Why boeing comercial aircraft use 7 as their numbering system?

Just how did Boeing come up with its successful 7-7 formula in the first place?





It was not because the number 7 is considered lucky.





Nor was the initial 707 designation the sine of its angel sweep, as some math-minded people still believe, according to Lombardi, who points out that the wing sweep of the 707 was 35 degrees, not 45 degrees.





In an article for Boeing's Frontiers magazine earlier this year, Lombardi had this explanation for the Boeing 7-7 jetliner names.





When the company began to expand into commercial airplanes after World War II, the engineering department divided model numbers into blocks of 100 for new products.





Models in the 300s and 400s would continue to represent aircraft (following the tradition of Boeing's 307 Stratoliner and 377 Stratocruiser).





The 500s would be used on turbine engines and the 600s for rockets and missiles. The 700s were set aside for future jet transports.





So why wasn't Boeing's first jetliner named the 700?





Boeing's marketing department decided the Model 700 did not have a ';good ring'; to it, Lombardi said, so they skipped ahead to 707.Why boeing comercial aircraft use 7 as their numbering system?
because 7 is a significant number in the bibleWhy boeing comercial aircraft use 7 as their numbering system?
7 is a lucky number in America! Plus Boeing 747 sounds cooler than Airbus 380.
my first flight was on DC8 and made no deference to me i thought was cool..
because 7 is lucky? whatever it was, it apparently worked