United States Government Accountability Office

GAO Report to Congressional Requesters

AVIATION SECURITY

Efforts to Strengthen 

International 

Passenger 

Prescreening are 

Under Way, but 

Planning and 

Implementation Issues 

Remain 

May 2007 

 

GAO-07-346 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

May 2007

AVIATION SECURITY

Efforts to Strengthen International 

Passenger Prescreening are Under Way, 

but Planning and Implementation Issues 

Remain

Highlights of GAO-07-346, a report to 

congressional requesters 

Passenger prescreening—a process

that includes matching passengers’ 

identifying information against 

records extracted from the U.S.

government terrorist watch list—is 

one of several security measures in 

place to help ensure the safety of 

commercial flights traveling to or 

from the United States. DHS has 

several efforts underway to

strengthen international aviation 

passenger prescreening. This

report focuses on certain elements

of the passenger prescreening 

process as well as some of the 

actions that DHS is taking or has 

planned to strengthen prescreening

procedures. This report is a limited 

version of the original November

2006 report as various agencies

that we reviewed deemed some of

the information in the original

report to be security sensitive. 

GAO’s work included interviewing

officials and assessing relevant 

documentation from federal 

agencies, U.S. and foreign air 

carriers, industry groups, and 

several foreign countries. 

What GAO Recommends

GAO recommended in November 

2006 that the Department of

Homeland Security (1) complete a 

strategic plan and develop an 

evaluation strategy for one of its

prescreening programs, (2) take

steps to ensure that international 

and domestic prescreening

programs are aligned, and (3) 

ensure full compliance with 

applicable privacy laws. DHS 

generally concurred with these 

recommendations. 

Customs and Border Protection (CBP), the Department of Homeland 

Security (DHS) agency responsible for international passenger prescreening, 

has planned or is taking several actions designed to strengthen the aviation 

passenger prescreening process. One such effort involves CBP stationing 

U.S. personnel overseas to evaluate the authenticity of the travel documents 

of certain high-risk passengers prior to boarding U.S.-bound flights. Under 

this pilot program, called the Immigration Advisory Program (IAP), CBP 

officers personally interview some passengers deemed to be high-risk and 

evaluate the authenticity and completeness of these passengers’ travel 

documents. IAP officers also provide technical assistance and training to air 

carrier staff on the identification of improperly documented passengers 

destined for the United States. The IAP has been tested at several foreign 

airports and CBP is negotiating with other countries to expand it elsewhere 

and to make certain IAP sites permanent. Successful implementation of the 

IAP rests, in part, on CBP clearly defining the goals and objectives of the 

program through the development of a strategic plan. 

A second aviation passenger prescreening effort designed to strengthen the 

passenger prescreening process is intended to align international passenger 

prescreening with a similar program (currently under development) for 

prescreening passengers on domestic flights. The Transportation Security 

Administration (TSA)—a separate agency within DHS—is developing a 

domestic passenger prescreening program called Secure Flight. If CBP’s 

international prescreening program and TSA’s Secure Flight program are not 

effectively aligned once Secure Flight becomes operational, this could result 

in separate implementation requirements for air carriers and increased costs

for both air carriers and the government. CBP and TSA officials stated that 

they are taking steps to coordinate their prescreening efforts, but they have 

not yet made all key policy decisions. 

In addition to these efforts to strengthen certain international aviation

passenger prescreening procedures, one other issue requires 

consideration in the context of these efforts. This issue involves DHS 

providing the traveling public with assurances of privacy protection as 

required by federal privacy law. Federal privacy law requires agencies to 

inform the public about how the government uses their personal 

information. Although CBP officials have stated that they have taken and 

are continuing to take steps to comply with these requirements, the 

current prescreening process allows passenger information to be used in 

multiple prescreening procedures and transferred among various CBP 

prescreening systems in ways that are not fully explained in CBP’s 

privacy disclosures. If CBP does not issue all appropriate disclosures, the 

traveling public will not be fully aware of how their personal information 

is being used during the passenger prescreening process. 

