Advisory on the Application of Federal Laws to the Acquisition and Use of Technology to Detect and Mitigate Unmanned Aircraft Systems

August 2020
The Federal Aviation Administration (FAA), Department of Justice (DOJ), Federal Communications
Commission (FCC), and Department of Homeland Security (DHS) are issuing an advisory guidance document to
assist non-federal public and private entities interested in using technical tools, systems, and capabilities to detect
and mitigate Unmanned Aircraft Systems (UAS). The advisory is intended to provide an overview of potentially
applicable federal laws and regulations, as well as some factors relevant to whether those laws may apply to
particular actions or systems.
Specifically, this advisory addresses two categories of federal laws that may apply to UAS detection and
mitigation capabilities: (1) various provisions of the U.S. criminal code enforced by DOJ; and (2) federal laws
and regulations administered by the FAA, DHS, and the FCC. The advisory does not address state and local laws,
which UAS detection and mitigation capabilities may also implicate. Neither does it cover potential civil liability
flowing from the use of UAS detection and mitigation technologies (e.g., the potential liability from causing
physical damage to persons or property as a result of mitigating a UAS threat, or civil liability and recovery for an
unlawful interception of wire, oral, or electronic communications under 18 U.S.C. § 2520).
This advisory is provided for informational purposes only. 	It is strongly recommended that, prior to the
testing, acquisition, installation, or use of UAS detection and/or mitigation systems, entities seek the advice of
counsel experienced with both federal and state criminal, surveillance, and communications laws. Entities should
conduct their own legal and technical analysis of each UAS detection and/or mitigation system and should not rely
solely on vendors’ representations of the systems’ legality or functionality. As part of that analysis, entities should
closely evaluate and consider whether the use of UAS detection and mitigation capabilities might impact the
public’s privacy, civil rights, and civil liberties. This is particularly important because potential legal prohibitions,
as discussed below, are not based on broad classifications of systems (e.g., active versus passive, detection versus
mitigation), but instead are based on the functionality of each system and the specific ways in which a system
operates and is used. A thorough understanding of both applicable law and the systems’ functionality will ensure
important technologies designed to protect public safety, by detecting and/or mitigating UAS threats, are used
effectively, responsibly, and legally.
Advisory on the Application of
Federal Laws to the Acquisition
and Use of Technology to Detect
and Mitigate Unmanned Aircraft Systems

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
I. Federal Criminal Laws
Congress has exclusively authorized the Departments of Defense, Energy, Justice, and Homeland Security to
engage in limited UAS detection and mitigation activities to counter UAS presenting a credible threat to covered
facilities or assets, notwithstanding certain otherwise potentially applicable federal criminal laws, including
various laws relating to surveillance.1 In addition, the FAA has been expressly authorized to engage in limited
testing activities notwithstanding certain federal criminal surveillance laws.2
Because no other entities have been granted that authority, it is important that state, local, tribal and territorial
(SLTT) and private sector entities without such statutory authority (including SLTT law enforcement organizations,
SLTT governments, and owners and operators of critical infrastructure, stadiums, outdoor entertainment venues,
airports, and other key sites) understand that federal laws may prevent, limit, or penalize the sale, possession, or
use of UAS detection and mitigation capabilities.3 Capabilities for detecting and mitigating UAS may implicate
federal criminal laws relating to surveillance, accessing or damaging computers, and damage to an aircraft. Below,
the advisory sets out separately how detection and mitigation capabilities may implicate these laws.
