The five-step chart method
- Locate the exact operation: coordinates, landmarks, airport relationship, and terrain elevation.
- Identify the airspace boundary: color, line style, floor, ceiling, and shelf.
- Convert altitude correctly: planned AGL plus terrain elevation when an MSL comparison is needed.
- Check airport and special-use hazards: runways, traffic patterns, heliports, TFRs, restricted areas, MOAs, and NOTAMs.
- Choose the approval path: Class G with no controlled-airspace authorization, LAANC, DroneZone, or a different mission plan.
Boundary recognition drill
| You see | Read it as | Next question |
|---|---|---|
| Solid blue rings | Class B shelves | What are the floor and ceiling at the site? |
| Solid magenta rings | Class C shelves | Is the site under the inner or outer shelf? |
| Dashed blue | Class D to the surface | Is LAANC available and what is the grid? |
| Dashed magenta | Class E to the surface | Authorization is still required |
| Faded magenta/blue | Class E begins above the surface | Will the planned altitude enter it? |
Facility Map trap
A grid value is not permission. It is a value the FAA uses to support authorization decisions. A requested altitude at or below the value may be processed rapidly through LAANC when the airport participates; the approved authorization and its conditions still control.
Practice calculations
AGL to MSL: terrain 1,250 ft MSL + planned 300 ft AGL = approximately 1,550 ft MSL.
Shelf check: if a Class C shelf floor is 1,600 ft MSL and terrain is 1,250 ft MSL, the shelf begins about 350 ft AGL at that location. A 400-ft AGL flight would enter controlled airspace.