www.gao.gov/cgi-bin/getrpt?GAO-07-346.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Cathy Berrick 

at (202) 512-3404 or berrickc@gao.gov. 
Contents 

Letter 1

Results in Brief 4

Background 6

DHS is Taking Steps to Strengthen the Current International

Passenger Prescreening Process 13 

CBP Has Not Fully Disclosed its Use of Personal Information 

during the Prescreening Process 20 

Conclusions 24

Recommendations for Executive Action 25 

Agency Comments and Our Evaluation 26 

Appendix I Objectives, Scope, and Methodology 31 

Appendix II Airline Liaison Officer Programs Implemented In 

Other Countries 35 

Appendix III APIS Quick Query (AQQ) and APIS Minus 60 

Minutes (APIS-60) 38 

Appendix IV Comments from the Department of Homeland 

Security 42 

Appendix V GAO Contacts and Staff Acknowledgments 45 

GAO Related Products 46 

Table 

Table 1: The Characteristics of Selected ALO Programs 36 

Page i GAO-07-346 Aviation Security
Figures 

Figure 1: Overview of Current Prescreening Activities for 

International Flights 8 

Figure 2: Overview of Current Differences between the Domestic 

and International Prescreening Process 13 

Figure 3: Immigration Advisory Program Process 15 

Figure 4: The interaction between CBP Prescreening Systems and 

Data Usage 22 

Page ii GAO-07-346 Aviation Security
Abbreviations 

AEA Association of European Airlines 

ALO Airline Liaison Officer 

APIS Advanced Passenger Information System

APP Advanced Passenger Processing 

AQQ APIS Quick Query 

ATA Air Transport Association of America 

ATS Automated Targeting System

CBP Customs and Border Protection 

CSI Container Security Initiative 

DHS Department of Homeland Security 

DIMIA Department of Immigration and Multicultural and 

Indigenous Affairs 

ETA Electronic Travel Authority 

EU European Union 

GPRA Government Performance and Results Act 

IAP Immigration Advisory Program

IATA International Air Transport Association 

ISI Immigration Security Initiative 

MIO Migration Integrity Officer 

NPRM Notice of Proposed Rulemaking 

NTC National Targeting Center

PNR Passenger Name Record 

TDY Temporary Duty 

TECS Treasury Enforcement Communications System

TSA Transportation Security Administration 

TSC Terrorist Screening Center 

TSDB Terrorist Screening Database 

TSOC Transportation Security Operations Center 

VWP Visa Waiver Program 

This is a work of the U.S. government and is not subject to copyright protection in the 

United States. It may be reproduced and distributed in its entirety without further 

permission from GAO. However, because this work may contain copyrighted images or 

other material, permission from the copyright holder may be necessary if you wish to 

reproduce this material separately. 

Page iii GAO-07-346 Aviation Security
United States Government Accountability Office

Washington, DC 20548 

 

May 16, 2007

The Honorable John Conyers, Jr. 

Chairman 

Committee on the Judiciary 

House of Representatives 

The Honorable Bennie G. Thompson

Chairman 

Committee on Homeland Security 

House of Representatives 

The Honorable Daniel K. Inouye 

Chairman 

The Honorable Ted Stevens 

Vice-Chairman 

Committee on Commerce, Science, and Transportation 

United States Senate 

The Honorable F. James Sensenbrenner, Jr. 

House of Representatives 

During 2005, a number of passengers that the U.S. government identified 

as a security risk were identified onboard international flights traveling to

or from the United States.1

 In certain cases, the resulting security risk was 

deemed high enough that the U.S. government diverted the flight from its 

intended destination, resulting in delays for passengers, costs to the air 

carriers, and government intervention. 

Preventing such high-risk passengers from boarding international flights

traveling to or from the United States is the goal of the nation’s 

international aviation passenger prescreening process.2

 These efforts 

include, among other things: 

• Identity matching: comparing passengers’ identifying information, 

such as name and date of birth, against records extracted from the U.S. 

 1

 The specific number of passengers identified by the U.S. government as a security risk is 

sensitive security information. 

2

 A separate process exists for prescreening passengers on U.S. domestic flights. 

Page 1 GAO-07-346 Aviation Security
government terrorist watch list containing the names of known or 

suspected terrorists.3

• Travel document review: evaluating the authenticity and

completeness of passengers’ passports and other travel documents. 

• Risk targeting: comparing passenger information against a set of 

targeting rules that are indicators of elevated passenger risk in an 

attempt to identify possible high-risk passengers who may not be on 

the terrorist watch list. 

The identity matching component of the international passenger 

prescreening process currently involves separate matching activities 

conducted by air carriers (prior to a flight’s departure) and the federal 

government (both before and after a flight’s departure). In 2004, Congress 

mandated that the Department of Homeland Security (DHS) issue a 

proposed plan for completing the U.S. government’s identity matching 

process before the departure of all international flights. Customs and 

Border Protection (CBP), the DHS agency charged with responsibility for 

conducting international aviation passenger prescreening, published its 

proposed plan to strengthen passenger prescreening in July 2006 in a 

notice of proposed rulemaking.4

 Appendix III provides more detail on the 

notice of proposed rulemaking and the two prescreening options that CBP 

provides to air carriers in the proposed rulemaking. 

