-stage turbine. The J35-A-4 was rated at 4,000 pounds of thrust (14.79 kilonewtons). The engine’s maximum speed was 8,000 r.p.m. The J35 was 14 feet, 0 inches (4.267 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter, and weighed 2,400 pounds (1,089 kilograms).

The maximum speed of the XB-45 was 494 miles per hour (795 kilometers per hour) at Sea Level and 516 miles per hour (830 kilometers per hour) at 14,000 feet (4,267 meters). The service ceiling was 37,600 feet (11,461 meters).

North American Aviation XB-45 45-59479 as a test bed for rocket assisted take-off, 24 September 1958. (U.S. Air Force)

The production B-45A Tornado was heavier and had better performance. It was operated by two pilots and carried a bombardier/navigator and a tail gunner. It was 75 feet, 4 inches (22.962 meters) long with a wingspan of 89 feet, 0 inches (27.127 meters) and overall height of 25 feet, 2 inches (7.671 meters).

The B-45A had a total wing area of 1,175 square feet (109.2 square meters). The leading edges were swept aft 3° 30′. Their angle of incidence was 3° with -3° 30′ twist and 1° dihedral.

The bomber’s empty weight was 45,694 pounds (20,726 kilograms) and maximum takeoff weight was 91,775 pounds (41,628 kilograms).

Cutaway illustration of the North American Aviation B-45 Tornado showing internal structure and arrangement. (U.S. Air Force)

The B-45A was powered by four General Electric J47-GE-13 turbojet engines. The J47 was an axial-flow turbojet with a 12-stage compressor and single stage turbine. It had a normal power rating of 4,320 pounds of thrust (19.216 kilonewtons) at 7,370 r.p.m.; military power, 5,200 pounds (23.131 kilonewtons) at 7,950 r.p.m. (30-minute limit); and maximum power rating of 6,000 pounds(26.689 kilonewtons) at 7,950 r.p.m., with water/alcohol injection (5-minute limit). The engine was 12 feet, 0.0 inches (3.658 meters) long, 3 feet, 3.0 inches (0.991 meters) in diameter and weighed 2,525 pounds (1,145 kilograms).

The B-45A Tornado had a cruise speed of 393 knots (452 miles per hour/728 kilometers per hour), and maximum speed of 492 knots (566 miles per hour (911 kilometers per hour) at 4,000 feet (1,219 meters). Its service ceiling was 46,800 feet (14,265 meters) and it had a maximum range of 1,886 nautical miles (2,170 statute miles/3,493 kilometers).

The bomb load was 22,000 pounds (9,979 kilograms). (It was capable of carrying the Grand Slam bomb.) Two Browning .50-caliber AN-M3  machine guns were mounted in the tail for defense, with 600 rounds of ammunition per gun.

41 B-45As were modified the the “Back Breaker” configuration, which enabled them to be armed with nuclear weapons.

The B-45 served with both the United States Air Force and the Royal Air Force. 143 were built, including the three XB-45 prototypes.

On 20 September 1948, the first production B-45A-1-NA Tornado, 47-001, was put into a dive to test the airplane’s design load factor. During the dive, an engine exploded, which tore off several cowling panels. These hit the horizontal stabilizer, damaging it. The B-45 pitched up, and both wings failed due to the g load. The prototype had no ejection seats and test pilots George Krebs and Nicholas Gibbs Pickard, unable to escape, were both killed.

George William Krebs

George William Krebs was born in Kansas City, Missouri, 5 March 1918. He was the first of three children of William J. Krebs, an advertising executive, and Betty Schmitz Krebs. He attended Southwest High School, graduating in 1935.

Krebs studied at the Massachussetts Instititute of Technology (M.I.T.) at Cambridge, Massachussetts. He was a member of the Sigma Chi fraternity.

In 1940, Krebs was the owner of a Luscombe airplane distributorship in Kansas City. He had brown hair, blue eyes and a ruddy complexion. He was 5 feet, 9 inches tall (1.75 meters) and weighed 135 pounds (61 kilograms).

George Krebs married Miss Alice Bodman Neal at Kansas City, Missouri, 26 December 1942. They had one son, William John Krebs II, born 1944.

During World War II, Krebs was employed as a test pilot at the North American Aviation, Inc., B-25 Mitchell medium bomber assembly plant at Kansas City, Kansas. Prior to taking over the XB-45 project, he was the chief test pilot at K.C.

