Aviation Security Measures and Domestic Terrorism Threats
January 15, 2021
Aviation Security Measures and Domestic Terrorism Threats
After the January 6, 2021, security breach of the United
In addition to the Selectee list, TSA relies on sets of rules to
States Capitol, some Members of Congress have advocated
temporarily assign certain passengers to two other lists it
restricting the air travel of individuals who may seek to
maintains, the Silent Partner and Quiet Skies lists.
incite or carry out further violence. The Federal Bureau of
Individuals may be placed on these lists based on their
Investigation (FBI) is reportedly considering placing
recent international travel patterns, and are subject to
individuals who illegally entered the Capitol on the
enhanced screening measures, including additional baggage
Transportation Security Administration (TSA) No-Fly List.
screening, for a period of time.
This In Focus discusses the circumstances under which air
Historically, the TSA lists and the broader TSDB have
carriers, TSA, and other federal authorities may restrict
focused mainly on international terrorist threats. The FBI
domestic airline travel in response to security threats.
most recently released data about its security lists in
The No-Fly List and Airline Passenger Prescreening
September 2011. At that time, about 98% of the roughly
420,000 identities contained in the TSDB referred to
The No-Fly List is one of several lists maintained by TSA
persons who were not U.S citizens or legal U.S. residents.
to identify passengers based on their risk to aviation safety
The No-Fly list then consisted of about 16,000 identities, of
and national security (See 49 U.S.C. §44903). As the name
which fewer than 500 referred to U.S. persons. The Selectee
implies, individuals on the No-Fly List are to be denied
list was said to also contain about 16,000 identities,
boarding and referred to law enforcement authorities when
although the FBI did not specify how many of those were
they arrive at an airport to check in for a commercial airline
U.S. persons. The TSDB apparently has grown
flight. In addition to the No-Fly List, TSA maintains lists of
considerably since then. According to press reports, about
individuals who are to receive special scrutiny during pre-
1.2 million people were on the watchlist in 2017, including
flight security screening and whose carry-on bags and
about 4,600 American citizens. Official updates regarding
checked baggage are to be examined more thoroughly. The
the size and scope of the No-Fly and Selectee lists,
primary list of such individuals is referred to as the Selectee
however, have not been made public.
List or Automatic Selectee List to indicate that these
individuals are to be automatically selected for enhanced
TSA was required to establish a procedural mechanism
screening. Enhanced screening may include measures such
enabling people to challenge their inclusion on the No-Fly
as pat-downs and chemical trade detection swabs to test for
list or other lists that effectively barred them from traveling
explosives residue. Passengers not on these lists may be
by air. The Department of Homeland Security’s Traveler
randomly selected for enhanced screening, and passengers
Redress Inquiry Program (TRIP) maintains a website
or baggage that trigger alarms during initial screening may
through which individuals who claim to have been
also undergo these additional measures.
misidentified may seek redress, but such individuals may be
barred from air travel or subject to enhanced screening until
Both the No-Fly and Selectee lists are subsets of the
their cases are adjudicated.
broader consolidated terrorist watchlist, formally known as
the Terrorist Screening Database or TSDB. The TSDB is
maintained by the FBI’s Terrorist Screening Center
Airline Blacklists
, which
Airlines’ contracts of carriage, to which passengers agree
is responsible for consolidating and disseminating terrorism
when they purchase tickets, oblige passengers to obey
data to federal, state, and local law enforcement, and
airline rules and policies and comply with crewmembers
international partners. TSA’s Secure Flight system checks
performing their duties. Airlines may refuse to provide
passenger names against these lists multiple times between
ticket purchase and the flight’s departure
service to individuals who refuse to wear masks or facial
, as the lists are
coverings for the duration of the flight, as airlines have
routinely updated. TSA may expand these Secure Flight
uniformly required in response to federal recommendations
checks to include the larger number of identities in the
to limit the spread of COVID-19. Airlines may also remove
complete TSDB when warranted by security conditions.
disruptive or uncooperative individuals from an airplane,
This can be done when specific threat intelligence suggests,
and may ban them from future flights. Airlines are not
for example, heightened security concerns regarding a
obligated to notify the Federal Aviation Administration
specific flight, flights along a specific route, flights from a
(FAA), TSA, other federal agencies, or other airlines of
certain region, or flights to a specific destination. TSA
individuals who have been banned from future flights. If
sometimes refers to this broader use of the complete TSDB
incidents are brought to their attention, however, FAA or
as the Expanded Selectee List, suggesting that, under such
TSA may investigate to determine whether individuals may
heightened security conditions, additional individuals may
have violated federal aviation safety or security regulations.
be selected for enhanced security screening. However, the
No-Fly list might not be expanded unless specific
information warrants inclusion of additional individuals on
that list.
https://crsreports.congress.gov
Aviation Security Measures and Domestic Terrorism Threats
Enforcement of Federal Aviation Regulations
all passengers and a requirement for TSA-approved armed
Airlines may notify FAA of passengers who are disruptive,
security personnel on board all flights.
disobey instructions from airline crewmembers , or interfere
The airspace surrounding Washington, DC is off limits to
with airline crew. If FAA determines that an individual
private aircraft, with certain exceptions. Flights operating in
violated 14 C.F.R. §121.580, which prohibits anyone from
a 30-mile outer ring beyond the Flight Restricted Zone
assaulting, threatening, intimidating, or interfering with a
above Washington, DC, a circle with a 15-nautical-mile
crewmember performing their duties , it may impose civil
radius extending from the surface to 18,000 feet, must file a
penalties and, in certain cases may refer cases to the
flight plan and maintain constant radio communication with
Department of Justice to assess whether federal criminal
air traffic controllers. Such flights are closely monitored.
statutes may have been violated.
