Tag Archives: Muroc Army Air Field

25 August 1947

Major Marion E. Carl, USN, with a Douglas D-558-I Skystreak at Muroc Dry Lake, 1947. (U.S. Navy)
Major Marion E. Carl, USMC, with a Douglas D-558-I Skystreak at Muroc Dry Lake, 1947. (U.S. Navy)

25 August 1947: Major Marion Eugene Carl, United States Marine Corps, flying the Douglas D-558-I Skystreak, Bu. No. 37970, set a new Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 3 Kilometer Straight Course, averaging 1,047.356 kilometers per hour (650.797 miles per hour).¹ The Skystreak was flown over a course laid out on Muroc Dry Lake, site of Muroc Army Air Field (now Edwards Air Force Base) in the high desert of Southern California.

Douglas D-558-I Skystreak Bu. No. 37970 makes a pass over the 3 kilometer course on Muroc Dry Lake. (U.S. Navy)
Douglas D-558-I Skystreak Bu. No. 37970 makes a pass over the 3 kilometer course on Muroc Dry Lake. (U.S. Navy)

Four passes were made over the course at an altitude of 200 feet (61 meters) or lower. Two runs were made in each direction to compensate for any head or tail winds. The official speed for a record attempt was the average of the two best consecutive passes out of the four.

Major Carl’s record exceeded one set by Commander Turner F. Caldwell, Jr., U.S. Navy, just five days earlier by 10.053 miles per hour (16.178 kilometers per hour).

Major Marion E. Carl, USMC, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (U.S. Navy)
Major Marion E. Carl, USMC, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (U.S. Navy) 

The D-558 Program was intended as a three phase test program for the U.S. Navy and the National Advisory Committee on Aeronautics (NACA) to investigate transonic and supersonic flight using straight and swept wing aircraft powered by turbojet and/or rocket engines. The Douglas Aircraft Company designed and built three D-558-I Skystreaks and three D-558-II Skyrockets. The Phase I aircraft were flown by Douglas test pilot Eugene Francis (“Gene”) May, Navy Project Officer Commander Turner F. Caldwell, Jr., and Major Marion Carl.

Major Marion E. Carl, USMC; Gene May, Douglas Aircraft Company; Commander Turner F. Caldwell, USN.
Major Marion E. Carl, USMC; Gene May, Douglas Aircraft Company; Commander Turner F. Caldwell, USN.

The D-558-I Skystreak (also referred to as the D-558-1) was a single-engine, straight winged, turbojet-powered airplane. It was built of magnesium and aluminum for light weight, but was designed to withstand very high acceleration loads. It was 35 feet, 8 inches (10.871 meters) long with a wingspan of 25 feet, 0 inches (7.62 meters) and overall height of 12 feet, 1¾ inches (3.702 meters). The airplane had retractable tricycle landing gear. Its empty weight was approximately 7,500 pounds (3,400 kilograms), landing weight at the conclusion of a flight test was 7,711 pounds (3,498 kilograms). The maximum takeoff weight was 10,105 pounds (4,583.6 kilograms). The aircraft fuel load was 230 gallons (870.7 liters) of kerosene.

The D-558-I was powered by a single Allison J35-A-11 turbojet engine. The J35 was a single-spool, axial-flow turbojet with an 11-stage compressor section, 8 combustion chambers and single-stage turbine. The J35-A-11 was rated at 5,000 pounds of thrust (22.24 kilonewtons). The engine was 12 feet, 1.0 inches (3.683 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter and weighed 2,455 pounds (1,114 kilograms). The J35-A-11 was a production version of the General Electric TG-180, initially produced by Chevrolet as the J35-C-3. It was the first widely-used American jet engine.

The D-558-I had a designed service ceiling of 45,700 feet (13,930 meters). Intended for experimental flights of short duration, it had a very short range and took off and landed from the dry lake at Muroc. (After 1949, this would be known as Edwards Air Force Base.) The experimental airplane was not as fast as the more widely known Bell X-1 rocketplane, but rendered valuable research time in the high transonic range.

