Visual Flight Rules/VFR

(1) Rules that govern the procedures for conducting flight
under visual conditions. The term “VFR” is also used in the
United States to indicate weather conditions that are equal
to or greater than minimum VFR requirements. In addition it
is used by pilots and controllers to indicate type of flight
plan. (2) Visual flight in which avoidance of collision
with other aircraft is dependent upon every pilot seeing
other aircraft and avoiding them. To enable pilots to
perform the collision avoidance function, the rules take
certain weather conditions into account, and specify basic
“rules of the air”. See categories under VFR.