A. Detection Capabilities
Systems that detect, monitor, or track UAS often rely on radio-frequency (RF), radar, electro-optical (EO),
infrared (IR), or acoustic capabilities, or a combination thereof. These capabilities detect the physical presence
of UAS or signals sent to or from the UAS. In general, whether a detection or tracking system implicates federal
criminal surveillance laws, such as the Pen/Trap Statute and the Wiretap Act, depends on whether it captures,
records, decodes, or intercepts, in whole or in part, electronic communications transmitted to and from a UAS
and/or controller, and the type of communications involved. Detection systems that emit electromagnetic waves or
pulses of sound or light that are reflected off an object and back to the detection system—such as radar, EO/IR, and
acoustic systems—are less likely to pose concerns under federal criminal surveillance statutes. Such technology
senses the sound or electromagnetic waves produced by or reflected from the UAS and does not capture, record,
decode, or intercept electronic communications. However, the use of such systems must also comply with laws
and regulations administered by the FCC and FAA, as discussed below.
By contrast, systems using RF capabilities to detect and track UAS by monitoring the communications passed
between a UAS and its ground control station may implicate the Pen/Trap Statute and Wiretap Act.
• 	The Pen/Trap Statute, 18 U.S.C. §§ 3121-3127, criminalizes the “use” or “installation” of a “device” or
“process” 	that 	“records,” 	“decodes,” 	or 	“captures” 	non-content4 	dialing, 	routing, 	addressing, 	or
signaling (“DRAS”) information. 	DRAS information is non-content information used to transmit or
process communications; depending on the system, this could include device serial numbers, cell site
information, media access control (MAC) addresses, the international mobile equipment identity (IMEI),
or the international mobile subscriber identity (IMSI). Use or installation of a pen register or trap and
1 See 10 U.S.C. § 130i, 50 U.S.C. § 2661, and 6 U.S.C. § 124n.
2 See 49 U.S.C. § 44810(g).
3 This advisory does not address the general authorities of public safety agencies, or specific actions they might take consistent with
governing law, to protect the public in exigent circumstances.
4 While non-content is not defined, content is defined in footnote 7, infra.

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
trace device is prohibited, unless conducted pursuant to a court order or when a statutory exception
applies.5 With respect to the Pen/Trap Statute, the exceptions state that they are limited only to providers
of wire or electronic communication services.
• 	Questions to consider:
n 	What information is the technology collecting (e.g., UAS type, manufacturer, model,
protocol, unique identifier, telemetry)?
n 	Is the information DRAS or content?
n 	Do any Pen/Trap exceptions apply?
• 	The Wiretap Act (also known as Title III), 18 U.S.C. §§ 2510 et seq., prohibits, among other things,
“intentionally intercept[ing]” the content of “any . . . electronic communication[,]” unless it is conducted
pursuant to a court order or a statutory exception applies.6 An “electronic communication” is defined, with
certain exceptions, as “any transfer of signs, signals, writing, images, sounds, data, or intelligence of any
nature transmitted in whole or in part by a wire, radio, electromagnetic, photoelectronic or photooptical
system that affects interstate or foreign commerce.” Id. § 2510(12).
5 Law enforcement may use such devices with a court order, but can only obtain such an order in furtherance of an ongoing criminal
investigation, see 18 U.S.C. § 3122(b)(2), and must use reasonably available technology that prevents the interception of the content of
a communication. See 18 U.S.C. § 3121(c). Private actors are unable to obtain a court order under the Pen/Trap Statute and, therefore,
must operate pursuant to one of the statute’s exceptions. The Pen/Trap Statute and Wiretap Act do not contain identical exceptions. For
example, while the Pen/Trap Statute includes an exception for use of a pen register or trap and trace device with the consent of a “user,” it
does not provide an exception based on the consent of a “party to the communication.” Compare 18 U.S.C. § 3121(b)(3), with 18 U.S.C.
§ 2511(2)(c). In addition, the Pen/Trap Statute does not include an analogue to the Wiretap Act’s exception allowing interception of
electronic communications that are “readily accessible to the general public.” Id. § 2511(2)(g)(i).