This report is a limited version of the original report that we provided to 

you on November 20, 2006. The various agencies we reviewed deemed 

some of the information in that report as Sensitive Security Information or 

Law Enforcement Sensitive. Therefore, this report omits our findings 

associated with vulnerabilities we identified in the existing passenger 

prescreening process and measures that could be taken to address those 

vulnerabilities. This report also omits key details regarding certain 

 3

 The U.S. government maintains a single consolidated terrorist watch list. Records are 

extracted from this consolidated list to conduct various screening activities including

aviation passenger prescreening. Additional information about the watch list can be found 

on pages 7 and 9. 

4

 71 Fed. Reg. 40035, July 14, 2006. A notice of proposed rulemaking (NPRM) is an

announcement published in the Federal Register of proposed new regulations or 

modifications to existing regulations, the first stage in the process of creating or modifying 

regulations. A notice of proposed rulemaking is intended to give the public an opportunity 

to comment on a proposed rule. 

Page 2 GAO-07-346 Aviation Security
procedures, timeframes and locations associated with the passenger 

prescreening process. The objectives of the original report addressed: 

• the main factors affecting the international passenger prescreening 

process, and the potential impact of these factors, and 

• the status of efforts to address these factors, and the issues, if any, that

could affect efforts to strengthen the international passenger 

prescreening process. 

This version of the report focuses on certain elements of the current 

international aviation passenger prescreening process as well as some of 

the actions that DHS is taking or has planned to strengthen prescreening 

procedures. More specifically this report’s content addresses: 

• the implementation of the Immigration Advisory Program (IAP), a CBP 

program that assesses risk levels for certain passengers in limited 

overseas locations; 

• the alignment of international and domestic passenger prescreening 

processes; and 

• compliance with privacy laws with respect to information collected to 

conduct international passenger prescreening. 

Although the information provided in this version of the report is more 

limited in scope, the overall methodology used for our initial report is 

relevant to this report as well because the information contained in this 

report was derived from the initial sensitive report. To address the 

objectives of our initial report we interviewed officials and obtained and

analyzed relevant documents from CBP, including the National Targeting 

Center (NTC); the Transportation Security Administration (TSA), 

including the Transportation Security Operations Center (TSOC); and the 

Terrorist Screening Center (TSC). To obtain a cross section of both 

domestic and foreign air carriers’ views about the international passenger 

prescreening process, including the impact of current U.S. prescreening 

requirements and the potential impact of future requirements, we 

interviewed officials from 13 air carriers that fly passengers to and from

Page 3 GAO-07-346 Aviation Security
the United States.5

 We also interviewed officials from two domestic air 

carrier and passenger travel associations and three international air carrier 

associations that represent the interests of air carriers and travelers to 

discuss the impact of current and potential future U.S. international 

prescreening requirements on their members. We met with foreign 

government officials in the Netherlands, Poland, the United Kingdom, 

Australia, and New Zealand to discuss the impact of current and potential 

future U.S. international prescreening requirements and obtain 

information about aviation prescreening programs in place in these 

countries. We also met with officials from the European Union to discuss 

the impact of U.S. prescreening requirements on air carriers with 

operations in Europe. Additionally, we interviewed and obtained 

documents from private sector companies that facilitate the electronic 

transmission of passenger data between air carriers and government 

agencies to determine their role, if any, in future international aviation

passenger prescreening initiatives. We conducted our work, which took

place from April 2005 through October 2006, in accordance with generally 

accepted government auditing standards. Appendix I contains more detail 

about our scope and methodology. 

DHS has several efforts underway to strengthen international aviation

passenger prescreening. Two of these efforts include: Results in Brief 

• Conducting overseas review of some high-risk passengers’ travel 

documents. One prescreening effort that CBP has under way is 

designed to increase the level of scrutiny given to the travel documents 

of certain high-risk passengers before they board international flights 

traveling to the United States. Under this pilot program, called the 

Immigration Advisory Program (IAP), CBP assigns officers to selected 

foreign airports where they utilize an automated risk-targeting system 

that identifies passengers as potentially high-risk—including 

passengers who do not need a visa to travel to the United States. CBP 

officers then personally interview some of these passengers and 

evaluate the authenticity and completeness of these passengers’ travel 

 5

 To help ensure the information we obtained was representative of air carriers that fly 

different volumes of passengers to the United States, we selected seven carriers that fly 

more than 1 million passengers annually into the United States, four carriers that fly 

between 500,000 and 1 million passengers annually into the United States, and two carriers 

that fly less than 500,000 passengers annually into the United States. 

