Definition
The section of Title 14 of the Code of Federal Regulations (14 CFR Part 91) that prescribes the basic VFR weather minimums, specifying the minimum flight visibility and required distance from clouds for aircraft operating under visual flight rules in each class of airspace and at various altitudes.
Plain English
The federal rule that tells you how far you must be able to see and how far you must stay from clouds when flying under visual flight rules. The required numbers change depending on what class of airspace you're in and how high you are.
Context Anchor
Seen in traffic pattern and airport operations discussions when deciding whether a pilot may legally operate under VFR in the reported weather.
Derivation
A legal “section” is one numbered part of a larger set of rules. In this citation, “91” points to Part 91, which covers general operating and flight rules, and “.155” identifies the specific rule about basic VFR weather minimums.
Why Pilots Care
Compliance ensures adequate separation from terrain, obstacles, and other aircraft during visual flight.
Intuition Check
Do not read “section 91.155” as just a page or paragraph in the handbook. It points to a federal regulation, and it gives minimum legal weather limits, not a guarantee that the weather is safe for every pilot or flight.
Example Sentence 1
Before departing, the pilot checked the ceiling and visibility against section 91.155 to confirm the flight could legally be conducted under VFR.
Example Sentence 2
Section 91.155 requires one mile visibility and flight clear of clouds when operating below 1,200 feet AGL in Class G airspace during the day.