If you’re a frequent flier, then you’ve likely been on a variety of different aircraft, from small and cramped, to cramped and complex. Smaller aircraft are often less spacious with only two rows of seating, whereas larger aircraft typically have two or more rows of seating. However, the most significant difference between different aircraft is not the size of the aircraft, but the weight. The weight is especially crucial for pilots because they need certain ratings to be able to fly bigger aircraft. For both air traffic controllers and pilots, the categories are crucial in notifying pilots of dangerous conditions in the wake of heavy planes. For a more detailed description of the differences between large and heavy aircraft, read on below.