1 GAO-02-822R Information on Arming Pilots

June 28, 2002

The Honorable Ernest F. Hollings

Chairman, Committee on Commerce,

 Science, and Transportation

United States Senate

Subject: Information Concerning the Arming of Commercial Pilots

Dear Mr. Chairman:

Since the terrorist attacks on September 11, 2001, legislation has been enacted to

enhance the nation’s approach to aviation security. Specifically, the Aviation and

Transportation Security Act created the Transportation Security Administration (TSA)

and, among other actions, federalized passenger and baggage screening staff at airports

and authorized the arming of commercial pilots, subject to the approval of the Under

Secretary of Transportation for Security and other conditions.1 On May 21, 2002, the

Under Secretary testified that he would not approve the arming of commercial pilots

because he believed they must focus exclusively on flying the aircraft. However, the

question of arming pilots remains open because H.R. 4635, introduced on May 1, 2002,

would require TSA to establish a program to arm pilots within 90 days of the bill’s

enactment. On June 19, 2002, the House Transportation and Infrastructure’s

Subcommittee on Aviation passed an amended version of H.R. 4635 to

• limit the maximum number of pilots participating in this pilot program to 2 percent of

the total number of pilots employed by air carriers and

• require that TSA address a number of procedural issues before beginning the

selection, training, and deputizing of pilots.

In addition, four other bills, introduced before the Aviation and Transportation Security

Act’s enactment, include proposals to carry weapons.2

 (See enc. I for more detailed

information.)

To facilitate congressional decision-making, you asked us to provide information on (1)

reasons for and against allowing pilots to carry firearms in the cockpit; (2) questions to

be addressed if pilots were to be armed; and (3) possible alternatives to arming pilots,

such as providing them with less-than-lethal weapons. On May 20, 2002, we briefed you

 1

P.L. 107-71, November 19, 2001.

2

H.R. 2958, H.R. 2896, H.R. 3171, and S. 1463.

United States General Accounting Office

Washington, DC 20548
2 GAO-02-822R Information on Arming Pilots

on the results of our work. This report summarizes the information we provided at that

time.

To obtain the information you requested, we analyzed a docket of over 7,500 comments

that the Federal Aviation Administration (FAA) had received by March 15, 2002, in

response to a request for comments, published in the Federal Register on December 31,

2001,3

 on whether pilots should be allowed to carry firearms in the cockpit.4 Our analysis

included all comments from airlines, trade associations, unions, other advocacy groups,

and aviation security firms and a sample of comments from individuals. In addition, we

examined available research studies on the potential risks and benefits of using firearms

on aircraft and possible alternatives, such as the use of less-than-lethal weapons. We

identified only one study that addressed the use of firearms on aircraft; this study

focused on structural damage to aircraft by ammunition and bombs. We also examined a

study by the National Institute of Justice, mandated by the Aviation and Transportation

Security Act, on the potential use of less-than-lethal weapons on aircraft.5

 To obtain

further information, we interviewed industry aviation security experts on the issue of

arming pilots with firearms or less-than-lethal weapons. Finally, we reviewed articles

and position papers by airlines, industry associations, pilot and flight attendant unions,

and other organizations. The detailed results of our analysis appear in enclosures II, III,

and IV. We performed our work in accordance with generally accepted government

auditing standards in May and June 2002.

Results in Brief

Without additional research, the potential benefits, risks, and costs of using weapons on

aircraft cannot be fully determined. Proponents’ and opponents’ views on allowing pilots

to carry firearms in the cockpit fell into four categories: the potential effectiveness, risk,

and cost-effectiveness of their carrying weapons, and the policy issues that would arise if

pilots were allowed to carry weapons. For example, proponents saw arming pilots as a

last line of defense if other security measures failed, while opponents considered the

current security enhancements, such as improved screening and increases in the number

of federal air marshals, sufficient. Views also differed on whether arming pilots with

firearms would be effective or safe. Proponents maintained that arming pilots would be

more cost-effective than other security enhancements, while opponents contrasted the

potentially high costs of the risks with the small benefits they anticipated. Finally, views

differed on the public policy implications of arming pilots. Proponents cited the

potential deterrent value of firearms and past regulatory precedents for arming pilots

 3

66 Fed. Reg. 67620. 4

According to FAA’s analysis, more than 96 percent of the comments favored the arming of pilots. FAA

noted that more than 99 percent of the comments were from individuals and pilots and that most of the

comments appeared to have been solicited by a few gun advocacy groups. FAA also noted that less than 1

percent of the comments were from organizations, such as industry associations, unions, airlines, public

interest groups, or security-related businesses.