Page 4 GAO-07-346 Aviation Security
documents. Successful implementation of the IAP rests, in part, on 

CBP clearly defining the goals and objectives of the program. 

• Aligning international and domestic prescreening programs. A 

second prescreening effort under way is designed to align international 

passenger prescreening with a similar program under development for 

prescreening passengers on domestic flights. The Transportation 

Security Administration—a separate agency within DHS—is developing

a domestic passenger prescreening program called Secure Flight. Once 

Secure Flight is operational, TSA will be operating a domestic 

passenger prescreening system, and CBP will be operating an 

international passenger prescreening system. As currently envisioned, 

both programs will screen passengers whose itinerary includes both an 

international flight and a domestic connection within the United States. 

If the two programs are not effectively aligned, each program could 

result in separate implementation requirements for air carriers. This 

could result in additional costs to the air carriers and the U.S. 

government, and cause confusion and inconvenience to passengers. 

CBP and TSA officials stated that they are taking some steps to 

coordinate their prescreening efforts, but they have not yet made all 

key policy decisions. 

In addition to these efforts to strengthen certain international passenger 

prescreening procedures, one other issue, while not aimed at

strengthening the capabilities of international aviation passenger 

prescreening, nonetheless requires consideration in the context of these 

efforts. This issue is: 

• Providing assurances of privacy protection as required by 

federal privacy law. Federal privacy law requires agencies to inform

the public about how the government uses their personal information. 

Although CBP officials have stated that they have taken and are 

continuing to take steps to comply with these requirements, the current 

prescreening process allows passenger information to be used in 

multiple prescreening procedures and transferred among various CBP 

prescreening systems in ways that are not fully explained in CBP’s 

privacy disclosures. Although CBP recently published additional 

privacy disclosures related to its use of passenger data during the 

prescreening process, CBP’s current public disclosures do not fully 

explain its uses of personal information during the entire prescreening 

process. If CBP does not issue all appropriate disclosures, the traveling 

public will not be fully aware of how their personal information is 

being used during the passenger prescreening process. 

Page 5 GAO-07-346 Aviation Security
To help DHS ensure progress on efforts to strengthen the international 

passenger prescreening process, we recommended in our November 2006

report that the Secretary of the Department of Homeland Security and the 

Commissioner of Customs and Border Protection take the following steps: 

(1) complete a strategic plan and develop an evaluation strategy for the 

Immigration Advisory Program pilot, (2) further align domestic and 

international passenger prescreening processes and coordinate 

prescreening efforts, and (3) ensure that international passenger 

prescreening programs are in full compliance with federal privacy laws. 

We provided a draft of this report to DHS and DOJ for their review and 

comment. DHS, in its written comments, generally concurred with the 

recommendations in the report. DHS and DOJ both provided technical 

comments that we incorporated as appropriate. In its written comments, 

DHS outlined the status of various efforts that it has in progress or 

planned to address the recommendations. For example, DHS stated that 

CBP has efforts under way to capture additional data in order to properly 

evaluate the IAP’s performance, and that there are ongoing efforts by CBP 

and TSA to align procedures, systems and functional requirements for 

their respective passenger prescreening programs. DHS also noted in its 

comments the recent and planned efforts to publish new privacy 

disclosure documents, such as the November 2006 system of records for 

its automated targeting system, which would supplement its other existing 

public disclosure documents. The full text of DHS’s comments is provided 

in appendix IV. 

Passenger prescreening is one security measure among many implemented 

both before and after the terrorist attacks of September 11 designed to 

strengthen the security of U.S. commercial aviation. Together, these 

various measures combine to form a multi-layered aviation security 

approach. Although the prescreening of passengers on international flights 

traveling to or from the United States predated the September 11, 2001 

terrorist attacks, this process was strengthened after the attacks. 

The current international passenger prescreening process relies on two 

different sets of passenger data and involves multiple prescreening steps 

carried out by air carriers and CBP. The two sets of passenger data 

include: 

Passenger Name Record (PNR) data, such as name, address, and 

billing information that passengers provide to air carriers, travel agents, or 

online travel companies when making a flight reservation. 

Background 

Current International 

Passenger Prescreening 

Process Relies on Two 

Different Sets of Passenger 

Data and Involves Multiple 

Steps 

Page 6 GAO-07-346 Aviation Security
Advance Passenger Information System (APIS) data, such as name, 

date and location of birth, and country of citizenship, which is derived 

from passports and other government-issued documents, such as visas, 

that most passengers must present to air carriers when checking in for 

international flights. 

