Tag Archives: National Advisory Committee for Aeronautics

4 November 1941

Lockheed YP-38 Lightning 39-689, manufacturer's serial number 122-2202. (Lockheed)
Lockheed YP-38 Lightning 39-689, manufacturer’s serial number 122-2202. (Lockheed Martin)
Ralph Burwell. Virden (Los Angeles Times)

4 November 1941: Lockheed test pilot Ralph Burwell Virden was conducting high speed dive tests in the first Lockheed YP-38 Lightning, Air Corps serial number 39-689 (Lockheed’s serial number 122-2202).

As the airplane’s speed increased, it approached what is now known as its Critical Mach Number. Air flowing across the wings accelerated to transonic speeds and began to form shock waves. This interrupted lift and caused a portion of the wing to stall. Air no longer flowed smoothly along the airplane and the tail surfaces became ineffective. The YP-38 pitched down into a steeper dive and its speed increased even more.

Designed by famed aeronautical engineer Clarence L. “Kelly” Johnson, the YP-38 had servo tabs on the elevator that were intended to help the pilot maintain or regain control under these conditions. But they increased the elevator’s effectiveness too well.

The Los Angeles Times described the accident:

     Witnesses said the twin-engined, double-fuselaged ship was booming westward at near maximum speed (unofficially reported to be between 400 and 500 miles an hour) when the duralumin tail assembly “simply floated away.”

     A moment afterward the seven-ton craft seemed to put on a burst of speed, the the high whine of its engines rising.

     It then went into a downward glide to about 1500 feet, then into a flat spin, flipped over on its back and shot earthward.

     Several persons said that they thought they had heard an explosion during the dive, but qualified observers doubted it. . .

     . . . Fellow pilots at Lockheed said, “Ralph was the best we had, especially in power dives.”

      Robert E. Gross, president of Lockheed, said, “Ralph Virden was a great pilot but an even greater man. If anyone ever had national defense at heart it was he, who every day was carrying the science of aviation into new and higher fields.”

     Various witnesses said the ill-fated ship’s tail assembly could be followed easily as its bright surfaces glinted in the sun during its drop to earth. It landed several blocks from the scene of the crash.

     Mrs. Jack Davenport of 1334 Elm Ave., left her ironing board when she heard the unfamiliar roar of the plunging plane’s engines.

     “I ran out and saw it passing over us, very low. It disappeared among the trees and then zoomed back into sight just before crashing in the next block,” she said. “It looked just like a toy airplane. I knew the pilot didn’t have a chance, as the ship was too low and going too fast.”

Los Angeles Times, Vol. LX, Wednesday, 5 November 1941, Page 1, Column 6, and Page 2, Column 5.

The YP-38 crashed into the kitchen of Jack Jensen’s home at 1147 Elm Street, Glendale, California. Fire erupted. Ralph Virden was killed. The airplane’s tail section was located several blocks away.

Another view of Lockheed YP-38 Lightning 39-689. It's factory serial number, "2202," is stenciled on the nose. (Lockheed Martin)
Another photograph of Lockheed YP-38 Lightning 39-689. The factory serial number, “2202,” is stenciled on the nose. (Lockheed Martin)

39-689 was the first of thirteen YP-38 service test aircraft that had been ordered by the U.S. Army Air Corps shortly after the XP-38 prototype, 37-457, had crashed on a transcontinental speed record attempt, 11 February 1939. 39-689 made its first flight 16 September 1940 with test pilot Marshall Headle at the controls. With hundreds of production P-38s being built, Lockheed continued to use the YP-38 for testing.

Newspaper phototograph of the wreckage of Lockheed YP-38 Lightning 39-689 at 1147 Elm Street, Glendale, California. (Los Angeles Times)
Newspaper photograph of the wreckage of Lockheed YP-38 Lightning 39-689 at 1147 Elm Street, Glendale, California. (Los Angeles Times)

The YP-38s were service test prototypes of a single-place, twin engine long range fighter with a unique configuration. There was not a fuselage in the normal sense. The cockpit, nose landing gear, and armament were contained in a central nacelle mounted to the wing. Two engines and their turbochargers, cooling systems and main landing gear were in two parallel booms. The booms end with vertical fins and rudders, with the horizontal stabilizer and elevator between them. The P-38 was 37 feet, 9–15/16 inches (11.530 meters) long, with a wingspan of 52 feet, 0 inches (15.850 meters) and height of 12 feet, 10 inches (3.952 meters).