Gene May did reach Mach 1.0 in 37970, 29 September 1948, though he was in a 35° dive. This was the highest speed that had been reached up to that time by an airplane capable of taking off and landing under its own power.

The three D-558-I Skystreaks made a total of 229 flights and Bu. No. 37970 made 101 of them. After the Douglas test program was completed, -970 was turned over to NACA as NACA 140, but it was quickly grounded after the crash of the number two aircraft, and was used for spare parts for number three.

Today, 37970 is in the collection of the National Naval Aviation Museum at Naval Air Station Pensacola, Florida. The other surviving Skystreak, Bu. No. 37972, is at the Carolinas Aviation Museum, Charlotte-Douglas International Airport, Charlotte, North Carolina.

This painting depicts Major Marion E. Carl's speed record attempt over the 3 kilometer course at Muroc Dry Lake. (Steve Cox, 24" x 30", acrylic on board)
This painting depicts Major Marion E. Carl’s speed record attempt over the 3 kilometer course at Muroc Dry Lake. (Steve Cox, 24″ × 30″, acrylic on board)

¹ FAI Record File Number 9865

© 2017, Bryan R. Swopes

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20 August 1947

Douglas D-558-I Skystreak Bu. No. 37970 makes a pass over the 3 kilometer course on Muroc Dry Lake. (U.S. Navy)
Douglas D-558-I Skystreak, Bu. No. 37970, makes a pass over the 3-kilometer course at Muroc Dry Lake. (U.S. Navy)

20 August 1947: At Muroc Dry Lake in the high desert of southern California, Commander Turner Foster Caldwell, Jr., United States Navy, flew the first of three Douglas D-558-I Skystreaks, Bu. No. 37970, to a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a 3 Kilometer Straight Course.¹

Four passes were made over the course at an altitude of 200 feet (61 meters) or lower. Two runs were made in each direction to compensate for any head or tail winds. The official speed for a record attempt was the average of the two best consecutive passes out of the four.

Commander Caldwell’s average speed was 1,031.178 kilometers per hour (640.744 miles per hour). He was awarded his second Distinguished Flying Cross for this flight.

Commander Turner F. Caldwell, jr., United States Navy with the number one Douglas D-558-I Skystreak, Bu. No. 37970, at Muroc dry Lake, 1947. (U.S. Naval Institute)
Commander Turner F. Caldwell, Jr., United States Navy, with the number one Douglas D-558-I Skystreak, Bu. No. 37970, at Muroc Dry Lake, 1947. (U.S. Naval Institute)

The D-558 Program was intended as a three-phase test program for the U.S. Navy and the National Advisory Committee on Aeronautics (NACA) to investigate transonic and supersonic flight using straight and swept wing aircraft powered by turbojet and/or rocket engines. The Douglas Aircraft Company designed and built three D-558-I Skystreaks and three D-558-II Skyrockets. The Phase I aircraft were flown by Douglas test pilot Gene May and Navy project officer, Commander Turner Caldwell.

Major Marion E. Carl, USMC, left, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (U.S. Navy)
Major Marion E. Carl, USMC, left, and Commander Turner F. Caldwell, Jr., USN, stand with the record-setting Douglas D-558-I Skystreak, Bu. No. 37970, on Muroc Dry Lake. (U.S. Navy)

The D-558-I Skystreak was a single-engine, turbojet-powered airplane. It was built of magnesium and aluminum for light weight, but was designed to withstand very high acceleration loads. It was 35 feet, 8 inches (10.871 meters) long with a wingspan of 25 feet (7.62 meters) and overall height of 12 feet, 1¾ inches (3.702 meters). The airplane had retractable tricycle landing gear. Its empty weight was approximately 7,500 pounds (3,400 kilograms), landing weight at the conclusion of a flight test was 7,711 pounds (3,498 kilograms). The maximum takeoff weight was 10,105 pounds (4,583.6 kilograms). The aircraft fuel load was 230 gallons (870.7 liters) of kerosene.

