According to 14 CFR Part 107, the remote pilot in command (PIC) of a small unmanned aircraft planning to operate within Class C airspace
Why →
Class C airspace requires prior ATC authorization per § 107.41. Visual observers are never required by Part 107 (though recommended), and flight plans are a manned aviation concept. Remote pilots do not file flight plans. Authorization is the mandatory requirement.The trap →
Visual observers are optional, not mandatory, in Part 107. You can fly solo as long as you maintain VLOS. Flight plans don't exist in the Part 107 framework. The single requirement entering Class C is ATC authorization.SOURCE → 14 CFR § 107.41, FAA UAG Sample Question 3CHECKED APR 21ACS I.B.K1MED