5

For publicly available information on this report, see the testimony of Sarah V. Hart, Director, National

Institute of Justice, Office of Justice Programs, before the Subcommittee on Aviation, House Committee on

Transportation and Infrastructure, May 2, 2002.
3 GAO-02-822R Information on Arming Pilots

(see enc. I), whereas opponents cited the moral dilemma pilots would face if they were

prohibited from using firearms outside the cockpit and passengers or crew members

were being threatened in the cabin (see enc. III). Opponents also said that arming pilots

would introduce from 10,000 to 100,000 guns into our society. Enclosure II summarizes

the reasons for and against arming pilots that we obtained from our analysis of FAA’s

docket and from our research and interviews.

If pilots were to be armed, a number of questions would need to be resolved, such as (1)

who would regulate and oversee pilots’ carriage of weapons; (2) what qualifications and

training would pilots need to carry weapons; (3) what types of weapons could be carried

and how would they be maintained, stored, and transported; (4) what modifications to

aircraft would be required; and (5) how much would it cost to arm pilots. FAA raised

some of these questions in its request for comments, and some respondents raised

additional questions and proposed solutions. Most respondents that addressed these

questions were proponents of arming pilots. Yet even these proponents expressed a

range of views on critical questions, such as whether pilots’ participation would be

voluntary, whether the use of firearms would be restricted to defending the cockpit, and

where the firearms would be stored between flights. The responses generally attempted

to maximize the effectiveness of any program to arm pilots while minimizing its risk to

safety and security. Opponents of arming pilots generally did not address these

questions or maintained that the questions could not be addressed in a way that would

sufficiently mitigate unacceptable risks to safety and security. Enclosure III summarizes

these questions.

The National Institute of Justice reviewed the information available on less-than-lethal

weapons, as mandated by the Aviation and Transportation Security Act, and identified

six general categories—electrical shock, chemical, impact projectile, physical restraint,

light, and acoustic.6

 While FAA’s request for comments did not identify particular types

of less-than-lethal weapons that might be used as alternatives to firearms, most of the

comments that FAA received on less-than-lethal weapons and most of the Institute’s

study focused on electric shock devices, which are already used outside aircraft for law

enforcement purposes, such as riot control. Proponents of arming pilots with these

devices emphasized their ability to incapacitate an aggressor without posing a lethal risk

to others, while opponents noted that recovery from electrical shock takes less than a

minute and that the effectiveness of the devices can be limited in a variety of ways.

Although one major U.S. carrier has tested electric shock devices onboard aircraft and

has found no effects on airworthiness, the Institute regards their effects on aircraft

avionics as unknown and favors further testing. Observations on the other less-thanlethal weapons focused primarily on their value as temporary deterrents to aggressors

and on the difficulty of controlling their effects. Enclosure IV provides more detailed

information on these weapons.

 6

Weapons in the first three categories already exist. Weapons in the last two categories are currently under

development. Because the effects of these less-than-lethal weapons are temporary, physical restraints,

which are not considered weapons, are often used in conjunction with them.
4 GAO-02-822R Information on Arming Pilots

In addition to less-than-lethal weapons, we identified other security enhancements that

organizations or individuals suggested as alternatives to arming pilots. These included

• providing additional training for pilots in maneuvers that could disable attackers,

such as steeply banking the aircraft;

• installing technical improvements that would allow the aircraft to be controlled from

the ground if the pilot were disabled or the aircraft were hijacked;

• adding other enhancements to cockpit security, including changes to the design and

equipment of aircraft that would (1) limit access to the cockpit by unauthorized

personnel, such as the double-door system used by El Al, Israel’s national airline or

(2) permit the flight crew to monitor cabin activities through the use of video

cameras in the cabin; and

• having more armed security or law enforcement officers onboard.

Detailed information was not available on the feasibility or cost of these suggested

alternatives.

Agency Comments

We provided the Department of Transportation with a draft of this report for its review

and comment. The Department generally agreed that the information in the report fairly

presented the range of opinions on the issue of arming pilots. The Department provided

technical corrections that we incorporated as appropriate.

- - - - -

We are sending copies of this report to the Secretary of Transportation and will make

copies available to others upon request. If you have any questions about our work,

please contact me at (202) 512-2834. Key contributors to this letter were Bonnie Beckett,

Michael Bollinger, Elizabeth Eisenstadt, David Goldstein, Heather Krause, Teresa Spisak,

and Alwynne Wilbur.

