Boeing B-47 Stratojet Medium / Heavy Bomber Aircraft
The Boeing B-47 scored many firsts in the realm of high-altitude jet-powered bomber aircraft - including a tricycle-style undercarriage configuration.
Authored By Dan Alex; Content ©www.MilitaryFactory.com
The swept-wing B-47 Stratojet produced by Boeing was a milestone in American bomber design in several ways. The system pioneered the now-traditional bomber layout found on many of today's bomber aircraft and offered up performance capabilities unheard of before then. As a post-war/Cold War aircraft design, the system was the epitome of what the American military sought in terms of high-level penetration systems capable of nuclear strikes deep within enemy territory.
The XB-47 was proposed as early as 1945 - the final year of World War 2 - and beat out a notable flying wing design proposed by the Northrop aviation firm. Two XB-47 prototypes were constructed as SN 46-065 and 46-066. Each was initially powered by 6 x Allison J35-GE-7 turbojet engines slung under each swept-back wing with both prototypes eventually receiving General Electric J47-GE-3 turbojets. The engines were split into pairings and single mounts as individual nacelles. The aircraft was crewed by three personnel made up of two pilots and a bombardier. From there, the first XB-47 achieved first flight in 1947.
With its immense size, the B-47 made use of no fewer than eighteen rocket-propelled boosters to help it achieve flight, resulting in a dazzling display of power and smoke upon take-off. To decrease runway landing distances, the Stratojet deployed a drag chute to significantly slow the airframe down upon landing - a practice utilized even today in modern aircraft types. An impressive inherent range meant that the B-47 was ideally suited to forward and rearward operating bases across Europe and the United States. In an age before accurate surface-to-air missile systems became the norm, the B-47 was really only threatened by the latest in the delta wing interceptors of the Soviet Union. As such, since the rear portion of any bomber was susceptible to attack from interceptors, the B-47 mounted two remote-controlled 12.7mm machine guns (later upgraded to 20mm cannons) in her tail. As far as her external design goes, the B-47 was conventional with a forward held cockpit (including glazed nosecone), a cylindrical fuselage and a conventional empennage mounting a single vertical tail fin and applicable horizontal planes. At rest, the aircraft took on a noticeable "nose up" position that required the use of a rolling ladder platform for the crew to gain entry. The undercarriage consisted of a pair of double-tired landing gear legs along the fuselage centerline with a pair of smaller single-tired legs under the inner pair of engine nacelles. With the advent of improved Soviet surface-to-air missile systems (SAM), the B-47 was forced to take more of a low-level bombing role and thus the structure was optimized for the rigors of such flight. Internal ordnance was finalized in the B-47E model which could carry 25,000lb of munitions in the form of 2 x Mk 15 nuclear drop bombs or up to 28 x 500lb conventional drop bombs.