Definition
The subsection of Title 14 of the Code of Federal Regulations, Part 91, Section 91.155 that sets out special VFR (Visual Flight Rules) weather minimums. It defines the reduced visibility and cloud clearance conditions under which a pilot may operate VFR within the lateral boundaries of controlled airspace at or below 10,000 feet MSL when an ATC clearance for special VFR has been obtained.
Plain English
It is the part of the rules that explains the lower weather limits a pilot is allowed to fly in around an airport's controlled airspace, but only after asking for and getting permission from air traffic control.
Context Anchor
Seen in VFR weather minimums tables, preflight weather planning, and discussions about whether an airport can be used legally under VFR.
Why Pilots Care
Compliance ensures the pilot can see and avoid terrain, obstacles, and other traffic without relying on instruments or ATC.
Grounding Statement
If the controlled airspace for the airport reaches the ground and the cloud ceiling is below 1,000 feet, normal VFR flight beneath that ceiling is not allowed there.
Intuition Check
Do not read section 91.155(b) as just a visibility rule. It is specifically about flying beneath a low ceiling in certain controlled airport airspace.
Example Sentence 1
The instructor pointed to section 91.155(b) and explained that the student would need a Special VFR clearance to depart with the current one-mile visibility.
Example Sentence 2
During preflight planning the instructor pointed out that section 91.155(b) allows one-mile visibility below 1,200 feet AGL in Class G during the day.