In addition, the report will be available at no charge on the GAO web site at

http://www.gao.gov.

Sincerely yours,

Gerald L. Dillingham

Director, Physical Infrastructure Issues.
Enclosure I

5 GAO-02-822R Information on Arming Pilots

Background Information on Arming Pilots

In 1961, regulations1 promulgated by the former Federal Aviation Agency, now the FAA,

exempted law enforcement officers and other persons authorized by air carriers, such as

pilots and other crew members, from a general prohibition against the carriage of

weapons aboard aircraft. In 1975, the FAA changed the provision covering the nation's

largest commercial carriers (known as part 121 carriers) to provide that law enforcement

officers or crew members, including pilots, could not carry weapons onboard aircraft

unless (1) the FAA Administrator, as well as the carrier, authorized the carriage of

weapons and (2) the individual successfully completed a course of training in the use of

the weapon. On July 21, 2001, FAA limited the carriage of weapons on aircraft to certain

law enforcement officers.2

Although pilots and other crew members are currently prohibited from carrying weapons

onboard aircraft, the Aviation and Transportation Security Act raises the possibility of

arming pilots in the future. Specifically, this act authorizes air carrier pilots to carry a

firearm in the cockpit if

• the Under Secretary of Transportation for Security approves;

• the air carrier approves;

• the firearm is approved by the Under Secretary; and

• the pilot has received proper training in the use of the firearm, as determined by the

Under Secretary.

TSA has issued regulations that will continue to allow the arming of pilots who operate

in special situations. Specifically, TSA will continue to allow guns onboard aircraft if

they are part of a state-required emergency kit. Alaskan law, for example, provides that

certain aircraft must have emergency equipment onboard, including a firearm, in case

they make a forced landing at a remote wilderness location.3 This regulation becomes

effective on June 24, 2002.

 1

These regulations initially responded to hijackings of U.S. aircraft to Cuba.

2

See 66 Fed. Reg. 37330.

3

49 C.F.R. 1544.103. 67 Fed. Reg. 8205, February 22, 2002.
Enclosure II

6 GAO-02-822R Information on Arming Pilots

Reasons for and against Arming Pilots

Issue Reasons presented by those in favor of

arming pilots

Reasons presented by those opposed to arming

pilots

Need We need a last line of defense if other

security measures fail.

Current security enhancements, such as improved

screening, increases in the number of federal air

marshals, and cockpit door reinforcement, are

sufficient.

Effectiveness Firearms are a highly effective means of

permanently disabling one or multiple

attackers.

Arming pilots is the best deterrent to

hijackers.

Firearms are not sufficiently effective compared with

the risks they present. Trained law enforcement

officials have only an 18 to 22 percent hit ratio in

armed confrontation. The cramped quarters of a

cockpit do not lend themselves to success.

Risk The risk to aircraft integrity, including

depressurizing aircraft or damaging vital

flight components, is very small.

The risk to other people onboard is very

small, particularly if the firearms are used

only in the cockpit and pilots are well

trained.

Only when all other measures have failed

would the pilot be authorized to use the

firearm to protect the cockpit.

Pilots are trained to do several tasks at once

and would be able to incorporate the use of

a firearm into their other tasks.

Many pilots have had previous military

training in the use of firearms.

The risk to aircraft integrity, including depressurizing

the aircraft or damaging vital flight components, is

significant.

The risk to other people is significant. The firearm

could be used against a pilot or other passengers.

Violence Policy Center cites statistics that 21

percent of officers killed with a handgun were shot

with their own weapon.

Accidental weapon discharge and pilot mishandling

of the weapon are also risks.

Pilots are trained to land aircraft quickly in an

emergency, and in an emergency this should be

their primary task. Firearms could distract pilots

from their critical mission of flying and landing the

aircraft.

Military training for ground combat differs

significantly from what would be needed to defend

the cockpit.

Generally, law-enforcement officers have serious

objections to arming pilots.

CosteffectivenessArming pilots is cost-effective when

compared with the cost of expanding the

federal marshal program or implementing

other security enhancements.

Arming pilots is not cost-effective when compared

with the risks it would present and the small

likelihood it would be beneficial.
Enclosure II

7 GAO-02-822R Information on Arming Pilots

Policy issues There is a precedent for arming pilots: FAA

authorized the arming of flight crew

members in the 1960s.

Section 128 of the Aviation and

Transportation Security Act permits air

carrier pilots to carry a TSA-approved

firearm into the cockpit if approved by the

Under Secretary for TSA and the carrier,

and if the pilot has received proper training.