6 The Wiretap Act contains several exceptions to the blanket prohibition, including for operators and service providers, for uses “in the
normal course of employment” that are a necessary incident to the rendition of services; for surveillance authorized under the Foreign
Intelligence Surveillance Act of 1978; and where a party to the communication has given prior consent to such interception. See, e.g.,
18 U.S.C. § 2511(2)(a)(i), (d) & (e). Law enforcement may also intercept communications without a court order in certain emergency
situations, provided an application for an order is made within 48 hours of the interception. Id. § 2518(7).

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
• 	The Wiretap Act has an exception for the interception of electronic communications that are “readily
accessibletothegeneralpublic.”Id.§2511(2)(g)(i).Section2510(16)defineswhichradiocommunications
do not fall into the foregoing exception. The Wiretap Act also has an exception for the interception of any
radio communications that are transmitted “by any . . . aeronautical communications system.”
Id. § 2511(2)(g)(ii)(IV). UAS RF control systems may be considered “aeronautical communications
systems” under the Act. 	However, existing case law raises questions as to the scope of both
exceptions.7
• 	Questions to consider:
n 	Are electronic communications being acquired?
n 	Are any acquired communications transmitted by a system that affects interstate or foreign
commerce (e.g., a system that is connected to the Internet or a mobile network)?
n 	Are any portions of the communications acquired by the technology “content?”8
n 	Do any of the Wiretap Act’s exceptions apply (e.g., is the person intercepting the
communications a party to the communication under 18 U.S.C. § 2511(2)(d))?
• 	18 U.S.C. § 2512 generally prohibits the manufacture, assembly, possession, sale, advertisement, and
distribution of devices that are “primarily useful for the surreptitious interception of wire, oral, or electronic
communications.”9 Section 2513 provides that any electronic, mechanical, or other device used, sent, carried,
manufactured, assembled, possessed, sold, or advertised in violation of § 2512 may be seized and forfeited to
the United States.
B. Mitigation Capabilities
Mitigation capabilities fall into two general categories: non-kinetic and kinetic. Non-kinetic solutions use
non-physical measures to disrupt or disable UAS, including RF, WiFi, or Global Positioning System (GPS) jamming;
spoofing; hacking techniques; and non-destructive directed energy weapons. 	Kinetic solutions may employ a
variety of measures capable of physically disrupting or disabling a UAS, including nets, projectiles, and lasers. The
use of non-kinetic or kinetic solutions may implicate federal criminal prohibitions against, among other things,
intercepting and interfering with communications, damaging a “protected computer,”10 and damaging an “aircraft.”
The term “aircraft” refers to “a civil, military or public contrivance invented, used, or designed to navigate, fly, or
travel in the air.” 18 U.S.C. § 31(a)(1). This definition is consistent with the meaning of “aircraft” in 49 U.S.C. §
40102(a)(6). 	In the FAA Reauthorization Act of 2018, Congress codified the term “unmanned aircraft” as “an
aircraft that is operated without the possibility of direct human intervention from within or on the aircraft.” 49
U.S.C. § 44801(11).
7 See Joffe v. Google Inc., 746 F.3d 920, 928-29 (9th Cir. 2013) (panel rehearing), cert. denied, 134 S. Ct. 2877 (2014).
8 Content is “any information concerning the substance, purport, or meaning of that communication.” 18 U.S.C. § 2510(8). Importantly,
machine-to-machine communications and data transfers between devices can be considered “content.”
9 The statute exempts “officer[s], agent[s], or employee[s] of, or [] person[s] under contract with, the United States, a State, or a political
subdivision thereof, in the normal course of the activities of the United States, a State, or a political subdivision thereof.” 18 U.S.C. §
2512(2)(b).
10 The term “protected computer” includes any computer that is used in or affecting interstate or foreign commerce or communication, or
that is used by or for a financial institution or the United States government. 18 U.S.C. §§ 1030(e)(1) & (2).

