The Boeing Model 367-80 , famously known as the Dash 80, is one of the most important aircraft ever built. Though it never entered commercial production, this revolutionary prototype laid the foundation for two of Boeing’s most successful aircraft families—the Boeing 707 and the KC-135 Stratotanker. Its influence reshaped both commercial jet travel and military aviation, marking the beginning of the modern jet age. Boeing Model 367-80 What Is the Boeing Model 367-80? The Boeing Model 367-80 was a four-engine jet aircraft prototype developed by Boeing in the early 1950s. Designed to prove the viability of large jet-powered transport aircraft, it first flew on July 15, 1954. ad At the time, Boeing took a massive financial risk by funding the project privately, investing approximately $16 million—a bold move that would ultimately redefine the company’s future. Why the Dash 80 Was So Important Birth of the Commercial Jetliner Before the Dash 80, commercial air travel relied heavily on ...