Arming pilots would introduce 10,000-100,000 guns

into our society, contradicting other efforts to

discourage the number of firearms in the

population.

Arming pilots might lead to other transportation

workers requesting to carry weapons onboard

aircraft. For example, the Maryland Pilots’

Association has petitioned to allow ship captains to

carry their weapons onboard aircraft when in transit

to their ships. In addition, it might lead to requests

for the arming of other transportation workers, such

as bus or taxi drivers.

Many air carriers oppose arming pilots because of

concerns about liability, training, and storage of the

weapons when not in use.

Sources: Comments received as of March 15, 2002, on FAA docket 2001-111229, published in the Federal Register

on December 31, 2001; testimonies on May 2, 2002, before the Subcommittee on Aviation, House Committee on

Transportation and Infrastructure, by Sarah V. Hart, Director, National Institute of Justice, Office of Justice Programs,

and Henry P. Krakowski, Vice President, Safety, Security, and Quality Assurance, United Airlines; literature search;

and interviews with aviation experts and officials from DOT, FAA, and TSA.
Enclosure III

8 GAO-02-822R Information on Arming Pilots

Questions to Be Addressed If Pilots Were to Be Armed

Topic Questions

Regulation and

oversight

• How would protocols be established and enforced?

• What entity would decide what types of weapons, ammunition, or aircraft

modifications would be required and whether airlines or pilots would have any

choice in these matters?

• What entity would be responsible for ensuring that only acceptable firearms and

ammunition were used on aircraft, and how would it accomplish this?

• How would the use of firearms by unauthorized persons be prevented?

• What entity would be responsible for establishing protocols for the use of

firearms and to minimize risks such as unauthorized use or accidental

discharge?

• How would the defensive efforts of armed pilots, air marshals, and other law

enforcement officers be coordinated?

Pilot qualifications • What qualifications, if any, would be used to establish which pilots would be

permitted to carry firearms?

• If carriage of a firearm were authorized, would carriage be at the pilot’s

discretion?

• What background checks or other screening would be required? Would all

pilots of commercial airlines be permitted to carry firearms?

• Would periodic recertification of pilots be required?

• What actions by a pilot, such as the commission of a felony or misdemeanor or

the abuse of alcohol or drugs, would trigger an automatic review of the right to

carry a firearm?

• Would pilots of cargo-only aircraft be permitted to carry firearms?

• Would any types of general aviation pilots be permitted to carry firearms?

• Would permission to carry firearms first be offered to those pilots with prior

military or law enforcement experience?

• Would the qualifications for using firearms be integrated into the existing

systems for establishing and maintaining airman qualifications, such as pilot

certifications and ratings?

Deputizing of pilots • Would pilots be deputized as law enforcement officers?

• What rights would this grant pilots beyond the carriage of weapons in aircraft

cockpits?

• How would this affect liability issues?

Training of pilots in

the use of firearms

• What entity would provide firearms training to pilots?

• Would the training require certification?

• How extensive would the initial training be and what would it cover?

• Would recurrent training be required, and if so, how often and what type?

• If the weapon were stored on the aircraft, would training be required for other

personnel who had access to the aircraft?
Enclosure III

9 GAO-02-822R Information on Arming Pilots

Topic Questions

When and where

to use firearms

• Under what circumstances would pilots be authorized to use firearms?

• Would pilots be restricted to using firearms to defend the cockpit?

• If there were two pilots, would one be permitted to use the firearm in the cabin

as long as the other remained in the cockpit?

• If a pilot had a firearm in the cockpit, would a severe disturbance in the cabin

present an unacceptable moral dilemma?

Type(s) of firearms

and ammunition

• What type(s) of firearms and ammunition would be most appropriate to meet the

dual purpose of maximizing the pilot’s ability to permanently disable an attacker

while minimizing the risk of damage to the aircraft and other people?

• What criteria would be used (e.g., simplicity, caliber, maintenance, reloading) in

authorizing types of weapons and ammunition?

• Which weapons have the least risk of accidental discharge?

• Are the weapons that have been authorized for use by FBI agents or air

marshals appropriate for pilots?

Maintenance of

firearms

• Who would be responsible for the maintenance and care of the firearms?

• What procedures would be required to ensure that the firearm was properly

maintained and cared for, and to reduce the possibility of accidental discharge?

Storage and

transportation of

firearms

• How would firearms be stored to minimize security risks?

• Would firearms be stored on the aircraft, at the airport, or with the pilot?

