The NPRM proposed that an operator or visual observer would be limited to operating no more than one small UAS at the same time. The NPRM explained that performing the duties required of a crewmember in real time is a concentration-intensive activity and as such, it is necessary to place a limitation on the number of UAS that a person can operate simultaneously. For the reasons discussed below, this rule will retain the proposed prohibition on the simultaneous operation of multiple small unmanned aircraft. This prohibition will be waivable if a person establishes that his or her simultaneous operation of more than one small unmanned aircraft can safely be conducted under the terms of a certificate of waiver.
NAAA, the California Agricultural Aircraft Association, NAMIC, Colorado Agricultural Aviation Association, and Schertz Aerial Services supported limiting operators or visual observers to operating only one small UAS at a time. The International Brotherhood of Teamsters urged the FAA to maintain all operational limits and safeguards presented in the NPRM, including the limit of one UAS per operator, until there is technological certainty that no workers, or the general public, would be at risk from automated package delivery.
Other commenters disagreed with the proposed limitation on the number of small UAS that a person can operate simultaneously. Several commenters asserted that technology currently exists to allow for the safe operation of multiple small UAS by a single operator. The Mercatus Center at George Mason University said existing and developing technologies “can more than compensate to the diminished concentration that operators might apply to each individual aircraft.” AirShip Technologies stated that it currently incorporates technology that will allow clusters of UAS with similar missions to be pre-programmed and controlled by one operator. Boeing and Aviation Management similarly said that current technology allows a group or swarm of multiple vehicles to operate safely and efficiently in highly automated modes.
The commenters also claimed that new operator consoles have been shown to be able to safely control multiple small UAS systems. The NJIT Working Group pointed to the Navy Low-Cost UAV Swarming Technology (LOCUST), which it said could be used for non-military purposes, such as first responder and search and rescue operations. Vision Services Group said multiple small UAS operations should be permitted if both the operator and visual observer possess a Permit to Operate and a valid Third Class Medical Certificate.
As discussed in the visual-line-of-sight section of this preamble, the remote pilot in command, the person manipulating the flight controls of the small UAS, and the visual observer (if one is used) are required to maintain visual awareness of the small unmanned aircraft and the surrounding airspace in order to minimize the risk of a mid-air collision with a manned aircraft. This activity requires active attention and operating more than one unmanned aircraft at the same time would split the concentration of the small UAS crewmembers. By decreasing the amount of attention that the remote pilot in command, person manipulating the flight controls, and visual observer can dedicate to each small unmanned aircraft, the operation of multiple small unmanned aircraft at the same time may introduce additional risk into the NAS. This risk would further be compounded if larger numbers of aircraft are operated at the same time because each aircraft would receive an even smaller fraction of each person’s attention.
The FAA recognizes that technology may allow a remote pilot in command to operate multiple small unmanned aircraft as one system. While such a system may, in some circumstances, help address the split-attention problem discussed above, it would introduce significantly more risk into the operation because of the remote pilot’s potentially reduced ability to resolve multiple aircraft or system failures to a safe outcome. For example, if one small unmanned aircraft in a multi-aircraft system loses its link to the control station, it may cause the whole system to break down, resulting in loss of positive control of multiple small unmanned aircraft and significantly increasing the risk to the NAS. The FAA notes that, at this time, none of the technologies cited by the commenters have established a necessary level of reliability through a nationally recognized formal testing process such as through ASTM International, SAE International, or civil aviation airworthiness certification. Accordingly, this rule will prohibit a person from manipulating the flight controls of more than one unmanned aircraft or acting as a remote pilot in command or visual observer in the operation of more than one unmanned aircraft at the same time. However, as discussed below, this prohibition will be subject to waiver.
Commenters including Aviation Management, Boeing, the Small UAV Coalition, and AIA said that the FAA should revise the rule to create the framework for the agency to be able to administratively approve multi-UAS operations. Several of those commenters, as well as Google, Amazon, and AUVSI, among others, supported allowing the operation of multiple small UAS per operator in certain cases using a risk-based approach. Amazon, for example, said the proposed provision should be revised to specifically permit the operation of multiple small UAS by a single operator “when demonstrated that this can be done safely.” The Small UAV Coalition said approval for the operation of multiple small UAS by a single operator would be based on a demonstration of operator ability and technological capabilities of the UAS.
DJI said it may be possible for an operator to operate more than one small UAS at a time if there are sufficient visual observers or detect-and-avoid technology. An individual said the rule should allow for the use of multiple small UAS by a single operator if all of the UAS are within the visual line of sight of either the operator or visual observer or if there is some other means of compliance for see-and-avoid for all small UAS involved in the operation.