The P-38’s wings had a total area of 327.50 square feet (30.43 square meters). Their angle of incidence was 2° and there was 5° 40′ dihedral. The leading edges were swept aft 5° 10′.

The YP-38 had an empty weight 11,171 pounds (5,067 kilograms). The gross weight was 13,500 pounds (6,123 kilograms) and the maximum takeoff weight 14,348 pounds (6,508 kilograms).

The YP-38 was powered by two counter-rotating, liquid-cooled, turbosupercharged 1,710.597-cubic-inch displacement (28.032 liter) Allison V-1710-27 right-hand tractor and V-1710-29 left-hand tractor, single overhead cam (SOHC) 60° V-12 engines (Allison Engineering Co. Models F2R and F2L) with a Normal Power rating of 1,000 horsepower at 2,600 r.p.m., and 1,150 horsepower at 3,000 r.p.m. for takeoff. They drove three-bladed Curtiss Electric constant-speed propellers with a diameter of 11 feet, 6 inches (3.505 meters) through a 2.00:1 gear reduction. In a change from the XP-38, the propellers rotated outboard at the top of their arc. The V-1710-27/-29 engines were 7 feet, 1-5/8 inches (2.175 meters) long, 2 feet, 5-9/32 inches (0.744 meters) wide and 3 feet, 0-17/32 inches (0.928 meters) high. The V-1710-27/-29 weighed 1,305 pounds (592 kilograms)

The YP-38 had a maximum speed of 405 miles per hour (651.8 kilometers per hour) at 10,000 feet (3,048 meters) and it could climb  from the surface to 20,000 feet (6,096 meters) in six minutes. Normal range 650 miles (1,046 kilometers).

Lockheed built one XP-38, thirteen YP-38s, and more than 10,000 production fighter and reconnaissance airplanes. At the end of World War II, orders for nearly 2,000 more P-38 Lightnings were cancelled.

Lockheed YP-38 39-692 in flight.(Hans Groenhoff Photographic Collection, Smithsonian Institution National Air and Space Museum NASM-HGC-967)

Ralph Burwell Virden was born 11 June 1898, at Audobon Township, Illinois. He was the second child of Hiram R. Virden, a farmer, and Nancy Carrie Ivy Virden.

Virden attended Bradley Polytechnic Institute at Peoria, Illinois. At the age of 17, 15 October 1918, Ralph Virden enlisted in the U.S. Army. With the end of World War I less than one month later, he was quickly discharged, 7 December 1918.

In 1919, Ralph Virden married Miss Florence I. McCullers. They would have two children, Kathryn and Ralph, Jr. Kathryn died in 1930 at the age of ten years.

Ralph Burwell Virden with a Boeing Model 40 mail plane, circa late 1920s. As a U.S. Air Mail pilot, Virden is armed with a .45-caliber Colt M1911 semi-automatic pistol. (San Diego Air and Space Museum Archives)
Boeing Airplane Company President Clairmont L. Egvtedt and United Air Lines Captain Ralph B. Virden examine a scale model of the Boeing 247D airliner. (Boeing)

During the mid-1920s, Virden flew as a contract mail pilot. He held Airline Transport Pilot Certificate No. 628, and was employed by Gilmore Aviation and Pacific Air Transport. For thirteen years, Virden was a pilot for United Air Lines. He joined Lockheed Aircraft Company as a test pilot in 1939. He had flown more than 15,000 hours.

Virden lived at 4511 Ben Ave., North Hollywood, California, with his  family. Ralph, Jr., now 19 years of age, was also employed at Lockheed. (Following his father’s death, the younger Virden enlisted in the United States Navy.)

After the accident, Lockheed, the Air Corps and the National Advisory Committee on Aeronautics (NACA) undertook an extensive test program of the P-38.

