The 747 is the result of a letter from Pan Am to Boeing in 1965: Dear Mr Boeing, Please build us a very big aeroplane soon. If it is pretty as well that will be a bonus. We will buy lots of them. Yours sincerely, Pan Am This letter, or at least a rather more formal version which was probably a great deal longer, was written in 1965. The first 747, the 747-100, rolled out of the Seattle works on 30th September 1968, and flew on 9th February 1969. The first commercial flight was with Pan Am between London and New York on 22nd January 1970.

The 747-200 is a heavier version, which entered service with KLM Royal Dutch Airlines (the oldest name in the airline business, incidentally) in February 1971. Its increased weight and improved range stemmed mainly from an increase in the fuel load. A freight version, the -200F, appeared in April 1972, together with a short-range high-capacity version for the Japanese domestic market, the 747SR. This carries 523 passengers.

1973 saw the start of planning for the 747SP, the first example appearing on 19th May 1975 with the first flight on 4th July. This is a special performance version, produced for services where the prodigious passenger-carrying capacity of its longer sisters is unnecessary. The aircraft is nearly 14.5 m shorter than the standard version, the tailfin some 1.5 m taller, and the tailplanes 3 m longer. Pan Am was the first customer for this, too. The last example of 45 was built in 1982.

In 1982 the upper deck of the -200 was stretched by 7 m to produce the 747-300. This first flew on 5th October 1982, and the initial customer was Swissair. The modification was also applied to existing 747's.