Obstruction numbers
When an obstruction is labeled with an elevation and a parenthetical height, learn to distinguish the top elevation above mean sea level from the height above local ground.
START HERE
Eight chart-reading habits that make the rest easier.
1
Start with the legendDo not guess at a symbol. The FAA chart legend is the reference for colors, boundaries, airport symbols, obstructions and other chart conventions.
2
Know AGL vs MSLAGL is height above the ground below you. MSL is referenced to mean sea level. Chart elevations and airspace labels can use different vertical references, so read the context.
3
Recognize common boundariesSolid blue is commonly associated with Class B boundaries, solid magenta with Class C, dashed blue with Class D, and dashed magenta with Class E beginning at the surface.
4
Read Class E shading carefullyA fuzzy magenta vignette commonly shows Class E beginning at 700 feet AGL; fuzzy blue commonly shows Class E beginning at 1,200 feet AGL.
5
Look for obstructionsTowers, antennas, terrain and other obstacles matter to site assessment even when your mission is far below manned-aircraft cruising altitudes.
6
Airports still matter in Class GAn airport can have active traffic even where prior ATC authorization is not required. You still must avoid interfering with other aircraft.
7
A chart is not an authorizationA sectional helps you understand the airspace. It does not itself grant permission to operate in controlled airspace.
8
Check current informationUse a current chart edition and check current NOTAMs, TFRs and authorization requirements before an actual operation.
Airspace floors and ceilings
Do not assume the airspace at the surface is the same as the shelf above it. Read the lower and upper boundaries for the exact place and altitude you intend to operate.
Controlled-airspace authorization
If your operation will be in controlled airspace that requires Part 107 authorization, use the appropriate FAA authorization process such as LAANC where available.
Charts change. Use current FAA chart products and current operational information for real flights. This guide is an introduction, not a substitute for the current chart legend or an airspace authorization.