Section 107.31 Visual line of sight aircraft operation.
(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.
My Commentary on Section 107.31 Visual line of sight aircraft operation.
Pay attention carefully to the regulations. They do allow for FPV racing under 107 provided you have a visual observer.
Currently, 14 CFR 91.113(b) imposes a generally applicable requirement that, during flight, “vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft.” This see-and-avoid requirement is at the heart of the FAA’s regulatory structure, mitigating the risk of aircraft colliding in midair. This requirement is currently satisfied in manned-aircraft operations by a pilot on board the manned aircraft looking out from inside the aircraft to see whether other aircraft are on a collision course with the pilot’s aircraft. However, the person controlling the small UAS cannot see other aircraft in the same manner because he or she is not inside the aircraft. That is why Public Law 112-95, section 333(b)(1) requires the FAA to consider, as a critical factor in this rulemaking, whether a small UAS operation is conducted “within visual line of sight.”
To address this issue, the NPRM proposed that the operator of the small UAS must always be capable of maintaining visual line of sight of the small unmanned aircraft unaided by any technology other than glasses or contact lenses. The NPRM also proposed creating a new position of visual observer to assist the operator in maintaining visual line of sight. Under that proposal, if a visual observer is used in the operation, then the visual observer could watch the small unmanned aircraft instead of the operator. However, if a visual observer was not used in the operation, then the operator would have to exercise his or her visual-line-of-sight capability to watch the small unmanned aircraft.
As proposed in the NPRM, the operator or visual observer would have to be able to see the small 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; (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. The NPRM also proposed that even if a visual observer is used, at all times during flight, the small unmanned aircraft must remain close enough to the operator for the operator to be capable of seeing the aircraft with vision unaided by any device other than corrective lenses. For the reasons discussed below, this rule will make three changes to the NPRM visual-line-of-sight framework but will otherwise finalize it as proposed. First, because of the change in the small UAS crewmember framework (discussed in the previous section of this preamble), this rule will replace the operator with the person manipulating the flight controls of the small UAS and the remote pilot in command, who in many instances will be the same person. Second, this rule will make clarifying amendments to the regulatory text. Third, this rule will make the visual-line-of-sight requirement waivable.
A number of commenters expressed concern about whether the visual-line-of-sight framework proposed in the NPRM would sufficiently mitigate risk. Foxtrot Consulting, the Air Medical Operators Association, the Professional Helicopter Pilots Association, and several individuals asserted that the unaided human eye is not adequate to see and avoid other aircraft. Additionally, these commenters argued that the small unmanned aircraft will be too small to be seen by a manned-aircraft pilot, and, with no lighting requirement, the unmanned aircraft may be all but invisible, particularly in minimum visual-flight-rules (VFR) conditions.
Similarly, commenters, including A4A and several individuals, questioned whether small UAS remote pilots would be capable of perceiving potential conflicts and responsibly complying with the principle of “see and avoid.” These commenters asserted that since small UAS are unmanned, they are inherently unable to comply with current “see and avoid” requirements of 14 CFR 91.113(b) in visual flight conditions. The commenters argued that a remote pilot may not have sufficient perceptual accuracy to determine whether or not a small unmanned aircraft is on a collision course with another aircraft. The Human Factors and Ergonomics Society suggested that the FAA conduct a systematic, scientific study of factors that affect an observer’s ability to estimate altitude and airspeed. A joint comment from Skycatch, Clayco, AECOM, and DPR Construction suggested that rather than relying merely on an operator’s eyesight, the FAA should employ a risk-based approach to allowing operations.
