The Boeing B-47 Stratojet was a long-range, turbojet-powered strategic bomber, notable for being the first aircraft designed to carry nuclear weapons.
In the 1950s and early 1960s, the B-47 Stratojet took a crucial role within the United States Air Force’s Strategic Air Command (SAC), serving both as a nuclear bomber and a reconnaissance aircraft.
The History of Boeing’s B-47 Stratojet
In the aftermath of World War II, the United States and the Soviet Union found themselves engaged in the Cold War. The looming threat of nuclear conflict led to an urgent need for advanced military technologies, particularly in the realm of strategic bombers. The demands were for a nuclear bomber capable of high-speed, high-altitude operations that could be used to strike targets in the Soviet Union. These features were crucial for evading enemy defenses and rapidly delivering nuclear payloads.
The B-47’s development can be traced to a demand put forth by the United States Army Air Forces (USAAF) in 1943, seeking a reconnaissance bomber that would leverage the emerging technology of jet propulsion. In response to the USAAF proposal, Boeing developed an aircraft that would not only meet the Air Force’s requirements but also set a new standard in aviation technology. The end result was the Boeing B-47 Stratojet.
On December 17, 1947, the first prototype, known as XB-47, successfully completed its first flight. In 1951, the B-47 officially entered operational service with the United States Air Force’s SAC and by the late 1950s it had become a central part of their bomber fleet.
The B-47’s versatility extended beyond its role as a bomber. It was adapted for various functions, including photographic reconnaissance, weather reconnaissance and electronic intelligence. While the B-47 never actually saw combat as a bomber, reconnaissance RB-47 versions occasionally encountered hostile fire, mainly when operating near or within Soviet airspace.
The aircraft continued to serve as a reconnaissance platform until 1969, with a few remaining in service as flying testbeds until 1977, when the program was officially cancelled and all aircraft retired.
B-47s were operated by the USAAF, United States Navy and Royal Canadian Air Force.
Stratojet design
Perhaps the most striking feature of the B-47 Stratojet was its swept wings. This innovative design element improved the aircraft’s performance, allowing it to reach high speeds and altitudes with greater efficiency. Also, the B-47 was a pioneer aircraft in airframe development and tactical deployment.
The B-47 was powered by General Electric J47 turbojet engines that contributed to its high-speed capabilities. By positioning its engines within nacelles beneath the wing, the B-47 introduced a significant post-World War II innovation in combat jet design, ultimately influencing the development of modern jet airliners.
The B-47 was engineered with a pressurized forward compartment, intended to accommodate a crew of three individuals. This crew configuration consisted of a pilot and copilot positioned in tandem under an elongated fighter-style bubble canopy, while a navigator/bombardier occupied a separate compartment located in the nose of the aircraft.
The B-47 also featured a bomb bay capable of efficiently carrying and delivering nuclear weapons. The bomb bay was the dedicated internal storage area within the aircraft’s fuselage where the bomber carried its payload of bombs or other munitions.
General aircraft reliability was good, the only major issue being with the avionics system. Extensive efforts were made to enhance its reliability, but avionics-related challenges persisted throughout the operational life of the B-47.
B-47 variants and roles
The B-47 program saw the development of various models, including the early production versions, the B-47A and B-47B.
It also served as a platform for reconnaissance missions and weather data collection, with the RB-47 and WB-47 variants at the forefront.
The EB-47 showcased the aircraft’s versatility in the realm of electronic warfare and electronic countermeasures.
Across the 28 different variants of the B-47, a total of 2,042 aircraft units were manufactured. The B-47E was the most popular variant, with 1,341 units being built.
Technical specifications
General specifications
| Length | 107 ft 1 in (32.64 m) |
|---|---|
| Wingspan | 116 ft 0 in (35.36 m) |
| Height | 28 ft 0 in (8.53 m) |
| Max Takeoff Weight | 221,000 lb (100,244 kg) |
| Engines | six General Electric J47-GE-25 turbojet, 7,200 lbf (32 kN) thrust each |
Performance specifications
| Maximum Speed | 607 mph (977 km/h) |
|---|---|
| Cruise Speed | 557 mph (896 km/h) |
| Service Ceiling | 40,500 ft (12,300 m) |
Armament
| Guns | two M24A1 autocannon |
|---|---|
| Bombs | 25,000 lb (11,340 kg) of artillery, including: |
| two Mk15 nuclear bombs or | |
| four B28 nuclear bombs or | |
| one B41 nuclear bomb or | |
| one B53 nuclear bomb or | |
| twenty-eight 500 lb (227 kg) conventional bombs |
Remembering the B-47
Today, the B-47 Stratojet is celebrated and preserved in aviation museums. Out of the original fleet, 23 B-47s remain, though none of these surviving aircraft are currently in an airworthy condition. All of these preserved B-47s are situated within the United States.