What effect does a tailwind have on landing distance?

A tailwind increases the landing distance because it effectively adds to the ground speed of the aircraft upon touchdown. When landing, the aircraft's approach speed is combined with the speed of the wind. A tailwind means that the aircraft is moving faster relative to the ground than it is to the air. This increased ground speed requires a longer distance to slow down to a stop. Additionally, the required braking distance will increase because the aircraft has more kinetic energy upon touchdown due to the increased ground speed. Therefore, one must account for this additional distance when planning landings in conditions with a tailwind.