One of the most fundamental rules governing small unmanned aircraft systems (sUAS) under Title 14 CFR Part 107 is the requirement to keep your drone within visual line of sight (VLOS) at all times during flight. This single requirement shapes nearly every operational decision a remote pilot makes — from how far to fly, to where to stand, to whether a visual observer is needed. Understanding exactly what VLOS means, why the FAA mandates it, and how it plays out in real operations is essential both for passing the Part 107 knowledge test and for flying legally and safely.
VLOS is not simply about being able to see the drone on a camera screen. It has a specific regulatory definition that demands direct, unaided human vision. Let's unpack every layer of that requirement.
What Visual Line of Sight Actually Means
Under 14 CFR §107.31, the remote pilot in command (RPIC), the person manipulating the controls, or a visual observer must be able to see the sUAS at all times during flight. Critically, this must be done with unaided vision — meaning no binoculars, spotting scopes, or zoom cameras may substitute for the naked eye. Corrective lenses such as eyeglasses and contact lenses are explicitly allowed because they correct vision to normal rather than magnify beyond it.
The regulation requires that the person maintaining VLOS be able to determine the aircraft's location, altitude, attitude, and direction of flight, and assess whether the aircraft is about to create a hazard to other aircraft, people, or property. This is an important distinction: seeing a blinking dot in the sky is not sufficient if you cannot tell which way the drone is pointed, how fast it is descending, or whether it is drifting toward a crowd. Real VLOS means meaningful situational awareness, not just a faint visual contact.
Who Must Maintain VLOS
The regulation places VLOS responsibility on a specific chain of people. The remote pilot in command has overall responsibility for the flight, but §107.31 allows the VLOS duty to be performed by a visual observer (VO). A VO is a person specifically designated by the RPIC whose sole job is to watch the aircraft and the surrounding airspace and communicate hazards to the RPIC. The RPIC may be looking at a ground control station screen or controller while the VO keeps eyes on the drone.
However, even when a VO is used, the RPIC remains directly responsible for the safe outcome of the flight. The VO does not hold a Part 107 certificate — they are a tool the RPIC uses to extend or manage VLOS. The RPIC and VO must maintain effective communication at all times, and that communication must be sufficient to allow the RPIC to react promptly to any hazard the VO reports.
It is also worth noting that first-person view (FPV) goggles or cameras alone do not satisfy VLOS. A pilot wearing FPV goggles and watching the drone's camera feed has no meaningful view of the surrounding airspace and cannot see other aircraft approaching from behind or from the sides. FPV flight is legal under Part 107 only if a visual observer with unaided sight of the drone is simultaneously present and in communication with the FPV pilot. The FPV pilot is the person manipulating the controls; the VO provides the required visual contact.
The BVLOS Exception and the Waiver Process
Beyond visual line of sight (BVLOS) operations — flying a drone beyond the range of unaided human vision — represent one of the most commercially valuable but heavily regulated capabilities in the UAS industry. Under the standard Part 107 rules, BVLOS is simply not permitted without a waiver. Section 107.200 authorizes the FAA to issue waivers to specific provisions of Part 107, including §107.31, if the applicant can demonstrate that the proposed operation can be conducted safely.
Obtaining a BVLOS waiver requires the applicant to submit a detailed safety case to the FAA showing how the operation will detect and avoid other aircraft, how command and control links will be maintained, how the operation will avoid populated areas or non-participating persons, and what redundancies exist in case of equipment failure. The FAA evaluates these applications case by case, and approval is not guaranteed. For the knowledge test, the key takeaway is that BVLOS requires an FAA waiver, not simply a certificate or permission from a local authority.
Why VLOS Exists — The Safety Rationale
The VLOS requirement reflects a core principle of aviation safety: see and avoid. Manned aviation has relied on the see-and-avoid concept for decades as the primary method of collision avoidance in visual meteorological conditions (VMC). When a remote pilot can see their drone, they can also scan the surrounding airspace for manned aircraft, birds, powerlines, and other hazards, and they can immediately maneuver to avoid a conflict.
Without VLOS, a drone operating in the national airspace system (NAS) becomes a largely invisible hazard to manned aircraft. Manned aircraft are not required to detect or avoid drones, and the transponder or ADS-B equipment fitted to most small UAS provides little or no protection. VLOS keeps the remote pilot in a position to act as the collision-avoidance system for their own aircraft.
The unaided vision requirement also prevents a false sense of security from technology. A camera mounted on a drone can show an excellent picture of what is in front of the drone while providing zero awareness of a helicopter approaching from behind or above. Unaided human eyes, when scanning properly, provide a roughly 200-degree horizontal field of view and allow detection of movement that a fixed camera would miss entirely.
Key Numbers and Rules
- §107.31 — The primary VLOS rule in Part 107; requires unaided visual contact throughout the flight.
- Unaided vision — Corrective lenses are allowed; binoculars, spotting scopes, and FPV cameras alone are NOT sufficient to meet VLOS.
- Visual Observer — May maintain VLOS on behalf of the RPIC, but the RPIC retains full legal responsibility for the operation.
- FPV flight — Only legal under Part 107 if a VO simultaneously maintains unaided VLOS and communicates with the FPV pilot.
- BVLOS waiver — Required under §107.200 to conduct operations beyond unaided visual range; there is no self-certification path for BVLOS under standard Part 107.
- Multiple aircraft — A single remote pilot may not operate more than one sUAS at a time; operating multiple aircraft simultaneously also requires a waiver (§107.35).
Practical VLOS Judgment in the Field
In practice, the maximum distance at which a pilot can maintain meaningful VLOS depends on the size of the drone, lighting conditions, background contrast, and individual visual acuity. A large industrial hexacopter might be visible and distinguishable at 1,500 feet, while a small racing quad might be impossible to orient at 400 feet against a pale sky. There is no single FAA-mandated maximum distance — the standard is whether the required situational awareness can actually be maintained.
Remote pilots should develop habits that support VLOS. Standing in an open area with a clear sky background makes the drone easier to track. Choosing bright-colored or high-visibility frames helps. Flying with a VO in complex environments — near obstacles, in busy airspace, or during commercial film operations — distributes the visual workload so the RPIC can manage the aircraft while the VO watches for traffic.
Weather and visibility also matter. Part 107 requires a minimum ground visibility of 3 statute miles from the control station (§107.51), but even legal visibility may not be sufficient to maintain VLOS if haze or glare degrades contrast. A remote pilot should continuously assess whether VLOS is actually being maintained throughout a flight, not just at takeoff.
Common Test Traps
- FPV = VLOS myth: A common wrong answer assumes that an FPV camera feed satisfies the VLOS requirement on its own. It does not — a VO providing unaided sight is always required when the RPIC is using FPV goggles.
- Binoculars are allowed: Wrong. Binoculars and spotting scopes may help locate a lost drone but do NOT satisfy the VLOS requirement because they are magnifying aids, not corrective lenses.
- Visual observer = certified pilot: The VO does not need a Part 107 certificate; the RPIC designates them and maintains responsibility for the flight.
- BVLOS just needs ATC permission: BVLOS requires an FAA waiver under §107.200, not simply air traffic control clearance or airspace authorization.
- Distance limit confusion: Part 107 sets no specific maximum distance in feet or miles for VLOS operations. The standard is whether the required situational awareness can be maintained with unaided vision — a judgment call that can vary by aircraft size and conditions.