Other commenters said the final rule needs to have the flexibility to accommodate emerging technology in this area. The Utah Governor’s Office of Economic Development stated that “[t]here must be a road map to, and provisions for, multiple UAS per operator to allow this technology to be tested and eventually implemented.” The University of Illinois at Urbana-Champaign said there should be an exception to the proposed restriction for research into developing technology to allow multiple drones to successfully navigate together. MPAA asserted that “as control systems improve it may become possible to operate more than one system at a time.” MPAA urged the FAA to provide a mechanism in the rules to allow additional flexibility for filming in controlled environments as such technology advances. The National Association of Broadcasters, National Cable & Telecommunications Association, and Radio Television Digital News Association said that given the speed at which technology is developing, the FAA should be open to considering automated systems that contemplate one person controlling multiple small UAS that demonstrate an equivalent level of safety to the requirements of the final rule.
The FAA acknowledges the points raised by the commenters that the risks discussed above may, at some point in the future, be mitigated through technology. However, as of this writing, the FAA does not have data on which to base a safety finding that the available technology for multiple simultaneous small unmanned aircraft operations by one person has matured to the extent necessary to allow these types of operations in a rule of general applicability. The FAA also acknowledges the benefits of research and development associated with the simultaneous operation of multiple unmanned aircraft and agrees that additional flexibility is called for in this rule so that the agency can administratively allow these types of operations based on operation-specific mitigations. Accordingly, the FAA has made the prohibition on the simultaneous operation of multiple small unmanned aircraft waivable on a case-by-case basis. To obtain a waiver, a person will have to demonstrate that his or her simultaneous operation of more than one small unmanned aircraft can safely be conducted under the terms of a certificate of waiver. The FAA recognizes the potential of one person being able to operate multiple small unmanned aircraft and will evaluate operations conducted under FAA-issued waivers to help inform future agency actions to enable the simultaneous operation of multiple small UAS. Amazon asserted that the proposed restriction is based on the flawed premises that small UAS must be operated under constant manual control and that FAA-recognized mitigation measures like flight termination systems are not already available today. Aerial Services and MAPPS stated that the FAA should allow the operation of swarms of UAS if the flight management system is capable of supporting it and each aircraft has rigid automated procedures in case of loss of signal.
As discussed previously, swarms of multiple small unmanned aircraft that are linked up to a single system introduce additional risk into the NAS because a single unmanned aircraft losing its link to the control system may destabilize the system and result in loss of positive control of multiple aircraft. Additionally, the FAA does not currently have data on which to base a finding that the pertinent technology has matured to the extent necessary to allow the safe operation of multiple small unmanned aircraft in a rule of general applicability. As such, the FAA will consider the use of this technology on a case-by-case basis via the waiver process.
AirShip Technologies and the NJIT Working Group cited military and non-military uses for clusters, swarms, and multiple UAS. These include combat, first responder missions, mapping, and search and rescue operations. Skycatch, Clayco, AECOM, DPR Construction, and AUVSI noted that the use of multiple UAS in a single operation allows for more efficient completion of complex tasks to include work over job sites without increasing the amount of time in flight or recharging of batteries.
The FAA agrees with the commenters that the operation of multiple unmanned aircraft may provide a valuable and broad spectrum of services. However, the technology necessary to mitigate risk associated with this type of operation is still in its infancy and has not yet been proven to meet a level of reliability sufficient to allow that technology to be relied on for risk mitigation in a rule of general applicability. As discussed previously, the waiver process will continue to be available for small UAS operations that fall outside the operational parameters of part 107.
The International Center for Law and Economics and Tech Freedom said the proposed restriction “fails to reflect the ‘best reasonably obtainable scientific, technical, economic, and other information,’” as required by Executive Order 12866. The commenters further stated that the FAA has a constitutional obligation to explore the adequacy of simultaneous operation technology. Otherwise, the commenters continued, the rule will greatly increase the cost of operating UAS, thus limiting their availability for both commercial and non-commercial uses that are protected by the First Amendment.
The FAA received over 4,500 comments on this rulemaking and none of the commenters (including the International Center for Law and Economics and Tech Freedom) submitted any data establishing the safety or maturity of simultaneous-operation technology. Based on the number and high quality of the comments submitted, the FAA believes that this lack of data was not an oversight but, rather, evidence of the fact that existing data about this technology is very limited at this time. The FAA will continue exploring the feasibility of this technology in future agency actions that will be informed, in part, by small UAS operations that will take place under a part 107 waiver allowing the operation of multiple small unmanned aircraft at the same time.