Visual Line of Sight Aircraft Operation

14 CFR § 107.31 is the visual line of sight rule in Part 107 Subpart B. Here is the operative federal text, quoted verbatim:

(a) With vision that is unaided by any device other than corrective lenses, the remote pilot in command, the visual observer (if one is used), and the person manipulating the flight control of the small unmanned aircraft system must be able to see the unmanned aircraft throughout the entire flight in order to:

(1) Know the unmanned aircraft's location;

(2) Determine the unmanned aircraft's attitude, altitude, and direction of flight;

(3) Observe the airspace for other air traffic or hazards; and

(4) Determine that the unmanned aircraft does not endanger the life or property of another.

(b) Throughout the entire flight of the small unmanned aircraft, the ability described in paragraph (a) of this section must be exercised by either:

(1) The remote pilot in command and the person manipulating the flight controls of the small unmanned aircraft system; or

(2) A visual observer.

Primary source: eCFR — 14 CFR § 107.31. Guidance: FAA Advisory Circular AC 107-2A.

14 CFR § 107.31 applies to every Part 107 small unmanned aircraft system operation — if you are flying a drone commercially under your remote pilot certificate, this rule binds you on every single flight. The duty falls on three named roles: the remote pilot in command, the person manipulating the flight controls, and the visual observer (if one is used). Recreational flyers operating under 49 U.S.C. § 44809 (the Exception for Limited Recreational Operations) have a separate, parallel visual line of sight requirement, but 14 CFR § 107.31 is the Part 107 rule and it is not optional unless you hold a waiver.

14 CFR § 107.31 is built around four capabilities you must maintain with unaided vision throughout the entire flight. If you cannot do all four with your own eyes (or corrective lenses), you are not legally maintaining visual line of sight. Here is the extractable breakdown:

No — under 14 CFR § 107.31 you may not use a first-person-view (FPV) camera feed or a monitor to satisfy the visual line of sight requirement. The rule states the vision must be "unaided by any device other than corrective lenses." Corrective lenses means ordinary glasses or contact lenses. FAA Advisory Circular AC 107-2A draws one practical line: a vision aid such as binoculars may be used momentarily to enhance situational awareness, but it cannot be the way you maintain visual line of sight — and FPV devices never satisfy the requirement at all:

VLOS must be accomplished and maintained by unaided vision, except vision that is corrected by the use of eyeglasses (spectacles) or contact lenses. Vision aids, such as binoculars, may be used only momentarily to enhance situational awareness... First person view devices may be used during operations, but do not satisfy the VLOS requirement.

You may fly FPV for the fun of it or for the camera shot — what you cannot do is let the FPV feed replace a human keeping eyes on the actual aircraft. The practical answer in the field: if you want to fly FPV under Part 107, you put a visual observer on the aircraft (under 14 CFR § 107.33) so a real person maintains unaided visual line of sight while you stare at the goggles.

14 CFR § 107.31 tolerates brief, momentary losses of sight — the FAA does not read "throughout the entire flight" to mean your eyeballs are welded to the aircraft every fraction of a second. FAA guidance recognizes that the person maintaining visual line of sight may lose sight of the small unmanned aircraft for brief moments, either because the aircraft momentarily passes behind an obstruction, or because the person needs to scan the airspace or glance down at the control station. The key word is momentary: a quick glance is fine; flying the drone behind a building and around the corner where you cannot see it is a violation.

14 CFR § 107.31 lets a visual observer hold the visual line of sight on your behalf, and 14 CFR § 107.33 governs how that works. A visual observer is a person the remote pilot in command designates to see the small unmanned aircraft and help see-and-avoid other aircraft and hazards. Under § 107.31(b), the visual line of sight duty can be exercised by either the remote pilot in command plus the person manipulating the controls, or by a visual observer — but 14 CFR § 107.33 requires that the remote pilot in command, the person manipulating the controls, and the visual observer maintain effective communication with each other at all times. The visual observer does not get to be a mile away with a radio — they must be positioned to actually see the aircraft and relay what they see to you immediately.

Yes — 14 CFR § 107.31 is listed in 14 CFR § 107.205 as a regulation subject to waiver, so the FAA can issue a Certificate of Waiver authorizing beyond visual line of sight (BVLOS) flight. To get one, you must show the Administrator the proposed operation can be conducted safely under the terms of the waiver — typically by demonstrating a detect-and-avoid capability, command-and-control link reliability, and a method to continuously know the aircraft's location, attitude, altitude, and direction without seeing it. One statutory limit: under § 107.205(c), no waiver of § 107.31 will be issued to allow the carriage of the property of another by aircraft for compensation or hire. Historically the 14 CFR § 107.31 BVLOS waiver has been among the hardest Part 107 waivers to obtain.

The most common 14 CFR § 107.31 mistake is treating the camera feed as visual line of sight. New Part 107 pilots get a beautiful 4K downlink on the controller, the drone shrinks to a dot, and they keep flying by the screen because "I can see it right there." That is exactly the failure mode the rule was written to prevent — the screen tells you what the camera sees, not where the aircraft is relative to a crop duster or a power line you never looked up to check. Visual line of sight under 14 CFR § 107.31 is about your eyes on the actual aircraft in the actual sky, scanning for the traffic and hazards the camera will never show you.

14 CFR § 107.31 is the keystone of Part 107 Subpart B because almost every other operating rule assumes you can see the aircraft. You cannot yield the right of way under 14 CFR § 107.37 if you cannot see the traffic you are supposed to yield to. The night operation rule, 14 CFR § 107.29, does not relax visual line of sight — you must still maintain it after dark (which is why an anti-collision light is required). And 14 CFR § 107.51 operating limitations (groundspeed, altitude, visibility, cloud clearance) only function if you can actually observe the aircraft to know you are within them. Visual line of sight is the thread that ties the whole subpart together.