Defensive measures have been put in place to intercept and
Federal Jurisdiction of Crimes Committed
interdict unauthorized non-commercial aircraft that stray
Aboard Aircraft
into the restricted zone.
In addition to FAA and TSA, federal law enforcement
Potential Limitations and Concerns
authorities have jurisdiction over criminal acts that occur on
While the No-Fly List might prevent some individuals
board aircraft. From the time the external doors of an
intent on carrying out violence from traveling on a
aircraft are closed in preparation for flight until they are re-
commercial airline flight, it would generally not restrict
opened, any domestic flight, a U.S.-bound flight, or a U.S.-
travel by other modes. Identities contained within the
registered aircraft operating anywhere in the world is said
to be within the “special aircraft ju
TSDB, however, could be shared with law enforcement on
risdiction of the United
an as-needed basis to restrict access to certain facilities and
States” (see 49 U.S.C. Chapter 465). Alleged federal crimes
events.
occurring in that jurisdiction are investigated by federal law
enforcement and prosecuted by the Department of Justice.
The various TSA lists may be of limited usefulness outside
These include air piracy, interference with air crew,
of the aviation security context. They would not, for
destruction of aircraft or aircraft facilities, carrying a
example, be capable of stopping individuals from lawfully
weapon or explosive device, and a host of serious crimes
transporting firearms to sites where armed protests are
incorporated by reference including assaults; maiming;
planned. In general, airline passengers, including
murder; manslaughter; attempted murder or manslaughter;
individuals that may be on the TSA Selectee or Enhanced
theft or attempted theft by force, violence, or deception; and
Selectee lists, are not prohibited from transporting firearms
sexual abuse.
aboard aircraft so long as the firearms are transported
unloaded and locked as checked baggage. On January 17,
Federal statutes require TSA to deploy Federal Air Marshal
2017, a mass shooting in a baggage claim area of the Fort
Service teams on all flights assessed to pose a high security
Lauderdale-Hollywood International Airport in Florida was
risk based on threat and vulnerability assessments. Air
perpetrated by an arriving passenger who had properly
marshal duties are focused on detecting and preventing
declared the handgun and two magazines used in the attack
terrorist attacks against an aircraft in flight, but in some
and had transported them in a locked box as required by
instances they may respond to violent criminal behavior
federal regulations. In mid-January 2021, some airlines
onboard an aircraft. Sworn federal, state, and local law
temporarily prohibited passengers from checking firearms
enforcement offers that receive training and TSA approval
on flights to the Washington, DC area. Somewhat relatedly,
may also carry firearms on board commercial flights under
proposals to impose a waiting period on the purchase of
limited circumstances and could assist in responding to
firearms by individuals on the No-Fly List or whose
criminal conduct. Additionally, under the Federal Flight
identities are included in the broader TSDB have been
Deck Officers program, TSA deputizes airline pilots who
introduced in recent Congresses, but have not been enacted.
volunteer to travel armed to protect the flight deck from
terrorist attacks. However, armed pilots would not typically
Significantly expanding the No-Fly List could increase the
intervene in incidents inside the aircraft cabin, but would
number of misidentifications, potentially resulting in
instead focus on diverting to an airport where law
delayed or denied boarding of more passengers. Further
enforcement resources on the ground could respond.
complicating matters is that some individuals who might be
targeted for inclusion on the No-Fly or Selectee lists based
Charter and General Aviation Flight Security
on suspected participation in the January 6, 2021, breach of
Actions to restrict the travel of certain individuals aboard
the U.S. Capitol or other domestic incidents may have been
scheduled airline flights may result in those individuals
previously cleared to participate in trusted traveler
instead seeking to travel on charter aircraft. Domestic
programs, such as TSA’s PreCheck or Customs and Border
charter flights are not routinely screened against the TSA
Protection’s Global Entry. Individuals who participate in
lists, and only passengers and their baggage traveling on
these programs are eligible for expedited screening at TSA
charters aircraft weighing more than roughly 100,000
airport checkpoints. While placement on the No-Fly or
pounds (somewhat larger than a typical Boeing 737) are
Selectee lists would presumably terminate an individual’s
required to undergo physical screening. For smaller jets,
participation in these programs, it may raise questions
passengers are not routinely screened, but flight crew must
regarding the effectiveness of threat assessments conducted
undergo security background checks. However, all charter
under these programs .
and private general aviation flights inbound to Washington
Reagan National Airport, regardless of size, are subject to
Bart Elias, Specialist in Aviation Policy
more extensive security measures, including screening of
IF11731
https://crsreports.congress.gov
Aviation Security Measures and Domestic Terrorism Threats
Disclaimer
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https://crsreports.congress.gov | IF11731 · VERSION 1 · NEW