ENR 1.4: ATS Airspace Classification - Federal Aviation Administration

ENR 1.4: ATS Airspace Classification ENR 1.4: ATS Airspace Classification 1. General 1.1 There are two categories of airspace or airspace areas: 1.1.1 Regulatory (Class A, B, C, D, and E airspace areas, restricted and prohibited areas). 1.1.2 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 Section ENR 5.1 , Prohibited, Restricted and Other Areas, paragraph 1 and Section ENR 5.2 , Military Exercise and Training Areas, paragraphs 1. through 3. 1.2 Within these two categories, there are four types: 1.2.1 Controlled. 1.2.2 Uncontrolled. 1.2.3 Special use. 1.2.4 Other airspace. 1.3 The categories and types of airspace are dictated by: 1.3.1 The complexity or density of aircraft movements. 1.3.2 The nature of the operations conducted within the airspace. 1.3.3 The level of safety required. 1.3.4 The national and public interest. 1.4 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. 1.5 General Dimensions of Airspace Segments 1.5.1 Refer to Title 14 of the U.S. Code of Federal Regulations (14 CFR) for specific dimensions, exceptions, geographical areas covered, exclusions, specific transponder/ADS-B or other equipment requirements, and flight operations. REFERENCE: See GEN 1.7, Annex 2, for U.S. Differences From ICAO Standards, Recommended Practices and Procedures. 1.6 Hierarchy of Overlapping Airspace Designations 1.6.1 When overlapping airspace designations apply to the same airspace, the operating rules associated with the more restrictive airspace designation apply. 1.6.2 For the purpose of clarification: 1.6.2.1 Class A airspace is more restrictive than Class B, Class C, Class D, Class E, or Class G airspace. 1.6.2.2 Class B airspace is more restrictive than Class C, Class D, Class E, or Class G airspace. 1.6.2.3 Class C airspace is more restrictive than Class D, Class E, or Class G airspace. 1.6.2.4 Class D airspace is more restrictive than Class E or Class G airspace. 1.6.2.5 Class E is more restrictive than Class G airspace. 1.7 Basic VFR Weather Minimums 1.7.1 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 ENR 1.4-1 .) NOTE: Student pilots must comply with 14 CFR Section 61.89(A) (6) and (7). 1.7.2 Except as provided in 14 CFR Section 91.157, Special VFR 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).) 1.8 VFR Cruising Altitudes and Flight Levels (See TBL ENR 1.4-2 .) TBL ENR 1.4-1 Basic VFR Weather Minimums Class A Not Applicable Not Applicable Class B 3 statute miles Clear of Clouds Class C 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal Class D 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal Class E Less than 10,000 feet MSL 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal At or above 10,000 feet MSL 5 statute miles 1,000 feet below 1,000 feet above 1 statute mile horizontal Class G 1,200 feet or less above the surface (regardless of MSL altitude). For aircraft other than helicopters: Day, except as provided in 14 CFR § 91.155(b) 1 statute mile Clear of clouds Night, except as provided in 14 CFR § 91.155(b) 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal For helicopters: Day ½ statute mile Clear of clouds Night, except as provided in §91.155(b) 1 statute mile Clear of clouds More than 1,200 feet above the surface but less than 10,000 feet MSL. Day 1 statute mile 500 feet below 1,000 feet above 2,000 feet horizontal Night 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal More than 1,200 feet above the surface and at or above 10,000 feet MSL. 5 statute miles 1,000 feet below 1,000 feet above 1 statute mile horizontal TBL ENR 1.4-2 VFR Cruising Altitudes and Flight Levels If your magnetic course (ground track) is: And you are more than 3,000 feet above the surface but below 18,000 feet MSL, fly: And you are above 18,000 feet MSL to FL 290, fly: 0 ∘ to 179 ∘ Odd thousands MSL, plus 500 feet (3,500; 5,500; 7,500, etc.) Odd Flight Levels plus 500 feet (FL 195; FL 215; FL 235, etc.) 180 ∘ to 359 ∘ Even thousands MSL, plus 500 feet (4,500; 6,500; 8,500, etc.) Even Flight Levels plus 500 feet (FL 185; FL 205; FL 225, etc.) 2. Controlled Airspace 2.1 General 2.1.1 Controlled Airspace. A generic term that covers the different classification of airspace (Class A, Class B, Class C, Class D, and Class E airspace) and defined dimensions within which air traffic control service is provided to IFR flights and to VFR flights in accordance with the airspace classification. (See FIG ENR 1.4-1 for Airspace Classes). Airspace classes are pronounced in the ICAO phonetics for clarification. The term “class” may be dropped when referring to airspace in pilot/controller communications. 