How is a large aircraft defined?

• A. It has a maximum takeoff weight of more than 5700kg
• B. It has a wingspan of more than 40m
• C. It has a height of more than 20m
• D. It has a maximum takeoff weight of more than 136 000kg

Answer: (A)

The key idea is that aircraft size is typically defined by how much they weigh at takeoff, because weight directly relates to performance, required systems, and regulatory treatment. In this definition, a large aircraft is one with a maximum takeoff weight greater than 5,700 kilograms. Crossing that threshold means the aircraft enters categories with more stringent certifications, maintenance demands, and operational considerations (such as runway length and airspace planning) than lighter aircraft.

Why not use wingspan or height? Those dimensions don’t consistently reflect an aircraft’s performance or the regulatory complexity it faces. Aircraft with similar MTOWs can have very different shapes, so one could have a long wingspan but not necessarily be heavier, or vice versa. Using weight provides a practical, uniform basis for sizing rules, equipment needs, and safety requirements across diverse designs.