Helicopter VFR weather minimums

FAR 91.155
Visual Flight Rules (VFR) weather minimums refer to the specific weather conditions that must be met for a helicopter pilot to operate under visual flight rules. These minimums are established to ensure a safe level of visibility and cloud clearance for pilots to navigate visually without relying on instrument flight rules (IFR). VFR weather minimums vary depending on the airspace classification and altitude being flown. Here are some general guidelines:

Class Golf airspace extends up to but not including 1,200 ft AGL, where class Echo takes over up to but not including 18,000 ft. MSL. Golf airspace is not depicted on any chart.

Daytime: The minimum visibility requirement is ½ statute mile (SM), and the pilot must remain clear of clouds.

Nighttime: The only difference from day to night, is an increased minimum visibility requirement of 1 SM.

Class E airspace is controlled airspace that is designated to serve a variety of terminal or en-route purposes.
Class echo starts at 1200 ft. AGL, unless otherwise specified.
Generally, if the airspace is not Class A, B, C, or D, and is controlled airspace it is Class E airspace. Echo airspace is usually used as a way for traffic to transition to an airport in IFR.

Special VFR operations are permitted but clearance must be obtained from the controlling facility.

Class Echo fills the gap between 1200 ft. to 18000 ft.

Class Echo airspace from the bottom area requires the following:

3 SM visibility.

Remain 500 ft. below the clouds.

Remain 1000 ft. above the clouds.

Remain 2000 ft. horizontally of the clouds.

That airspace from the surface to 2500 ft. AGL (depicted in MSL), surrounding those airports that have a control tower, but do not have the traffic to warrant a radar controller. The configuration of each class Delta airspace is individually tailored, and the airspace will normally be designed to contain specific procedures or operations often conducted within it.

Class Delta airspace from the bottom area requires the following:

3 SM visibility.

Remain 500 ft. below the clouds.

Remain 1000 ft. above the clouds.

Remain 2000 ft. horizontally of the clouds.

That airspace from the surface to 4000 ft. above the airport elevation (charted in MSL) surrounding those airports that are busier than class Delta airspace and have a certain number of IFR flights. Although the configuration of each class Charlie airspace is individually tailored, the airspace usually consists of the following dimensions:

Class Charlie airspace from the bottom area requires the following:

3 SM visibility.

Remain 500 ft. below the clouds.

Remain 1000 ft. above the clouds.

Remain 2000 ft. horizontally of the clouds.

That airspace from the surface to 10000 ft. MSL surrounding the nation’s busiest airports. Class Bravo airspace is always individually tailored to each specific airport.

The weather minimums are simple for Class Bravo airspace since it's so tightly controlled:

3 SM visibility.

Remain clear of clouds.

That airspace from 18,000 ft. MSL up to FL600, requiring an IFR rated pilot with an IFR flight plan. Class Alpha airspace is not depicted on any map. Instead, it lies as a blanket on all airspace, starting at 18,000 ft. MSL up to FL600.

No VFR traffic is allowed in Class Alpha airspace. An IFR flight plan is required.

91.157
Should the current weather or visibility be below visual meteorological conditions, ATC may still allow flights under VFR rules under certain circumstances.

Special VFR operations may only be conducted when you:

Have an ATC clearance

Remain clear of clouds

Are the only aircraft at the airport operating under SVFR

Stay within the boundaries of the airspace

A helicopter can operate with zero visibility with an SVFR clearance – As long as it remains clear of clouds. SVFR can be requested in all classes of airspace except for alpha. SVFR is available at day and night.