Preflight Inspection Procedures
Before a remote pilot ever raises a throttle or taps "arm" on a controller, two Part 107 regulations already apply: one says the aircraft has to actually be safe to fly, and the other spells out exactly what the remote pilot in command must check and do before every single flight to find that out. This lesson covers 14 CFR 107.15 and 14 CFR 107.49 in full — the legal foundation for everything else in this module — and walks through how a remote pilot turns those regulations into an actual, repeatable preflight routine.
What the regulation says, in full
14 CFR 107.15 is short, but it is the single most important regulation in this entire module — every other lesson exists to explain how a remote pilot actually satisfies it. It reads, in full:
14 CFR 107.15(b) — The remote pilot in command must discontinue the flight when he or she knows or has reason to know that the small unmanned aircraft system is no longer in a condition for safe operation.
Notice the structure: paragraph (a) creates two duties — the aircraft must actually be safe, and the remote pilot must inspect it before flight to confirm that. Paragraph (b) creates a third, separate duty that continues into the flight itself: if the remote pilot learns or should have learned that the aircraft is no longer safe, once airborne, the flight must be discontinued. This is not a one-time, preflight-only obligation. It runs from before takeoff through the entire flight.
Why this regulation is written as a performance standard, not a checklist
Part 107 covers an enormous range of aircraft — a sub-1-pound camera drone and a much larger, more complex mapping platform can both be operated under the same rule. Because of that variety, 107.15 does not specify what to inspect or how; it simply requires the outcome (a safe aircraft) and assigns the responsibility for achieving it (the remote pilot in command). This is why 14 CFR 107.49, covered next, exists as a companion regulation: it fills in specific, mandatory preflight actions that apply to every operation regardless of aircraft type, while still leaving room for aircraft-specific details to come from the manufacturer (covered in Lesson B of this module).
“Knows or has reason to know” — the standard in 107.15(b)
The phrase “knows or has reason to know” sets an objective standard, not just a subjective one. It is not enough to claim ignorance if a reasonable remote pilot, paying proper attention, would have recognized the aircraft was no longer safe — a warning light, an unusual vibration, a control input that isn't responding correctly, a battery voltage reading that has dropped further than expected. A remote pilot who notices a problem and keeps flying anyway is in violation, and so is a remote pilot who should have noticed a problem (because it was observable through the telemetry or the aircraft's behavior) but wasn't paying attention.
- Actual knowledge: the remote pilot directly observes a problem — an error message, a visible piece of damage, an alarming flight characteristic.
- Constructive knowledge (“reason to know”): the information needed to recognize the problem was available — on a telemetry screen, in an audible alert, in the aircraft's visible behavior — whether or not the remote pilot actually looked at it in the moment.
Worked scenario: a mid-flight decision under 107.15(b)
You are flying a rooftop solar panel inspection when your ground control station displays a sudden battery voltage sag well outside the normal discharge curve for that pack, alongside a compass calibration warning that appeared partway through the flight. Nothing has visibly gone wrong with the aircraft's flight path yet. Under 107.15(b), this is exactly the situation the regulation addresses: you now have reason to know the aircraft may no longer be in a condition for safe operation, and the correct action is to discontinue the flight — land promptly and safely — rather than continue the inspection and hope the readings resolve themselves.
Eight physical inspection points a remote pilot should check before every flight to satisfy 14 CFR 107.15's condition-for-safe-operation duty.
View LargerWhat the regulation says, in full
Where 107.15 sets the general standard, 14 CFR 107.49 spells out five specific, mandatory things the remote pilot in command must do before every flight. It reads, in full:
(a) Assess the operating environment, considering risks to persons and property in the immediate vicinity both on the surface and in the air. This assessment must include:
(1) Local weather conditions;
(2) Local airspace and any flight restrictions;
(3) The location of persons and property on the surface; and
(4) Any other ground hazards.
(b) Ensure that all persons directly participating in the small unmanned aircraft system operation are informed about operating conditions, emergency procedures, contingency procedures, roles and responsibilities of each participant, and potential hazards;
(c) Ensure that all control links between ground control station and the small unmanned aircraft are working correctly;
(d) If the small unmanned aircraft is powered, ensure that there is enough available power for the small unmanned aircraft system to operate for the intended operational time; and
(e) Ensure that any object attached or carried by the small unmanned aircraft is secure and does not adversely affect the flight characteristics or controllability of the aircraft.
107.49(a): assessing the operating environment
This is the broadest of the five duties, and it is deliberately not limited to the aircraft itself — it is about the environment the flight will happen in. The four named sub-elements cover weather (is it within safe operating limits for this aircraft and this mission), airspace and flight restrictions (do you have any needed authorization, and are there active TFRs), people and property on the surface (who and what is in the area the aircraft will fly over or near), and other ground hazards (power lines, towers, uneven terrain for launch and recovery, wildlife). This assessment happens every time, immediately before the specific flight — a general familiarity with the area from a previous visit does not substitute for reassessing current conditions.
107.49(b): briefing participants
Any operation involving more than just the remote pilot alone — a visual observer, a person manipulating the controls, ground crew, or clients present on site — requires briefing every participant on operating conditions, emergency and contingency procedures, each person's specific role and responsibilities, and potential hazards. This briefing has to happen before the flight, not be assumed from a general understanding of how the operation usually runs; conditions, hazards, and roles can all change from one job site to the next.