The Lockheed YP-38 Lightning, 39-690, was sent to the NACA Research Center at Langley Field, Virginia. This photograph is dated 4 February 1942. (NASA)
The second Lockheed YP-38 Lightning, 39-690, was sent to the NACA Langley Research Center at Langley Field, Virginia. This photograph is dated 4 February 1942. (NASA)
Lockheed YP-38 39-690 in the NACA Full Scale Tunnel, December 1944. (NASA)
Lockheed YP-38 39-690 in the NACA Full Scale Tunnel, December 1944. (NASA)
Lockheed YP-38 Lightning 39-690, serial number 122-2203. (NASA)
Lockheed YP-38 Lightning 39-690, serial number 122-2203. (NASA)
Lockheed YP-38 #2 in the NACA full-scale wind tunnel at Langley, Virginia. (NASA)
Lockheed YP-38 Lightning, 39-690 (122-2203), in the NACA Langley Research Center’s full-scale wind tunnel at Langley Field, Virginia, December 1944. (NASA)
Lockheed YP-38 Lightning 39-690. (NASA)
Lockheed YP-38 Lightning 39-690. (NASA)
Lockheed YP-38 Lightning 39-690. (NASA)
Lockheed YP-38 Lightning 39-690. (NASA)
Lockheed YP-38 Lightning 39-690. (NASA)
Lockheed YP-38 Lightning 39-690. (NASA)
Lockheed YP-38 Lightning 39-690, 122-2203. (NASA)
Lockheed YP-38 Lightning 39-690, 122-2203. (NASA)

© 2018, Bryan R. Swopes

27 October 1954

NACA's chief project test pilot for the Douglas X-3, in the cockpit of the research aircraft, circa 1954-1956. (LIFE Magazine via Jet Pilot Overseas)
NACA’s chief project test pilot for the Douglas X-3, Joe Walker, in the cockpit of the research aircraft, circa 1954-1956. (LIFE Magazine via Jet Pilot Overseas)

October 27, 1954: Between August 1954 and May 1956, Joseph A. Walker, the National Advisory Committee for Aeronautics’ chief project test pilot for the Douglas X-3 supersonic research aircraft, made twenty research flights in the “Stiletto.”

On the tenth flight, 27 October, Walker took the X-3 to an altitude of 30,000 feet (9,144 meters). With the rudder centered, he put the X-3 into abrupt left aileron rolls, first at 0.92 Mach and then at Mach 1.05. Both times, the aircraft violently yawed to the right and then pitched down. Walker was able to recover before the X-3 was completely out of control.

Screen Shot 2015-10-20 at 12.08.52
The Douglas X-3 during NACA flight testing, 1954-1956. (LIFE Magazine via Jet Pilot Overseas)

This was a new and little understood condition called inertial roll coupling. It was a result of the aircraft’s mass being concentrated within its fuselage, the gyroscopic effect of the turbojet engines and the inability of the wings and control surfaces to stabilize the airplane and overcome its rolling tendency. (Just two weeks earlier, North American Aviation’s Chief Test Pilot George S. Welch had been killed when the F-100A Super Sabre that he was testing also encountered inertial roll coupling and disintegrated.)

A post-flight inspection found that the X-3 had reached its maximum design load. The airplane was grounded for the next 11 months.

Unlike its predecessors, the Bell Aircraft Corporation's X1 and and X-2 rocketplanes, teh turbojet-powered Douglas X-3 took off under its own power. here, its two Westinghouse J37 engines are stirring up teh sand on Runway 35 at Rogers Dry Lake. (LIFE Magazine via jet Pilot Overseas)
Unlike its predecessors, the Bell Aircraft Corporation’s X1 and and X-2 rocketplanes, the turbojet-powered Douglas X-3 took off under its own power. Here, its two Westinghouse J37 engines are stirring up the sand on Runway 35 at Rogers Dry Lake. (LIFE Magazine via jet Pilot Overseas)

The Douglas X-3, serial number 49-2892, was built for the Air Force and NACA to explore flight in the Mach 1 to Mach 2 range. It was radically shaped, with a needle-sharp nose, very long thin fuselage and small straight wings. Two X-3 aircraft had been ordered from Douglas, but only one completed.

The X-3 was 66 feet, 9 inches (20.345 meters) long, with a wing span of just 22 feet, 8.25 inches (6.915 meters). The overall height was 12 feet, 6.3 inches (3.818 meters). The X-3 had an empty weight of 16,120 pounds (7,312 kilograms) and maximum takeoff weight of 23,840 pounds (10,814 kilograms).