North American Aviation B-25 Mitchell medium bombers near completion at the Kansas City, Kansas, bomber plant. (Alfred T. Palmer)
Nicholas Gibbs Pickard

Nicholas Gibbs Pickard was born at Brooklyn, New York, 5 November 1916. He was the second of three children of Ward Wilson Pickard, a lawyer, and Alice Rossington Pickard.

During World War II, Pickard served as a ferry pilot for the Royal Air Force Transport Command.

On 21 January 1944, Captain Pickard married Miss Kathleen Baranovsky at Montreal, Quebec, Canada. They had two daughters, Sandra and Manya.

Following the war, Pickard was employed as a test pilot by North American Aviation.

Nicholas Gibbs Pickard was buried at the Pacific Crest Cemetery, Redondo Beach, California.

The tenth production North American Aviation B-45A-1-NA Tornado, 47-011, in flight. (U.S. Air Force)

© 2019, Bryan R. Swopes

13 March 1977

The number 2 Sikorsky S-76 makes teh type's first flight, 13 March 1977. (Sikorsky Historical Archives)
The number 2 Sikorsky S-76 prototype, s/n 76002, makes the type’s first flight, 13 March 1977. (Sikorsky Historical Archives)

13 March 1977: The protoype Sikorsky S-76A Spirit made its first flight at the company’s Development Flight Center, West Palm Beach, Florida (06FA). This was the number two aircraft, serial number 76002, registered N762SA. Sikorky’s chief pilot, John Dixson, and S-76 program test pilot Nicholas D. Lappos were in the cockpit.

Test pilot Nick Lappos is congratulated following teh first flight of the Sikorsky S-76, 13 March 1977. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Test pilot Nick Lappos is congratulated by His Majesty King Hussein bin Talal of Jordan following the first flight of the Sikorsky S-76, 13 March 1977. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

The prototype was rolled out 11 January 1977.

The Sikorsky S-76 is a twin-engine medium helicopter designed to carry up to 12 passengers 400 nautical miles (460.3 statute miles, 740.8 kilometers) for the offshore oil industry. It is flown by two pilots and is certified for instrument flight. The helicopter can be configured to carry up to thirteen passengers.

The S-76 is used as a passenger transport, executive or VIP aircraft, and in law enforcement, search and rescue, or military service. It is also widely used as a medical transport helicopter.

Prototype Sikorsky S-76A rollout, 11 January 1977. (Sikorsky Historical Archives)

In 1979, Sikorsky proposed the new helicopter for consideration as the U.S. Coast Guard Short Range Recovery Helicopter, along with competitors Aérospatiale and Bell Helicopter. The S-76 was considered to be the most suitable of the three but the company made a business decision to withdraw before any contract was awarded. The Aérospatiale SA-365 Dauphin variant was finally selected and became the MH-65 Dolphin.

Air Logistics accepted the first Sikorsky S-76A production helicopter 27 February 1979. (Sikorsky, a Lockheed Martin Company)
Air Logistics accepted the first Sikorsky S-76A production helicopter, 27 February 1979. (Sikorsky, a Lockheed Martin Company)

The S-76A has an overall length of 52 feet, 6 inches (16.002 meters) with rotors turning, and overall height of 14 feet, 6 inches (4.420 meters). It had an empty weight of 7,132 pounds (3,235 kilograms) and a maximum gross weight of 10,500 pounds (4,763 kilograms).

The four-bladed, fully-articulated main rotor has a diameter of 44 feet, 0 inches (13.411 meters). The main rotor hub is constructed of forged aluminum and uses elastomeric bearings to allow for blade flapping and lead-lag. The blades are made of composite materials formed around a hollow titanium spar. The blade tips are swept to reduce the formation of blade tip vortices. Each blade is 19 feet, 11¾ inches long (6.090 meters). The main rotor turns counter-clockwise, as seen from above. (The advancing blade is on the right.) At 107% NR, the maximum speed with power on, the rotor turns 313 r.p.m.

A four-bladed tail rotor with a diameter of 8 feet, 0 inches (2.438 meters) is mounted on the left side of a pylon in a pusher configuration. The tail rotor turns clockwise as seen from the helicopter’s left. (The advancing blade is below the axis of rotation.)

A Turboméca-powered Sikorsky S-76C in flight over the City of New York. (Sikorsky, a Lockheed Martin Company)

The S-76A was originally powered by two Allison 250-C30 turboshaft engines mounted side-by-side, behind the main transmission. The engines were rated at 557 shaft horsepower (maximum continuous power). 100% torque is 564 foot-pounds. Later production models have used Turboméca and Pratt & Whitney Canada engines.

