Every rule in this chapter serves one phrase from § 107.15: condition for safe operation. The section sets the airworthiness bar for a drone plainly — no person may operate a small unmanned aircraft system unless it is in a condition for safe operation, and prior to each flight the remote pilot in command must check the aircraft to determine that it is. Chapter 2 met this as one item on the preflight duty; here it is the foundation the rest of the chapter builds on. Whatever else you inspect or maintain, you are doing it to satisfy this standard.

The duty runs in two directions, not one. Before flight comes the affirmative check under § 107.15(a) — you confirm the aircraft is fit before you launch. But § 107.15(b) reaches into the flight itself: no person may continue flight of the small unmanned aircraft when he or she knows or has reason to know that it is no longer in a condition for safe operation. So the standard is not a gate you clear once at takeoff and forget — it is a continuing obligation to stop flying the moment the aircraft stops being safe, whether that is a warning on your controller or a control surface you can see is failing.

What § 107.15 does not do is tell you how. It fixes the standard but prescribes no checklist, no inspection procedure, and no maintenance schedule — those are left to the operator. The FAA fills the gap with guidance rather than regulation: AC 107-2A devotes a full chapter to how to inspect and maintain a small UAS, and points back to § 107.15 as the requirement all of it serves. That split — a firm rule for the WHAT, FAA guidance for the HOW — is the shape of this whole chapter, so it is worth keeping straight which is which as we go.