The FAA recognizes that one of the issues with small UAS is that a person on the ground cannot see and avoid other aircraft in the same manner as a pilot who is inside a manned aircraft. The FAA also agrees that due to relative size of aircraft, a remote pilot will most likely be able to see and avoid a manned aircraft before the manned-aircraft pilot will see the small UAS. This issue is not unique to small UAS; manned vehicles currently in the NAS range from a few hundred pounds to 1.4 million pounds and pilots have similar challenges regarding see-and-avoid. The FAA has mitigated the risk in this rule through operational parameters that reduce the risk of a midair collision. Because of the limits on their access to airspace that is controlled or at higher altitudes, small unmanned aircraft will avoid busy flight paths and are unlikely to encounter high-speed aircraft that would be difficult for the remote pilot to see-and-avoid. Additionally, as discussed below, this rulewill also specify minimum requirements for weather and visibility to maximize the remote pilot’s ability to see incoming manned aircraft and avoid a collision with those aircraft. The FAA disagrees with the notion that remote pilots operating under the visualline-of-sight framework of this rule will be incapable of perceiving potential conflicts with other aircraft. In many cases, the remote pilot’s perspective from the ground may be better than the perspective of a pilot onboard an aircraft because the remote pilot is not confined to a cockpit with vision obscured by the fuselage or flight control surfaces. The remote pilot is thus able to observe airspace 360° around the unmanned aircraft, including airspace above and below. Thus, the person maintaining visual line of sight will be able to see potential conflicts with manned aircraft. Furthermore, as discussed below, this rule will require the small unmanned aircraft to always yield the right of way to other users of the NAS.
Several commenters, including the News Media Coalition, NAMIC, and Drone Labs, LLC objected to the proposed limitation that visual line of sight must be maintained unaided by any technology other than corrective lenses. These commenters suggested that the rule allow the use of first-person-view (FPV) technology, arguing that available technologies have advanced to the point that operators can use FPV to meet or exceed the visual-line-of-sight requirements proposed in the NPRM. United Parcel Service (UPS) asserted that FPV technology has been safely and effectively used in the UAS hobbyist community for many years.
The Drone User Group Network stated that FPV operations should be permitted with mandatory use of a spotter. Predesa said that a wearable heads-up display that combines the FPV from the small UAS and a wider-angle view from a ground camera located near the operator may provide the same risk mitigation as that afforded by the visual observer. The University of Washington and a joint submission by the State of Nevada Governor’s Office of Economic Development, the Nevada Institute for Autonomous Systems, and the Nevada FAA-designated UAS Test Site said that current FPV technologies offer a wider field of vision than the human eye. DJI stated that existing technology already provides superior orienting abilities over visual observers. One individual referenced a 2004 test conducted by NASA that indicated that FPV cameras mounted on pan-tilt gimbals can be used to scan virtually the entire airspace. This commenter also acknowledged FPV limitations “…such as the field-of-view of the camera (too wide provides less detail, too narrow limits situational awareness), total field-ofregard, clarity, and range of the transmitted video.”
Some commenters, including the University of California, the National Roofing Contractors Association, and, AIA, stated that use of a FPV device should be allowed to meet the visual-line-of-sight requirements of this rule under certain circumstances, such as when other navigation and control technologies are available in the vehicle (e.g., autonomous flight, onboard geo-fencing, sense-and-avoid technology) and mitigating measures are required (e.g. altitude, weight, location, and speed limitations, location or the use of visual observers). Exelon and Skyview Strategies said that FAA should include specific criteria or standards under which the technology would be allowed to be used, either alone or in conjunction with other technologies and procedures.
Other commenters supported the NPRM’s proposed limitation on the use of technology to maintain visual line of sight. Commenters, including NAAA, ALPA, SkySpecs, and the U.S. Hang Gliding & Paragliding Association, pointed out that FPV technology remains unproven and unreliable and the FPV field of view is limited. ALPA specifically stated that “[t]he use of an on-board camera cannot replace the awareness provided by direct observation by the operator/pilot or designated visual observer.” FPV technology works by transmitting video feed from a camera carried by the small unmanned aircraft to the control station. The problem with relying on FPV technology for the ability to see and avoid other aircraft in the NAS is that an FPV camera’s field-of-view is currently either very limited (narrow-field-of-view lens ≤ 30 degrees horizontal and 10 degrees vertical) or distorted (usually fish-eyed if using a widefield-of-view lens). A narrow field-of-view lens poses a safety issue because it restricts the user’s peripheral vision, which is used to detect incoming aircraft or other objects that may pose a safety hazard. A wide-field-of-view lens poses a safety issue because it reduces the angular resolution available to the user, making it necessary for an object in the monitor to be closer to the camera before it covers enough pixels for the remote pilot to be able to detect it. In addition, FPV relies on a video transmitter to broadcast the image to the remote pilot. These transmitter/receiver units are commonly available in several frequency bands from 900 MHz to 5.8 GHz, each frequency band having distinct advantages and disadvantages as to range, susceptibility to interference, and ability to penetrate foliage. As of this writing, the FAA does not have validated data to indicate whether FPV can be used to safely conduct operations beyond visual line of sight and if so, what FPV performance specifications are required to support those operations. The FAA acknowledges that FPV cameras have been used by hobbyists for many years and that the technology is advancing rapidly within the growing industry. However, as discussed previously, FPV cameras have technical limitations and the FAA does not possess the data necessary to support a regulatory standard at this time.
