VFR Rules

For a exposition of this point, we'll base that tutorial upon the U.S. rules concerning the airspace. The U.S. reglementation is basically based unto the distinction made between the airspace lying over 18,000 ft, and the airspace lying below. The following tutorial may easily be extrapolated to the airspaces of other countries. Generally, as far as the VFR, and IFR rules, more detailed views are given in the tutorials dedicated to such subjects like the navigation under those conditions

A VFR (VFR stands for 'Visual Flight Rules') flight is a flight performed under such weather conditions that the pilot of the plane can keep the visual contact with the ground. Pilots holding the PPL are authorized to such flight only! When flying VFR, inside the controled airspace included, it is not necessary to enter in contact with the aerial controllers. In the USA, for example, the controled airspace is beginning at 1,200 ft/AGL. A pilot, beyond that limit, may usefully tune his radio to the frequency of the aerial control which has authority on the area where he is flying, as, without himself communicating with the controllers, he will be able to listen to the radio-communications of the other planes in the area, thus increasing his situational awareness. When the pilot has filed a flight plan -which is not mandatory in VFR conditions- he will mandatorily have to contact the aerial controllers all along his route. One may fly a VFR flight until the limit of the 18,000 ft. Any flight beyond has to be obligatorily flewn in IFR conditions. A IFR flight is a instrument flight only as the pilot does not use any landmark on the ground only. One may make a difference between the low altitude VFR flight, and the high altitude VFR one, or 'low VFR' and 'high VFR'. A low VFR flight mostly is performed by the basic GA planes, like a Cessna 172SP. A high VFR flight mostly concerns the more advanced GA planes, like a Baron 58, or some commercial planes which may choose to fly VFR, under 18,000 ft

• as far as the landmarks on the ground are concerned, a pilot on a low VFR flight is making use of the standard aeronautical charts (in the USA, they are called 'sectional charts'). Those are those charts displaying the terrain in colors and with a fairly high geographical accuracy, along with the miscellaneous aeronautical informations useful to a flight. A example of those charts is to be found among the ones offered in some FS franchises. High VFR flights are using charts of the same type albeit of a smaller scale. Such charts are displaying a less geographical details as the pilot, in that case, is flying at a higher altitude!
• as far as the aerial routes are concerned, a VFR flight can not use the 'Victor Airways', those low altitude aerial routes, which is a network of published routes mostly existing in the USA. Those routes are extant for altitudes below the 18,000 mark and may be used for the IFR flights only. A VFR flight, whatever its altitude, must always be flewn along a draw which will have been drawn between the departure, and the arrival terrains! Such a straight line must eventually take in account the varied prohibited, restricted, etc. areas along the route. That may eventually makes that the pilot will have to split his flight into several legs. A VFR route may -or not- be close to a low IFR route, or cross one. That doesn't pose any trouble, as the reglementary flight altitudes for the VFR and IFR conditions are different. VFR flights have to establish their altitude function of the 'hemispheric rule', with altitudes ending with 500, like 3,500, 4,500 ft, etc. IFR flight, whatever the heading they are flying to, have to fly altitudes in straight thousands, like 3,000, 4,000 ft, etc.

As far numbers, data or rules useful to privale pilot flying VFR are concerned, here are some

• VFR weather conditions: 3 NM visibility, 2000 ft of horizontal distance to the clouds, or 1000ft above or 500ft below the clouds (for high VFR -which does not concern much of private pilots: 5 NM visi, 1NM horizontal, 1000ft above or below)
• special weather conditions: in Class B airspace (large airports) 3NM visi and out of clouds; in non-controled airspace below 1200ft AGL, visi 1NM, out of clouds. Flight is forbiddent in Classe B, C, D and E airspace when ceiling is below 1000ft or visibility under 3NM as a pilot must then be authorized to 'special VFR' rules for takeoff or landing with a 1NM visi and out of clouds. Special VFR is forbidden at most of large airports and forbidden at night when the pilot is not IFR qualified
• hemispheric rule: when flying on a 0-179 degree heading, the altitude of the flight must be in odd thousands of feet PLUS 500 (3500, 5500, etc). On a 180-359° headcing, even thousands of feet PLUS 500 (4500, 6500, etc)
• fuel quantity: a private pilot, for a VFR flight, must embark the fuel quantity necessary for the flight PLUS a 30-minute of flight reserve (for night VFR, that reserve is of 45 mn of flight)
• minimal altitude: above populated areas 1000ft above the higher obstacle in a radius of 2000ft; above sparsely populated areas, at least 500ft AGL; above any person, ship, vehicle, installation: 500ft above those
• flight plan: pilots are not obliged to a flight plan when flying a VFR flight. When one is used, the pilot has to close that plan 30 mn after landing as the rescue operations would be triggered otherwise
• 1 US gallon of aviation fuel weighs 6 lbs
• for older planes, specs are often given in mph, multiply any value by 0.87 to obtain the equivalent in kts