This photograph shows two of the three D-558-I Skystreaks being inspected by U.S. navy officials at the Douglas Aircraft Company plant. In the foreground is the number two aircraft, Bu. No. 37971, with the sections o fte hfuselage separted for better viewing. The entire nose section, including teh cockpit, coul dbe jettisoned in an emergency. The second aircraft is Bu. No. 37970, th eSkystrak flown by CDR Caldwell for his speed record. In the background is another Douglas airplane, the famous AD Skyraider. (Douglas Aircraft Company)
This photograph shows two of the three D-558-I Skystreaks being inspected by U.S. Navy officers at the Douglas Aircraft Company plant. In the foreground is the number two aircraft, Bu. No. 37971, with the sections of the fuselage separated. The entire nose section, including the cockpit, could be jettisoned in an emergency. Just beyond that, two wing tip fuel tanks are displayed on a cart. The second aircraft is Bu. No. 37970. An Allison J35-A-11 jet engine is shown between that and the last airplane, another Douglas product, the famous AD Skyraider. (Douglas Aircraft Company)

The D-558-I was powered by a single Allison J35-A-11 turbojet engine. The J35 was a single-spool, axial-flow turbojet with an 11-stage compressor section, 8 combustion chambers and single-stage turbine. The J35-A-11 was rated at 5,000 pounds of thrust (22.24 kilonewtons). The engine was 12 feet, 1.0 inches (3.683 meters) long, 3 feet, 4.0 inches (1.016 meters) in diameter and weighed 2,455 pounds (1,114 kilograms). The J35-A-11 was a production version of the General Electric TG-180, initially produced by Chevrolet as the J35-C-3. It was the first widely-used American jet engine.

The D-558-I had a designed service ceiling of 45,700 feet (13,930 meters). Intended for experimental flights of short duration, it had a very short range and took off and landed from the dry lake at Muroc. (After 1949, this would be known as Edwards Air Force Base.) The experimental airplane was not as fast as the more widely known Bell X-1 rocketplane, but rendered valuable research time in the high transonic range.

Gene May did reach Mach 1.0 in 37970, 29 September 1948, though he was in a 35° dive. This was the highest speed that had been reached up to that time by an airplane capable of taking off and landing under its own power.

The three D-558-I Skystreaks made a total of 229 flights and Bu. No. 37970 made 101 of them. After the Douglas test program was completed, -970 was turned over to NACA as NACA 140, but it was quickly grounded after the crash of the number two aircraft, and was used for spare parts for number three.

Today, 37970 is in the collection of the National Naval Aviation Museum at Naval Air Station Pensacola, Florida. The other surviving Skystreak, Bu. No. 37972, is at the Carolinas Aviation Museum, Charlotte-Douglas International Airport, Charlotte, North Carolina.

Rear Admiral Turner F. Caldwell, Jr., USN, circa 1960. (U.S. Navy)
Rear Admiral Turner F. Caldwell, Jr., United States Navy, circa 1960. (U.S. Navy)
Midshipman Turner F. Caldwell, jr., 1935. (U.S. Navy)

Turner Foster Caldwell, Jr., was born 17 November 1913 at Narbeth, Pennsylvania. He was the first of four children of Lieutenant Turner Foster Caldwell and Eleanor Polk Owings Caldwell. The senior Caldwell was a graduate of Yale University, New Haven, Connecticut, and was commissioned as an ensign, United States Navy, through the Reserve Officers Training Corps (R.O.T.C). Commander Caldwell was assigned to the U.S. Naval Academy, Annapolis, Maryland, 1 September 1930, and was promoted to the rank of captain, 1 October 1930. He retired from the Navy 1 August 1940.

Turner Foster Caldwell, Jr., entered the United States Naval Academy as a midshipman, 12 June 1931. He graduated and was commissioned an Ensign, United States Navy, 6 June 1935.

Ensign Caldwell was promoted to the rank of Lieutenant (Junior Grade), with date of rank 6 June 1938. He was assigned as a flight instructor at NAS Pensacola, Florida. On that same day, Lieutenant (j.g.) Caldwell married Miss Helen Adele Glidden of Coronado, California, at Yuma, Arizona. They would have four children.

By 1940, Lieutenant (j.g.) Caldwell was assigned to Scouting Squadron Five (VS-5). On 7 December 1941, VS-5 was aboard USS Yorktown (CV-5) at Norfolk Virginia.

