AIM Text
Use reasonable restraint in exercising the prerogative of VFR flight, especially in terminal areas. The weather minimums and distances from clouds are minimums. Giving yourself a greater margin in specific instances is just good judgment.
- Approach Area. Conducting a VFR operation in a Class B, Class C, Class D, and Class E surface area when the official visibility is 3 or 4 miles is not prohibited, but good judgment would dictate that you keep out of the approach area.
- Reduced Visibility. It has always been recognized that precipitation reduces forward visibility. Consequently, although again it may be perfectly legal to cancel your IFR flight plan at any time you can proceed VFR, it is good practice, when precipitation is occurring, to continue IFR operation into a terminal area until you are reasonably close to your destination.
- Simulated Instrument Flights. In conducting simulated instrument flights, be sure that the weather is good enough to compensate for the restricted visibility of the safety pilot and your greater concentration on your flight instruments. Give yourself a little greater margin when your flight plan lies in or near a busy airway or close to an airport.
Source: FAA Aeronautical Information Manual · current edition · paragraph 4-3-16.
The short answer
This AIM section is FAA advisory guidance urging reasonable restraint when exercising VFR flight in terminal areas. It stresses that weather minimums and cloud distances are minimums, and recommends extra margin near approach areas, in reduced visibility/precipitation, and during simulated instrument flights with a safety pilot.
Research Notes
Common Questions
Can I fly VFR in a Class B, C, D, or E surface area at 3 miles visibility?
The AIM notes that conducting a VFR operation in a Class B, Class C, Class D, or Class E surface area when official visibility is 3 or 4 miles is not prohibited, but good judgment dictates keeping out of the approach area. The published minimums are minimums, and a greater margin is just good judgment.
Should I cancel IFR and go VFR when it’s precipitating near my destination?
The AIM recognizes precipitation reduces forward visibility. Although it may be legal to cancel an IFR flight plan whenever you can proceed VFR, it is good practice when precipitation is occurring to continue IFR operation into a terminal area until you are reasonably close to your destination.