When the B-52 was designed in 1948, the most powerful engines developed only 17,000 pounds of thrust. Thus, eight are required to get the plane airborne. Today”s engines can develop 78,000 pounds of thrust, so if the plane were designed today it might only have two engines. The new Rolls Royce engines are designed to still provide only 17,000 pounds of thrust, so as not to require redesign of the wings, but to improve fuel efficiency and increased range. The remaining 76 operational B-52H’s are 62 years old, The primary structural components are never replaced. The main reason for their longevity is that the usage has not been as severe as was projected. We designed the B-52G/H in 1956 for high-altitude bombing. The emphasis in the structural design was minimum weight, to maximize range. But in 1961, at the height of the Cold War, we redesigned the structure to meet SAC’s new, more severe usage and service life requirements. These notably included low level terrain avoidance training, often under extreme gust and maneuver conditions. The emphasis in structural design shifted to toughness and durability. As Chief of Structures Technology at Boeing-Wichita at the time of the redesign. I am honored to say I chose the materials, the analysis methods, and the limiting stress levels for the redesign. I am now 96 and I am thrilled to see these planes still flying, and projected to do so for many more years. During the Cold War, SAC required the entire fleet to be airborne within 15 minutes to avoid being destroyed on the ground by Soviet ICBM’s. “COCOA” alert exercises were frequently performed to practice this. The flight crews did not know if it were for practice, or for real.