A central prescreening activity involves matching identifying information 

about passengers—including name and date of birth—against the No Fly 

and Selectee Lists that are extracted from the TSC’s Terrorist Screening 

Database (TSDB) to identify potential security threats in a process often 

called identity matching. The identity matching step is conducted by both 

air carriers and the U.S. government. Federal requirements state that air 

carriers must transmit APIS data to CBP no later than 15 minutes before 

flight departure for international flights originating in the United States 

and no later than 15 minutes after flight departure for international flights

bound for the United States. In addition to these data, CBP occasionally 

uses commercial data or data from other government databases during 

this process to help confirm a passenger’s identity. 

A second prescreening activity, separate from identity matching, involves

using risk assessment tools to analyze passenger data to assess the 

security risk that a passenger might pose. This constitutes an effort to 

identify high-risk passengers that may not be on the No Fly or Selectee 

Lists. Specifically, CBP uses an automated system, called the Automated 

Targeting System-Passenger (ATS-P), that uses available passenger data to

apply a set of CBP-generated targeting “rules” that CBP has determined 

are associated with increased passenger risk. CBP uses both PNR and 

APIS data to apply the ATS-P rules. This comparison results in a risk 

assessment for each passenger indicating the passenger’s relative security 

risk. 

A third prescreening activity involves the review of passengers’ travel 

documents for evidence of forgery or fraudulent use. Depending on the 

passenger, this document review can occur at three separate time frames 

during the process of flying internationally, as follows: (1) the State 

Department reviews the travel documents in advance of travel for 

passengers who are required to obtain a visa in advance of their travel, (2) 

air carrier personnel review passengers’ travel documents for authenticity

upon check-in for flights, and (3) CBP officers review passenger travel 

documents either upon the passengers’ arrival in the United States or, in

some cases, prior to their departure for the United States. Figure 1 

provides an overview of the current passenger prescreening activities as 

set against the basic steps typically taken to fly internationally—including

Page 7 GAO-07-346 Aviation Security
obtaining a flight reservation and ticket, checking in for a flight, departing 

from one country, and arriving in another. 

Figure 1: Overview of Current Prescreening Activities for International Flights 

Source: GAO.

1.

Passenger makes

reservation and 

buys ticket

Passenger checks in 

at airport

2.

Plane departs from 

U.S. or foreign country 

3.

Plane arrives in the 

U.S. or foreign country

Data used for

 prescreening

Prescreening

activities involving

the use of data 

Other key 

prescreening

activities

 

Passenger Name 

Record (PNR) data: 

supplied by passenger 

when buying ticket 

Air carrier compares 

PNR data with 

watch list before

flight departs

CBP uses PNR and APIS 

data, both before and 

after flight departs, to 

determine using ATS-P

if passenger not on 

watch list represents 

elevated risks 

Advanced Passenger 

Information System 

(APIS) data: contained 

in passport 

At check-in, air carrier 

verifies travel documents 

such as passport 

and visa 

CBP compares APIS 

data with watch list. 

This process occurs 

both before and after 

flight departs

AIRPORT

When flight arrives 

in the United States, 

CBP evaluates 

passenger’s 

travel documents 

for authenticity

PNR data used

APIS data used

b

a

a An additional prescreening step occurs for those passengers traveling to the United States from nonvisa waiver program countries. For these passengers this additional step involves State Department 

officers reviewing the authenticity of their passports prior to issuing a travel visa. 

b In several overseas locations, CBP also reviews the travel documents of selected high-risk 

passengers through a pilot program. See page 14 for more details on the pilot program.

 

Page 8 GAO-07-346 Aviation Security
Before a passenger receives a boarding pass, the air carriers conduct an 

initial identity match, which (along with CBP’s identity matching process) 

constitutes the first step of the international passenger prescreening 

process. To complete this prescreening step, air carriers compare PNR 

data (information that is self-reported by passengers when they make a 

flight reservation) against the No Fly and Selectee Lists to determine if 

there are any identity matches. This prescreening step is required to occur 

prior to flight departure. The No Fly and Selectee Lists are extracted from

the TSC’s TSDB, the consolidated federal government terrorist watch list 

(which contains the names of known or suspected terrorists). Persons on 

the No Fly List are deemed to be a threat to civil aviation and are therefore 

to be precluded from boarding an aircraft traveling to, from, or within the 

United States. Being on the Selectee List does not mean that the person 

will not be allowed to board an aircraft or enter the United States. Instead, 

persons on this list receive additional security screening prior to being 

permitted to board an aircraft—this screening may involve a physical 

inspection of the person and a hand-search of their luggage. 