The FAA also acknowledges the comments concerning technological or operational mitigations that could be used in conjunction with FPV. However, those mitigations have significant potential shortcomings that need to be explored prior to allowing them to be used in the NAS. For example, one of the commenters suggested the use of pan-tilt camera systems to mitigate for the shortcomings in FPV technology. While a pan-tilt system can allow a narrow-angle camera to scan a wider field of view, the system is still significantly inferior to the peripheral vision of the human eye, which can discern movement across the entire field of view, approaching 180 degrees in normal vision. Another commenter suggested the use of a wearable heads-up display. However, while a wearable heads-up display could possibly address some concerns about low-quality resolution present in wideangle cameras, sharing the screen area with a second ground-based camera feed could further compound the resolution issue. Additionally, the ability for a camera to provide a wider field of view also generally carries with it the significant downside of needing increased radio bandwidth for the higher resolution video. This could make the video feed more susceptible to increased noise interference or it could reduce the angular resolution, affecting target discernibility.
While data on FPV technology and potential associated mitigations is currently limited, the FAA recognizes the potential for this technology to provide a means of operating a small UAS beyond visual line of sight. For this reason, the FAA is currently conducting a pathfinder initiative with BNSF Railroad to gather safety data on operating beyond the visual line of sight of the remote pilot in rural/isolated areas. The FAA is also conducting a second pathfinder initiative with PrecisionHawk to gather data on UAS flights in rural areas outside the remote pilot’s direct vision. The FAA anticipates that data from these initiatives could help inform its approach to extend visual line of sight operations in future agency actions.
Further, to reflect the changing state of UAS technology and the limited data available at this time, the FAA has made the visual-line-of-sight requirements of this rule waivable. An applicant will be able to obtain a waiver for an operation conducted differently than what is required by the visual-line-of-sight requirements of part 107 if the applicant demonstrates that his or her operation can safely be conducted under the terms of a certificate of waiver. The FAA also emphasizes that this rule does not prohibit the use of FPV devices as long as the device is not used to meet the visual-line-of-sight requirements of part 107.
Several commenters argued that small UAS operations should be permitted to go beyond visual line of sight when certain other technologies are used. Predesa argued that visual pattern recognition technology to detect terrain and aircraft hazards could be used to mitigate the risk associated with beyond-visual-line-of-sight operations. The Oregon Department of Aviation, the Agricultural Technology Alliance, and the New Hampshire Department of Transportation Bureau of Aeronautics (New Hampshire Department of Transportation), among others, asserted that utilizing geo-fencing to constrain unmanned aircraft flight should safely permit beyond-visual-line-of-sight operations. In addition to these, other technologies suggested by the commenters included light detection and ranging (LIDAR), Traffic Collision Avoidance System (TCAS), automatic dependent surveillance broadcast (ADS-B), and automated navigation. The National Ski Areas Association noted that “collision detection and avoidance systems are in development,” and said that the final rule needs to “recognize and accommodate” these and other technological innovations. Many of the technologies suggested by the commenters only partially mitigate possible hazards. For instance, automated navigation and geo-fencing could protect against terrain and ground obstructions but would not reveal manned aircraft transiting the flight area. Conversely, TCAS could reveal transponder-equipped aircraft but would be ignorant of terrain or non-transponder-equipped aircraft. Some of the mentioned technologies, such as LIDAR and visual pattern recognition, have potential to detect both ground and airborne obstacles, but no commenters provided data to support a particular standard or a testing means to validate the ability and reliability of that technology. As of this writing, the FAA does not have sufficient data to find that a technology can safely satisfy the see-and-avoid requirement of part 107. Consequently, the FAA will consider these situations on a caseby-case basis through the waiver process. The FAA will also use the waiver process as one means by which to evaluate new technologies as they become more developed. Commenters, including Boeing Commercial Airplanes (Boeing), News Media Coalition, the Newspaper Association of America, NAMIC, Amazon, and Google, argued that a visual-line-of-sight requirement is unnecessary over certain areas such as those that are unpopulated, private property, controlled-access facilities, or where activities would be unduly restricted by a visual-line-of-sight requirement, and that operational safeguards could be employed to ensure safe beyond-visual-line-of-sight operations. The types of unduly restricted activities could include newsgathering events where people must remain at a distance from the event, agriculture operations, underwriting or adjusting claims in dangerous locations, responses to natural disasters, firefighting, search and rescue, and law enforcement operations. The types of operational safeguards proposed could include operating under FAA-imposed restrictions on weight, range, location, and altitude; and operating along pre-programmed and pre-approved paths through the use of mapping, navigation, and contingency management software.