It was to have been powered by two Westinghouse J46 engines, but when those were unsatisfactory, two Westinghouse XJ34-WE-17 engines were substituted. This was an axial flow turbojet with 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 XJ34-WE-17 was 14 feet, 9.0 inches (4.496 meters) long, 2 feet, 1.0 inch (0.635 meters) in diameter and weighed 1,698 pounds (770 kilograms).

The X-3 had a maximum speed of 706 miles per hour (1,136 kilometers per hour) and a service ceiling of 38,000 feet (11,582 meters).

The X-3 was very underpowered with the J37 engines, and could just reach Mach 1 in a shallow dive. The X-3′s highest speed, Mach 1.208, required a 30° dive. It was therefore never able to be used in flight testing the supersonic speed range for which it was designed. Because of its design characteristics, though, it was very useful in exploring stability and control in the transonic range.

At one point, replacing the X-3’s turbojet engines with two Reaction Motors XLR-11 rocket engines was considered. Predictions were that a rocket-powered X-3 could reach Mach 4.2. However, with Mach 2 Lockheed F-104 becoming operational and North American Aviation’s X-15 hypersonic research rocketplane under construction, the idea was dropped. Technology had passed the X-3 by.

In addition to Douglas Aircraft test pilot Bill Bridgeman, the Douglas X-3 was flown by Air Force test pilots Lieutenant Colonel Frank Everest and Major Chuck Yeager and  NACA pilot Joe Walker.

Joe Walker resumed flight testing the X-3 in 1955. Its final flight was 23 May 1956. After the flight test program came to an end, the X-3 was turned over to the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

NACA test pilot Joe Walker with the Douglas X-3. (LIFE Magazine via Jet Pilot Overseas)
NACA test pilot Joe Walker with the Douglas X-3. (LIFE Magazine via Jet Pilot Overseas)

© 2018, Bryan R. Swopes

24 October 1953

Convair YF-102 52-7994 on Rogers Dry Lake, Edwards Air Force Base, California. (San Diego Air and Space Museum Archive)
Convair YF-102 52-7994 on Rogers Dry Lake, Edwards Air Force Base, California. (San Diego Air and Space Museum Archive)

24 October 1953: At Edwards Air Force Base, California, Richard Lowe Johnson, Chief Test Pilot for the Convair Division of the General Dynamics Corporation, took the first prototype YF-102 Delta Dagger, serial number 52-7994, for its first flight.

The YF-102 was a single-seat, single-engine, delta wing fighter designed as an all-weather, missile-armed, Mach 2 interceptor. It was developed from the earlier, experimental, Convair XF-92 Dart. The F-102 was planned for a Westinghouse XJ67-W-1 engine, but when that was not ready in time, a Pratt & Whitney J57-P-11 afterburning turbojet engine was substituted. The J57 was a two-spool, axial-flow engine with a 16-stage compressor section (9 low- and 7-high-pressure stages) and a 3-stage turbine section (1 high- and 2 low-pressure stages). The J57-P-11 was rated at 10,000 pounds of thrust (44.482 kilonewtons), and 16,000 pounds (71.172 kilonewtons) with afterburner.

The first prototype Convair YF-102 Delta Dagger, 52-7994, was completed at the Convair plant in San Diego, 2 October 1953. (U.S. Air Force)
The first prototype Convair YF-102 Delta Dagger, 52-7994, was completed at the Convair plant in San Diego, 2 October 1953. (Convair Division of General Dynamics)

The prototype had finished assembly at the Convair plant in San Diego, California, on 2 October 1953. It was then shipped by truck to Edwards Air Force Base in the high desert of southern California where final preparations and testing was carried out.

The National Advisory Committee for Aeronautics (NACA) had tested scale models of the YF-102 in the 8-foot HST wind tunnel at the Langley Memorial Aeronautical laboratory and found that significant shock waves were produced at near-sonic speeds. Surprisingly, shock waves were created at the trailing edge of the delta wing. The shock waves caused very high drag that would keep the aircraft from reaching Mach 1, even with the more powerful engine planned for production models.

