Jet

Released in 1977 as part of the inaugural wave of the Lego Technic line, then known as Expert Builder, the 8504 Jet marked an early experimentation with the system's potential for mechanical movement. The set was designed to showcase the new stud-based construction method which allowed for more complex, articulated models compared to traditional system bricks. It represented the brand's shift toward appealing to older builders interested in structural engineering and functional play.

The model was designed to mirror the streamlined aesthetics of late 1970s aerospace design, utilizing a limited color palette of white, red, and blue. While simple by modern standards, its reliance on specialized technic components and beams signaled a departure from the blocky shapes typical of the era. Upon its release, it was well-received for its playability and served as a foundational example of how Lego could integrate mechanical principles into its iconic building sets.