• If the firearm were stored on the aircraft or in the airport, what kind of lock and

container would be used to ensure security, and how would access be

controlled?

• If the firearm remained with the pilot, how would the authority be established for

the pilot to carry the firearm from home to work or during overnight stays in

other cities, states, or foreign countries? Given that it is not uncommon for pilots

to cross state lines in their commute between home and the place their work

duties begin, how would jurisdictional issues regarding interstate travel with a

concealed firearm be resolved?

• If the firearm remained with the pilot, how would the firearm be transported

through the airport to the aircraft? Would current screening procedures be

revised? Would separate screening facilities for pilots be established to

facilitate pilots getting through security without delays while minimizing their

contact with the public while in possession of a firearm?

• How would the security and liability risks associated with each option be

addressed?

• Are the procedures that have been established for federal air marshals on these

matters appropriate for pilots?

Aircraft

modifications

• Would aircraft modifications be required for the storage of weapons?

• Would aircraft modifications be required to reduce the possibility of damage to

key aircraft components caused by a bullet?
Enclosure III

10 GAO-02-822R Information on Arming Pilots

Topic Question

International

issues

• How would pilots handle firearms when flying to or from other countries?

• Are the procedures that have been established for air marshals on this matter

appropriate for pilots?

• Would foreign pilots flying for a foreign air carrier be permitted to carry firearms

when flying on routes in the United States?

Cost • Is arming pilots a cost-effective way to increase aviation security?

• How much would it cost to purchase firearms and ammunition for pilots, train

pilots, service and maintain firearms, and make any necessary modifications to

aircraft?

• Would liability concerns raise insurance costs?

• What other costs would be involved?

• What entity would bear the cost of arming pilots?

• Would arming pilots be less expensive than sufficiently expanding the air

marshal program?

Coordination • How would armed pilots coordinate with air marshals and other law enforcement

officers on the aircraft to minimize risk and confusion?

Sources: Comments received as of March 15, 2002, on FAA docket 2001-111229, published in the Federal Register

on December 31, 2001; testimonies on May 2, 2002, before the Subcommittee on Aviation, House Committee on

Transportation and Infrastructure, by Sarah V. Hart, Director, National Institute of Justice, Office of Justice Programs,

and Henry P. Krakowski, Vice President, Safety, Security, and Quality Assurance, United Airlines; literature search;

and interviews with aviation experts and officials from DOT, TSA, and FAA.
Enclosure IV

11 GAO-02-822R Information on Arming Pilots

Less-Than-Lethal Weapons

The National Institute of Justice has identified six general categories of less-than-lethal

weapons—electrical shock, chemical, impact projectile, physical restraint, light, and acoustic.

Weapons in the first three categories already exist. Weapons in the last two categories are

currently under development. Because the effects of these less-than-lethal weapons are

temporary, physical restraints, which are not considered weapons, are often used in conjunction

with them. The following table provides information, where applicable, on the types of weapons

in each category, their benefits and disadvantages, and their readiness for deployment.

Electric shock Characteristics

Types • Handheld direct-contact weapon: Has two probes that are pressed

against an aggressor’s skin or clothing. When the operator presses a

switch, the skin contact and pressed switch complete a circuit and the

subject receives a debilitating and possibly painful electrical shock.

• Dart-firing electrical shocking device: Fires two barbs connected to

trailing wires that lead back to the operator; contact with the subject’s

skin or clothing completes an electrical circuit, and an electrical

discharge automatically results.

Benefits • Immediately incapacitates an aggressor, who loses control over muscles

and nerves and cannot perform coordinated action.

• Not likely to kill or maim.

• Can be reactivated repeatedly as long as the wires remain attached to

the assailant.

• Can be used in a confined space, especially if handheld.

• Not likely to damage buildings or aircraft fuselages or to ignite standard

solids or black gunpowder.

• Easier to control than chemicals and less likely to cause damage than

blunt instruments, such as beanbag weapons.

• Easy to operate—little training needed.

Disadvantages • Does not disable an aggressor for long—recovery takes less than a

minute.

• Highly motivated and trained aggressors may be able to withstand the

effects.

• Can be used on only one aggressor at a time and requires immediate

use of physical restraints.

• Can be deflected by a book or dinner tray; may be foiled by thick

clothing; may not penetrate soft body armor.

• Effectiveness substantially limited if one probe lands on a nonconductive

surface (e.g., concrete, asphalt, or wood).

• Range of dart version may be too great for the cockpit or inadequate for

the cabin.