Caldwell was promoted to Lieutenant, 1 January 1942. He was a Douglas SBD-3 Dauntless scout bomber bomber pilot with Scouting Squadron Five (VS-5) aboard U.S.S. Yorktown (CV-5) and commanded the squadron with its 18 SBD-3s aboard U.S.S. Enterprise (CV-6) during the occupation of Guadalcanal and the Battle of the Eastern Solomons.

Two Douglas SBD-3 Dauntless dive bombers from VB-5, USS Yorktown, 1942. (U.S. Navy)

Between March and September 1942 he was three times awarded the Navy Cross, the U.S. Navy’s second-highest award for valor after the Medal of Honor. He was promoted to lieutenant commander (temporary) 1 May 1943, and to commander, 1 March 1944. (He retained the permanent rank of lieutenant until after the war.)

Later he commanded a night fighter group of F6F Hellcats and TBM Avengers, CVLG(N)-41, assigned to USS Enterprise (CV(N)-6). For his actions during that period he was awarded his first Distinguished Flying Cross and the Legion of Merit.

After the war, Caldwell commanded Carrier Air Group 4 (CVG-4) aboard USS Franklin D. Roosevelt (CVB-42). He was promoted to the rank of captain, 1 July 1954. Captain Caldwell commanded the “long-hull” Essex-class aircraft carrier USS Ticonderoga (CVA-14), from 5 September 1959 to 24 August 1960.

USS Ticonderoga (CVA-14) underway off the Philippines, 24 May 1960. (San Diego Air and Space Museum Archives)

Captain Caldwell was promoted to the rank of rear admiral, 1 April 1963. He rose to the rank of Vice Admiral, 1 November 1967, and served as Director of Anti-Submarine Warfare Plans. Admiral Caldwell retired from the Navy in May 1971. He died at Kilmarnock Hospital, Rappahannock, Virginia, 12 October 1991.

Douglas D-558-I Skystreak, Bu. No. 37970, at the National Naval Aviation Museum, Naval Air Station Pensacola, Florida. (U.S. Navy)
Douglas D-558-I Skystreak, Bu. No. 37970, at the National Naval Aviation Museum, Naval Air Station Pensacola, Florida. (U.S. Navy)

¹ FAI Record File Number 9864

© 2017, Bryan R. Swopes

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15 August 1951

William Barton Bridgeman (TIME Magazine)
William Barton Bridgeman (Boris Artzybasheff/TIME Magazine)

15 August 1951: Just 8 days after he set an unofficial world speed record of  Mach 1.88 (1,245 miles per hour; 2,033.63 kilometers per hour) Douglas Aircraft Company test pilot William Barton (“Bill”) Bridgeman flew the rocket-powered United States Navy/National Advisory Committee on Aeronautics (NACA) Douglas D-558-II Skyrocket, Bu. No. 37974, to a world record altitude at Edwards Air Force Base in the high desert of Southern California.

The Skyrocket was airdropped at 34,000 feet (10,363 meters) from a highly-modified U.S. Navy P2B-1S Superfortress, Bu. No. 84029. The mother ship was a U.S. Air Force Boeing B-29-95-BW Superfortress, 45-21787, transferred to the Navy and flown by another Douglas test pilot, George R. Jansen.

Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)
Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)

The flight plan was for Bridgeman to fire the rocket engine and allow the Skyrocket to accelerate to 0.85 Mach while climbing. The Skyrocket was powered by a Reaction Motors LR8-RM-6 engine, which produced 6,000 pounds of thrust. As the rocketplane continued to accelerate to Mach 1.12, the test pilot was to pull up, increasing the angle of climb while holding an acceleration rate of 1.2 Gs. This would result in a constantly increasing angle of climb. When it reached 50°, Bridgeman was to maintain that, climbing and accelerating, until the rocket engine ran out of fuel.

Initially, the plan was to continue climbing after engine shutdown until the D-558-II was approaching stall at the highest altitude it could reach while on a ballistic trajectory. There were differing expert opinions as to how it would behave in the ever thinner atmosphere. On the morning of the flight, Douglas’ Chief Engineer, Ed Heinemann, ordered that Bridgeman push over immediately when the engine stopped.

