When an event is reportable, § 107.9 gives you no later than 10 calendar days after the operation to report it to the FAA, in a manner acceptable to the Administrator. Two phrases in that sentence matter. “Calendar days” is the same whole-day counting as the recurrency clock in Chapter 9 — it runs straight through weekends and holidays, so ten days means ten days. And “in a manner acceptable to the Administrator” means the rule does not lock you to one form or channel; you use the reporting method the FAA currently accepts. Ten days is not a long window, so a reportable event is something to act on, not to sit on.

The property threshold has more inside it than a single figure. Section 107.9 makes damage to property other than the small unmanned aircraft reportable — unless one of two conditions is met: the cost of repair, including materials and labor, does not exceed $500; or, if the property is a total loss, its fair market value does not exceed $500. Either test can put minor damage below the line, and only one has to. So a scratched fence that costs $300 to fix is not reportable, and a destroyed sign worth $2,000 is. The number is the same $500 either way; what changes is whether you measure it by repair cost or by what the property was worth.

The injury trigger leans on a term Part 107 itself never defines: “serious injury.” For its meaning, the FAA’s guidance fills the gap. AC 107-2A explains that a serious injury is one qualifying as Level 3 or higher on the Abbreviated Injury Scale (AIS) — an anatomical severity scale used in emergency medicine — and notes the FAA uses that AIS Level 3 threshold across its other regulations. Read this as guidance on how the FAA interprets the word, not as text sitting in the rule: § 107.9 says “serious injury,” and the advisory circular is where the working definition actually lives.