107.49(c), (d), and (e): the aircraft-specific checks
The final three elements are specific to the aircraft and its equipment. Paragraph (c) requires confirming the control link between the ground control station and the aircraft is actually working — not just powered on, but responding correctly. Paragraph (d) requires confirming there is enough available power (battery charge, fuel, whatever applies) for the intended operational time, with a safety margin, not just enough to get airborne. Paragraph (e) applies specifically to any object attached to or carried by the aircraft — a camera payload, a delivery package, a sensor — requiring that it is secured and does not degrade the aircraft's flight characteristics or controllability.
- Control link check: verify responsiveness on all control axes and any critical secondary functions (gimbal, return-to-home trigger) before takeoff, not just a power-on confirmation.
- Power margin check: plan for enough power to complete the mission plus a safe reserve for contingencies, not exactly enough to land with zero margin.
- Attached-object check: confirm secure mounting and evaluate whether the added weight or drag noticeably changes handling before committing to the full mission profile.
| Regulation | What it requires | When it applies | Notes |
|---|---|---|---|
| 14 CFR 107.15(a) | Aircraft must be in a condition for safe operation; remote pilot must inspect before flight | Before every flight | General performance standard — no specific inspection items listed |
| 14 CFR 107.15(b) | Discontinue flight if aircraft is no longer safe | During flight, once the condition is known or should be known | Objective standard: “knows or has reason to know” |
| 14 CFR 107.49(a) | Assess weather, airspace, people/property, and ground hazards | Before every flight | Covers the environment, not just the aircraft |
| 14 CFR 107.49(b)–(e) | Brief participants; verify control link, power, and secure attachments | Before every flight | Specific, mandatory items that apply regardless of aircraft type |
Running a Compliant Preflight Inspection
A practical sequence that satisfies both 14 CFR 107.15 and 14 CFR 107.49 on any Part 107 operation.
Assess the operating environment first, before touching the aircraft
Check current weather against the aircraft's operating limits, confirm airspace status and any needed authorization, and walk the site to identify people, property, and ground hazards.
Brief every participant
Cover operating conditions, emergency and contingency procedures, individual roles, and potential hazards with any visual observer, second controller operator, or on-site personnel involved in the operation.
Physically inspect the airframe
Check propellers for cracks, chips, or looseness; inspect the airframe and arms for damage; confirm the battery is properly seated and latched; check the gimbal, camera, and any sensors for secure mounting.
Verify the control link and all critical functions
Power on the aircraft and controller, confirm the link connects and holds, and test responsiveness on all control axes plus any critical secondary function (gimbal control, return-to-home) before takeoff.
Confirm available power for the full intended flight
Check battery charge or fuel state against the planned mission duration plus a safe reserve, accounting for wind, temperature, and payload effects on consumption.
Confirm any carried object is secure
If carrying a payload beyond the standard camera — a sensor, a delivered item — verify secure attachment and briefly assess whether it changes the aircraft's handling before committing to the full mission.
Monitor continuously once airborne
The 107.15(b) duty to discontinue an unsafe flight runs through the entire operation — keep watching telemetry, aircraft behavior, and the surrounding environment, not just at the start.
| Mistake | Why it happens | Correct understanding | Regulation / source |
|---|---|---|---|
| Skipping the physical inspection because “it flew fine yesterday” | Treating the aircraft's condition as static between flights | 107.15 requires an inspection before every flight, not periodically — damage or wear can occur between flights even in storage. | 14 CFR 107.15(a) |
| Assuming a successful control link connection means the whole aircraft is ready | The link is the most visible confirmation on the controller screen | 107.49(c) requires confirming the link works correctly, but it is only one of five separate preflight duties — environment, briefing, power, and attachments are separate checks. | 14 CFR 107.49 |
| Continuing a flight after noticing an anomaly because the aircraft “still seems to be flying fine” | No visible crisis yet, so it feels premature to land | 107.15(b)'s “knows or has reason to know” standard requires discontinuing the flight once a safety-relevant condition is recognized, not waiting for a visible failure. | 14 CFR 107.15(b) |
| Checking weather once in the morning and treating it as covering the whole day's flights | Convenience — rechecking feels redundant | 107.49(a) requires assessing conditions before flight; weather, especially wind and visibility, can change meaningfully within hours. | 14 CFR 107.49(a) |
| Skipping the participant briefing when working with a familiar, experienced visual observer | Assuming shared understanding from past operations | 107.49(b) requires briefing on this operation's specific conditions and hazards, which can differ from the last job even with the same team. | 14 CFR 107.49(b) |
Does 14 CFR 107.49 require a written checklist?
No. The regulation requires performing the five listed actions before flight, but it does not mandate a specific written form or checklist. Using a written or app-based checklist is strongly recommended as good practice because it helps ensure nothing is missed, but it is not itself a regulatory requirement.
Does 107.15 specify how often to inspect the aircraft?
Yes, implicitly: before every flight. The regulation does not describe a periodic schedule (weekly, monthly, after a set number of flight hours) — it requires an inspection prior to each individual flight, every time.
What should I do if I notice a problem mid-flight but I'm not sure it's serious?
14 CFR 107.15(b)'s standard is “knows or has reason to know” the aircraft is no longer safe. If an observed condition genuinely gives you reason to question the aircraft's safety, the correct response is to discontinue the flight and land promptly rather than continue and hope the issue resolves itself.
Does 107.49's participant briefing requirement apply if I'm flying completely alone?
107.49(b) specifically addresses briefing “all persons directly participating” in the operation. If you are the only person involved, there is no other participant to brief, but the other four elements of 107.49 — environment assessment, control link, power, and secure attachment — still apply in full.
Test Your Knowledge
Answer the questions below to check your understanding. Every answer can be found in the lesson above.