Bill Bridgeman stuck to the engineers’ flight plan. As the Skyrocket accelerated through 63,000 feet (19,200 meters), it started to roll to the left. He countered with aileron input, but control was diminishing in the thin air. The next time it began there was no response to the ailerons. Bridgeman found that he had to lower the Skyrocket’s nose until it responded, then he was able to increase the pitch angle again. At 70,000 feet (21,336 meters), travelling Mach 1.4, he decided he had to decrease the pitch angle or lose control. Finally at 76,000 feet (23,165 meters), the engine stopped. Following Heinemann’s order, Bridgeman pushed the nose down and the D-558-II went over the top of its arc at just 0.5 G.

Bill Bridgeman. (Unattributed)
Bill Bridgeman. (Unattributed)

“In the arc she picks up a couple of thousand feet. The altimeter stops its steady reeling and swings sickly around 80,000 feet. The altitude is too extreme for the instrument to function.

“Eighty thousand feet. It is intensely bright outside; the contrast of the dark shadows in the cockpit is extreme and strange. It is so dark lower in the cockpit that I cannot read the instruments sunk low on the panel. The dials on top, in the light, are vividly apparent. There seems to be no reflection. It is all black or white, apparent or non-apparent. No half-tones. It is a pure, immaculate world here.

“She levels off silently. I roll right and there it is. Out of the tiny windows slits there is the earth, wiped clean of civilization, a vast relief map with papier-mâché mountains and mirrored lakes and seas. . . .

“It is as if I am the only living thing connected to this totally strange, uninhabited planet 15 miles below me. The plane that carries me and I are one and alone.”

The Lonely Sky, William Bridgeman with Jacqueline Hazard, Castle and Company LTD, London, 1956, Chapter XXII at Page 268.

After the data was analyzed, it was determined that William Bridgeman and the Douglas Skyrocket had climbed to 79,494 feet (24,230 meters), higher than any man had gone before. This was the last flight that would be made with a Douglas test pilot. The rocketplane was turned over to NACA, which would assign it the number NACA 144.

A Douglas D-558-II Skyrocket, Bu. No. 37974. glides back toward Rogers Dry Lake at Edwards Air force Base. A North American Aviation F-86E-1-NA Sabre, 50-606, flies chase. Major Charles E. "Chuck" Yeager frequently flew as a chase pilot for both Bill Bridgeman and Scott Crossfield. (NASA)
A Douglas D-558-II Skyrocket, Bu. No. 37974, glides back toward Rogers Dry Lake at Edwards Air Force Base. A North American Aviation F-86E-1-NA Sabre, 50-606, flies chase. Lieutenant Colonel Frank K. “Pete” Everest and Major Charles E. “Chuck” Yeager frequently flew as chase pilots for both Bill Bridgeman and Scott Crossfield. (NASA)

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, testing 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.

The D-558-II Skyrocket was Phase II of a planned three phase experimental flight program. It was designed to investigate flight in the transonic and supersonic range. It was 46 feet, 9 inches (14.249 meters) long with a 25 foot (7.62 meter) wing span. The wings were swept back to a 35° angle. The Skyrocket was powered by a Westinghouse J34-WE-40 11-stage axial-flow turbojet engine, producing 3,000 pounds of thrust, and a Reaction Motors LR8-RM-6 four-chamber rocket engine, which produced 6,000 pounds of thrust. The rocket engine burned alcohol and liquid oxygen.

There were three D-558-2 Skyrockets. Between 4 February 1948 and 28 August 1956, they made a total of 313 flights. Bill Bridgeman’s speed and altitude record-setting Skyrocket, Bu. No. 37974, NACA 144, is in the collection of the Smithsonian Institution National Air and Space Museum.

Douglas D-558-2 Skyrocket, Bu. No. 37974, NACA 144. (NASA)

© 2016, Bryan R. Swopes

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7 August 1951

William Barton Bridgeman. (Boris Artzybasheff/TIME Magazine)

7 August 1951: Douglas Aircraft Company test pilot William Barton Bridgeman flew the rocket-powered U.S. Navy/NACA/Douglas D-558-2 Skyrocket, Bu. No. 37974 (NACA 144), to a record speed of Mach 1.88 (1,245 miles per hour/2,034 kilometers per hour) at Muroc Dry Lake (later Edwards Air Force Base) in the high desert of southern California.