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
Jamming technologies are designed to block or interfere with authorized radio communications.11 Examples
of jamming include transmitting RF signals from a jammer at a higher “signal strength” than the RF signals being
used to navigate or control the aircraft; preventing a cellular, WiFi, or Bluetooth-enabled device from connecting
to a network (such as a cellular system or the Internet); or preventing a GPS unit from receiving positioning signals
from a satellite. Spoofing technologies can replicate and replace or modify signals, and can lead to loss of control
over the UAS’s navigation and communications link (e.g., its link to its ground controller). Hacking techniques
generally focus on the UAS’s communications link and/or the onboard computer processors.
Jamming, spoofing, and hacking technologies should be evaluated under the federal criminal statutes below
(including the aircraft sabotage and aircraft piracy provisions), in addition to the laws discussed above with regard
to detection. Because jamming and spoofing are also likely to implicate laws relating to the RF spectrum, parties
should carefully review the information in Section II, below, as well.
• 	The Computer Fraud and Abuse Act (CFAA), 18 U.S.C. § 1030, among other things, prohibits intentionally
accessing a “protected computer” without authorization and thereby obtaining information, or intentionally
damaging a protected computer without authorization, including by transmitting a program, information,
code, or command that causes such damage.12 The CFAA broadly defines the term “protected computer”13
in a manner that could include UAS control systems.
• 	Interference with the Operation of a Satellite, 18 U.S.C. § 1367, generally prohibits “obstruct[ing] or
hinder[ing] any satellite transmission.”14 Jamming, spoofing, degrading or otherwise interfering with GPS
signals to a UAS or ground control station could be prohibited under this section, as well as jamming or
interfering with any control signals sent to a UAS directly from a satellite.
• 	Communication Lines, Stations, or Systems, 18 U.S.C. § 1362, prohibits “willfully or maliciously injur[ing]
or destroy[ing] . . . means of communication operated or controlled by the United States, or used or
intended to be used for military or civil defense functions of the United States,” as well as by “hinder[ing]
or delay[ing] the transmission of any communication” over such means of communication. This statute
could apply if UAS detection and/or mitigation operations willfully or maliciously degrade or otherwise
hinder any frequency or transmissions, including cellular or WiFi signals, with a demonstrable use or
intended use by the military or by SLTT law enforcement or emergency personnel engaged in civil defense
functions.
Finally, it is possible for mitigation capabilities that destroy, seize, or exercise control of a UAS to implicate
federal criminal laws that otherwise apply to “aircraft,” as that term is statutorily defined. While all kinetic solutions
will likely have one or more of these capabilities implicating those laws, non-kinetic solutions should also be
evaluated for compliance.
11 Authorized radio communications include radio communications operating pursuant to federal authorizations or FCC licenses and
those operating without a license but pursuant to FCC rules.
12 The statute exempts the “lawfully authorized investigative, protective, or intelligence activity of a law enforcement agency of the United
States, a State, or a political subdivision of a State.” 18 U.S.C. § 1030(f).
13 See id. § 1030(e)(1), (2).
14 The statute exempts “any lawfully authorized investigative, protective, or intelligence activity of a law enforcement agency or of an
intelligence agency of the United States.” Id. § 1367(b).

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
• 	The Aircraft Sabotage Act, 18 U.S.C. § 32(a), criminalizes certain destructive actions with respect to
“aircraft,” including damaging, destroying, or disabling those aircraft.
• 	The Aircraft Piracy Act, 49 U.S.C. § 46502, criminalizes the act of seizing or exercising control of an
“aircraft” with “wrongful intent.” 	An intent to seize or exercise control of an aircraft without the legal
authorization to do so could involve wrongful intent.
II. 	Additional Federal Laws Relating to Aviation and Spectrum
In addition to implicating federal criminal laws, the acquisition, installation, testing, and use of UAS detection
or mitigation technologies may implicate laws and regulations administered by the FAA and the FCC relating
to aviation and RF spectrum. 	UAS response measures may also implicate existing aviation security laws and
regulations administered by the Transportation Security Administration (TSA).
