Tag Archives: Strategic Bomber

6 March 1961

Boeing B-52H-135-BW Stratofortress 60-0006. (United States Air Force)

6 March 1961: The B-52H is the final version of the Boeing B-52 Stratofortress intercontinental strategic bomber. There are discrepancies as to the date of its first flight, with sources varying by as much as eight months. One very reliable source writes that the flight took place on 20 July 1960. A U.S. Air Force publication says that it was in March 1961, and another source (Boeing) says that it was 6 March 1961. (This third date is convenient, so, for no other reason, I’ve posted this article using that date.)

The U.S. Air Force contracted 62 B-52H Stratofortresses, serial numbers 60-0001 through 60-0062, on 6 May 1960. A second group of 40, serials 61-0001 through 61-0040, were ordered later. All were built at the Boeing Wichita plant.

A fourth source identifies the aircraft in the photograph above, Boeing B-52H-135-BW Stratofortress 60-0006, (Boeing serial number 464-371) as the first B-52H to fly. The existence of a nice aerial portrait suggests that this may be correct.

The B-52H, like the B-52G, is a re-engineered aircraft, structurally different from the XB-52, YB-52, and B-52A–B-52F Stratofortress variants. It is lighter, carries more internal fuel, giving it a longer unrefueled range, and is strengthened for low-altitude flight. The B-52H is also equipped with quieter, more efficient turbofan engines.

A Boeing B-52H Stratofortress carries four Douglas Skybolt ALBMs. (U.S. Air Force)
A Boeing B-52H Stratofortress carries four Douglas GAM-87 Skybolt ALBMs. (U.S. Air Force)

The B-52H was developed to carry four Douglas GAM-87 Skybolt air-launched ballistic missiles on pylons mounted under the wings, inboard of the engines. The Skybolt was armed with a 1-megaton W-59 thermonuclear warhead. The program was cancelled, however, and the North American Aviation AGM-28 Hound Dog air-launched cruise missile was used instead. (Interestingly, the Hound Dog’s Pratt & Whitney J52-P-3 turbojet engine could be used to supplement the B-52’s takeoff thrust, and then refueled from the bomber’s tanks before being air-launched.)

Boeing B-52G Stratofortress aremd with two North American Aviation AGM-28 Hound Dog ACLMs. (U.S. Air Force)
Boeing B-52G-105-BW Stratofortress 58-0216 armed with two North American Aviation AGM-28 Hound Dog ALCMs. (U.S. Air Force)

The B-52H is a sub-sonic, swept wing, long-range strategic bomber. It was originally operated by a crew of six: two pilots, a navigator and a radar navigator, an electronic warfare officer, and a gunner. (The gunner was eliminated after 1991). The airplane is 159 feet, 4 inches (48.565 meters) long, with a wing span of 185 feet (56.388 meters). It is 40 feet, 8 inches (12.395 meters) high to the top of the vertical fin. The B-52H uses the vertical fin developed for the B-52G, which is 22 feet, 11 inches (6.985 meters) tall. This is 7 feet, 8 inches (2.337 meters) shorter than the fin on the XB-52–B-52F aircraft. The bomber has an empty weight of 172,740 pounds (78,354 kilograms) and its Maximum Takeoff Weight (MTOW) is 488,000 pounds (221,353 kilograms).

The most significant difference between the B-52H and the earlier Stratofortresses is the replacement of the eight Pratt & Whitney J57-series turbojet engines with eight Pratt & Whitney Turbo Wasp JT3D-2 (TF33-P-3) turbofans, which are significantly more efficient. They are quieter and don’t emit the dark smoke trails of the turbojets. The TF-33 is a two-spool axial-flow turbofan engine with 2 fan stages, a 14-stage compressor section (7-stage intermediate pressure, 7-stage high-pressure) and and a 4-stage turbine (1-stage high-pressure, 3-stage low-pressure). Each engine produces a maximum of 17,000 pounds of thrust (75.620 kilonewtons). The TF33-P-3 is 11 feet, 10 inches (3.607 meters) long, 4 feet, 5.0 inches (1.346 meters) in diameter and weighs 3,900 pounds (1,769 kilograms).

