UAS 250 Module 3: Airspace Classification and Operational Requirements Notes

Airspace Overview and Classification

• Principles of Airspace Categorization: The categories and specific types of airspace are determined based on several factors, including:

  • The complexity or density of aircraft movements within the area.

  • The specific nature of the operations conducted within that airspace.

  • The required level of safety needed for those operations.

  • National or public interests.

• The Four Major Types of Airspace:

  1. Controlled Airspace: Airspace where Air Traffic Control (ATC) services are provided according to the airspace classification.

  2. Uncontrolled Airspace: Airspace where ATC does not exercise authority; primarily designated as Class G.

  3. Special Use Airspace: Areas where activities must be confined or where limitations are imposed on aircraft operations not participating in those activities.

  4. Other Airspace: A general category that captures remaining airspace areas such as Military Training Routes (MTRs) and Temporary Flight Restrictions (TFRs).

Airman Certification Standards (ACS) and Study Resources

• ACS Navigation: This lesson covers the Five Major ACS Areas of Operation. Specifically:

  • Area of Operation II: Airspace

  • Task A: Airspace Classification

  • Task B: Airspace Operational Requirements

• Primary Study Resources:

  • Remote Pilot Study Guide (FAA-G-8082-22): Dated August $2016$. This serves as a core expansion on the Knowledge Elements found in the ACS. It is the responsibility of the Remote Pilot-In- Command (RPIC) to ensure currency by checking $www.faa.gov$.

  • Advisory Circular 107-2A (AC 107-2A): Released on $2/1/2021$. This document provides guidance for Part $107$ compliance, including airman certification, aircraft registration, marking, and airworthiness. It contains mandatory terms like "must" for statutory requirements but does not carry the literal force of law itself.

  • Sectional Aeronautical Charts: The standard tool for Visual Flight Rules (VFR) navigation at a scale of $1:500,000$, named after major cities and used to identify terrain, obstacles, and airspace boundaries.

Controlled Airspace Classifications

Controlled airspace is a generic term covering various classifications with defined dimensions where ATC service is provided. For sUAS operations, the most relevant classes are B, C, D, and E.

• Class B Airspace:

  • Dimensions: Typically extends from the surface ($SFC$) up to $10,000\,\text{feet MSL}$.

  • Characteristics: Surrounds the nation's busiest airports. It consists of a surface area and two or more layers.

  • Visual Metaphor: Resembles an "upside-down wedding cake."

  • Requirements: A remote pilot must obtain ATC authorization prior to operating here.

• Class C Airspace:

  • Dimensions: Extends from the surface up to $4,000\,\text{feet}$ above the airport elevation (noted in $MSL$ on charts).

  • Structure: Includes a surface area with a $5\,\text{nautical mile (NM)}$ radius and an outer circle with a $10\,\text{NM}$ radius stretching from $1,200\,\text{feet}$ to $4,000\,\text{feet}$ above the airport elevation.

  • Operations: Surrounds airports with an operational control tower and radar approach control that see significant traffic.

  • Requirements: Remote pilots MUST receive ATC authorization before entering.

• Class D Airspace:

  • Dimensions: Generally extends from the surface to $2,500\,\text{feet}$ above the airport elevation (noted in $MSL$).

  • Configuration: Individually tailored for airports with operational control towers.

  • Requirements: ATC authorization is mandatory for sUAS operations.

• Class E Airspace:

  • Definition: Controlled airspace not classified as A, B, C, or D. It constitutes a large portion of U.S. airspace to ensure safe separation.

  • Lower Limits: Often starts at $1200\,\text{feet AGL}$. In some areas, it begins at the surface ($SFC$) or $700\,\text{feet AGL}$.

  • Upper Limits: Extends up to, but does not include, $18,000\,\text{feet MSL}$. It also exists above Flight Level ($FL$) $600$ ($60,000\,\text{feet MSL}$).

  • Visual Metaphor: If Class B, C, and D are ice cubes in a glass, Class E is the water that fills in all the gaps around them.

  • Requirements: In most cases, remote pilots do NOT need ATC authorization.

• Class A Airspace:

  • Dimensions: Starts at $18,000\,\text{feet MSL}$ and extends up to $60,000\,\text{feet}$.

  • Note: sUAS do not operate in Class A, and it is not a focus of the Remote Pilot Written Exam.

Uncontrolled Airspace: Class G

• Definition: That portion of the airspace that has not been designated as Class A, B, C, D, or E.

• Vertical Limits: Extends from the surface to the base of the overlying Class E (controlled) airspace.

• Requirements: Remote pilots do NOT need ATC authorization to operate in Class G.

Special Use and Other Airspace

• Special Use Airspace Categories:

  • Prohibited Areas: Flight is purely prohibited for national security or welfare.