The FAA recognizes that the location of a small UAS flight could affect the inherent risk of the operation. However, as discussed previously, there is currently limited data concerning operations conducted beyond visual line of sight. The FAA is working to acquire additional safety data as part of its pathfinder initiatives, but that data will not be available within the timeframe envisioned by this rule. Because there are a significant number of variables involved in each individual operating environment and because the FAA has limited data on beyond-line-of-sight operations, this rule will not include a standard of general applicability for these types of operations. Instead, the FAA will consider each individual operating environment (as well as any mitigations) on a case-by-case basis as part of its consideration of a waiver application.
Several commenters, including the American Farm Bureau and the American Petroleum Institute, suggested that beyond-line-of-sight operations should be permitted over privately owned land where the operator would be able to close access to nonparticipants. These commenters provided examples of pipelines and utility lines.
The FAA recognizes that controlling the ground in the vicinity of the flight could mitigate hazards to persons and property on the ground. However, the primary concern underlying the visual-line-of-sight restriction in this rule is risk to other aircraft in the air. Because a property owner is generally limited in how much he or she can restrict other aircraft from operating near the property, the fact that a property is privately owned is not, by itself, sufficient to allow beyond-visual-line-of-sight operations. As discussed earlier, individuals wishing to operate beyond visual line of sight will be able to apply for a waiver, and the FAA will examine individual operating environments on a case-by-case basis as part of its evaluation of a waiver application.
AIA and JAM Aviation suggested that the first sentence of § 107.31 should be amended to read: “With vision that is unaided by any device other than corrective lenses, the operator and visual observer must be able to see the unmanned aircraft throughout the entire flight.” One individual stated § 107.31(b) should be amended to read: “Determine the unmanned aircraft’s attitude, altitude, and direction of flight.” The commenter said the change is needed because for multi-rotor UAS, the direction of flight could be quite different from the nominal “front” of the aircraft. According to this commenter, the proposed wording could lead to confusion on what “direction” meant, whether it was the UAS’s path or the direction (bearing) from the remote pilot’s position.
As an initial matter, the FAA notes that, as discussed in section III.E.1 of this preamble, the NPRM-proposed position of operator has been replaced by the remote pilot in command. Additionally, the remote pilot in command is not required to be the person who manipulates the flight controls of the small UAS. Accordingly, this rule will require both the remote pilot in command and the person manipulating the flight controls of the small UAS to possess the ability to maintain visual line of sight of the small unmanned aircraft.
In response to the concerns raised by the commenters, the FAA has also clarified the regulatory text of § 107.31. As amended, § 107.31 states that the remote pilot in command, the visual observer (if one is used), and the person manipulating the flight control of the small UAS 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. This visual-line-of-sight ability must be exercised throughout the entire flight of the small unmanned aircraft by either: (1) the visual observer; or (2) the remote pilot in command and person manipulating the flight controls of the small UAS (if that person is not the remote pilot in command).
Several commenters, including Modovolate, Small UAV Coalition, and Southern Company, asked the FAA to make clear that brief interruptions to visual line of sight should be permitted. One commenter asked that a quantitative limit on what qualifies as a momentary interruption should be established. Another individual asked the FAA to make clear that the remote pilot’s primary mission is to scan the area for other aircraft and not to keep “eyes on” the small unmanned aircraft.
