Types of Airspace

Aug 11, 2025

Overview

This lecture covers the six classes of airspace relevant to pilots, focusing on the differences between controlled and uncontrolled airspace and their key characteristics.

Types of Airspace

  • There are four main types: controlled, uncontrolled, special use, and other airspace.
  • This lesson focuses on controlled and uncontrolled airspace; special use and other types will be discussed later.

Controlled vs. Uncontrolled Airspace

  • Controlled airspace includes Classes A, B, C, D, and E.
  • In controlled airspace, ATC (Air Traffic Control) may provide radar services and maintain separation, especially for instrument flights.
  • Uncontrolled airspace is Class G, where ATC does not provide radar services and aircraft operate with fewer restrictions.

The Six Classes of Airspace

  • Class A: Ranges from 18,000 feet MSL to FL600 (60,000 feet); requires IFR clearance and not used by VFR pilots.
  • Class B: Surrounds major airports ("busy"); surface to 10,000 feet AGL; shaped like an upside-down wedding cake; ATC clearance required to enter.
  • Class C: Crowded but less busy; typically extends from surface to 4,000 feet AGL; upper level 10-mile radius; ATC communication required before entry.
  • Class D: Surrounds small towered airports; cylindrical, 5-mile diameter; surface to 2,500 feet AGL; must communicate with tower before entry.
  • Class E: "Everywhere else"; usually starts at 1,200 feet AGL and extends to the base of Class A; can start at 700 feet in busy areas; still controlled.
  • Class G: Uncontrolled; near the ground, typically from surface up to controlled airspace above; least restrictive.

Key Terms & Definitions

  • MSL (Mean Sea Level) — Standard reference for altitude.
  • AGL (Above Ground Level) — Height above the actual ground.
  • ATC (Air Traffic Control) — Service managing aircraft traffic for safety.
  • IFR (Instrument Flight Rules) — Flight operations using instruments, often in controlled airspace.
  • VFR (Visual Flight Rules) — Flying by visual navigation, typically less restricted.

Action Items / Next Steps

  • Memorize the six airspace classes and the phonetic alphabet.
  • Review details for Class B airspace in the next lesson.
  • Await future lessons on special use and other airspace types.