The D-558-2 was airdropped at 34,000 feet (10,363 meters) from a Navy P2B-1S Superfortress, Bu. No. 84029 (a U.S. Air Force Boeing B-29-95-BW Superfortress, 45-21787, transferred to the Navy and heavily modified as a drop ship) flown by another Douglas test pilot, George Jansen.

Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)

In his autobiography, Bridgeman described the flight:

We are at 34,000 feet. My cue. Ten cold minutes preparing the ship for flight. The trap door springs and releases the captive Skyrocket swollen with explosive propellants. She blasts into flight.

Thirty seconds and I am supersonic. Sixty-eight thousand feet and this is it. Over the rim. Easy. The electrically controlled stabilizer flies her now. It takes over for me. At .6 G I push over just enough to get my speed. I am on the ragged edge between .6 G and .8 G. It is working! Everything is going according to my plan. It is so easy this time. Surely I cannot be breaking my last record without having to pay for it. The Machmeter is moving up, fluttering toward the Number 2. . . the rockets sputter and the fuel is gone. That’s all she wrote.

Late that afternoon the official speed attained by the Skyrocket reduced from data and film came out  of the aerodynamicists’ office. Mach 1.88.

The Lonely Sky, William Bridgeman, Castle and Company LTD, London, 1956, Chapter XXII at Page 260.

NACA 144, a Douglas D-558-II Skyrocket, Bu. No. 37974, parked on Muroc Dry Lake. (NACA E-1441)

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 end of the war, then he flew for Trans-Pacific Air Lines in the Hawaiian Islands and Southwest Airlines in San Francisco, before joining the Douglas Aircraft Company as a production test pilot. He flew new AD Skyraiders as they came off the assembly line at El Segundo, California. Bridgeman soon was asked to take over test flying the D-558-2 Skyrocket test program at Muroc Air Force Base.

Screen Shot 2016-08-07 at 11.13.14

The D-558-II Skyrocket was Phase II of a planned three phase experimental flight program. It was designed to investigate flight in the transonic and supersonic range. It was 46 feet, 9 inches (14.249 meters) long with a 25 foot (7.62 meter) wing span. The wings were swept back to a 35° angle. The Skyrocket was powered by a Westinghouse J34-WE-40 11-stage axial-flow turbojet engine, producing 3,000 pounds of thrust, and a Reaction Motors LR8-RM-6 four-chamber rocket engine, which produced 6,000 pounds of thrust. The rocket engine burned alcohol and liquid oxygen.

There were three D-558-2 Skyrockets. Between 4 February 1948 and 28 August 1956, they made a total of 313 flights. The Skyrocket flown by Bill Bridgeman to Mach 1.88 is in the collection of the Smithsonian Institution National Air and Space Museum.

NACA 144, a Douglas D-558-II Skyrocket, on display at the National Mall Building, Smithsonian Institution. (NASM)
NACA 144, a Douglas D-558-II Skyrocket, on display at the National Mall Building, Smithsonian Institution. (NASM)

© 2017, Bryan R. Swopes

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25 June 1946

Northrop XB-35 taking of at Northrop Field, Hawthorne, California. (U.S. Air Force)
Northrop XB-35 taking off at Northrop Field, Hawthorne, California. (U.S. Air Force)

25 June 1946: Northrop Corporation experimental test pilot Max R. Stanley and flight engineer Dale Schroeder made the first flight of the Northrop XB-35 “Flying Wing,” serial number 42-13603, from the factory’s airfield at Hawthorne, California, to Muroc Army Air Field (now, Edwards Air Force Base). The initial flight lasted 55 minutes.

Max R. Stanley (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers))
Max R. Stanley (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

The Los Angeles Times reported:

On June 25, 1946, Stanley piloted the first Flying Wing, the B-35, which was a four-engine 172-foot-long, boomerang-shaped craft, from Northrop’s Hawthorne Airport to what was then the Muroc Army airfield east of Palmdale.

