During its relatively obscure service life, often overshadowed by the Boeing B-47, the North American B-45 made significant contributions to the U.S. Air Force, including many pioneering ‘firsts’.
By the end of World War II, the jet engine had been developed as a reliable source of propulsion, and while nations were beginning to build arsenals of advanced jet-powered fighters and interceptor aircraft, the United States Army Air Forces (USAAF) had a fleet of aging piston-engine bombers that could be easy targets.
Class of ’47
With the increasing development of jet propulsion in fighter aircraft, the USAAF Air Material Command began a competition for a new bomber in 1944. The bomber was jet-propelled and could carry mixed bombs or single 22,000-pound bombs and deliver weapons from an altitude of 40,000 feet.
This is a light bomber with a gross weight between 80,000 and 200,000 pounds. Simply strapping a jet engine to an existing airframe like the Boeing B-29 was not an option.
Convair, Boeing, Martin, and North American Aviation all submitted designs, and each made its first flight in 1947. This aircraft was known as ‘Class ’47’.
Submissions included Convair’s sleek and beautiful XB-46, which only looked fast. Martin produced the straight-wing XB-48, powered by six jet engines and utilizing tandem dual-wheel bicycle-style landing gear. Boeing’s entry was a radically engineered swept-wing design powered by six engines known as the XB-47, which later became known as the B-47 Stratojet. North America submitted the XB-45, a straight-wing design powered by four engines.
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North American signed a contract to develop the proposal on September 8, 1944, and began work on three prototypes in 1945. Defense spending was cut at the end of World War II, but the project came back to the forefront in 1946 as tensions with the Soviet Union grew increasingly heated.
The XB-45, also known as the NA-130 within North America, first flew on March 17, 1947, at Moorock Dry Lake (Edwards Air Force Base), California, with Paul Brewer and test pilot George Krebs. This aircraft was the first of the ’47 model to take off, and was the first four-jet engine-powered American bomber to achieve flight test status. The first prototype and its crew were later lost during a test program that battled technical problems and setbacks. However, political pressure drove efforts to qualify the aircraft as quickly as possible.
A pair of Allison-built General Electric J-35-A-4 engines in two nacelles suspended below the wings failed to deliver impressive performance, reaching a top speed of 516 mph. Wingtip tanks can extend range, which is disappointing, but not enough to be impressive.
The fighter-like canopy accommodated two pilots, while the bombardier sat in the glassed nose section. The aircraft’s only defensive weapons were a pair of Browning M3 .50 caliber machine guns with a rear gunner positioned in the tail.
Because the Boeing and Martin design prototypes were still two years away, the USAAF evaluated the first two designs, Convair’s XB-46 and North American’s XB-45. The XB-45 was chosen because it was further along in development and cheaper. On January 2, 1947, a contract was signed to produce the B-45A Tornado.
B-45A
A total of 96 B-45A variants were produced, first flying in February 1948 and entering service in November. The first production block of 22 aircraft, designated B-45A-1s, retained the J35 engines and were mostly assigned to training units within the Air Training Command (ATC), while the remaining 74 were upgraded with J47-GE-7/9 engines, designated B-45A-5s, and assigned to the 47th Bombardment Group at Barksdale Air Force Base (AFB), Louisiana.
The B-45A was the first jet bomber operated by the United States Air Force. It was also one of the first aircraft to utilize Mach number to define maximum speed.
The B-45A is 75 feet 4 inches long, 25 feet 2 inches tall, has a wingspan of 89 feet, and weighs approximately 46,000 pounds. Maximum takeoff weight was just over 91,000 lb and maximum speed was 566 mph. It had a range of 1,192 miles and an operational ceiling of 46,000 feet. It could carry up to 22,000 pounds of bombs, both conventional and nuclear.
Initially, the B-45A was not equipped with a bomb fire control system, and its engines, cockpit gauges, and gyros failed. The engines proved particularly problematic, and the bombing and navigation radars also caused problems. Pressurization problems often prevent operation even at certain altitudes.
In 1952, several B-45s were part of the following programs: Operation Fandango Converting aircraft for British nuclear missions. Modifications included additional fuel storage and improved defense systems. It served as Tactical Air Command’s (TAC) front-line deterrent against the threat of large Soviet and Warsaw Pact armored forces deployed in Eastern Europe.
