Visual Flight Rules (VFR) are a set of regulations under which a pilot operates an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Using the VFR flight rules, the pilot must be able to operate the aircraft with visual reference to the ground, and by visually avoiding obstructions and other aircraft.
Except when operating as a special VFR flight, all VFR flights shall be conducted in VMC conditions of visibility and distance from clouds equal to or greater than the minima presented in the table described in the VFR Minima documentation.
Except when a clearance is obtained from an air traffic control unit, VFR flights shall not take off or land at an aerodrome within a control zone, or enter the aerodrome traffic zone or traffic pattern:
All VFR flights shall not be flown except for take-off, landing or except by emission from the appropriate authority:
Some countries adopt a minimum height above 1000ft over natural parks and reserves. Some countries also make a minimum height of flight between 1000ft to 5000ft over cities.
Unless authorized by the appropriate ATS authority, VFR flights shall not be operated:
- above FL 200;
- at transonic and supersonic speeds
VFR flights above FL 290 are forbidden in RVSM airspace.
The maximum VFR flight level is ICAO defined. According to your national regulation (AIP), it may be different.
For military aircraft, please consult Special Operations Department for HQ rules or your Special Operations rules of your division to have the exact limitations.
Except where otherwise indicated in air traffic control clearances or specified by the appropriate ATS authority, VFR flights when operated above 900 m (3 000ft) from the ground or water shall be conducted at a light level/altitudes appropriate to the track as specified in the following levels :
The cruise altitude (flight level) for VFR flights must be chosen using these assigned rules and must follow the semicircular rules depending on the heading of the aircraft. Check VFR cruise altitude documentation in order to have the full table with explanations including semi-circular rules.
An air traffic control clearance shall be obtained prior to operating a controlled flight or a portion of a flight as a controlled flight:
In those cases, an aircraft operated as a controlled flight shall maintain continuous voice communication and establish two-way communication with the appropriate air traffic control unit.
Note that in IVAO, the pilot must use text mode if the voice communication is not possible.
An aircraft operated in accordance with the visual flight rules which wishes to change to compliance with the Instrument Flight Rules shall:
In a controlled aerodrome, the air traffic controller can issue a special VFR clearance to an aircraft, which is below the VMC minima in his controlled zone, in order to let him reach a new zone where the weather conditions are in line with the VMC rules.
Special VFR clearance use depends on your local regulation (ATS authority): This type of clearance can be forbidden in some countries or at some airfields. Flight visibilities reduced to not less than 1500m (clear of clouds) is permitted for special VFR flights at speeds that give adequate opportunity to observe other traffic or any obstacles in time to avoid collision.
The night VFR flight -- called NVFR sometimes -- is a VFR flight which is partly performed during the aeronautic night.
In some countries or airfields, night VFR flights are not allowed. Please consult your national and local regulations.