Air Carriers Use Passenger 

Data Obtained during 

Reservation Process to 

Conduct a Comparison 

against the No Fly and 

Selectee Lists 

Examples of PNR data that may be collected at the time a reservation is 

made include a passenger’s name, home address, telephone number, 

frequent flyer information, and e-mail address. If an air carrier determines 

that a passenger’s identity matches an identity on the No Fly List, TSA 

requires the carrier to contact the TSA Office of Intelligence so U.S. 

authorities can further verify whether the passenger’s identity matches the 

watch-listed identity.6

 

 6

 For example, in some cases a passenger may have the same name as a person listed on 

the No Fly or Selectee Lists, and an air carrier may require assistance from TSA to verify 

whether the person is, in fact, the same person. 

Page 9 GAO-07-346 Aviation Security
CBP also conducts an identity matching process after air carriers conduct

their identity matching, but CBP’s process utilizes APIS data. These data 

are generally gathered from the passenger’s passport—a document 

required of almost all passengers flying into and out of the United States.7

In most instances, these data are recorded electronically from the 

traveler’s machine-readable passport. This process records information 

from the passport directly into the air carrier’s computer systems, thereby 

avoiding potential errors that could occur by key-stroking the data. CBP 

uses the APIS data to conduct identity matching using its automated 

systems including its law enforcement databases and the No Fly and 

Selectee Lists, which CBP transfers to its Treasury Enforcement 

Communications System (TECS).8

 If this review produces a positive match 

to the No Fly List, the TSA Office of Intelligence is contacted to confirm

the match. 

While the above prescreening activities focus on determining whether any

passengers are on the No Fly and Selectee Lists, CBP also conducts a 

second prescreening step to identify other passengers, not on the No Fly 

and Selectee Lists, but who may nonetheless present a potential security 

risk. This step is a risk targeting process that occurs for international 

flights traveling to or from the United States. CBP conducts this risktargeting using a computer-based system called the Automated Targeting

System-Passenger. This system compares passenger data (both PNR and 

APIS data), along with data from government databases (including the 

TSDB), against a set of targeting rules. According to CBP officials, this 

risk-targeting process reflects CBP’s experience with indicators of 

possible illegal or other activities that CBP is responsible for monitoring. 

This comparison results in a risk assessment for each passenger that CBP 

uses to determine if the passenger requires additional CBP contact—either 

CBP Uses Passenger Data 

Obtained during Passenger 

Check-in to Conduct an 

Identity-matching 

Procedure 

CBP Identifies Passengers 

Not on the No Fly and 

Selectee Lists Who May 

Present Security Risks 

 7

Prior to January 23, 2007, an exception to this rule existed for citizens of the United States, 

and visiting citizens of Canada, Mexico, and Bermuda when entering the United States from

most countries in the Western Hemisphere. However, under a plan required by the

Intelligence Reform and Terrorism Prevention Act of 2004, as amended, all U.S. citizens, 

and citizens of Canada, Bermuda, and Mexico traveling to the United States as 

nonimmigrant visitors, generally must present a valid passport at air ports-of-entry. 

8

 TECS is the principal law enforcement system supporting CBP’s counter-terrorism and 

regulatory compliance missions. TECS consists of multiple databases that maintain 

investigative case information, border-crossing information, passenger information, and

other information provided by other government agencies related to the inspection of 

persons crossing the border. CBP uses automated systems to screen large amounts of data

against information in the TSDB, including names on the No Fly and Selectee Lists. 

Page 10 GAO-07-346 Aviation Security
before the passenger boards a U.S.-bound aircraft or upon the passenger’s 

arrival in the United States. If a passenger’s risk assessment indicates an 

elevated security risk, CBP may decide to take additional security actions

to gather more information about the passenger. Additionally, CBP can 

also decide that a passenger’s risk level is sufficiently elevated that the 

passenger should be prevented from boarding a flight. If the flight is 

abroad, CBP officials stated that they can coordinate with State 

Department Officers to contact U.S. Embassy Legal Attaché officials 

assigned abroad at foreign embassies and consular offices. These Legal 

Attaché officers coordinate with foreign law enforcement personnel to 

identify, interview, or inspect the passenger before allowing the passenger 

to board the flight. 

A third prescreening step involves air carriers and CBP determining the 

authenticity of passenger travel documents. Before issuing boarding 

passes on flights departing from or arriving in the United States, air 

carriers are required to review each passenger’s travel documents, 

including passports and visas, to verify that the passenger is properly 

documented for the intended destination. For U.S.-bound passengers, air 

carriers are also required to validate that the passenger’s passport 

information matches the APIS data that the air carriers electronically 

submit to CBP. CBP provides periodic training to air carrier personnel to 

help them determine the authenticity and completeness of passenger 

travel documents. CBP’s review of passenger documentation can occur in 

multiple locations. For example, CBP is always required to inspect travel 

documents for passengers on international flights arriving in the United 

States. However, in some overseas locations, CBP officials also review 

passenger documents prior to the passenger boarding a U.S.-bound 

international flight. 

