## 3 − 1 − 1. General 

a. There are two categories of airspace or airspace areas: 

1. Regulatory (Class A, B, C, D and E airspace areas, restricted and prohibited areas); and 

2. Nonregulatory (military operations areas [MOA], warning areas, alert areas, controlled firing areas [CFA], and national security areas [NSA]). 

## NOTE − 

Additional information on special use airspace (prohibited areas, restricted areas [permanent or temporary], warning areas, MOAs [permanent or temporary], alert areas, CFAs, and NSAs) may be found in Chapter 3, Airspace, Section 4, Special Use Airspace, paragraphs 3 − 4 − 1 through 3 − 4 − 8 . 

b. Within these two categories, there are four types: 

1. Controlled, 

2. Uncontrolled, 

3. Special use, and 

4. Other airspace. 

c. The categories and types of airspace are dictated by: 

1. The complexity or density of aircraft movements, 

2. The nature of the operations conducted within the airspace, 

3. The level of safety required, and 

4. The national and public interest. 

d. It is important that pilots be familiar with the operational requirements for each of the various types or classes of airspace. Subsequent sections will cover each class in sufficient detail to facilitate understanding. 

## Chapter 3. Airspace 

## Section 1. General 

## 3 − 1 − 2. General Dimensions of Airspace Segments 

Refer to Title 14 of the U.S. Code of Federal Regulations (CFR) for specific dimensions, excep- tions, geographical areas covered, exclusions, specific transponder/ADS − B or other equipment requirements, and flight operations. 

## 3 − 1 − 3. Hierarchy of Overlapping Airspace Designations 

a. When overlapping airspace designations apply to the same airspace, the operating rules associated with the more restrictive airspace designation apply. 

b. For the purpose of clarification: 

1. Class A airspace is more restrictive than Class B, Class C, Class D, Class E, or Class G airspace; 

2. Class B airspace is more restrictive than Class C, Class D, Class E, or Class G airspace; 

3. Class C airspace is more restrictive than Class D, Class E, or Class G airspace; 

4. Class D airspace is more restrictive than Class E or Class G airspace; and 

5. Class E is more restrictive than Class G airspace. 

## 3 − 1 − 4. Basic VFR Weather Minimums 

a. No person may operate an aircraft under basic VFR when the flight visibility is less, or at a distance from clouds that is less, than that prescribed for the corresponding altitude and class of airspace. (See TBL 3 − 1 − 1.) 

## NOTE − 

Student pilots must comply with 14 CFR Section 61.89(a) (6) and (7). 

b. Except as provided in 14 CFR Section 91.157, Special VFR Weather Minimums, no person may operate an aircraft beneath the ceiling under VFR within the lateral boundaries of controlled airspace designated to the surface for an airport when the ceiling is less than 1,000 feet. (See 14 CFR Section 91.155(c).) 