The B-52H has a cruise speed of 525 miles per hour (845 kilometers per hour). It has a maximum speed of 632 miles per hour (1,017 kilometers per hour) at 23,800 feet (7,254 meters)—0.908 Mach. The service ceiling is 47,700 feet (14,539 meters). The unrefueled range is 8,000 miles (12,875 kilometers). With inflight refueling, its range is limited only by the endurance of its crew.

The B-52H was armed with a 20 mm M61 Vulcan 6-barreled cannon in place of the four .50-caliber machine guns of the earlier variants.
The B-52H was armed with a 20 mm M61A1 Vulcan 6-barreled rotary cannon in place of the four .50-caliber machine guns of the earlier variants. The gun was removed after 1991.

The B-52H was armed with a 20mm M61A1 Vulcan six-barreled rotary cannon in a remotely-operated tail turret. The gun had a rate of fire of 4,000 rounds per minute, and had a magazine capacity of 1,242 rounds. After 1991, the gun and its radar system were removed from the bomber fleet. The flight crew was reduced to five.

The B-52H can carry a wide variety of conventional free-fall or guided bombs, land-attack or anti-ship cruise missiles, and thermonuclear bombs or cruise missiles. These can be carried both in the internal bomb bay or on underwing pylons. The bomb load is approximately 70,000 pounds (31,751 kilograms).

A Boeing B-52H Stratofortress dropping forty-five M117 750-pound (340 kilogram) general purpose bombs. (Senior Airman Carlin Leslie, U.S. Air Force)

The first of 102 B-52H Stratofortresses entered service on 9 May 1961. The last one, 61-0040, was rolled out 26 October 1962. Beginning in 2009, eighteen B-52H bombers were placed in climate-controlled long term storage at Tinker Air Force Base, Oklahoma. As of December 2015, fifty-eight of the bombers remained in the active fleet of the United States Air Force and eighteen are assigned to the Air Force Reserve. In 2014, the entire fleet began a major avionics upgrade. The B-52H is expected to remain in service until 2040.

An ordnance crew loads a rotary launcher with 8 cruise missiles into teh bomb bay of a B-52H Stratofortress. (Senior Airman Amber Ashcraft/U.S. Air Force)
An ordnance crew loads a rotary launcher with 8 cruise missiles into the bomb bay of a B-52H Stratofortress. (Senior Airman Amber Ashcraft/U.S. Air Force)

60-0006, the first B-52H to fly, crashed while making a ground-controlled (GCA) approach to Wright Patterson Air Force Base, Dayton, Ohio, at 2:07 a.m., 30 May 1974. The bomber’s rudder and elevators failed. Although 60-0006 was destroyed, all seven airmen on board, Captains Charles Brown, Robert E. Smith, William G. Heckathorn, Paul C. Hoffman, 1st Lieutenants John D. Weaver, James R. Villines, and 2nd Lieutenant Robert E. Pace, survived the accident without serious injuries.

Wreck of Boeing B-52H-135-NW Stratofortress 60-0006 at Wright-Patterson AFB, 30 May 1974. (Dayton Daily News Archive)
Wreck of Boeing B-52H-135-BW Stratofortress 60-0006 at Wright-Patterson AFB, 30 May 1974. Two AGM-28 Hound Dog ACLMs are lying in the background. (Dayton Daily News Archive)
A Boeing B-52H Stratofortress during a deterrent patrol near the Democratic People’s Republic of North Korea, 2016. The bomber is carrying a load of Mk.84 2,000-pound JDAM “smart” bombs. (Master Sgt. Lance Cheung, U.S. Air Force)
Boeing B-52H-165-BW Stratofortress 61-0007 takes off at Tinker Air Force Base on a functional test flight, 30 August 2016. The airplane, named “Ghost Rider,” was overhauled after being stored for eight years at The Boneyard, Davis-Monthan Air Force Base, Arizona. 61-0007 is the very first B-52 to have been “regenerated.” (Kelly White/U.S. Air Force)