The current prescreening process is under revision and under a proposed 

plan, the U.S. government will take over the process of identity matching 

passengers against the No Fly and Selectee Lists from the air carriers prior 

to flight departures. As part of the Intelligence Reform and Terrorism

Prevention Act of 2004,9

 Congress mandated that DHS issue a notice of 

proposed rulemaking (NPRM) by February 16, 2005, that would allow CBP 

Air Carriers and CBP 

Evaluate the Authenticity 

of Passenger Travel

Documents 

Federal Law Mandated 

That CBP Publish a Plan to 

Alter Its Prescreening 

Process 

 9

 Intelligence Reform and Terrorism Prevention Act of 2004, Pub. L. No. 108-458, 118 Stat. 

3638, Section 4012. 

Page 11 GAO-07-346 Aviation Security
to conduct its comparison of passenger information against the No Fly and 

Selectee Lists before the departure of all international flights traveling to

or from the United States. CBP issued its NPRM on July 14, 2006, and 

provided for a public comment period.10 

Prescreening Passengers 

on Domestic Flights 

Involves a Different 

Process 

Concurrent to the changes that are being considered for conducting 

international passenger prescreening, TSA, the agency charged with 

ensuring the security of all modes of transportation, is in the process of 

modifying domestic passenger prescreening procedures. TSA is required, 

by the Intelligence Reform and Terrorism Prevention Act of 2004, to 

develop a prescreening program through which TSA would assume the 

domestic watch list matching function currently conducted by air carriers 

prior to domestic flight departures. TSA has named this prospective 

prescreening program Secure Flight.

As we have reported in our prior work on Secure Flight, currently only air 

carriers—and not the U.S. government—match passenger information 

against the No Fly and Selectee Lists to prescreen passengers on domestic 

flights. 11 We have also reported that TSA has faced significant 

management challenges in the past in developing the Secure Flight 

program, and that key policy decisions that would affect the effectiveness 

of the program had not yet been made. In 2006, TSA announced that it was 

delaying the development of Secure Flight in order to reassess the 

program’s goals, requirements, and capabilities. The current domestic 

prescreening process also requires that air carriers operate the ComputerAssisted Passenger Prescreening System (CAPPS), which identifies 

passengers for secondary screening based on certain travel behaviors 

reflected in their reservation information that are associated with threats 

to aviation security, as well as through a random selection of passengers.12 

 10 71 Fed. Reg. 40035, July 14, 2006. CBP granted an extension to the comment period in 

response to a request by the aviation industry. As a result of the extension, comments on

the proposed rule were due by October 12, 2006. 

11 GAO, Aviation Security: Significant Management Challenges May Adversely Affect 

Implementation of the Transportation Security Administration’s Secure Flight Program,

GAO-06-374T (Washington, D.C.: Feb. 9, 2006). GAO, Aviation Security: Secure Flight

Development and Testing Under Way, but Risk Should Be Managed as System Is Further

Developed, GAO-05-356 (Washington, D.C.: Mar. 28, 2005). 

12 Although the air carriers currently conduct the watch list matching and CAPPS 

prescreening functions, these processes are required and overseen by TSA. 

Page 12 GAO-07-346 Aviation Security
Figure 2 highlights the main steps of, and differences between, the 

prescreening of passengers on domestic and international flights. 

Figure 2: Overview of Current Differences between the Domestic and International Prescreening Process 

Source: GAO, MapArt (map). 

Prescreening for domestic flights

(originating and ending within the United States)

 Identity-matching conducted by air carriers

 Data for matching identities to watch list comes 

 from passenger-reported PNR information 

 Computer Assisted Passenger Prescreening System 

 (CAPPS) used by air carriers to identify potential 

 high-risk passengers not on watch list 

Prescreening for international flights

(originating or ending in a foreign country)

 Identity-matching conducted by both air carriers 

 and CBP

 Data for matching identitites to watch list comes from 

 passenger-reported PNR information and APIS passport information 

 Passenger risk assessment conducted by CBP to identify 

 potential high-risk passengers not on watch lista

 

U.S. EUROPE

ASIA AFRICA

AUSTRALIA

SOUTH AMERICA

NORTH AMERICA

U.S.

a International flights departing from the United States that are operated by U.S. air carriers are 

required to also operate CAPPS to identify passengers for secondary screening. This occurs in 

addition to the risk assessments being conducted by CBP. 