Convair YF-102 with the original fuselage. (NASA)
Convair YF-102 53-1785 with the original fuselage, photographed 31 December 1954. (NASA)

The Republic YF-105 fighter bomber had similar problems, though it did pass the speed of sound. Both aircraft were significantly redesigned to incorporate the “Area Rule,” developed by NACA aerodynamicist Richard T. Whitcomb. Rather than considering the aerodynamics of the fuselage independently, the frontal area of the wings and tail surfaces had to be included to reduce drag. This produced the “wasp waist” or “Coke bottle” shape that the production models of these two fighters were known for.

Convair built two YF-102s before the design was changed, resulting in the YF-102A prototypes and the production F-102A Delta Dagger.

The first prototype Convair YF-102 Delta Dagger, 52-7994, on Rogers Dry Lake, October 1953. (U.S. Air Force)
The first prototype Convair YF-102 Delta Dagger, 52-7994, on Rogers Dry Lake, October 1953. (U.S. Air Force)

Several problems showed up on the YF-102’s first flight. Severe buffeting was encountered at high sub-sonic speed. As predicted by NACA, aerodynamic drag prevented the YF-102 from reaching Mach 1 in level flight. There were also problems with the landing gear, the fuel system, and the J57 engine did not produce the rated power.

The production F-102A was considerably larger than the YF-102. The fuselage was lengthened, the wing area and span were increased, and the vertical fin was taller. A more powerful J57-P-23 engine was used. These and other changes increased the F-102A’s gross weight by nearly 1,800 pounds (815 kilograms).

Convair YF-102 52-7994 parked on the dry lake bed, Edwards AFB, California. (U.S. Air Force)

On 2 November 1953, just nine days after the first flight, the Pratt & Whitney J57-P-11 engine flamed out during a test flight. Dick Johnson was unable to restart it and made a forced landing in the desert. The  YF-102 was severely damaged and Dick Johnson badly hurt. The flameout was traced to a problem with the the fuel control system. The prototype was written off.

Convair YF-102 Delta Dagger 52-7994. (U.S. Air Force)
Convair YF-102 Delta Dagger 52-7994 just before touchdown on Rogers Dry Lake. (U.S. Air Force)
Wreck o fConvair YF-102 52-994 near Edwards Air focre Base, 2 Novemnber 1953. (U.S. Air Force)
Wreck of Convair YF-102 52-7994 near Edwards Air Force Base, 2 November 1953. (U.S. Air Force)

Richard Lowe Johnson ¹ was born at Cooperstown, North Dakota, 21 September 1917. He was the eighth of nine children of Swedish immigrants, John N. Johnson, a farmer, and Elna Kristina Helgesten Johnson, a seamstress.

Dick Johnson attended Oregon State College at Corvallis, Oregon, as a member of the Class of 1943. He was a member of the Sigma Alpha Epsilon (ΣΑΕ) fraternity.

Dick Johnson was a pitcher for the college baseball team, and later, played for the Boston Red Sox “farm” (minor league) system.

On 18 June 1942, Johnson enlisted as a private in the Air Corps, United States Army. On 5 November, he was appointed an aviation cadet and assigned to flight training.

Aviation Cadet Johnson married Miss Juanita Blanche Carter, 17 April 1943, at Ocala, Florida. The civil ceremony was officiated by Judge D. R. Smith.

After completing flight training, on 1 October 1943, Richard L. Johnson was commissioned as a second lieutenant, Army of the United States (A.U.S.).

Lieutenant Johnson was assigned to the 66th Fighter Squadron, 57th Fighter Group, Twelfth Air Force, in North Africa, Corsica, and Italy, flying the Republic P-47 Thunderbolt. He was promoted to first lieutenant, A.U.S., 9 August 1944, and just over three months later, 26 November 1944, to the rank of captain, A.U.S. On 14 May 1945, Captain Johnson was promoted to the rank of major, A.U.S. (Major Johnson was assigned a permanent rank of first lieutenant, Air Corps, United States Army, on 5 July 1946, with a date of rank retroactive to 21 September 1945.)

Republic P-47D-25-RE Thunderbolt 42-26421, assigned to the 66th Fighter Squadron, 57th Fighter group, Twelfth Air Force. This airplane was purchased by the employees of Republic Aviation. (American Air Museum in Britain UPL 25505)

During World War II, Major Johnson flew 180 combat missions with the 66th Fighter Squadron. He is officially credited with one air-to-air victory, 1 July 1944. Johnson was awarded the Silver Star, the Distinguished Flying Cross with two oak leaf clusters (3 awards), and the Air Medal with twelve oak leaf clusters (thirteen awards).