The FAA understands and accepts that the person maintaining visual line of sight may lose sight of the unmanned aircraft for brief moments of the operation. This may be necessary either because the small unmanned aircraft momentarily travels behind an obstruction or to allow the person maintaining visual line of sight to perform actions such as scanning the airspace or briefly looking down at the small UAS control station. For example, a remote pilot in command stationed on the ground utilizing a small unmanned aircraft to inspect a rooftop may lose sight of the aircraft for brief periods while inspecting the farthest point of the roof. As another example, a remote pilot in command conducting a search operation around a fire scene with a small unmanned aircraft may briefly lose sight of the aircraft while it is temporarily behind a dense column of smoke.
However, the FAA emphasizes that even though the remote pilot in command may briefly lose sight of the small unmanned aircraft, he or she always has the see-and-avoid responsibilities set out in §§ 107.31 and 107.37. The circumstances of what would prevent a remote pilot from fulfilling those responsibilities will vary depending on factors such as the type of UAS, the operational environment, and distance between the remote pilot and the unmanned aircraft. For this reason, the FAA declines to specify a quantitative value to an interruption of visual contact as it would have the effect of potentially allowing a hazardous interruption or prohibiting a reasonable one.
With regard to the comment concerning keeping “eyes on” the small unmanned aircraft, the FAA notes that the principles of scanning, long taught to manned aircraft pilots, include the dangers of “tunnel vision” and that an effective scan must encompass all areas of the environment a hazard could come from. The FAA agrees that to comply with § 107.31, the person maintaining visual line of sight must effectively scan the area and not necessarily be focused on constant visual contact with the small unmanned aircraft. Several commenters suggested that the FAA impose a numerical limit on how far away a small unmanned aircraft may travel from the person maintaining visual line of sight. ALPA, NBAA, NAAA, and the State of Nevada, Nevada Institute for Autonomous Systems and Nevada FAA-designated UAS Test Site, commenting jointly, argued that an appropriate specific numerical distance should be imposed and be based on study or test data. Predesa stated that a numerical limit can be determined by the performance of the UAS, taking into account a margin that allows for winds and wind gusts, and power characteristics of the UAS battery. FLIR Systems, Inc., Aviation Management, the City and County of Denver, Colorado, and two individuals proposed specific numerical limits the FAA should impose on the area of operation. The numerical recommendations of these commenters varied widely from 1000 feet to 3 miles. An individual commenter suggested that some form of reliable and verifiable documenting of distance should be required.
The FAA declines to impose a numerical limit on how far away a small unmanned aircraft can travel from the person maintaining visual line of sight. A prescriptive numerical limit would not take into account situational-dependent operating factors and may preclude operations that could otherwise be conducted safely. Additionally, no commenter provided data to substantiate the belief that a numerical standard would provide a higher level of safety than the visual-line-of-sight standard proposed in the NPRM. This rule will also not include a documentation requirement regarding the distance of a small unmanned aircraft. A distance documentation requirement would impose an unjustified cost on the public because the permissible distance of the small unmanned aircraft from the remote pilot in command will be situation-specific. For example, a remote pilot in command operating in excellent visibility conditions will be able to fly the small unmanned aircraft farther away from him or herself and still maintain visual line of sight. Conversely, a remote pilot in command operating in poorer visibility conditions will have a more limited area where he or she can fly the small unmanned aircraft and still maintain the required visual line of sight.
PlaneSense, Inc. and Cobalt Air, LLC, in a joint submission, stated that the rule should also require that the operator or a visual observer have line of sight to the ground over which the small unmanned aircraft is flying. However, requiring a remote pilot or visual observer to have line of sight to the ground will not enhance the safety of this rule, and may prohibit certain operations that could otherwise be conducted safely under part 107. For instance, a small UAS operation over a disaster area containing no persons or property on the ground would not need to have line of sight to the ground to ensure the safe operation of the small UAS.
Airports Council International – North America suggested that the first sentence of § 107.31 should be amended to read: “With vision that is unaided by any device other than corrective lenses, the operator or visual observer must be able to see the unmanned aircraft and other aircraft to which the unmanned aircraft could pose a collision risk throughout the entire flight in order to….”