© 2017, Bryan R. Swopes

1 March 1950

The first Boeing B-47A Stratojet, 49-1900. (U.S. Air Force)

1 March 1950: The first production Boeing B-47 Stratojet, B-47A 49-1900 (Boeing serial number 450001), was rolled off the assembly line at Boeing’s Wichita, Kansas, Plant II.

The Wichita Eagle reported:

“FIRST B-47A PRODUCTION MODEL SHOWN—First production model of the B-47A Stratojet bomber is shown above, surrounded by Boeing-Wichita officials as it rolled from the assembly line at the local plant Wednesday. (Other pictures on Page 4.)”

First Stratojet Rolls Off B-47 Assembly Line Here

Boeing-Wichita Puts New Model Into Production

Six-Jet Speed Bomber Even More Powerful Than Its Predecessor

     Boeing-Wichita’s first B-47 Stratojet bomber rolled off final assembly Wednesday at the local plant, less than 18 months after the Air Force gave the go-ahead signal to build the big, six-jet, swept-wing bomber here.

     The airplane was given to an Air Force aircraft engineering inspection board. The board will examine it for a week, alterations will be made in the shops, if any are needed, and it will be ready to fly.

     The first production model of the already-famous bomber has been designated the B-47A. It is almost identical in appearance to the experimental XB-47s, which were built in the Seattle, Wash., plant of the Boeing Aircraft Company, but the resemblance ends there.

More Powerful than XB-47

     This is a more powerful airplane, Boeing officials say. Instead of the six jet engines of 4,000 pounds thrust each which powered the first experimental Stratojet, this first production model is powered by six jet engines of 5,200 pounds thrust each.

     Additional internal improvements have been made based on experience gained in the XB-47 flight test program, which was moved from Moses Lake, Wash., with the arrival here of the first XB-47. The second “X” came here in October.

     Recently one of the experimental models got a test of rocket assisted takeoff at Municipal Airport where an expansion program costing nearly $1,000,000 has been started to accommodate the B-47 flight testing program.

Holds Speed Record

     The first production model climaxes more than six years of jet bomber design study and development by Boeing. The first experimental flight was made at Moses Lake Dec. 17, 1947, more than 26 months ago.

     In February, 1949, an XB-47 was piloted to an unofficial, all-time, all-type transcontinental speed record. It flew 2,289 miles from Moses lake to Andrews Air Force Base, in three hours, 46 minutes. The average speed was 607.8 miles per hour. The record-breaking airplane was equipped with the smaller jet engines.

     At Boeing-Wichita, closed down following World War II when 1,644 B-29 Superforts were built there, the first production model climaxes a reactivation begun in March, 1948.

     Six months later came the Air Force “letter of intent” and B-47 Stratojet production got underway in Wichita.

“ASSEMBLY LINE IS SHOWN—Part of the assembly line which produced Boeing-Wichita’s first Stratojet six engine bomber is shown above. Three more Stratojets, designated B-47A, are shown being assembled.”
“CLOSE-UP OF B-47A SHOWN—Here’s a close-up of the first production model of the B-47A Stratojet bomber which rolled from the Boeing-Wichita assembly line Wednesday. In the center of the crowd, above, J. Earl Schaefer, vice president and general manager of Boeing, happily makes the rounds congratulating workers and officials who built the bomber.”

The Wichita Eagle, Vol. 24, Number 50, Wednesday 1 March 1950, Page 1, Column 7, and Page 4, Columns 5–8

Boeing B-47A Stratojet 49-1900. (U.S. Air Force 061024-F-1234S-007)

B-47A 49-1900 made its first flight 25 June 1950.

