Most planes use a long runway before takeoff to gain enough speed for the plane to lift up into the air. Most airplanes can take off only if they are moving fast enough.

Most airplanes require a runway because they need to reach a specific minimum airspeed to generate lift. Lift is created when air moves over the wings; the faster the plane moves, the more upward force is generated. Since wings are fixed, the only way to get that air moving fast enough is to accelerate the entire aircraft along a long, flat surface. The runway provides the necessary distance for the engines to propel the plane to its "takeoff speed." Similarly, during landing, a runway is essential to provide a safe, unobstructed space for the aircraft to dissipate its kinetic energy using brakes and thrust reversers. While Vertical Take-Off and Landing (VTOL) aircraft like Harriers or helicopters exist, they are significantly less fuel-efficient for long-distance travel, which is why the vast majority of commercial aviation in 2026 still relies on the traditional runway system.