Non-designated Class E (floor at 700 ft AGL).

• The drone’s 400 ft AGL ceiling sits beneath the Class E floor → you’re in Class G (uncontrolled) from the ground up to 700 AGL.
• Example numbers: terrain 398’ MSL, drone at 400’ AGL = 798’ MSL — still below the 700 AGL Class E floor.
• Practical upshot: under shaded-magenta (non-designated) E, sUAS pilots almost never cross into Class E, so no authorization is needed.