Designed by Boeing, the Stratojet was a high-subsonic-speed strategic bomber and reconnaissance aircraft, in service from 1951 until 1977. The B-47 could fly higher and faster than jet fighters of the early 1950s, and it was also highly maneuverable. The B-47 was flown by a two pilots in a tandem cockpit. A navigator/bombardier was at a station in the nose. The crew area was pressurized.

This photograph shows Boeing B-47A Stratojet 49-1905. The single-piece plexiglas nose of 49-1900 has been replaced by four separate windows. (U.S. Air Force)

The Boeing B-47A Stratojet was the first production model of the B-47 series. The B-47A was 106 feet, 10 inches (32.563 meters) long with a wingspan of 116 feet, 0 inches (35.357 meters), and an overall height of 27 feet, 11 inches (8.509 meters). The wings were shoulder-mounted with the leading edges swept aft to 36° 37′. Their angle of incidence was 2° 45′ and there was no dihedral. (The wings were very flexible, showing marked anhedral on the ground and flexing upward when in flight.) The B-47A had an empty weight of 73,240 pounds (33,221 kilograms), and a maximum takeoff weight of 157,000 pounds (71,214 kilograms).

The B-47A was powered by six General Electric J47-GE-11 turbojet engines in four nacelles mounted on pylons below the wings. This engine had a 12-stage axial-flow compressor, eight combustion chambers, and single-stage turbine. The J47-GE-11 had a maximum power rating of 5,610 pounds of thrust (24.95 kilonewtons) at 8,030 r.p.m. (30-minute limit), and continuous power rating of 4,860 pounds (21.62 kilonewtons) at 7,450 r.p.m.  It had a maximum diameter of 3 feet, 3.0 inches (0.991 meters), length of 12 feet, 0.0 inches (3.658 meters), and weighed 2,475 pounds (1,123 kilograms).

The B-47A was also equipped with 18 Aerojet 14AS1000 solid-fuel rocket engines (ATO) located in the aft fuselage. These produced a maximum 18,000 pounds of thrust (80.07 kilonewtons) for 14 seconds. (49-1901 did not have provisions for ATO.)

A Boeing B-47A Stratojet demonstrates a rocket-assisted takeoff (ATO) The configuration of windows in the nose differs from that of 49-1905, in the image above. (McMahan Photo Archive)

The B-47A Stratojet had maximum speed of 474 knots (545 statute miles per hour/878 kilometers per hour) at 35,000 feet (10,668 meters). The bomber’s speed was limited to 0.815 Mach due to buffeting. The service ceiling was 46,200 feet (14,082 meters) and the combat ceiling, 44,300 feet (13,503 meters).

The B-47A had a maximum ferry range of 2,856 nautical miles (3,287 statute miles/5,289 kilometers) at 424 knots, and a combat radius with a 10,000 pound (4,536 kilograms) bomb load of 1,350 nautical miles (1,554 statute miles/2,500 kilometers). The maximum fuel load was 9,518 gallons (36,030 liters) carried in four fuselage tanks.

The B-47A had space and provisions to mount two Browning AN-M3 .50-caliber machine guns in a remotely-operated tail turret.

Boeing B-47A Stratojet 49-1900 with its bomb bay doors open. (Mary Evans Picture Library)

The B-47A could carry a single T-14 22,000 pound (9,979 kilogram) or T-10 12,000 pound (5,443 kilogram) general purpose bomb (both were U.S. versions of the British World War II Grand Slam and Tallboy bombs); up to 16 1,000 pound (454 kilogram) general purpose bombs; or one 10,000 pound (4,536 kilogram) nuclear bomb.

The B-47As were considered as training aircraft and most were assigned to the 306th Bomb Wing (Medium) at MacDill Air Force Base, Florida.