  • Restricted Areas: Flight is not hazardous to the aircraft, but the activities within are hazardous. Authorization from the controlling agency is required.

  • Warning Areas: Airspace three nautical miles outward from the coast containing hazardous activities.

  • Military Operation Areas (MOAs): Airspace defined to separate nonhazardous military activities from IFR (Instrument Flight Rules) traffic.

  • Alert Areas: Areas that may contain high volumes of pilot training or unusual types of aerial activity.

  • Controlled Firing Areas (CFA): Areas containing hazardous activities that must be suspended if a spotter/radar identifies an incoming aircraft. These are NOT charted.

• Other Airspace Areas:

  • Military Training Routes (MTR): Low-altitude, high-speed military flight training routes (VR and IR routes).

  • Temporary Flight Restrictions (TFR): Short-term restrictions for events like sports games, VIP travel, or disasters.

  • Parachute Jump Aircraft Operations: Areas where frequent jumps occur.

  • National Security Areas (NSA): Airspace over sensitive ground facilities; pilots may be requested to avoid them.

  • Terminal Radar Service Area (TRSA): Airspace where ATC provides radar services to all VFR and IFR aircraft; the primary airport within is usually Class D.

Airspace Operational Requirements and Limitations

• Weather Minimums (§107.51):

  • Minimum Flight Visibility: Must be at least $3\,\text{statute miles (sm)}$, as observed from the location of the control station.

    • Flight Visibility Definition: The average slant distance from the control station at which unlighted objects (day) or lighted objects (night) can be seen.

    • Distance Conversion: $1\,\text{statute mile (sm)} = 0.87\,\text{nautical miles (nm)}$. $1\,\text{nautical mile (nm)} = 1.15\,\text{statute miles (sm)}$.

  • Minimum Distance from Clouds: The sUA must stay at least $500\,\text{feet}$ below the cloud and $2,000\,\text{feet}$ horizontally from the cloud.

• Night Operations and Lighting (§107.29):

  • Definitions:

    • Evening Civil Twilight: Period from sunset until $30\,\text{minutes}$ after sunset.

    • Morning Civil Twilight: Period from $30\,\text{minutes}$ before sunrise until sunrise.

    • Night: The period between the end of evening civil twilight and the beginning of morning civil twilight.

  • Requirements: To fly at night/twilight, the aircraft must have anti-collision lighting visible for at least $3\,\text{statute miles (sm)}$. The RPIC must also complete updated knowledge/training for night operations.

  • Manned Aircraft Position Lights: Red on the left wingtip, green on the right wingtip, and white on the tail.

• Operations Near Airports:

  • Right-of-Way: The remote PIC must yield right-of-way to all other aircraft, including those on the airport surface.

  • Traffic Patterns: Remote PICs should avoid operating in traffic patterns or published approach corridors.

  • Communication: Local Airport Advisory (LAA) is an advisory service on a dedicated frequency at landing airports when the tower is not operating.

NOTAM System and Flight Service

• NOTAM (Notice to Air Missions): Time-critical aeronautical information that is temporary or was not known early enough for publication.

  • Reasons for NOTAMs: Hazards (air shows, rockets, kite flying), VIP flights, broken obstacle lights, bird flocks (BIRDTAMs).

• Flight Service: Provides pilots with weather, aeronautical info, pilot briefings, flight planning, search and rescue coordination, and online resources at $1800wxbrief.com$.

• Online NOTAM Sources: FAA NOTAM Search, National Flight Data Center (NFDC) portal, and commercial sites like $www.fltplan.com$.

Questions & Discussion

• Q: What are the four (4) types of airspace?

  • A: Controlled, Uncontrolled, Special Use, and Other.

• Q: How far do you need to stay away from an airport when flying your drone?

  • A: It is determined by what airspace one is operating within (Remote Pilot must check specific airspace rules).

• Q: What color is the airport associated with Class B Airspace?

  • A: Blue, signifying it is a controlled airport.

• Q: How do we know what the vertical limit is for Class D Airspace?

  • A: It is enclosed in brackets but is generally $2,500\,\text{feet MSL}$.

• Q: What color is the airport in the center of Class E Airspace to the surface (SFC)?

  • A: Magenta, signifying it is a controlled airport.

• Q: Who grants you permission to fly in a Restricted Area?

  • A: Controlling Facility.

• Q: What airspace is a TRSA associated with?

  • A: Class D.

• Q: What is the primary purpose of the ATC system?

  • A: To prevent collisions between aircraft and organize/expedite the flow of traffic.

• Q: What is the minimum flight visibility required for a control station?

  • A: No less than $3\,\text{statute miles}$.