The last B-45As were retired from frontline bombing roles in 1958. A total of 14 were converted to target tugs and redesignated as TB-45A. The bomb bay contains cable reels and equipment for attaching the Chance Vought target glider. A single B-45A became the engine test bed used by Westinghouse and was designated the JB-45A. The proposed variant with improved fire control and radar systems, designated the B-45B, was never built.
B-45C
The B-45C had a reinforced airframe to allow for a higher takeoff weight, increased to 110,000 lb, along with a heavier canopy. The power of the updated J-47 engine has been increased. The plane could now reach speeds of 570 miles per hour and could refuel in-flight. The first B-45C flew on May 3, 1949, and a total of 43 were ordered. However, only 10 will be produced. The remaining 33 airframes will be converted to RB-45Cs.
The B-45C was the first jet bomber to drop an atomic device, twice in atmospheric nuclear tests over the Pacific in 1951 and 1952. The Mark 7 warhead they tested was for the Thor missile.
Tornado’s new twist
Perhaps the version of the B-45 that contributed most to the Cold War effort was the RB-45C reconnaissance version. The final 33 B-45s to be built were converted to RB-45Cs, delivered between June 1950 and October 1951. One RB-45C was later converted into an engine test bed used by General Electric and designated JB-45C.
Changes have been made internally to camera setup, including some that take advantage of new technologies for low-level, high-speed photography. A total of 12 cameras were mounted in four fuselage positions, 25 M122 photoflash bombs and an additional fuel tank in the bomb bay. Water injection through spray tanks mounted beneath each engine nacelle provided additional takeoff power. Rocket assisted takeoff (RATO/JATO) was also used.
The first multi-engine jet bomber/reconnaissance aircraft to be refueled in flight was the RB-45C coupled with a Boeing KB-29 tanker in the fall of 1950.
During the Korean War, the RB-45C flew reconnaissance missions under cover of darkness over North Korea and ‘MiG Alley’. MiG-15s appeared on the scene not long after the RB-45Cs arrived. According to Soviet records, an RB-45C was shot down by a MiG-15 on December 4, 1950, and one piloted by Colonel Charles E. McDonough went missing that day.
First operated by the 91st Strategic Reconnaissance Wing (SRW), the RB-45C provided a platform for U.S. Air Force units surveilling the Soviet Union, including some RB-45Cs in British national insignia.
Tornado behind the iron curtain
Flying American-owned RB-45Cs painted with Royal Air Force (RAF) markings and operated from RAF Sculthorpe in England, British aircrews flew top-secret missions over the Soviet Union during the Cold War. Electronic and photographic information was collected from 1952 to 1954. This mission was not made public until the Public Records Act of 1994 made the mission open to the public.
Since the United States government had banned them from flying missions over its airspace, it was decided that RAF aircrews would fly the missions from American aircraft painted with RAF markings. At the time, the only aircraft capable of deep penetration reconnaissance missions was the new RB-45C. Four aircraft were assigned to the aircraft known as . Operation Ju Jitsu.
Relying heavily on aerial refueling from the KB-29P, the mission was conducted behind the Iron Curtain in an attempt to gather information on the power and location of Soviet bombers to develop a target list. The flight was largely successful, without encountering enemy aircraft or fire. But the program ended when squadron leader John Crampton brought his RB-45C under anti-aircraft fire and came close to being intercepted by a MiG-15.
Service termination
After playing a significant role during the early Cold War, the B-45 eventually abandoned most of its mission as a nuclear deterrent against a Soviet ground invasion in Europe, flying highly classified reconnaissance flights to the more capable and advanced Boeing B-47. The B-45, an interesting and important part of aviation history, has faded into oblivion.
Most of the 143 B-45s currently on display have been retired, leaving three forgotten B-45s that ended service in the late 1950s. The B-45A is on display at the Castle Aviation Museum in Atwater, California. The B-45C is on display at the National Museum of the U.S. Air Force near Dayton, Ohio, and the RB-45C is stored at the Strategic Air Command and Air and Space Museum in Ashland, Nebraska.
