In the late 1960s, air travel had become so popular that runways were getting crowded. The Boeing 707 and the Douglas DC-8 had revolutionized long-distance travel, but airlines needed something bigger. Pan-Am Airlines gave Boeing 28 months to deliver a solution. The pressure was on. In 1966, Boeing set to work designing the world’s first jumbo jet: the 747.
The 747 was also the impetus for a big advancement in jet-engine technology. None of the engines available were strong or efficient enough so Pratt & Whitney had to design a new one. The result was the JT9D, the first turbofan. But as with most things new, there were problems. Engine casings deformed during take-off on early test flights, causing turbine blades to grind against the casing sides. Boeing fixed the problem, and in doing so, proved the worthiness of the the high-bypass-ratio jet engine.
Actually manufacturing a plane of this size challenged every part of the industry and the teething process set many standards still used today. The 747 had structural redundancy, redundant hydraulic systems, and four main landing gear. Airport terminals had to be enlarged in order to handle increased passenger and luggage loads. Boeing had to build a 200 million-cubic-foot assembly plant; by interior volume alone, that building was the the largest ever constructed.
On January 21, 1970, the first 747 passenger flight took place, from New York to London. Within 6 months, 747s had transported more than a million passengers and changed air travel forever. The aircraft has transported millions more since, but also space craft and even the President of the United States. Hit play to learn more.