During a relatively obscure service life, often overshadowed by the Boeing B-47, the North American B-45 made a significant contribution to the U.S. Air Force, including many pioneering ‘firsts.’
In the waning months of World War 2, the jet engine had been developed into a reliable propulsion source, and while nations began building arsenals of advanced jet-powered fighter and interceptor aircraft, the United States Army Air Force (USAAF) possessed a fleet of aging piston engine bombers that would be easy targets.
The Class of ‘47
In response to the increasing development of jet propulsion in fighter aircraft, the USAAF Air Material Command initiated a competition in 1944 for a new bomber. The bomber was to be jet-propelled, carry a mixed bomb load or single 22,000 lb bomb and be capable of dropping weapons at 40,000 ft altitude.
This would be a light bomber with a gross weight between 80,000 and 200,000 pounds. Simply strapping jet engines to existing airframes, such as the Boeing B-29, was not an option.
Convair, Boeing, Martin, and North American Aviation all submitted designs, with each one making their initial flights in 1947. These aircraft became known as the ‘Class of ‘47’.
Submissions included Convair’s sleek and beautiful XB-46 that only looked fast. Martin produced the straight-wing XB-48 that was powered by six jet engines and utilized tandem dual-wheeled bicycle-style landing gear. Boeing’s entry was a radically designed swept-wing design powered by six engines, known as the XB-47, later to become known as the B-47 Stratojet. North American submitted the XB-45, a straight-wing design powered by four engines.
A Tornado is spawned
North American received a contract to develop its proposal on Sept. 8, 1944, and began work on three prototypes in 1945. The end of World War 2 created defense cuts, but ever increasingly heated tensions with the Soviet Union in 1946 would bring the project back to the forefront.
The XB-45, also known inside North American as the NA-130, first flew on Mar. 17, 1947, with test pilot George Krebs at the controls along with Paul Brewer at Muroc Dry Lake (Edwards Air Force Base), California. It was the first aircraft of the Class of ’47 to take to the air, and the first American bomber powered by four jet engines to achieve flight-test status. The first prototype and crew would later be lost during a test program that fought technical problems and setbacks; however political pressure pushed the efforts to qualify the aircraft as soon as possible.
Two pairs of Allison-built General Electric J-35-A-4 engines in two nacelles slung under the wings failed to provide impressive performance, with speed topping out at 516 mph. Wingtip tanks could extend a disappointing range, but not enough to be impressive.
A fighter-like canopy housed the two pilots while the bombardier sat in a glazed nose section. The aircraft’s sole defensive armament, a pair of Browning M3 .50 caliber machine guns, was manned by a rear gunner in the tail.
The Boeing and Martin design prototypes were still two years away so the USAAF evaluated the first two designs: the XB-46 from Convair and North American’s XB-45. The XB-45 was further along in development and cost less, so it was chosen. On Jan. 2, 1947, a production contract was signed for the B-45A Tornado.
The B-45A
A total of 96 B-45A variants were produced, the first flying in February 1948 and entering service in November. The first production block of 22 aircraft, designated B-45A-1 retained the J35 engines and were assigned to mostly training units within the ATC (Air Training Command) and the remaining 74 upgraded to J47-GE-7/9 engines being designated B-45A-5 and assigned to the 47th Bombardment Group at Barksdale Air Force Base (AFB) in Louisiana.
The B-45A was the first operational jet bomber in USAF service. It was also one of the first aircraft to have its maximum speed defined utilizing Mach numbers.
The B-45A had a length of 75 ft 4 in, height of 25 ft 2 in, wingspan of 89 ft, and weighed in at around 46,000 lb empty. Maximum takeoff weight was just over 91,000 lb and maximum speed was 566 mph. Range was 1,192 miles and service ceiling was 46,000 ft. Up to 22,000 lb of bombs, both conventional and nuclear types, could be carried.
Initially the B-45A was not equipped with bomb fire control systems and suffered failures with engines, cockpit gauges, and gyrocompasses. The engines proved especially troubling and the bombing and navigational radar also caused issues. Often pressurization issues prevented operation at certain altitudes as well.