A. Laws Relating to Aviation Safety and Efficiency15
Non-federal entities should evaluate UAS detection activities for compliance with laws and regulations
administered by the FAA, including but not limited to the following:
15 This subsection is limited to the discussion of UAS detection systems because, as previously indicated, only certain federal agencies
have been expressly authorized by Congress to mitigate UAS notwithstanding certain federal laws. The FAA does not support the use of
mitigation systems by any entities that do not have express authority from Congress.

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
• 	Use of Airspace. 	49 U.S.C. § 40103 establishes a public right of transit through the navigable airspace
and vests the FAA with authority to ensure the safety of aircraft and the efficient use of airspace. 	This
includes ensuring that compliant aircraft (including UAS) may move through the airspace without
improper interference. For example, detection systems may lead to the identification of both legitimate
airspace users as well as unlawful activity. Additional analysis is necessary to identify whether an operation
identified by a detection system is in violation of FAA regulation before engaging in an operational
response. This also includes identifying and working to address any potential collateral impacts of detection
technology or systems on the safe and efficient operation of the National Airspace System.
• 	Airport Operating Certificates. 49 U.S.C. § 44706, as implemented by 14 CFR Part 139, prescribes the
rules governing the certification and operation of airports in the United States. 	Holders of Airport
Operating Certificates issued under 14 CFR Part 139 must protect navigational aids. See 14 CFR § 139.333.
Commercial service airport operators may also need to update the contents of their airport certification
manuals to include operating procedures for the use of a UAS detection system. 	See id. § 139.203.
Moreover, the installation or use of UAS detection systems by sponsors of commercial service airports may
also implicate other regulatory requirements under CFR Title 14. 	The FAA has provided extensive
information to airport sponsors, which can be accessed at: https://www.faa.gov/airports/airport_
safety/#SafetyGuidance.
• 	Structures Interfering with Air Commerce. 49 U.S.C. § 44718, as implemented in 14 CFR Part 77, requires
entities proposing construction or alteration of existing structures in the vicinity of an airport to provide
the FAA with notice. See also FAA Order 7400.2M, Procedures for Handling Airspace Matters (Feb. 28,
2019). 	The required notice allows the FAA to conduct an aeronautical study of the potential for the
proposed structure and any electromagnetic broadcast signals to create a hazard to air navigation, including
interference with aircraft and navigational aids.16 Entities seeking to install or use equipment for UAS
detection activities should also evaluate whether 14 CFR Part 77 requires them to provide the FAA with
advance notice of proposed construction or alteration.
• 	Project Grant Application Approval Conditioned on Assurances About Airport Operations. 	49 U.S.C.
§ 47107 establishes obligations for recipients of grant funds for an airport development project to maintain
and operate airport facilities safely and efficiently and in accordance with specified conditions. Airports
subject to such conditions may need to ensure that the installation or use of a UAS detection system does
not introduce a hazard that cannot be mitigated, consistent with applicable grant assurance obligations,
such as Grant Assurance 20, Hazard Removal and Mitigation. 	In addition, such airports may need to
ensure that UAS detection systems and associated structures are accurately reflected in the Airport Layout
Plan consistent with Grant Assurance 29, Airport Layout Plan.
For additional information concerning these laws, please contact the Office of National Security Programs
and Incident Response at the FAA.
16 Non-federal entities are encouraged to independently validate the performance and characteristics of UAS detection systems being
considered. 	Significant deviations between vendor claims and real world operation, including the potential for RF emissions and
interference, have been observed by the FAA.

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
B. Laws Relating to Transportation/Airport Security
Through its broad authorities, the TSA oversees the implementation and ensures the adequacy “of security
measures at airports and other transportation facilities.” 49 U.S.C. § 114(f)(11). TSA may also take appropriate
action to address threats, including coordination of security measures with other agencies and to impose
requirements on transportation stakeholders, through regulations, security directives, emergency amendments,
and security programs. See 49 U.S.C. § 114(f)(4) & (l)(1)-(2); 49 U.S.C. § 44932; 49 CFR § 1542.105(d), 1542.303,
1544.305, 1544.105(d), 1546.105(d).
