June 22, 2023
Secondary Cockpit Barriers for Airline Aircraft
For the past two decades, there has been continuing policy
remained a top priority for the organization since. In 2011,
interest in enhancing airline in-flight security with
RTCA, Inc., an independent standards development
secondary cockpit barriers. A secondary cockpit barrier,
organization for aviation, developed guidance on the design
also known as an installed physical secondary barrier
and operational procedures for aircraft secondary barrier
(IPSB), typically consists of a lockable gate constructed of
systems. In 2015, FAA issued an advisory recognizing the
metal rods, bars, and cables or similar intrusion-resistant
RTCA guidance on secondary barriers as a means to block
materials that retracts when not in use. A suitable barrier is
access to the flight deck using an IPSB as an acceptable
designed to be positioned between the aircraft cabin and the
alternative to commonly employed methods that rely on
cockpit; occupy sufficient space so that it cannot be
cabin crew monitoring and impeding access to the flight
circumvented by going over, under, or around it; and be
deck with galley carts or other aircraft equipment.
resistant to intrusion, including forceful attempts to pull it
open or down or push through it. An IPSB primarily serves
Congressional Action
as a means to prevent or deter access to the aircraft cockpit
Since the 108th Congress in 2004 (see H.R. 4801), various
when a cockpit door is briefly opened, for example, when a
legislative proposals have been introduced seeking action to
pilot exits the cockpit to use the lavatory, when the flight
require secondary cockpit barriers on certain commercial
crew are served food, or during shift changes on long-haul
aircraft. In the 113th Congress, the Saracini Aviation Safety
flights.
Act of 2013 (H.R. 1775, S. 1495) was introduced. The bill,
named after Captain Victor J. Saracini, whose hijacked
Historical Context
airplane was flown into the South Tower of the World
Following the September 11, 2001 (9/11), terrorist attacks,
Trade Center in New York City in the 9/11 attacks, would
the Federal Aviation Administration (FAA) mandated
have mandated the installation and use of secondary cockpit
hardened cockpit doors that are resistant to forcible
barriers on all aircraft that are required by regulation to
intrusion and small firearms on most passenger airline
have hardened cockpit doors. This generally includes all
aircraft and large, all-cargo airplanes operated in the United
airliners with 20 or more passenger seats and any all-cargo
States. Regulations generally require those doors to remain
aircraft with a payload capacity greater than 7,500 pounds.
closed and locked for the entire duration of a flight with
Similar legislation offered in the 114th Congress (H.R. 911,
few exceptions, and special procedural measures must be
S. 911) and 115th Congress (H.R. 911) would have
taken in those rare instances when a door is opened to deter
mandated secondary cockpit barriers on commercial aircraft
potential attempts to breach a cockpit. However, security
with more than 75 passenger seats or with a maximum
concerns over potential flight deck breaches by terrorists or
gross takeoff weight of 75,000 pounds. Section 336 of the
unruly passengers have prompted continued interest in
FAA Reauthorization Act of 2018 (P.L. 115-254), titled the
secondary cockpit barriers.
Saracini Aviation Safety Act of 2018, mandated an FAA
order by October 5, 2019, requiring installation of a
The investigation of the National Commission on Terrorist
secondary flight deck barrier on all newly manufactured
Attacks Upon the United States (the 9/11 Commission) did
aircraft delivered to U.S. passenger airlines.
not find conclusive evidence as to how the 9/11 hijackers
gained access to the aircraft flight decks in those attacks,
Regulatory Action
but did find evidence of the terrorists making specific
In response to the statutory mandate in the FAA
inquiries and plotting to exploit opportunities when cockpit
Reauthorization Act of 2018, FAA convened an Aviation
doors were opened. The pre-9/11 industry-wide common
Rulemaking Advisory Committee Working Group on flight
strategy of cooperating with hijackers and avoiding direct
deck secondary barriers in March 2019. The working
confrontation would have rendered physical barriers, such
group’s February 2020 report to the FAA contained cost
as hardened cockpit doors and secondary barriers, largely
estimates and recommendations regarding the engineering
irrelevant. After the 9/11 attacks, the installation of
and design of IPSBs, including loads and forces to
hardened cockpit doors and implementation of procedures
withstand, placement in aircraft cabins, crew training, and
to defend the cockpit against any intrusions have prompted
operational procedures. It advised against expanding the
reviews of potential vulnerabilities, including during times
requirement to include all-cargo aircraft and suggested that
when cockpit doors are opened in flight.
ISPBs may be unnecessary on smaller aircraft that operate
In 2004, United Airlines and Northwest Airlines (Northwest
strictly on short-haul flights, and may be procedurally
later merged with Delta) equipped some widebody jets with
impractical on flights staffed by one cabin crewmember. In
secondary cockpit barriers; other airlines did not follow
August 2022, FAA published proposed rulemaking, and in
suit. In 2007, the Air Line Pilots Association (ALPA)
June 2023 it issued a final rule that would require
published a position paper urging government action to
installation of secondary cockpit barriers on newly
mandate secondary cockpit barriers by 2010; the issue has
delivered airline aircraft, and would require those barriers
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Secondary Cockpit Barriers for Airline Aircraft
to be closed and locked whenever the flight deck door is
Enhanced Aviation Safety Act of 2023 (H.R. 911, S. 911)
opened. The regulation would generally impose new design
would mandate installation of secondary cockpit barriers on
requirements for delivered aircraft placed in service with
all U.S. passenger airliners. A provision in the Securing
U.S. air carriers that are currently required by FAA to have
Growth and Robust Leadership in American Aviation Act
a hardened cockpit door. It would not apply to any all-cargo
(H.R. 3935) would instead direct FAA to convene a
airplanes or to foreign passenger airliners operated to and
rulemaking committee to make recommendations regarding
from the United States. The rule is to apply to all new
additional mandates for other airline aircraft not included in
aircraft placed in service with U.S. air carriers beginning in
the current regulation. If the entire passenger airline fleet of
the summer of 2025.