The FAA declines this suggestion because the requirement to be aware of other aircraft is already encompassed by the pertinent regulatory text of part 107. Specifically, § 107.31(a)(3) will require the remote pilot in command, the visual observer (if one is used), and the person manipulating the flight controls of the small UAS (if that person is not the remote pilot in command) to be able to see the unmanned aircraft throughout the entire flight in order to observe the airspace for other air traffic or hazards. Other aircraft are considered air traffic and are thus covered by the regulatory text of § 107.31(a)(3).
The Washington State Department of Transportation, Aviation Division concurred “with the line-of-sight and reduced visibility parameters as described, with the exception that certain verified research and development operations … be allowed on a case-by-case basis, and for unique situations such as aerial observation to support firefighting where redundant systems may alleviate line-of-sight and visibility limitations.”
As an initial matter, the FAA notes that operations, such as those in support of firefighting, will not be subject to the provisions of part 107 if conducted as public aircraft operations. With regard to case-by-case determinations, the visual-line-of-sight restrictions of this rule will be subject to waiver. This means that a person will be able to apply for and obtain a certificate of waiver from the provisions of § 107.31 if the person establishes that the proposed operation can safely be conducted under the terms of a certificate of waiver. The FAA will evaluate waiver requests on a case-by-case basis.
Commenters including several state farm bureau federations and FLIR Systems argued that a visual-line-of-sight requirement could potentially negate the cost and time savings associated with small UAS operations conducted over large swaths of land because the requirement would necessitate multiple flights to complete the operations. According tothese commenters, the potential safety risks associated with operations would also increase because more frequent takeoffs and landings would be required.
The commenters did not provide any data showing that there is increased risk or costs associated with the takeoff or landing of a small unmanned aircraft. As such, the FAA declines to change this rule on the basis suggested by the commenters. However, as discussed in sections III.E.1 and III.E.3.a.i of this preamble, this rule has been changed from the NPRM to allow: (1) the flight of a small unmanned aircraft over a sparsely populated area from a moving vehicle; and (2) a remote pilot in command to extend the area of operation by handing off control mid-flight to another remote pilot in command. Both of these changes, as well as the ability to apply for a waiver, will allow for additional operational flexibility under this rule.
A large number of commenters, including the Airborne Law Enforcement Association, Embry-Riddle Aeronautical University, and the Associated General Contractors of America, argued that visual line of sight should not apply to certain specific operations. Those operations included: • Public safety/emergency. • Conservation-focused operations. • Operations by electric utilities for line inspection or for storm-damage restoration. • Oil industry inspections. • Property inspections. • Agriculture. • Newsgathering. • Operations within a structure.
As an initial matter, the FAA does not regulate UAS operations conducted inside an enclosed structure. Similarly, as discussed earlier in this preamble, part 107 will not apply to public aircraft operations unless they voluntarily choose to operate as civil aircraft. Most public safety operations are conducted as public aircraft operations and will continue to be authorized by COA. Therefore, these types of operations, when conducted in accordance with a COA, will be unaffected by the requirements of part 107.
With regard to the other operations suggested by the commenters, there is currently no data indicating that the nature of the small UAS operation mitigates the risk associated with operations conducted beyond visual line of sight. The FAA recognizes that there are a variety of uses for UAS that this rulemaking will not enable. However, there are also a number of small UAS uses that will be enabled by this rule. If the FAA were to delay issuance of this rule until it had sufficient data to generally allow beyond-visual-line-ofsight operations, the societal benefits that could be realized by immediately allowing operations within visual line of sight would be delayed as well. Thus, the FAA will utilize the incremental approach discussed earlier in this preamble, under which the FAA will issue a rule for the lowest risk UAS activities while pursuing future rulemaking to expand their use. Additionally, as discussed previously, the waiver authority in this rule will enable the FAA to examine, on a case-by-case basis, any mitigation provided by the operating environment in the specific operations discussed by the commenters.