Airports seeking to deploy, buy, or purchase UAS detection or mitigation systems should consider laws,
regulations, and security requirements related to local aviation security response. For example, TSA regulations
require each operator of an airport regularly serving air carriers to establish an air transportation security program
(ASP). See 49 U.S.C. §§ 114 and 44903; 49 CFR Part 1542. Among other requirements, the ASP must provide
law enforcement personnel in the number and manner adequate to support the program. 49 CFR § 1542.215. In
addition, TSA’s enforcement authorities include the ability of the Administrator, in consultation with the airport
operator and law enforcement authorities, to order the deployment of personnel at any secure area of the airport
to counter threats to aircraft and aircraft operations or to address national security concerns, such as those posed
by UAS. 49 U.S.C. § 44903(h)(1).
For additional information or coordination, please contact your local TSA Federal Security Director.
C. Laws Relating to the Radiofrequency Spectrum
Any systems that involve emission of radio waves, including radar, must be evaluated for compliance with
laws and regulations administered by the FCC, including but not limited to the following:
• 	Authorizations for Use of Spectrum. Authorized non-federal radio communications include unlicensed
operations and operations on frequencies requiring individual licenses.
• 	Transmissions on frequencies authorized for unlicensed operations, such as common WiFi and
Bluetooth frequencies, do not require a license but may nevertheless implicate statutory or regulatory
prohibitions against harmful interference as well as other requirements.
• 	Operating on a frequency allocated for licensed private-sector use (such as on the bands used by mobile
phones) is subject to licensing requirements and other regulation at the federal level. See 47 U.S.C.
§ 301.
n 	For example, use of radar to detect UAS requires a Radiolocation Service license from the FCC.
General guidance regarding how to prepare and file an application is available at
https://www.fcc.gov/wireless/bureau-divisions/mobility-division/industrial-business/industrial-
business-licensing.Theapplicationmustidentifythelocationsandfrequencieswheretheapplicant
proposes to operate as well as provide other technical information. Equipment vendors may be
able to assist with gathering this information. No prior frequency coordination is required, but if
the applicant proposes to operate near a U.S. Government facility, it may wish to consult with
appropriateFederalofficialsbeforeapplyinginordertoavoidhavingtheapplicationrejectedwhen
the FCC conducts its Federal coordination.

Advisory on the Application of Federal Laws to the Acquisition and Use of
Technology to Detect and Mitigate Unmanned Aircraft Systems
• 	Marketing, Sale, or Operation of Jammers. 	47 U.S.C. § 302a prohibits most non-federal entities from
manufacturing, importing, shipping, selling, or using devices that fail to comply with FCC regulations
regarding devices that can interfere with radio reception, including transmitters designed to block, jam, or
interfere with wireless communications. 47 U.S.C. § 302a(b).
• 	Interference with Radio Communications. 47 U.S.C. § 333 prohibits “willfully or maliciously interfer[ing]
with or caus[ing] interference to any radio communications of any station licensed or authorized by [the
FCC] or operated by the United States Government.”
Guidance disclaimer: This advisory is provided for informational purposes only. Guidance documents, like this
document, are not binding and lack the force and effect of law, unless expressly authorized by statute or expressly
incorporated into a contract, grant, or cooperative agreement. Consistent with Executive Order 13891 and the
Office of Management and Budget implementing memoranda, the issuing Departments will not cite, use, or rely
on any guidance document that is not accessible through the issuing Departments’ guidance portals, or similar
guidance portals for other Executive Branch departments and agencies, except to establish historical facts. To the
extent any guidance document sets out voluntary standards (e.g., recommended practices), compliance with those
standards is voluntary, and noncompliance will not result in enforcement action. Guidance documents may be
rescinded or modified in the issuing Departments’ complete discretion, consistent with applicable laws.
9.95.300-UAS