NACA 150, the first Boeing B-47A Stratojet,49-1900, decelerates after landing at Edwards Air Force Base, California, circa 1953. (NASA Photo E-1004)

The first B-47A, 49-1900, was tested by the U.S. Air Force at Wright Field, Ohio, and then at the National Advisory Committee for Aeronautics’ Langley Memorial Aeronautical Laboratory at Hampton, Virginia, where it was identified as NACA 150. It was later transferred to the NACA High Speed Flight Research Station at Edwards Air Force Base in the high desert of southern California. It flew there from 1953 to 1957. 49-1900 was placed in storage at Davis-Monthan Air Force Base, Tucson, Arizona, 28 February 1958.

Boeing B-47A Stratojet 49-1900 as NACA 150, at Edwards AFB, California. Note the reconfigured nose. (NASA)

B-47A production ended in June 1951, as production shifted to the B-47B. Just ten B-47As were built.

A total of 2,032 B-47s were built by a consortium of three aircraft manufacturers: Boeing Airplane Company, Wichita, Kansas; Douglas Aircraft Company, Tulsa, Oklahoma; Lockheed Aircraft Company, Marietta, Georgia.

Seven Boeing B-47A Stratojets at the Boeing Airplane Co. Plant II, Wichita, Kansas, 26 June 1951. (U.S. Air Force)

© 2023, Bryan R. Swopes

12 February 1959

Convair B-36J-10-CF Peacemaker, 52-2827, the last B-36 built. (U.S. Air Force)
Convair B-36J-75-CF Peacemaker, 52-2827, the last B-36 built. (U.S. Air Force)

The Last Peacemaker: This gigantic airplane, a Convair B-36J-75-CF Peacemaker, serial number 52-2827, was the very last of the ten-engine strategic bombers built by the Convair Division of General Dynamics at Fort Worth, Texas. It was completed 1 July 1954. On 14 August, it was delivered to the Strategic Air Command, 92nd Bombardment Wing, Heavy, at Fairchild Air Force Base, Washington. In April 1957, 52-2827 was assigned to the 95th Bombardment Wing, Heavy, at Biggs Air Force Base, El Paso, Texas.

The last one built, 52-2827 was also the last operational B-36.

Convair B-36J-10-CF Peacemaker 52-2827 at Amon Carter Field, Fort Worth, Texas, 12 February 1959. (Unattributed)
Convair B-36J-75-CF Peacemaker 52-2827, City of Fort Worth, at Amon Carter Field, Fort Worth, Texas, 12 February 1959. (Unattributed)

On 12 February 1959, after 4 years, 5 months, 30 days service, the Air Force returned the bomber to Fort Worth. 52-2827 departed Biggs Air Force Base at 11:00 a.m., under the command of Major Frederick J. Winter. Other pilots were Colonel Gerald M. Robinson, commanding the 95th Wing, and Captain Wilson P. Smith. (Colonel Robinson flew as first pilot during the takeoff, while Major Winter flew the landing.) The bomber’s crew were hand-picked, and included two navigators, two flight engineers, an observer, two radio operators, two gunners and a crew chief. Ten newspaper, radio and television reporters were on board as well.

Crew of City of Fort Worth

The B-36 touched down at Amon Carter Field at 2:55 p.m. The Peacemaker’s log book was closed out with a total of 1,414 hours, 50 minutes, flight time.

After a ceremony attended by thousands, the bomber was officially retired. A bugler blew “Taps,” and then the Peacemaker was towed away.

It was put on display at Amon Carter Field. After decades of neglect, the bomber was placed in the care of the Pima Air and Space Museum at Tucson for restoration and display.

