航空空域クラスと航空空域分類の理解

Understanding Airspace Class and Aviation Airspace Classification Flight Training , Safety Understanding Airspace Class and Aviation Airspace Classification July 14, 2024 Paul Wynns In this article, we will cover everything you need to know about airspace classes. Understanding these classes is essential for safe and efficient flying, whether you are a seasoned pilot or just starting your aviation journey. Let's dive into the intricacies of airspace areas to ensure you have a clear understanding. What is an Airspace Class? An airspace class is a designated area of the sky defined by the Federal Aviation Administration (FAA) to manage air traffic efficiently and safely. The FAA uses letters like Class A, Class B, etc., to differentiate these airspaces. Airspace can be either controlled or uncontrolled. Controlled airspace is where Air Traffic Control (ATC) manages traffic, while uncontrolled airspace is where ATC does not actively control aircraft. Airspace Classification Chart Types of Airspace: Controlled vs. Uncontrolled Airspace Areas Controlled Airspace Controlled airspace is a region where ATC services are provided. Pilots operating within these areas are subject to certain rules and requirements to ensure safe and efficient traffic flow. Controlled airspace includes Class A, B, C, D, and certain parts of Class E. Class A : Encompasses airspace from 18,000 feet MSL up to 60,000 feet MSL, primarily used for IFR traffic. Operations in Class A airspace must be conducted under an IFR flight plan. Class B : Surrounds the busiest airports, requiring ATC clearance to enter. Class B airspace is defined by its boundaries and configuration. Within Class B airspace, pilots need to hear explicit clearance to enter the airspace. Class C : Found around large, less busy airports, requiring two-way radio communication with ATC. The configuration of each Class C airspace is tailored to the airport's needs. Class D : Encloses smaller airports with a control tower, necessitating two-way radio communication with ATC. Class D airspace areas are typically cylindrical. Class E : Covers controlled airspace not classified as A, B, C, or D, facilitating ATC management of IFR flights. Designated Class E airspace begins at different altitudes depending on the area. Uncontrolled Airspace Uncontrolled airspace, designated as Class G, is where ATC does not provide services. Pilots operate under less stringent rules compared to controlled airspace but must still adhere to specific visibility and cloud clearance requirements. Class G : Starts at the surface and extends upwards until it meets controlled airspace, with varying visibility and cloud clearance rules depending on altitude and time of day. Class A Airspace What is Class A Airspace? Class A airspace, also known as Class Alpha, covers the entire United States. It starts at 18,000 feet Mean Sea Level (MSL) and extends up to 60,000 feet MSL. This airspace is not depicted on any charts as it blankets the entire country. Requirements and Characteristics IFR Only : Class A airspace is strictly for Instrument Flight Rules (IFR) operations. Pilots must be on an IFR flight plan and have ATC clearance to enter. Equipment : Pilots need a Mode C transponder and Automatic Dependent Surveillance-Broadcast (ADS-B) Out. Above Flight Level (FL) 240, Distance Measuring Equipment (DME) is required. Speed Limit : The speed limit in Class A airspace is Mach 1. Class B Airspace What is Class B Airspace? Class B airspace, or Class Bravo, surrounds the 37 busiest airports in major cities. It is depicted on sectional charts using solid blue lines. Each sector has an altitude block with a floor and a ceiling, listed in hundreds of feet above sea level. Characteristics and Entry Requirements Structure : In 3D, Class B airspace resembles an upside-down wedding cake, with multiple layers extending outward from the central airport. Entry : Pilots need ATC clearance to enter Class B airspace. They must have a Mode C transponder and ADS-B Out within a 30 nautical mile radius, depicted as a magenta circle on charts. VFR Weather Minimums : At least three statute miles of visibility and staying clear of clouds are required. Speed Limits : 250 knots within Class B and 200 knots below and through VFR corridors. Individual Tailoring : Each Class B airspace area is individually tailored to fit the needs of the surrounding airports. Class C Airspace What is Class C Airspace? Class C airspace exists around large airports that are less busy than those in Class B. It is typically found around medium-sized cities and depicted with magenta lines on sectional charts. Structure and Requirements Structure : The inner core extends from the surface to 4,000 feet Above Ground Level (AGL) with a radius of 5 nautical miles. The outer shell extends from 1,200 feet AGL to 4,000 feet AGL with a radius of 10 nautical miles. Entry : Pilots must establish two-way radio communication with ATC. A Mode C transponder and ADS-B