In 1946, was assigned to the Air Materiel Command Engineering Test Pilot School at the Army Air Forces Technical Base, Dayton, Ohio (Wright-Patterson Air Force Base). He was the second U.S. Air Force pilot to be publicly acknowledged for breaking the “sound barrier.”

A few weeks after arriving at Dayton, Major Johnson met Miss Alvina Conway Huester, the daughter of an officer in the U.S. Navy. Dick Johnson and his wife Juanita were divorced 8 January 1947, and he married Miss Huester in a ceremony in Henry County, Indiana, 10 January 1947. They would have three children, Kristie, Lisa and Richard.

Richard L. Johnson waves from the cockpit of the record-setting North American Aviation F-86A-1-NA Sabre, 47-611.

Dick Johnson set a Fédération Aéronautique Internationale (FAI) World Record Speed Over a 3 Kilometer Course,² flying the sixth production North American Aviation F-86A-1-NA Sabre, serial number 47-611, at Muroc Air Force Base, California (renamed Edwards AFB in 1949).

During the Korean War, Major Johnson was sent to the war zone to supervise field installations of improvements to the F-86 Sabre. He was “caught” flying “unauthorized” combat missions and was sent home.

Convair Chief Test Pilot Richard Lowe Johnson. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

Lieutenant Colonel Johnson resigned from the Air Force in 1953 to become the Chief Test Pilot for the Convair Division of General Dynamics. He made the first flights of the YF-102 and the F-106A Delta Dart, 26 December 1956. He also made the first flight of the F-111 on 21 December 1964.

In 1955, Johnson was one of the six founding members of the Society of Experimental test Pilots.

Dick Johnson was Chief Engineering Test Pilot for the General Dynamics F-111 “Aardvark.” In 1967, the Society of Experimental Test Pilots awarded Johnson its Iven C. Kincheloe Award for his work on the F-111 program. In 1977, Dick Johnson, then the Director of Flight and Quality Assurance at General Dynamics, retired.

In 1998, Dick Johnson was inducted into the Aerospace Walk of Honor at Lancaster, California. His commemorative monument is located in front of the Lancaster Public Library on W. Lancaster Boulevard, just West of Cedar Avenue. ³

Lieutenant Colonel Richard Lowe Johnson, United States Air Force, (Retired), died 9 November 2002 at Fort Worth, Texas. He was buried at Arlington National Cemetery, Arlington, Virginia, on 7 January 2003.

Chief Test Pilot Dick Johnson in the cockpit of a Convair B-58A Hustler. (Courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

¹ Several sources spell Johnson’s middle name as “Loe.”

² FAI Record File Number 9866

³ Various Internet sources repeat the statement that “Richard Johnson has been honored with. . . the Thompson Trophy, Mackay Trophy, Flying Tiger Trophy, Federation Aeronautique Internationale Gold Medal and Golden Plate Award of the American Academy of Achievement. . . .” TDiA has checked the lists of awardees of each of the appropriate organizations and has not found any support for the statement.

© 2018, Bryan R. Swopes

20 October 1952

Douglas X-3 (NASA)
Douglas X-3 49-2892. Rogers Dry Lake is in the background. (NASA)

20 October 1952: At Edwards Air Force Base, California, Douglas Aircraft Company test pilot William Barton (“Bill”) Bridgeman made the first test flight of the X-3 twin-engine supersonic research airplane. During a high-speed taxi test five days earlier, Bridgeman and the X-3 had briefly been airborne for approximately one mile over the dry lake bed, but on this flight he spent approximately 20 minutes familiarizing himself with the new airplane.

William Barton “Bill” Bridgeman, 1916–1968. (Loomis Dean/LIFE Magazine)

Bill Bridgeman had been a Naval Aviator during World War II, flying the Consolidated PBY Catalina and PB4Y (B-24) Liberator long range bombers with Bombing Squadron 109 (VB-109), “The Reluctant Raiders.”

Bridgeman stayed in the Navy for two years after the war, then he flew for Trans-Pacific Air Lines in the Hawaiian Islands and Southwest Airlines in San Francisco, before joining Douglas Aircraft Co. as a production test pilot. He checked out new AD Skyraiders as they came off the assembly line at El Segundo, California. He soon was asked to take over test flying the D-558-2 Skyrocket test program at Muroc Air Force Base (now, Edwards AFB.) With the Skyrocket, he flew higher—79,494 feet (24,230 meters)—and faster—Mach 1.88—than any pilot had up to that time.

