FAA Federal Aviation Regulations (FARS, 14 CFR)

(a) Except as provided in paragraph (b) of this section and §91.157, no person may operate an aircraft under VFR when the flight visibility is less, or at a distance from clouds that is less, than that prescribed for the corresponding altitude and class of airspace in the following table:

------------------------------------------------------------------------
Distance from
Airspace                Flight visibility         clouds
------------------------------------------------------------------------
Class A.......................  Not Applicable........  Not Applicable.
Class B.......................  3 statute miles.......  Clear of Clouds.
Class C.......................  3 statute miles.......  500 feet below.
1,000 feet
above.
2,000 feet
horizontal.
Class D.......................  3 statute miles.......  500 feet below.
1,000 feet
above.
2,000 feet
horizontal.
Class E:
Less than 10,000 feet MSL...  3 statute miles.......  500 feet below.
1,000 feet
above.
2,000 feet
horizontal
At or above 10,000 feet MSL.  5 statute miles.......  1,000 feet
below.
1,000 feet
above.
1 statute mile
horizontal.
Class G:
1,200 feet or less above the
surface (regardless of MSL
altitude).
Day, except as provided in      1 statute mile........  Clear of clouds.
§ 91.155(b).
Night, except as provided in    3 statute miles.......  500 feet below.
§ 91.155(b).                                           1,000 feet
above.
2,000 feet
horizontal.
More than 1,200 feet above the
surface but less than 10,000
feet MSL
Day...........................  1 statute mile........  500 feet below.
1,000 feet
above.
2,000 feet
horizontal.
Night.........................  3 statute miles.......  500 feet below.
1,000 feet
above.
2,000 feet
horizontal.
More than 1,200 feet above the  5 statute miles.......  1,000 feet
surface and at or above                                 below.
10,000 feet MSL.                                       1,000 feet
above.
1 statute mile
horizontal.
------------------------------------------------------------------------

(b) Class G Airspace. Notwithstanding the provisions of paragraph (a) of this section, the following operations may be conducted in Class G airspace below 1,200 feet above the surface:

(1) Helicopter. A helicopter may be operated clear of clouds if operated at a speed that allows the pilot adequate opportunity to see any air traffic or obstruction in time to avoid a collision.

(2) Airplane. When the visibility is less than 3 statute miles but not less than 1 statute mile during night hours, an airplane may be operated clear of clouds if operated in an airport traffic pattern within one-half mile of the runway.

(c) Except as provided in §91.157, no person may operate an aircraft beneath the ceiling under VFR within the lateral boundaries of controlled airspace designated to the surface for an airport when the ceiling is less than 1,000 feet.

(d) Except as provided in §91.157 of this part, no person may take off or land an aircraft, or enter the traffic pattern of an airport, under VFR, within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport --

(1) Unless ground visibility at that airport is at least 3 statute miles; or

(2) If ground visibility is not reported at that airport, unless flight visibility during landing or takeoff, or while operating in the traffic pattern is at least 3 statute miles.

(e) For the purpose of this section, an aircraft operating at the base altitude of a Class E airspace area is considered to be within the airspace directly below that area.

[Doc. No. 24458, 56 FR 65660, Dec. 17, 1991, as amended by Amdt. 91-235, 58 FR 51968, Oct. 5, 1993]