Out are required. VFR Weather Minimums : Three statute miles of visibility and specific cloud clearance requirements (1,000 feet above, 500 feet below, and 2,000 feet horizontally from clouds). Speed Limit : 200 knots within a 4 nautical mile radius of the airport, and 250 knots below 10,000 feet MSL. Defined Airspace : Class C airspace is defined by its specific boundaries and the configuration of each Class C airspace. Class D Airspace What is Class D Airspace? Class D airspace surrounds airports that are not as busy as those in Class C. It is depicted with dashed blue lines on sectional charts. Characteristics and Entry Requirements Structure : Typically cylindrical with a radius of about 4.25 nautical miles, extending from the surface to 2,500 feet AGL. Entry : Pilots must establish two-way radio communication with ATC before entering. VFR Weather Minimums : Similar to Class C with three statute miles of visibility and the same cloud clearance requirements. Speed Limit : 200 knots. Defined Airspace : A Class D airspace area is tailored to the operational needs of the airport. Class E Airspace What is Class E Airspace? Class E airspace, or Class Echo, encompasses all controlled airspace that is not classified as A, B, C, or D. It allows ATC to manage IFR aircraft outside of other controlled airspaces. Structure and Characteristics Standard Floor : Typically starts at 1,200 feet AGL across most of the country. Transition Areas : Shaded magenta areas on charts depict transition zones where Class E starts at 700 feet AGL to assist IFR aircraft flying in and out of airports. Surface Areas : Dashed magenta lines indicate Class E airspace extending to the surface around certain airports. Entry : No specific entry requirements, but pilots must follow VFR weather minimums. VFR Weather Minimums : Below 10,000 feet MSL, the requirements are the same as Class C and D. Above 10,000 feet MSL, visibility increases to five statute miles with 1,000 feet above, 1,000 feet below, and one statute mile horizontally from clouds. Beginning of Class E : Class E airspace begins at different altitudes depending on the specific airspace areas. Class G Airspace What is Class G Airspace? Class G airspace, or Class Golf, is uncontrolled airspace where ATC does not manage aircraft. It starts at the surface where controlled airspace does not exist. Characteristics and Requirements Visibility and Cloud Clearance : Below 10,000 feet MSL during the day, pilots need one statute mile of visibility and to stay clear of clouds. At night, the requirements increase to three statute miles of visibility, with specific cloud clearances. High Altitude : Above 1,200 feet AGL and below 10,000 feet MSL, stricter cloud clearance applies both day and night. Over 10,000 feet MSL and above 1,200 feet AGL, the requirements are similar to Class E high altitude. Traffic Pattern Exception : At night, within half a mile of the runway, pilots only need one mile of visibility and to stay clear of clouds. Special Use Airspace Special Use Airspace (SUA) is designated for specific activities that may pose a risk to non-participating aircraft. These areas are established to ensure safety and can either be restricted, prohibited, or for specific activities like military operations. Types of Special Use Airspace Prohibited Areas : Airspace where flight is strictly prohibited for security or other reasons. For example, P-56 over Washington D.C. Restricted Areas : Areas where flight is restricted due to the presence of unusual or hazardous activities, such as military training. Pilots must have permission to enter these areas. Warning Areas : Extending from 3 nautical miles outward from the coast of the U.S., these areas warn non-participating pilots of potential danger. Military Operations Areas (MOAs) : Segregated areas for military training activities. Pilots can fly through MOAs but should exercise extreme caution. Alert Areas : Areas with high volumes of pilot training or unusual aerial activity. Controlled Firing Areas (CFAs) : Areas where activities are suspended immediately if non-participating aircraft are detected. Importance of Special Use Airspace Special Use Airspace ensures that activities that could be hazardous to other aircraft are safely contained. It provides a structured environment for military training, security operations, and other activities that require airspace segregation. ATS Airspace What is ATS Airspace? ATS (Air Traffic Services) airspace includes all airspace within which air traffic control services are provided. This encompasses controlled airspace (Classes A, B, C, D, and E) and certain parts of uncontrolled airspace (Class G). Importance of ATS Airspace ATS airspace is crucial for managing both IFR and VFR flights, ensuring separation and safety across various airspace areas. It is part of the broader National Airspace System and helps coordinate flights within the airspace in the United States and internationally. International Civil Aviatio