The S-76A has a cruise speed and maximum speed (VNE) of 155 knots (178 miles per hour/287 kilometers per hour). (The helicopter’s cruise speed is the same as its maximum.) The service ceiling is 15,000 feet (4,572 meters). The maximum altitude for takeoff and landing is 6,900 feet (2,103 meters).

Over a five-day period, 4–9 February 1982, Sikorsky test pilots Nicholas D. Lappos, William Frederick Kramer, Byron Graham, Jr., David R. Wright, and Thomas F. Doyle, Jr., set a series of twelve Fédération Aéronautique Internationale (FAI) speed, time-to-climb and sustained altitude world records while flying a Sikorsky S-76A helicopter, N5445J, at Palm Beach, Florida. These included an absolute world speed record for helicopters (186.69 knots/214.83 miles per hour/345,74 kilometers per hour). Nine of these records remain current.¹

The Sikorsky S-76 remains in production, with more than 1,100 helicopters built. There were 307 S-76A and S-76A+ variants produced, followed by the S-76B, S-76C, -C+ and -C++. The current production model is the S-76D.

Sikorsky S-76D N7621Y, c/n 761021. (Sikorsky, a Lockheed Martin Company)

¹ See “This Day in Aviation” https://www.thisdayinaviation.com/4-february-1982/

© 2019, Bryan R. Swopes

12 March 1955

Jean Boulet (1920–2011)
Chief Test Pilot Jean Boulet (1920–2011)

12 March 1955:  Société nationale des constructions aéronautiques du Sud-Est (SNCASE) Chief Test Pilot Jean Boulet and Flight Test Engineer Henri Petit made the first flight of the SE.3130 Alouette II prototype, F-WHHE, at Buc Airfield, near Paris, France.

Powered by a Societé Anonyme Turboméca Artouste II B1 turboshaft engine, the Alouette II was the first gas turbine powered helicopter to enter series production. SNCASE would become Aérospatiale, later, Eurocopter, and is now Airbus Helicopters.

SNCASE SE.3130 Alouette II No. 01 prototype, F-WHHF, with test pilot Jean Boulet and Henri Petit, 12 March 1955. (Eurocopter)
SNCASE SE.3130 Alouette II No. 01 prototype, F-WHHE, with test pilot Jean Boulet and Henri Petit, 12 March 1955. (Airbus Helicopters)

The Alouette II is a 5-place light helicopter operated by a single pilot. The fuselage is 31 feet, 8.5 inches (9.665 meters) long. The landing skids have a width of 6 feet, 10 inches (2.083 meters). With rotors turning, the overall length of the Alouette II is 39 feet, 6.5 inches (12.052 meters). Its height is 9 feet, 0.25 inches (2.750 meters) to the top of the main rotor mast. (Optional wide-track skids, or installation of an Alouette III three-blade tail rotor will change dimensions slightly.)

The three-bladed fully-articulated main rotor has a diameter of 33 feet, 5.5 inches (10.198 meters). It turns clockwise, as seen from above. (The advancing blade is on the left side of the helicopter.) Normal main rotor speed, NR, is 350–360 r.p.m. In autorotation, the allowable range is 280–420 r.p.m. The two-blade anti-torque rotor is 5 feet, 11.5 inches (1.816 meters) in diameter and turns clockwise, as seen from the helicopter’s left side. (The advancing blade is below the axis of rotation.) The tail rotor turns at 2,020 r.p.m.

The SE.3130 has an empty weight of 1,934 pounds (877 kilograms), depending on installed equipment, and minimum operating weight of 2,050 pounds (930 kilograms). The maximum permissible weight is 3,300 pounds (1,497 kilograms).

SNCASE SE.3130 No. 01, F-WHHE. (Airbus Helicopters)

The prototype was powered by one Turboméca Artouste II B1 turboshaft engine. The Artouste II B1 is a single-shaft turboshaft engine with a single-stage centrifugal flow compressor section and a three-stage axial-flow turbine. The turbine drives both the compressor and an output drive shaft through reduction gearbox. As installed in the Alouette II, the engine was certified for operation at 33,000–34,000 r.p.m (N1), with transient overspeeds to 35,000 r.p.m. It is capable of producing 400 shaft horsepower, but was derated to 360 shaft horsepower at 5,780 r.p.m. (N2) for installation in the Alouette II.

