FAR 91.155 — VFR Weather Minimums
FAR 91.155 sets VFR visibility and cloud clearance minimums by airspace class and altitude, plus special rules for Class G and surface-area airports.
In Plain English
FAR 91.155 establishes the minimum flight visibility and distance from clouds you must maintain when flying under VFR. The required values depend on airspace class and altitude:
- Class A: VFR not permitted.
- Class B: 3 SM visibility, clear of clouds.
- Class C and D: 3 SM, 500 below / 1,000 above / 2,000 horizontal.
- Class E below 10,000 MSL: same as C/D (3-152).
- Class E at or above 10,000 MSL: 5 SM, 1,000 below / 1,000 above / 1 SM horizontal.
- Class G ≤1,200 AGL, day: 1 SM, clear of clouds.
- Class G ≤1,200 AGL, night: 3 SM and 3-152 cloud clearances (with limited traffic-pattern exceptions).
- Class G >1,200 AGL but <10,000 MSL: 1 SM day / 3 SM night, 3-152.
- Class G at or above 10,000 MSL: 5 SM, 1,000/1,000/1 SM.
Special rules in paragraph (b) allow helicopters and certain aircraft in the traffic pattern to operate at reduced minimums clear of clouds. Under paragraphs (c) and (d), you may not operate beneath a ceiling under 1,000 feet within surface-based controlled airspace, and you may not take off, land, or enter the pattern at a Class B/C/D/E surface airport unless ground visibility is at least 3 SM (or flight visibility if ground isn't reported). Why it matters: these limits keep you in conditions where you can see and avoid traffic and terrain.
Regulation Text
14 CFR § 91.155§ 91.155 Basic VFR weather minimums.
(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:
(b)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)A helicopter may be operated clear of clouds in an airport traffic pattern withinmile of the runway or helipad of intended landing if the flight visibility is not less thanstatute mile.
(2)If the visibility is less than 3 statute miles but not less than 1 statute mile during night hours and you are operating in an airport traffic pattern withinmile of the runway, you may operate an airplane, powered parachute, or weight-shift-control aircraft clear of clouds.
(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.
[Docket 24458, 56 FR 65660, Dec. 17, 1991, as amended by Amdt. 91-235, 58 FR 51968, Oct. 5, 1993; Amdt. 91-282, 69 FR 44880, July 27, 2004; Amdt. 91-330, 79 FR 9972, Feb. 21, 2014; Amdt. 91-330A, 79 FR 41125, July 15, 2014]
1 statute mile horizontal.
1,000 feet above.
1,000 feet below.
5 statute miles
More than 1,200 feet above the surface and at or above 10,000 feet MSL
2,000 feet horizontal.
1,000 feet above.
500 feet below.
3 statute miles
Night
2,000 feet horizontal.
1,000 feet above.
500 feet below.
1 statute mile
Day
More than 1,200 feet above the surface but less than 10,000 feet MSL
Clear of clouds.
1 statute mile
Night, except as provided in § 91.155(b)
Clear of clouds
⁄statute mile
Day
For helicopters:
2,000 feet horizontal.
1,000 feet above.
500 feet below.
3 statute miles
Night, except as provided in § 91.155(b)
Clear of clouds.
1 statute mile
Day, except as provided in § 91.155(b)
For aircraft other than helicopters:
1,200 feet or less above the surface (regardless of MSL altitude)
Class G:
1 statute mile horizontal.
1,000 feet above.
1,000 feet below.
5 statute miles
At or above 10,000 feet MSL
2,000 feet horizontal.
1,000 feet above.
500 feet below.
3 statute miles
Less than 10,000 feet MSL
Class E:
2,000 feet horizontal.
1,000 feet above.
500 feet below.
3 statute miles
Class D
2,000 feet horizontal.
1,000 feet above.
500 feet below.
3 statute miles
Class C
Clear of Clouds.
3 statute miles
Class B
Not Applicable.
Not Applicable
Class A
Distance from clouds
Flight visibility
Airspace
Oral Exam Questions a DPE Might Ask
Q1What are the basic VFR weather minimums for Class C airspace?
Per FAR 91.155, Class C requires 3 statute miles flight visibility and cloud clearance of 500 feet below, 1,000 feet above, and 2,000 feet horizontal.
Q2You're flying VFR in Class E airspace at 11,500 feet MSL. What visibility and cloud clearance do you need?
FAR 91.155 requires 5 statute miles visibility with 1,000 feet below, 1,000 feet above, and 1 statute mile horizontal cloud clearance at or above 10,000 feet MSL.
Q3Can you take off VFR from a Class D airport when the reported ground visibility is 2 statute miles?
No. FAR 91.155(d) prohibits VFR takeoff, landing, or pattern entry in Class B, C, D, or E surface areas unless ground visibility is at least 3 statute miles.
Studying for a checkride?
Related Sections in Part 91