The last Peacemaker, Convair B-36J-10-CF 52-2827, comes to the end of the assembly line at Fort Worth, Texas. (University of North Texas Libraries)
The last Peacemaker, Convair B-36J-75-CF 52-2827, comes to the end of the assembly line at Fort Worth, Texas. (University of North Texas Libraries)

Convair B-36J 52-2827 is one of 14 “Featherweight III” high altitude variants. It was built without the six retractable defensive gun turrets of the standard B-36, retaining only the two M24A1 20 mm autocannons in the tail. This reduced the crew requirement to 13. It is 162 feet, 1 inch (49.403 meters) long with a wingspan of 230 feet (70.104 meters) and overall height of 46 feet, 9 inches (14.249 meters). The empty weight is 166,125 pounds (75,353 kilograms) and loaded weight is 262,500 pounds (119,068 kilograms). Maximum takeoff weight is 410,000 pounds (185,973 kilograms).

The B-36J has ten engines. There are six air-cooled, supercharged 4,362.49 cubic-inch-displacement (71.488 liter) Pratt & Whitney Wasp Major C6 (R-4360-53) four-row, 28-cylinder radial engines placed inside the wings in a pusher configuration. These had a compression ratio of 6.7:1 and required 115/145 aviation gasoline. The R-4360-53 had a Normal Power rating of 2,800 horsepower at 2,600 r.p.m. Its Military Power rating was 3,500 horsepower at 2,800 r.p.m., and 3,800 horsepower at 2,800 r.p.m. with water injection—the same for Takeoff. The engines turned three-bladed Curtiss Electric constant-speed, reversible propellers with a diameter of 19 feet, 0 inches (5.791 meters) through a 0.375:1 gear reduction. The R-4360-53 is 9 feet, 9.00 inches (2.972 meters) long, 4 feet, 7.00 inches (1.397 meters) in diameter, and weighs 4,040 pounds (1,832.5 kilograms).

Four General Electric J47-GE-19 turbojet engines are suspended under the wings in two-engine pods. The J47 is a  single-shaft axial-flow turbojet engine with a 12-stage compressor section, 8 combustion chambers, and single-stage turbine. The J47-GE-19 was modified to run on gasoline and was rated at 5,200 pounds of thrust (23.131 kilonewtons).

The B-36J Featherweight III had a cruise speed of 230 miles per hour (370 kilometers per hour) and a maximum speed of 418 miles per hour (673 kilometers per hour). The service ceiling was 43,600 feet (13,289 meters) and its combat radius was 3,985 miles (6,413 kilometers). The maximum range was 10,000 miles (16,093 kilometers).

The B-36 was designed during World War II and nuclear weapons were unknown to the Consolidated-Vultee Aircraft Corporation engineers. The bomber was built to carry up to 86,000 pounds (39,009 kilograms) of conventional bombs in the four-section bomb bay. It could carry the 43,600 pound (19,777 kilogram) T-12 Cloudmaker, a conventional explosive earth-penetrating bomb. When armed with nuclear weapons, the B-36 could carry several Mk.15 3.8 megaton thermonuclear bombs. By combining the bomb bays, one Mk.17 15-megaton thermonuclear bomb could be carried.

Bomb, Mark 17, displayed with Convair B-36J Peacemaker at the National Museum of the United States Air Force. (U.S. Air Force)
Bomb, Mark 17 Mod 2, displayed with Convair B-36J Peacemaker at the National Museum of the United States Air Force. (U.S. Air Force)

Between 1946 and 1954, 384 B-36 Peacemakers were built. They were never used in combat. Only four still exist.

Convair B-36J-10-CF 52-2827 at the Pima Air and Space Museum, Tucson, Arizona. (B-36 Peacemaker Museum)
Convair B-36J-75-CF 52-2827 at the Pima Air & Space Museum, Tucson, Arizona. (B-36 Peacemaker Museum)

© 2019, Bryan R. Swopes

4 February 1969

North American Aviation XB-70A-1-NA Valkyrie 62-0001. (U.S. Air Force)

4 February 1969: The North American Aviation XB-70A-1-NA Valkyrie, 62-0001, made its very last flight from Edwards Air Force Base, California, to Wright-Patterson Air Force Base, Ohio. NASA Research Test Pilot Fitzhugh L. Fulton, Jr., Lieutenant Colonel, U.S. Air Force (Retired), and Lieutenant Colonel Emil Sturmthal, U.S. Air Force, were the flight crew for this final flight.