• Sparks can ignite some flammable liquids, vapors, or sensitive

explosives.

• Requires preventative maintenance—batteries must be fully charged.
Enclosure IV

12 GAO-02-822R Information on Arming Pilots

Electric shock

(cont.) Characteristics

Readiness for

deployment

• Deployment has begun.

• Presently used by three international foreign carriers.

• At least one domestic carrier has provided training and another three are

moving forward on using these items.

• One carrier has tested devices on all types of aircraft it flies and has

found no effect on airworthiness and negligible effects on electrical and

electronic equipment during testing, and has purchased several hundred

devices.

• National Institute of Justice considers weapon’s effects on aircraft

avionics and other critical systems unknown—favors further testing.

Chemicals

Types • Tear gas and pepper spray

• Anesthetics or calmative chemicals

Benefits • Tear gas, pepper spray can limit mobility of an aggressor.

• Anesthetics or calmative chemicals could be released, potentially

remotely, into the cabin to incapacitate all passengers, including

hijackers, until the plane can be safely landed.

Disadvantages • Chemicals cannot be adequately controlled in an aircraft and may

contaminate pilots and flight attendants, although handheld dispensers

of pepper spray offer better control than tear gas.

• Some individuals may become more violent in response to the use of

these chemicals.

• Tear gas and pepper spray have reversible, but not rapidly reversible,

effects--problematic if flight crew is affected.

• Anesthetics or calmative chemicals

• do not take effect rapidly,

• may create unacceptable health risks to infants and persons with

upper respiratory problems, and

• may prevent other passengers from helping to immobilize or restrain

hijackers.

Readiness for

deployment

• Remains under study or development.

• Should be tested in multiple aircraft settings before any deployment.

Impact

projectiles

Types • Rubber bullet or blunt trauma projectile

Benefits • May be appropriate in the aircraft’s cabin, where restrictions on space

are less severe and the risk of damage to critical systems or injury to the

flight crew are reduced.

Disadvantages • Degree of incapacitation varies greatly.

• Effect can wear off quickly.

• Not designed for use in confined spaces—launched from a pump-action

shotgun or a single round tear gas gun that requires two hands to

operate.

• Large and not designed to be easily carried on a belt or in a pocket.

Readiness for

deployment

• Should be tested in multiple aircraft settings before any deployment.
Enclosure IV

13 GAO-02-822R Information on Arming Pilots

Physical

restraintsa

Characteristics

Types • Handcuffs

• Nets—also exist in a prototype electrified design

• Surface chemicals applied to surfaces to make them extremely slippery

or extremely sticky, to impede the movement of an aggressor

Benefits • Handcuffs and flexible cuffs—common and useful in conjunction with

less-than-lethal weapons

Disadvantages • Nets are probably not adequate to incapacitate a determined and trained

hijacker.

• Surface chemicals could impede efforts of passengers and crew to

subdue hijacker.

• Deployment may not be fast enough to be helpful.

• Net guns are not practical in the cabin.

Readiness for

deployment

• Effect of electrified nets on aircraft electrical systems is unknown—

further testing is needed.

Light

Types • Bright white lights or lasers can produce a “wall of light” that may deter

an aggressor from attacking someone behind the light.

Benefits • Lower power level could be used to distract or delay the advance of an

aggressor and provide time for passengers and crew to protect

themselves or restrain the aggressor.

Disadvantages • May not prevent determined aggressor from using a weapon.

• If powerful enough to disable an aggressor, may cause eye damage.

Readiness for

deployment

• Still being developed by the Department of Defense with support from

the National Institute of Justice.

• Should be tested in multiple aircraft settings before any deployment.

Acoustics

Types • A sound source produces acoustic energy at audible and inaudible

frequencies.

Benefits • “Ear-splitting” audible sounds halt the advance of an aggressor.

Readiness for

deployment

• Still being developed by the Department of Defense with support from

the National Institute of Justice.

• Should be tested in multiple aircraft settings before any deployment.

a

Although not considered weapons, physical restraints are used in conjunction with less-than-lethal

weapons.

Sources: Comments received as of March 15, 2002, on FAA docket 2001-111229, published in the Federal Register

on December 31, 2001; interviews with aviation experts; and testimonies on May 2, 2002, before the Subcommittee

on Aviation, House Committee on Transportation and Infrastructure, by Sarah V. Hart, Director, National Institute of

Justice, Office of Justice Programs, and Henry P. Krakowski, Vice President, Safety, Security, and Quality

Assurance, United Airlines.

(540026)