Weather Conditions Precluding VFR Flight
When weather conditions encountered enroute preclude compliance with VFR rules, a
pilot can be expected to do one of the following:
Alter the route of flight so as to be able to continue under VFR conditions
Remain in VFR conditions until he or she can file a change of flight plan from the
air and obtain an IFR clearance
Remain VFR and land at an alternate airport
Special VFR Operations
As an air traffic controller, you must be familiar with Special Visual Flight Rules (SVFR)
operations and understand what you can and cannot do in these situations and what to
expect from the aircraft.
Special Visual Flight Rules
There are exceptions to the VFR weather minimums we have discussed. SVFR
operations in weather conditions less than basic VFR minima are authorized under the
following conditions:
At any location not prohibited by 14 CFR Part 91, Appendix D, or when an
exemption to 14 CFR Part 91 has been granted and an associated LOA
established
Only within the lateral boundaries of Class B, Class C, Class D, or Class E
surface areas, below 10,000 feet MSL
Only when requested by the pilot
On the basis of weather conditions reported at the airport of intended
landing/departure
When weather conditions are not reported at the airport of intended
landing/departure and the pilot advises that VFR cannot be maintained and
requests SVFR
NOTE
14 CFR Part 91 does not prohibit SVFR
helicopter operations.
Do not assign a fixed altitude when applying vertical separation. Instead, clear SVFR
aircraft at or below an altitude that is at least 500 feet below conflicting IFR traffic but
not below the minimum safe altitude as prescribed in CFR, Part 91.
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