In 1952, several B-45s were part of a program known as Operation Fandango to modify the aircraft for nuclear missions from the United Kingdom. Modifications included additional fuel storage and an improved defensive system. These served as the Tactical Air Command’s (TAC) frontline deterrent against the threat of massive Soviet and Warsaw Pact armor forces poised 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 re-designated TB-45As. The bomb bay would house a cable reel and equipment for the attachment of Chance Vought target glider. A single B-45A would become an engine test bed used by Westinghouse and designated the JB-45A. A proposed variant with improved fire-control and radar systems designated the B-45B was never built.
The B-45C
The B-45C had a strengthened airframe to permit a higher take-off weight which increased to 110,000 lb along with a heavier canopy. Updated J-47 engines increased power. The plane was now capable of 570 mph and also equipped for inflight refueling. The first B-45C flew on May 3, 1949 and a total of 43 were ordered. Only ten would be produced however. The remaining 33 airframes would be converted to the RB-45C.
The B-45C was the first jet bomber to drop an atomic device, dropping two in atmospheric nuclear tests over the Pacific in 1951 and 1952. The Mark 7 warhead they tested was intended for the Thor missile.
A new twist for the Tornado
Perhaps the version of the B-45 that made the most contributions to Cold War efforts was the RB-45C reconnaissance version. The final 33 B-45s to be built would be converted to RB-45Cs delivered between June 1950 and October 1951. One RB-45C would later be converted to an engine test-bed used by General Electric and designated the JB-45C.
Changes were made internally for camera installations, including some that would utilize new techniques for low-level high-speed photography. A total of 12 cameras in four fuselage positions were carried along with 25 M122 photoflash bombs and additional fuel tanks in the bomb bay. Water injection via a jettisonable tank fitted under each engine nacelle provided additional takeoff power. Rocket-assisted take-off (RATO/JATO) was also used.
The first multi engine jet bomber/reconnaissance aircraft to be refueled inflight was an RB-45C that connected with a Boeing KB-29 tanker in the fall of 1950.
During the Korean War, RB-45Cs flew surveillance missions over North Korea and ‘MiG Alley’ often during hours of darkness. MiG-15s appeared on the scene not long after the RB-45Cs arrived. Soviet records show an RB-45C was downed by a MiG-15 on Dec. 4, 1950, and one piloted by Capt. Charles E. McDonough did go missing on that day.
First operated by the 91st Strategic Reconnaissance Wing (SRW), the RB-45Cs provided a platform for USAF units keeping watch on the Soviet Union, including some RB-45Cs in British national insignia.
Tornados behind the Iron Curtain
Flying American-owned RB-45Cs painted in RAF (Royal Air Force) markings and operating from RAF Sculthorpe in the United Kingdom, British crews carried out highly classified missions conducting overflights of the Soviet Union during the Cold War. Electronic and photographic intelligence was gathered during a period of 1952-1954. The missions were not revealed until 1994 when the Public Records Act allowed the missions to become public knowledge.
Americans were prohibited by their government at the time of conducting overflight missions, so it was decided RAF crews would take on the task in American aircraft painted in RAF markings. At the time the only aircraft in inventory capable of making the deep-penetration reconnaissance missions was the new RB-45C. Four aircraft were allocated for what was known as Operation Ju Jitsu.
Relying heavily on aerial refueling from KB-29Ps, missions were flown behind the Iron Curtain in attempts to gather information on Soviet bomber strength and locations in order to develop a target list. The flights were successful for the most part without encountering enemy aircraft or fire. However the program was ended when the squadron leader, John Crampton, had his RB-45C come under anti-aircraft fire and was close to being intercepted by MiG-15s.
End of Service
After filling important roles in the early days of the Cold War, the B-45 would eventually surrender most of its duties as a nuclear deterrent to a Soviet ground invasion in Europe and flying highly classified reconnaissance flights to the more capable and advanced Boeing B-47. An interesting and important part of aviation history, the B-45 faded into oblivion.
There are currently three surviving B-45s out of the 143 produced on display as most were scrapped and the aircraft forgotten at the end of their service in the late 1950s. A B-45A is on display at Castle Air Museum in Atwater, California. The National Museum of the United States Air Force near Dayton, Ohio, has a B-45C on display, and an RB-45C resides at the Strategic Air Command & Aerospace Museum in Ashland, Nebraska.