On arrival at Wright-Patterson, Fulton closed out the log book and handed it over to the curator of the National Museum of the United States Air Force.

The Mach 3+ prototype strategic bomber and high-speed, high-altitude research airplane had completed 83 flights for a total of 160 hours, 16 minutes of flight time.

Lieutenant Colonel Emil Sturmthal, USAF and Fitzhugh Fulton, NASA, with the North American Aviation XB-70A-1-NA 62-0001 at Edwards AFB, California. (Chris Walmsley/Rockwell International)
Lieutenant Colonel Emil Sturmthal, USAF and Fitzhugh Fulton, NASA, with the North American Aviation XB-70A-1-NA 62-0001 at Edwards AFB, California. (Chris Walmsley/Rockwell International)

62-0001 was the first of three prototype Mach 3+ strategic bombers. (The third prototype, XB-70B 62-0208, was not completed.) The Valkyrie utilized the most advanced technology available. Materials and manufacturing techniques had to be developed specifically to build this airplane. It is a large delta wing airplane with a forward canard and two vertical fins. The outer 20 feet (6.096 meters) of each wing could be lowered to a 25° or 65° angle for high speed flight. Although this did provide additional directional stability, it actually helped increase the compression lift, which supported up to 35% of the airplane’s weight in flight.

The XB-70A is 185 feet, 10 inches (56.642 meters) long with a wingspan of 105 feet (32.004 meters) and overall height of 30 feet, 9 inches (9.373 meters). Fully loaded, the Valkyrie weighs 534,700 pounds (242,535 kilograms).

It is powered by six General Electric YJ93-GE-3 turbojet engines which were rated at 22,000 pounds of thrust (97.86 kilonewtons) at Sea Level, and 31,000 pounds (137.89 kilonewtons) with afterburner. The J93 was a single-shaft axial-flow turbojet with an 11-stage compressor section and two-stage turbine. It was 235.0 inches (5.969 meters) long, 55.0 inches (1.397 meters) in diameter, and weighed 4,770 pounds (2,164 kilograms).

The maximum speed achieved was Mach 3.1 (2,056 miles per hour, or 3,308.8 kilometers per hour) at 73,000 feet (22,250 meters). The service ceiling is 73,350 feet (23,357 meters).

The second Valkyrie, XB-70A-2-NA 62-0207, was destroyed when it crashed after a mid-air collision with a Lockheed F-104N Starfighter flown by NASA Chief Research Test Pilot Joseph A. Walker, 8 June 1966. Both Walker and the B-70’s co-pilot, Major Carl S. Cross, U.S. Air Force, were killed.

XB-70A Valkyrie 62-0001 is in the collection of the National Museum of the United States Air Force.

North American Aviation XB-70A-1-NA Valkyrie 62-0001 at Wright-Patterson Air Force Base, Ohio. (U.S. Air Force)
North American Aviation XB-70A-1-NA Valkyrie 62-0001 at Wright-Patterson Air Force Base, Ohio. (U.S. Air Force)
 North American Aviation XB-70A-1-NA Valkyrie 62-0001 at Wright-Patterson Air Force Base, Ohio. This photograph shows the twelve elevons that act as elevators, flaps and ailerons, the swiveling action of the vertical fins, open drag chute doors and the variable exhaust outlets. (U.S. Air Force).
North American Aviation XB-70A-1-NA Valkyrie 62-0001 at Wright-Patterson Air Force Base, Ohio. This photograph shows the twelve elevons that act as elevators, flaps and ailerons, the swiveling action of the vertical fins, open drag chute doors and the variable exhaust outlets. (U.S. Air Force).

