RegulationsDifficulty 2/5
A remote pilot needs to inspect a 900-ft communications tower. Under Part 107, what is the maximum altitude the sUAS may fly while within a 400-ft radius of the tower?
- A1,300 ft AGL
- BAny altitude, because towers are exempt
- C400 ft AGL
- D900 ft AGL
Show answer and rationale
Correct: A. §107.51 limits flight to 400 ft AGL unless the aircraft stays within a 400-ft radius of a structure, in which case it may fly up to 400 ft above the structure's immediate uppermost limit: 900 + 400 = 1,300 ft AGL. Airspace authorization may still be required.
- C — 400 ft AGL is the general limit, not the structure exception.
- D — The limit is 400 ft above the top of the structure, not level with it.
- B — There is no blanket exemption; the 400-ft-above-structure rule applies.