roughly 5,900 aircraft were to fall under such requirements,
the total fleetwide cost to comply would be approximately
Airline Fleet Composition
$71 million under the CBO assumption of a top per aircraft
According to FAA data for 2022, U.S. mainline passenger
cost of $12,000, or $207 million if the per aircraft cost is
air carrier fleets included a total of 3,915 jets, and regional
$35,000 as FAA expects. These amounts might be
carriers operated another 2,002 aircraft, including 1,623
somewhat higher, however, since retrofit installations might
jets. Airlines operated another 935 all-cargo jet aircraft. In
cost more than installations on brand-new aircraft.
total, about 6,800 aircraft were operated by U.S. air carriers,
FAA estimated that about 828 million passengers flew in
of which about 5,900 were engaged in passenger-carrying
2022, and it forecasts that annual passenger enplanements
operations. FAA expects the passenger air carrier fleet to
will surpass 900 million in 2023 and 1 billion within a
grow at an average annual rate of 1.7%, the regional air
decade. Based on future average annual enplanements of
carrier fleet to grow at an average rate of 1.0% per year, and
950 million, the barriers would need to remain in service
the all-cargo fleet to grow 3.7% per year on average over
for about 8 years to bring the cost per passenger
the next 20 years. Additionally, FAA estimates a fleet
enplanement to below one cent if the cost per airplane is
retirement rate of 3.57% among U.S. air carriers, which
$12,000. If the cost per airplane is $35,000, then the
would result in replacements of about 240 to 250 aircraft
barriers would need to remain in service for about 22 years
per year in the United States. In total, over the next several
to bring the per passenger cost down to one cent, which
years, about 350 new aircraft are expected to enter air
would be slightly less than FAA estimates of a typical
carrier service annually, of which about 300 would be
airplane lifecycle of 25 years. So, for newer aircraft, per-
placed in passenger airline service. At that rate, it would
passenger costs over the lifespan could be less than one cent
take roughly 28 years before most aircraft in passenger
across the airplane’s service life and would likely be a few
airline service would have secondary cockpit barriers
cents per passenger on average. Per-passenger costs would
installed, although FAA assumes most of the passenger
be somewhat higher if airlines were required to equip older
airline fleet would be equipped in 25 years, by 2047.
aircraft close to the end of service with secondary barriers
Cost Estimates and Anticipated Security Benefits
because those barriers would be in service for a shorter
time. Airlines would also incur the additional costs to equip
In 2017, the Congressional Budget Office (CBO) estimated
replacement aircraft with secondary barriers. So, total costs
the industry-wide cost of IPSBs on new aircraft delivered to
and per-passenger costs would vary across the industry,
passenger airlines would be under $15 million annually,
with somewhat lower costs incurred by airlines with
based on a per airplane cost between $5,000 and $12,000.
relatively newer aircraft fleets and higher costs incurred by
In contrast, FAA estimated present value annualized costs
airlines with older fleets. In general, the longer the aircraft
of $16 million to $17 million through 2047 based on higher
and the secondary cockpit barriers remain in service
per airplane costs of $35,000 for purchase, installation, and
without the need for major repair or replacement, the lower
training. FAA also assumes additional costs in the total
the per-aircraft and per-passenger costs of installing and
airplane lifecycle, bringing total annualized costs to the
maintaining the barriers will be.
airline industry to roughly $20 million to $29 million per
year from 2023 through 2072.
Given that it will take over two decades to achieve
widespread proliferation of secondary cockpit barriers
In considering the potential costs of a major terrorist event,
under the current regulation that only applies to newly
as demonstrated by the 9/11 attacks, and the potential
delivered passenger aircraft, Congress may choose to weigh
benefits of disrupting or deterring such an occurrence, it is
the potential security benefits and associated monetary
difficult to gauge the probability of a large-scale attack or to
costs in assessing whether to require secondary cockpit
independently assess the degree to which a single measure,
barriers on the existing fleet of passenger aircraft currently
like a secondary cockpit barrier, might disrupt such an
operated by U.S. airlines. In addition, Congress might also
attack amid a complex and multilayered approach to
contemplate the installation of secondary cockpit barriers
aviation security. Nonetheless, FAA concluded that, if
on foreign flights operated to and from the United States as
secondary cockpit barriers are completely effective at
well as onboard all-cargo aircraft, to more broadly address
thwarting attacks, installing them would be cost effective,
potential security risks from hijackings.
assuming the probability of an attempted terrorist attack is
at least 0.66% per year, or approximately one attempt of
that scale every 150 years.
Bart Elias, Specialist in Aviation Policy
Further Considerations for Congress
IF12435
Congress may seek to expand the number of aircraft subject
to secondary cockpit barrier requirements. The Saracini


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Secondary Cockpit Barriers for Airline Aircraft


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