FAA Part 107 Remote Pilot (UAG)Airspace and Operating RequirementsMedium

On a sectional chart, a remote pilot sees a dashed blue line encircling an airport, compared to a dashed magenta line encircling another nearby airport. What is the key difference between these two symbols?

  1. AThe blue dashed line indicates Class D airspace with an operating control tower, while the magenta dashed line indicates a Class E surface area without a control tower
  2. BThe blue line indicates a heliport, while the magenta line indicates a seaplane base
  3. CThe blue dashed line indicates a restricted area, while the magenta line indicates a prohibited area
  4. DBoth lines represent identical Class G airspace with different visibility requirements
Show answer & explanation

Correct answer: A. The blue dashed line indicates Class D airspace with an operating control tower, while the magenta dashed line indicates a Class E surface area without a control tower

A dashed blue line denotes Class D airspace, which has an operating control tower, while a dashed magenta line denotes a Class E surface area, which extends controlled airspace to the ground at an airport without a control tower (or where the tower is not always staffed).

Why the other options are wrong

  • B. Heliports and seaplane bases have their own distinct symbols unrelated to these lines.
  • C. Restricted and prohibited areas use different chart symbology (hatched blue lines with P/R designators), not dashed circles.
  • D. These are both controlled, not uncontrolled Class G, airspace symbols.

Sectional Chart Airspace Boundary Colors

Dashed blue lines denote Class D airspace (towered airports); dashed magenta lines denote Class E surface areas (typically non-towered or part-time towered airports).

  • Blue dashed circle = Class D, control tower in operation
  • Magenta dashed circle = Class E surface area extending to ground
  • Solid magenta line = Class E starting at 700 ft AGL
  • Solid blue line = Class B; solid magenta band circles = Class C

Memory trick: Blue Dash = Big Tower (D); Magenta Dash = Missing Tower (E surface)

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