Douglas X-3 parked on Rogers Dry Lake, 1956 (NASA)
Douglas X-3 parked on Rogers Dry Lake, 1956 (NASA)

The Douglas X-3, serial number 49-2892, was built for the Air Force and NACA to explore flight in the Mach 1 to Mach 2 range. It was radically shaped, with a needle-sharp nose, very long thin fuselage and small straight wings. The X-3 was 66 feet, 9 inches (20.345 meters) long, with a wing span of just 22 feet, 8.25 inches (6.915 meters). The overall height was 12 feet, 6.3 inches (3.818 meters). The X-3 had an empty weight of 16,120 pounds (7,312 kilograms) and maximum takeoff weight of 23,840 pounds (10,814 kilograms).

It was to have been powered by two Westinghouse J46 engines, but when those were unsatisfactory, two Westinghouse XJ34-WE-17 engines were substituted. This was an axial flow turbojet with 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 XJ34-WE-17 was 14 feet, 9.0 inches (4.496 meters) long, 2 feet, 1.0 inch (0.635 meters) in diameter and weighed 1,698 pounds (770 kilograms).

The X-3 had a maximum speed of 706 miles per hour (1,136 kilometers per hour) and a service ceiling of 38,000 feet (11,582 meters).

This view of the Douglas X-3 shows its very small wings and tail surfaces. (NASA)
This view of the Douglas X-3 shows its very small wings and tail surfaces. (NASA)

The X-3 was very underpowered with the J34 engines and could just reach Mach 1 in a shallow dive. Its highest speed, Mach 1.208, required a 30° dive. The research airplane was therefore never able to be used in flight testing in the supersonic speed range for which it was designed. Because of its design characteristics, though, it became useful in exploring stability and control problems encountered in the transonic range.

Two X-3 aircraft had been ordered from Douglas, but only one completed.

In addition to Bill Bridgeman, the Douglas X-3 was flown by Air Force test pilots Major Chuck Yeager and Lieutenant Colonel Frank Everest, and NACA High Speed Flight Station research pilot Joseph A. Walker.

NACA flight testing began in August 1954. On the tenth flight, 27 October, Joe Walker put the X-3 into abrupt left aileron rolls at 30,000 feet (9,144 meters), first at 0.92 Mach and then at Mach 1.05. Both times, the aircraft violently yawed to the right and then pitched down.

This was a new and little understood condition called inertial roll coupling. It was a result of the aircraft’s mass being concentrated within its fuselage, the torque reactions and gyroscopic effect of the turbojet engines and the inability of the wings and control surfaces to stabilize the airplane and overcome its rolling tendency. (Just two weeks earlier, North American Aviation’s Chief Test Pilot George S. Welch had been killed when the F-100A Super Sabre that he was testing also encountered inertial roll coupling and disintegrated.) A post-flight inspection found that the X-3 had reached its maximum design load. The X-3 was grounded for the next 11 months.

Joe Walker resumed flight testing the X-3 in 1955. It’s last flight was 23 May 1956. After the flight test program came to an end, the X-3 was turned over to the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

Douglas X-3 49-2892 at the National Museum of the United States Air Force. (NASM)

© 2016, Bryan R. Swopes

15 October 1952

William Barton Bridgeman
William Barton Bridgeman. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

15 October 1952: At Edwards Air Force Base, California, Douglas Aircraft Company test pilot William Barton (“Bill”) Bridgeman, while conducting high speed taxi tests, took a short flight in the new Douglas X-3. The experimental airplane flew about one mile (1.6 kilometers) over the dry lake bed before touching down. The official first flight would come five days later on 20 October.

In his biography, The Lonely Sky, Bill Bridgeman discussed his concerns about taking on the new project:

Then one morning Johnny called me to his office. "Bill, we would like you to take a look at the X-3. Maybe you would like to test her. She's in the final stages over in Hangar Three. Go over and take a look at the mock-up. See what you think. . ." On the ground floor in front of a door marked KEEP OUT. SECRET PROJECT MX656. . . . — The Lonely Sky, by William Bridgeman and Jacqueline Hazard, Cassell and Company Limited, London, 1956, Chapter XXIII at Page 276.
Mock-up of the Douglas X-3 (U.S. Air Force)
William B. Bridgeman with the Douglas X-3.
William B. Bridgeman with the Douglas X-3.