Emerging from the cockpit after the 55-minute flight, Stanley told The Times: “She handled beautifully.”

But taxiing along the rabbit-infested Hawthorne runway, he had had momentary doubts, he conceded 50 years later: “I looked out and I was not gaining speed on this rabbit. I thought, either something’s wrong or that’s one hell of a fast rabbit.”

Flight test crew of Northrop's XB-35 at Northrop Field, Hawthorne, California, 1946.
The flight test crew of the Northrop XB-35 at Northrop Field, Hawthorne, California, 1946. Max Stanley is just to the left of center. (Unattributed)

The XB-35 was designed as an aerodynamically efficient heavy bomber. It had a length of 53 feet, 1 inch (16.180 meters), a wingspan of 172 feet (52.426 meters) and overall height of 20 feet, 1 inch (6.121 meters). The wing was 37 feet 6 inches (11.430 meters), front to back, at the center, and tapered to 9 feet (2.743 meters) at the tips. The total wing area was 4,000 square feet (371.61 square meters). The prototype weighed 89,560 pounds (40,624 kilograms) empty, with a gross weight of 180,000 pounds (81,647 kilograms).

This view of the Northrop XB-35 Flying W 42-13603 on the ramp at Muroc Air Force Base shows the pusher arrangement of four-bladed contra-rotating propellers. In the background, a turbojet-powered YB-49 is in a right bank.. (U,S. Air Force)
This view of the first prototype Northrop XB-35, 42-13603, the “Flying Wing,” on the ramp at Muroc Air Force Base shows the pusher arrangement of four-bladed contra-rotating propellers. In the background, a turbojet-powered Northrop YB-49 is in a steep bank. (U.S. Air Force)

The XB-35 was powered by four air-cooled, supercharged and turbocharged 4,362.49 cubic-inch-displacement (71.49 liter) Pratt & Whitney Wasp Major TSB1P-RGD (R-4360-17 or  -21) four-row 28-cylinder radial engines with a compression ratio of 7:1. The R-4360-17 was rated at 2,500 horsepower at 2,550 r.p.m at 40,000 feet (12,192 meters), and 3,000 horsepower at 2,700 r.p.m., for takeoff. It could maintain the takeoff rating to an altitude of 40,000 feet (12,192 meters) for Military Power. The engines were mounted completely inside the wing and were connected to a remote propeller drive unit by drive shafts. The engines were direct drive, while the propeller gear boxes had a 0.381:1 reduction ratio. The R-4360-17 was 5 feet, 7.00 inches (1.702 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 3,306 pounds (1,499.6 kilograms).

Northrop XB-35 42-13603 in flight with early contra-rotating propellers. (U.S. Air Force)

The propellers were dual three-bladed contra-rotating assemblies located in pusher configuration at the wing’s trailing edge. (These were quickly changed to four-bladed propellers, which were smoother in operation and more efficient.)

Northrop XB-35 42-13603. (U.S. Air Force)
Northrop XB-35 42-13603. (U.S. Air Force)

The XB-35 had a cruising speed of 183 miles per hour (295 kilometers per hour) at 39,700 feet (12,100 meters) and maximum speed was 391 miles per hour (629 kilometers per hour) at 35,000 feet (10,668 meters). With a crew of nine, and another six relief crewmembers, the bomber had a range of 8,150 miles (13,116 kilometers).

The production Northrop B-35 would have been armed with twenty .50-caliber machine guns for defense and a maximum bomb load of 51,200 pounds (23,223 kilograms).

The XB-35 was plagued by unresolved problems with the propeller gear boxes which eventually forced Jack Northrop to ground the aircraft until the engine and propeller manufacturers could come up with a solution, which was to change from piston to turbojet engines. That version became the YB-49. Because of the continuing problems, though, 42-13603 was grounded after only 19 flights, and with its sister ship, XB-35 42-38323, was scrapped in August 1949.

Northrop XB-35 in flight. (U.S. Air Force)
A Northrop XB-35 in flight. (U.S. Air Force)

© 2017, Bryan R. Swopes

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