Planes as big as the 747 needed high-bypass turbofan engines. High-bypass turbofans can produce twice the power of turbojets, and also use a lot less fuel. General Electric made the first of these engines. However, it was making the engines for the C-5 Galaxy. It did not make engines for airliners until later. Pratt & Whitney was also working on this type of engine. In 1966, Boeing, Pan Am and Pratt & Whitney designed a new engine, the JT9D, for the 747.
Boeing used some special devices to make the plane make more lift. This was done so that the 747 could take off from shorter runways. The 747 has a lot of flaps on the wing. The flaps make the wings bigger by 21 percent. They also make 90 percent more lift when they are used.
Boeing tried to give the 747 to Pan Am by the end of 1969. This meant that Boeing only had 28 months to design the aircraft. The people who worked on the 747 had the nickname "The Incredibles".
Boeing did not have a factory big enough to make the new plane. Boeing thought about putting their factory in 50 different cities. They eventually decided to build their factory in Seattle, near Everett, Washington. Boeing bought the factory in June 1966.
Designing the 747 was very difficult. Building its factory was also not easy. Boeing's president, William M. Allen, asked Malcolm T. Stamper to be in charge of the building of the Everett factory. He was also asked to begin building the 747. The factory is the biggest building ever built (by volume). It has been made bigger many times so that Boeing can build even bigger planes.
Before the first 747 was put together, parts and systems were being tested. In one important test, 560 volunteers evacuated a replica of a 747 cabin using the emergency chutes. The first evacuation took two and a half minutes. However, the FAA says that the maximum time for an evacuation is 90 seconds. Many of the volunteers were hurt. More evacuations happened, and they eventually reached the 90 seconds. However, they also caused a lot of injuries. Evacuating from the top deck of the plane was difficult. Instead of using the usual slides, the volunteers had to leave the plane using a harness. The plane's taxiing also had to be tested. Boeing made "Waddell's Wagon" (named after a 747 test pilot, Jack Waddell) to train the pilots. "Waddell's Wagon" was a replica of a 747 cockpit which was put on the roof of a truck. This helped pilots to learn how to taxi the plane.
On September 30, 1968, the first 747 was finished. People from the 26 airlines that had ordered the 747 were also there. The 747 first flew on February 9, 1969. Its pilots were Jack Waddell and Brien Wygle. There was a small problem with the flaps, but the 747 handled well.
The testing was delayed because of some problems with the JT9D engines. For example, the engines stalled if the throttles were moved too quickly. This meant that 747s could not be delivered for many more months. 20 planes were stuck at the factory while they were waiting on engines. On December 13, 1969 the test plane was being taken to have some changes made to it. The pilot, Ralph C. Cokely landed too early and did not reach the runway. One of the landing gears was ripped off, and two of the engines were damaged. However, Boeing took the 747 to the 28th Paris Air Show in mid-1969. There, the public saw the 747 for the first time.
Designing the 747 and building the new factory cost a lot of money. This meant that Boeing had to borrow a lot of money from a bank. Just before the first aircraft was finished, Boeing had to keep asking for more money. If Boeing was not given this money, the company could have collapsed. Boeing was in over $2 billion in debt. Allen said, "It was really too large a project for us." However, the 747 program was a success. Boeing was the only company to make very big planes for many years.
The very first time a 747 was used by an airline was on January 22, 1970. Pan Am used it to fly from New York to London. The flight was supposed to happen on the evening of January 21. However, the engines on the aircraft overheated. Pan Am had to find another plane, which took six hours.
The 747 did quite well when it first began to be used. Some people thought that airports would not be able to handle such a big plane. However, they could. There were some problems, but they were quite small and they were fixed quickly. After Pan Am began to use the plane, other airlines began to use their 747s. Boeing thought that a lot of 747s would be sold because airlines wanted a plane which could fly for a long time, not because it was so big.
The recession of 1969-1970 was very bad for Boeing. For over a year after September 1970, it only sold two 747s. None were sold to an American airline for over three years. Some airlines did not have enough passengers to fly the 747. Therefore, they replaced them with the McDonnell Douglas DC-10 and Lockheed L-1011 TriStar. American Airlines eventually only used its 747s to carry cargo. In 1983, AA gave its 747s to Pan Am. Pan Am gave American Airlines some smaller planes. Delta Air Lines also stopped using its 747s after many years. Delta would later merge with Northwest Airlines, which operates 747s.
Flights which landed in smaller cities became quite usual in the 1980s. This was bad for the 747. However, many airlines still used the 747 to fly across the Pacific.
The first type of 747 was called the 747–100. After this, Boeing made the , which has a higher MTOW (maximum takeoff weight), and the (Short Range). The -100SR could carry more passengers. A higher MTOW means that the plane can carry more fuel and fly further. In 1971, Boeing made the . It had better engines and a higher MTOW. Airliner and cargo versions of the were made. The 747SP (special performance) was also made. It began being used in 1976.
In 1980, Boeing made the 747–300. The first 747-300 was made in 1983. Its upper deck was longer, it flew faster and it could hold more passengers. The −300 was first called the 747SUD for "stretched upper deck". Then it was called the 747-200 SUD, then the 747EUD, and finally it was called the 747–300.
In 1985, Boeing began to design the 747-400. This type has a glass cockpit. This meant that only two people were needed in the cockpit. It also had new engines and a new cabin. The workers who made the 747-400 were not very experienced and Boeing wanted them to work for longer than they needed to. This meant that there were some problems with the first 747-400s. The −400 began being used by airlines in 1989.
In 1991, 1,087 passengers were taken to Israel on a 747. This was a part of Operation Solomon. The Antonov An-225 cargo transport is the world's biggest plane. The Hughes H-4 Hercules has the biggest wingspan, but it only flew once.
Since the 747-400 was made, many more types of 747 have been suggested. Boeing said that they would make the 747-500X and in 1996. These new planes would have cost more than US$5 billion to design and make. Airlines did not like it enough, so Boeing decided not to make the planes. In 2000, Boeing said it would make a 747X to rival the Airbus A3XX. However, airlines did not like the 747X enough, so it was cancelled. A year later, Boeing began concentrating on the Sonic Cruiser. The Sonic Cruiser was stopped, so Boeing then focused on the Boeing 787 Dreamliner. Some of the ideas that Boeing had for the 747X were used on the 747-400ER.
In 2004, Boeing said that it might work on the 747 Advanced. Boeing decided to go ahead with this. The 747 Advanced used some things from the 787 to make the 747's design more modern. The 747 was the world's biggest passenger plane until the Airbus A380 was finished in 2007.
On November 14, 2005, Boeing said it had changed the name of the 747 Advanced to the Boeing 747-8. The last 747-400s were made in 2009. On February 8, 2010, the 747-8 Freighter made its first flight. Cargolux got the first 747–8 in 2011. Eventually, the 747 will be replaced by "Y3".