A number of commenters, including the National Roofing Contractors Association, Vail Resorts, Rocky Mountain Farmers Union, and MAPPS, suggested that small UAS operators should be permitted to extend their visual line of sight through the use of one or more visual observers who maintain visual line of sight while in constant communication with the operator. Continental Mapping Consultants, Inc. (Continental Mapping) similarly advocated for the use of one “or many” remote visual observers “daisy chained” throughout the operational area, while in constant contact with each other and the operator. The National Association of Broadcasters, the National Cable & Telecommunications Association, and Radio Television Digital News Association also asked the FAA to reconsider its proposed prohibition on a relay or “daisy chain” of visual observers. Specifically, the commenters said that the FAA should revise § 107.33(b) to require that either the operator or a visual observer be able to see the small UAS at all points during the flight.
The Colorado Cattlemen’s Association asserted that “adequate operational and public safety can be ensured” if operator visual line of sight is augmented by an additional visual observer who maintains visual line of sight while in communication with the operator. The association did not advocate for an “extensive or unlimited number” of observers to extend the range of UAS operations, but said a reasonable balance can be reached to allow more practical uses of UAS (such as operations on cattle ranches).Allowing remote pilots to extend their visual line of sight through the use of one or more visual observers may introduce new hazards into the operation. As discussed in the next section of this preamble, the visual observer’s role in the operation is limited to simply maintaining visual line of sight and communicating what he or she sees to the remote pilot.Allowing “daisy chaining” of visual observers to fly the unmanned aircraft beyond line of sight of the remote pilot in command would result in a delay in the remote pilot’s reaction time because the visual observer would have to verbalize any hazard and the remote pilot would be unable to look up and directly see the situation. Instead, the remote pilot would have to respond to the hazard by formulating and executing a maneuver based on his or her understanding of the information received from the visual observer rather than a direct visual perception of the hazard.
Because a delay in reaction time may introduce new hazards into the operation, this rule will retain the requirement that the remote pilot in command and the person manipulating the flight controls of the small UAS (if that person is not the remote pilot in command) must be able to see the small unmanned aircraft throughout the entire flight. However, as discussed earlier, the visual-line-of-sight requirements of this rule will be waivable. Additionally, the FAA notes that it is currently engaged in research and testing on how a communication error could affect the ability of the remote pilot to correctly apply avoidance maneuvers, and this data will help inform future agency actions.
Textron Systems, the National Association of Realtors, Trimble Navigation, and ArgenTech Solutions recommended that this rule provide an operator with the ability to hand off control and responsibility for flight during the course of an operation. Textron Systems recommended that the rule “allow passing of ‘operator in command’ during flight operations as long as the system and the operational construct meet other requirements of the rule.” Trimble proposed that the FAA should explicitly permit multiple operators using networked radios and control stations to operate a single UAS. Under Trimble’s proposal, operators would transition control of the UAS from one operator to another while ensuring see-and-avoid concerns are met. Trimble also asserted that the technology needed to network radios and control stations is utilized in other countries for small UAS operations and has been found to be effective. The National Association of Realtors added that “daisy chaining” operators does not pose a safety concern because “[t]he real-time corrections necessary to perfect an UAS flight could be made instantaneously, rather than the observer communicating with the operator and there being a lag in the time the correction is orally given and then made within the operation.” NetMoby, on the other hand, recommended prohibiting hand-off ability because it could create an “endless daisy chain of operators.”
The FAA agrees with the commenters who stated that transfer of control of a small UAS should be allowed between certificated remote pilots. This can be accomplished while maintaining visual line of sight of the UAS and without loss of control. Multiple certificated remote pilots handing off operational control does not raise the same safety concerns as a daisy chain of visual observers because, unlike a visual observer, the remote pilot in command will have the ability to directly control the small unmanned aircraft. Thus, two or more certificated pilots transferring operational control (i.e. the remote pilot in command designation) to each other does not raise the delayed-reaction-time issue that arises with visual observers having to communicate what they see to another person who actually manipulates the small UAS flight controls.
Accordingly, as discussed in section III.E.1 of this preamble, multiple certificated remote pilots may choose to transfer control and responsibility while operating a small UAS. For example, one remote pilot may be designated the remote pilot in command at the beginning of the operation, and then at some point in the operation another remote pilot may take over as remote pilot in command by orally stating that he or she is doing so. The FAA emphasizes that as the person responsible for the safe operation of the UAS, any remote pilot who will assume remote-pilot-in-command duties should be aware of factors that could affect the flight.