SE.3130 Alouette II three-view illustration with dimensions. (SNCASE)

The helicopter has an economical cruise speed of 92 knots (106 miles per hour/170 kilometers per hour) at 33,000 r.p.m., and a maximum speed (VNE) of 105 knots (121 miles per hour/194 kilometers per hour) at Sea Level, which decreases with altitude. Sideward or rearward flight (or operation in tailwinds or crosswinds) is limited to 18 knots (20 miles per hour/33 kilometers per hour).

The Allouette II is limited to a maximum operating altitude of 14,800 feet (4,511 meters). At 1,350 kilograms (2,976 pounds) the Alouette II has a hover ceiling in ground effect, HIGE, of 3,400 meters (11,155 feet) and hover ceiling out of ground effect of 1,900 meters (6,234 feet). At 1,500 kilograms the Alouette II’s HIGE is 2,000 meters (6,560 feet) and HOGE is 600 meters (1,968 feet).

The SE.3130 Alouette was in production from 1956 until 1975. It was marketed in the United States by the Republic Aviation Corporation’s Helicopter Division. More than 1,300 of these helicopters were built.

Jean Boulet hovers the prototype SE.3130 Alouette II, F-WHHF, 12 March 1955. (Eurocopter)
Jean Boulet hovers the prototype SNCASE SE.3130 No. 01, F-WHHE. (Airbus Helicopters)

Jean Ernest Boulet was born 16 November 1920, in Brunoy, southeast of Paris, France. He was the son of Charles-Aimé Boulet, an electrical engineer, and Marie-Renée Berruel Boulet.

He graduated from Ecole Polytechnique in 1940 and the Ecole Nationale Supérieure de l’aéronautique In 1942. (One of his classmates was André Edouard Turcat, who would also become one of France’s greatest test pilots.)

Following his graduation, Boulet joined the Armée de l’Air (French Air Force)and was commissioned a sous-lieutenant. He took his first flight lesson in October. After the surrender of France in the Nazi invaders, Boulet’s military career slowed. He applied to l’Ecole Nationale Supérieure de l’Aéronautique in Toulouse for post-graduate aeronautical engineering. He completed a master’s degree in 1943.

During this time, Boulet joined two brothers with La Resistance savoyarde, fighting against the German invaders as well as French collaborators.

In 1943, Jean Boulet married Mlle Josette Rouquet. They had two sons, Jean-Pierre and Olivier.

In February 1945, Sous-lieutenant Boulet was sent to the United States for training as a pilot. After basic and advanced flight training, Boulet began training as a fighter pilot, completing the course in a Republic P-47D Thunderbolt. He was then sent back to France along with the other successful students.

On 1 February 1947 Jean Boulet joined Société nationale des constructions aéronautiques du Sud-Est (SNCASE) as an engineer and test pilot. He returned to the United States to transition to helicopters. Initially, Boulet and another SNCASE pilot were sent to Helicopter Air Transport at Camden Central Airport,  Camden, New Jersey, for transition training in the Sikorsky S-51. An over-enthusiastic instructor attempted to demonstrate the Sikorsky to Boulet, but lost control and crashed. Fortunately, neither pilot was injured. Boulet decided to go to Bell Aircraft at Niagara Falls, New York, where he trained on the Bell Model 47. He was awarded a helicopter pilot certificate by the U.S. Federal Aviation Administration, 23 February 1948.

Test pilot Jean Boulet (center), with Mme. Boulet and the world-record-setting Alouette II.

As a test pilot Boulet made the first flight in every helicopter produced by SNCASE, which would become Sud-Aviation and later, Aérospatiale (then, Eurocopter, and now, Airbus Helicopters).

While flying a SE 530 Mistral fighter, 23 January 1953, Boulet entered an unrecoverable spin and became the first French pilot to escape from an aircraft by ejection seat during an actual emergency. He was awarded the Médaille de l’Aéronautique.

Jean Boulet was appointed Chevalier de la légion d’honneur in 1956, and in 1973, promoted to Officier de la Légion d’honneur.

Jean Boulet had more than 9,000 flight hours, with over 8,000 hours in helicopters. He set 24 Fédération Aéronautique Internationale world records for speed, distance and altitude. Four of these are current.

Jean Boulet wrote L’Histoire de l’Helicoptere: Racontée par ses Pionniers 1907–1956, published in 1982 by Éditions France-Empire, 13, Rue Le Sueuer, 75116 Paris.

Jean Ernest Boulet died at Aix-en-Provence, in southern France, 15 February 2011, at the age of 90 years.

© 2019, Bryan R. Swopes