© 2019, Bryan R. Swopes

17 January 1966

Boeing KC-135A-BN Stratotanker 58-0004 refuels Boeing B-52G-75-BW Stratofortress 57-6741. These are the same type aircraft that were involved in the 1966 Palomares Incident. (Boeing)

17 January 1966: A United States Air Force Boeing B-52G-115-BW Stratofortress, 58-0256, and its 7-man crew, along with a second B-52, were flying an Airborne Nuclear Alert patrol over the Mediterranean Sea. The bomber, call sign “Tea 16,” was armed with four Mark 28 nuclear bombs carried in its bomb bay.

At approximately 10:30 a.m., the two B-52s rendezvoused with two Boeing KC-135A-BN Stratotankers, based at Morón Air Base, Spain, for the second aerial refueling of the mission. The aircraft were at 31,000 feet (9,448 meters) off the southern coast of Spain.

Major Larry G. Messinger, a veteran of World War II, aboard as a relief pilot, was flying Tea 16 from the left seat. The aircraft commander, Captain Charles J. Wendorf, was in the right, co-pilot’s seat, while 1st Lieutenant Richard J. Rooney, the assigned co-pilot, rode in the Instructor Pilot’s seat.

Major Messinger later said, “We came in behind the tanker, and we were a little bit fast, and we started to overrun him a little bit. . . .”

A boom operator’s view as a B-52 Stratofortress refuels. (John E. Considine/NASM)

B-52G 58-0256 collided with the refueling boom of “Troubadour 14” (KC-135A 61-0273). The boom penetrated the bomber’s fuselage, broke structural members and the left wing broke off. The B-52 exploded. The fully-loaded tanker, on fire, went into a steep dive. At 1,600 feet (488 meters), it also exploded.

The four crewmen aboard the tanker were killed. Three of the seven men on the B-52 ejected, and the co-pilot, who was not in an ejection seat, literally fell out of the disintegrating bomber. The navigator’s parachute did not open and he was killed. Three others were unable to escape the doomed airplane and were also killed.

Wreckage of B-52G 58-0256 at Palomares, Spain, January 1966. (Kit Talbot/The New York Times)

As the B-52 broke apart, the four nuclear bombs it carried in the bomb bay fell free. Three of them fell near the fishing village of Palomares. In two of these, the conventional explosives that “implode” the plutonium to start a chain reaction, detonated on impact, but a nuclear explosion did not occur. However, plutonium was scattered over the area. The third bomb was recovered intact, though it was slightly damaged. The retarding parachute of the fourth Mark 28 opened and it was carried offshore by the wind and fell into the Mediterranean Sea.

A massive recovery operation took place. The fourth bomb was recovered after five months. It had come to rest in an underwater canyon at a depth of 2,550 feet (777 meters).

1,400 tons of soil was packed into more than 6,000 steel drums and taken to the United States.
1,400 tons of soil was packed into more than 6,000 steel drums and taken to the United States.

558 acres (226 hectares) of land in and around Palomares was contaminated. The soil was removed and placed in steel barrels for transportation to the United States for burial at the Savannah River Plant, a nuclear reservation in South Carolina.

Three airmen position a B28Y1 1.1 megaton thermonuclear bomb for loading aboard a B-52 Stratofortress. (U.S. Air Force)
Three airmen position a B28Y1 thermonuclear bomb for loading aboard a B-52 Stratofortress. (TSgt. Boyd Belcher, U.S. Air Force)

The Mark 28 was a two-stage radiation-implosion thermonuclear bomb which was designed by the Los Alamos National Laboratory and produced from January 1958 to May 1966. In 1968, it was redesignated B28. More than 4,500 were manufactured in as many as 20 variants. Explosive yield varied between 70 kilotons and 1.45 megatons. The B28Y1 in the photograph above is a 1.1 megaton weapon. The bomb remained in service until 1991.

© 2019, Bryan R. Swopes