Then one morning Johnny called me to his office. “Bill, we would like you to take a look at the X-3. Maybe you would like to test her. She’s in the final stages over in Hangar Three. Go over and take a look at the mock-up. See what you think. . . ” On the ground floor in front of a door marked KEEP OUT. SECRET PROJECT MX656. . .

I climbed aboard. In order to get into the cockpit, the seat was mechanically lowered to the ground. There was a button to raise the elevator. It buzzed ominously as it very slowly lifted me into the nose. Visibility was extremely poor from her windows, they were faired-in exaggerations of the Skyrocket slits. It was impossible to see the ground. The thin, insecure looking wings were so far behind me that they were out of sight. It would take some weighing to decide whether or not I wanted to bet my life on the integrity of this ship. . .

I was afraid to take on this airplane. I was also afraid someone else would accept the challenge. And I was afraid that I would decide to accept it.

The Lonely Sky, William Bridgeman with Jacqueline Hazard, Cassell and Company Limited, London, 1956, Chapter XXIII at Page 276–278.

Douglas X-3 Stilleto

The Douglas X-3, serial number 49-2892, was built for the Air Force and the National Advisory Committee for Aeronautics (NACA) to explore flight in the Mach 1 to Mach 2 range. It was radically shaped, with a needle-sharp nose, very long thin fuselage and small straight wings. The X-3 was 66 feet, 9 inches (20.345 meters) long, with a wing span of just 22 feet, 8.25 inches (6.915 meters). The overall height was 12 feet, 6.3 inches (3.818 meters). The X-3 had an empty weight of 16,120 pounds (7,312 kilograms) and maximum takeoff weight of 23,840 pounds (10,814 kilograms).

It was to have been powered by two Westinghouse J46 engines, but when those were unsatisfactory, two Westinghouse XJ34-WE-17 engines were substituted. This was an axial flow turbojet with 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 XJ34-WE-17 was 14 feet, 9.0 inches (4.496 meters) long, 2 feet, 1.0 inch (0.635 meters) in diameter and weighed 1,698 pounds (770 kilograms).

The X-3 had a maximum speed of 706 miles per hour (1,136 kilometers per hour) and a service ceiling of 38,000 feet (11,582 meters).

Three-view drawing of the Douglas X-3. (NASA)
Three-view drawing of the Douglas X-3. (NASA)

The X-3 was very underpowered with the J34 engines, and could just reach Mach 1 in a shallow dive. The X-3′s highest speed, Mach 1.208, required a 30° dive. It was therefore never able to be used in flight testing the supersonic speed range for which it was designed.

The X-3 was prone to Inertial Roll Coupling, a newly discovered and very dangerous situation in which an aircraft goes out of control in all three axes. Because of its design characteristics—a very long, thin, fuselage, small wings and tail surfaces, and concentrated mass—the X-3 was very useful in exploring stability and control in the transonic range.

At one point, replacing the X-3’s turbojet engines with two Reaction Motors XLR-11 rocket engines was considered. Predictions were that a rocket-powered X-3 could reach Mach 4.2. However, with Mach 2 Lockheed F-104 becoming operational and North American Aviation’s X-15 hypersonic research rocketplane under construction, the idea was dropped. Technology had passed the X-3 by.

Two X-3 aircraft had been ordered from Douglas, but only one completed. In addition to Bill Bridgeman, the Douglas X-3 was flown by Air Force test pilots Major Chuck Yeager and Lieutenant Colonel Frank Everest, and NACA test pilot Joseph A. Walker.

After the flight test program came to an end in May 1956, the X-3 was turned over to the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

The Douglas X-3 in flight, just a few feet above the dry lake bed at Edwards AFB, California. (Cropped from a LIFE Magazine image at Jet Pilot Overseas)
The Douglas X-3 in flight, just a few feet above the dry lake bed at Edwards AFB, California. (Cropped detail from a LIFE Magazine image at Jet Pilot Overseas)

© 2016, Bryan R. Swopes