2.1.2 IFR Requirements. IFR operations in any class of controlled airspace requires that a pilot must file an IFR flight plan and receive an appropriate ATC clearance. 2.1.3 IFR Separation. Standard IFR separation is provided to all aircraft operating under IFR in controlled airspace. 2.1.4 VFR Requirements. It is the responsibility of the pilot to insure that ATC clearance or radio communication requirements are met prior to entry into Class B, Class C, or Class D airspace. The pilot retains this responsibility when receiving ATC radar advisories. (See 14 CFR Part 91.) REFERENCE: 14 CFR Part 91. 2.1.5 Traffic Advisories. Traffic advisories will be provided to all aircraft as the controller's work situation permits. 2.1.6 Safety Alerts. Safety Alerts are mandatory services and are provided to ALL aircraft. There are two types of Safety Alerts, Terrain/Obstruction Alert and Aircraft Conflict/Mode Intruder Alert. 2.1.6.1 Terrain/Obstruction Alert. A Terrain/Obstruction Alert is issued when, in the controller's judgment, an aircraft's altitude places it in unsafe proximity to terrain and/or obstructions. FIG ENR 1.4-1 Airspace Classes 2.1.6.2 Aircraft Conflict/Mode C Intruder Alert. An Aircraft Conflict/Mode C Intruder Alert is issued if the controller observes another aircraft which places it in an unsafe proximity. When feasible, the controller will offer the pilot an alternative course of action. 2.1.7 Ultralight Vehicles. No person may operate an ultralight vehicle within Class A, Class B, Class C, or Class D airspace or within the lateral boundaries of the surface area of Class E airspace designated for an airport unless that person has prior authorization from the ATC facility having jurisdiction over that airspace. (See 14 CFR Part 103.) 2.1.8 Unmanned Free Balloons. Unless otherwise authorized by ATC, no person may operate an unmanned free balloon below 2,000 feet above the surface within the lateral boundaries of Class B, Class C, Class D, or Class E airspace designated for an airport. (See 14 CFR Part 101.) 2.1.9 Parachute Jumps. No person may make a parachute jump, and no pilot in command may allow a parachute jump to be made from that aircraft, in or into Class A, Class B, Class C, or Class D airspace without, or in violation of, the terms of an ATC authorization issued by the ATC facility having jurisdiction over the airspace. (See 14 CFR Part 105.) 2.2 Class A Airspace 2.2.1 Definition. Generally, that airspace from 18,000 feet MSL up to and including FL 600, including the airspace overlying the waters within 12 nautical miles off the coast of the 48 contiguous States and Alaska; and designated international airspace beyond 12 nautical miles off the coast of the 48 contiguous States and Alaska within areas of domestic radio navigational signal or ATC radar coverage, and within which domestic procedures are applied. 2.2.2 Operating Rules and Pilot/Equipment Requirements. Unless otherwise authorized, all persons must operate their aircraft under IFR. REFERENCE: 14 CFR Section 71.33, Sections 91.167 through 91.193, Sections 91.215 through 91.217, and Sections 91.225 through 91.227. 2.2.3 Charts. Class A airspace is not specifically charted. 2.3 Class B Airspace 2.3.1 Definition. Generally, that airspace from the surface to 10,000 feet MSL surrounding the nation's busiest airports in terms of IFR operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface area and two or more layers (some Class B airspace areas resemble upside-down wedding cakes), and is designed to contain all published instrument procedures once an aircraft enters the airspace. An ATC clearance is required for all aircraft to operate in the area, and all aircraft that are so cleared receive separation services within the airspace. The cloud clearance requirement for VFR operations is “clear of clouds.” 2.3.2 Operating Rules and Pilot/Equipment Requirements. Regardless of weather conditions, an ATC clearance is required prior to operating within Class B airspace. Pilots should not request a clearance to operate within Class B airspace unless the requirements of 14 CFR Sections 91.131, 91.215, and 91.225 are met. Included among these requirements are: 2.3.2.1 Unless otherwise authorized by ATC, aircraft must be equipped with an operable two-way radio capable of communicating with ATC on appropriate frequencies for that Class B airspace. 2.3.2.2 No person may take off or land a civ