Most flights end with nothing to file. A few do not, and the difference is drawn precisely enough that it is worth knowing before you need it rather than after — § 2.5 gave the duty and its two headline numbers, a report within 10 calendar days and a $500 property-damage threshold, but the detail inside each is where a working pilot gets the call right or wrong. Start with the triggers. § 107.9 makes an operation reportable if it involved at least one of two things: serious injury to any person or any loss of consciousness, or damage to property other than the small unmanned aircraft above the threshold. The two run on different terms. The injury trigger is about people and ignores cost entirely — a loss of consciousness is reportable whatever the flight cost anyone. The property trigger is about dollars alone. And damage to your own drone counts under neither; the rule’s concern is harm to people and to other people’s property, not the loss of your own aircraft.

The property threshold is not one test but two, and only one of them has to be satisfied to stay below the line. § 107.9 makes damage to property other than the aircraft reportable unless EITHER the cost of repair, including materials and labor, does not exceed $500; OR, where the property is a total loss, its fair market value does not exceed $500. That distinction does real work, because the two measures can point opposite ways on the same object. An old fence panel might cost $900 to repair properly and be worth $200 standing — a total loss below the line, and no report due. A newer item damaged lightly runs the other way. The figure is $500 in both tests; what changes is whether you are measuring what it costs to put right or what it was worth to begin with.

Three phrases in that sentence do more work than they look like. The clock is stated in “calendar days” and it runs from the operation — ten days after the flight, not ten days after anyone asks you about it. “In a manner acceptable to the Administrator” leaves the reporting channel to the FAA rather than fixing one in the rule, so the form to use is whatever the agency currently accepts. And “serious injury” is the hardest, because Part 107 never defines it. AC 107-2A fills the gap: the FAA reads a serious injury as one qualifying at Level 3 or higher on the Abbreviated Injury Scale (AIS) — an anatomical severity scale used in emergency medicine — and applies that same AIS Level 3 threshold across its other regulations. Read that as guidance on how the agency 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.