CBP has several efforts under way to strengthen certain international 

passenger prescreening processes. One such effort involves the placement 

of CBP personnel overseas to interview some high-risk passengers and 

inspect their travel documents in advance of their departure to the United

States. This program also incorporates a mechanism to provide air carrier

personnel with additional training on identifying fraudulent travel 

documents. As it revises the international passenger prescreening process, 

CBP is also attempting to align its process with the prospective program to 

prescreen passengers on domestic flights, which will be administered by 

the TSA. 

DHS is Taking Steps 

to Strengthen the 

Current International 

Passenger 

Prescreening Process 

Page 13 GAO-07-346 Aviation Security
One program, currently in place but supplemental to the primary 

international passenger prescreening processes, is a program that provides 

additional scrutiny to passengers and their travel documents at foreign 

airports prior to their departure for the United States. This program, called 

the IAP,13 is a pilot program that began in 2004 and was designed to 

identify and target potential high-risk passengers. Under the IAP pilot, 

CBP has assigned trained officers to foreign airports where they 

personally interview pre-identified high-risk passengers, conduct 

behavioral assessments, and evaluate the authenticity of travel documents 

prior to the passenger’s departure to the United States. The pilot program 

has been tested in several foreign airports, and CBP is negotiating with 

other countries to expand it elsewhere and to make certain IAP sites 

permanent. 

Immigration Advisory 

Program Developed to 

Increase Review of Travel 

Documents for Some HighRisk Passengers at Foreign 

Airports 

The IAP pilot serves both national security and immigration functions. 

According to CBP, the purpose of the IAP is to (1) prevent passengers 

identified as security threats from boarding international flights bound for 

the United States, (2) provide no board recommendations to the air 

carriers for passengers who are not properly documented for entry into 

the United States, (3) provide training to air carrier personnel on how to 

detect fraudulent travel documents, (4) provide advance notice to U.S. 

authorities of passengers that warrant closer inspection upon their arrival 

in the United States, (5) collect law enforcement information on known or 

suspected criminal aliens and smugglers, and (6) share information with 

foreign government and law enforcement officials regarding trends in 

illegal travel. CBP officials and others have also stated that a secondary 

benefit of the IAP pilot is to help facilitate the legitimate travel of 

passengers, particularly U.S. citizens. Figure 3 depicts how the IAP works 

at international airports. 

 13 IAP, or the Immigration Advisory Program, was initially referred to as the Immigration 

Security Initiative (ISI). Prior to the development of IAP, the legacy Immigration and 

Naturalization Service operated the Immigration Control Officers program, which was 

similar to IAP in that it stationed U.S. immigration officers abroad to screen U.S.-bound

passengers in order to validate travel documents. 

Page 14 GAO-07-346 Aviation Security
Figure 3: Immigration Advisory Program Process 

Source: GAO.

1. NTC vets PNR data for each 2. 

passenger flying to the U.S. using 

ATS-P and other security databases 

to estimate passenger flight risk 

NTC sends IAP officers risk 

assessments for all passengers 

departing the airport that day

5.

3.

Based on their assessments, 

IAP officers may make “no board” 

recommendations to air carriers 

for certain passengers

IAP officers prioritize flights and 

passengers to be interviewed 

each day

4. IAP officers interview high-risk 

passengers flying to the U.S. 

and examine their travel 

documents

U.S. 

NTC 

IAP 

NTC search 

NO

BOARD

The IAP pilot began at several sites in 2004. Each site consists of a group 

of IAP officers and a team leader. Team leaders are typically assigned to 

longer posts as compared to other IAP officers. Expansion of the pilot 

program to other locations has already begun. The Intelligence Reform 

and Terrorism Prevention Act of 2004 requires that CBP identify 50 foreign 

Perceived Successes of IAP Led 

CBP to Expand the Program 

Page 15 GAO-07-346 Aviation Security
airports for further expansion of the IAP, and CBP has subsequently 

completed this list.14

CBP has reported several successes through the IAP pilot. According to 

CBP documents, from the start of the IAP pilot in June 2004 through 

February 2006, IAP teams made more than 700 no-board recommendations 

for inadmissible passengers and intercepted approximately 70 fraudulent 

travel documents. CBP estimated that these accomplishments equate to 

about $1.1 million in cost avoidance for the U.S. government associated 

with detaining and removing passengers who would have been turned 

away after their flights landed, and $1.5 million in air carrier savings in 

avoided fines and passenger return costs.15 According to CBP, these 

monetary savings have defrayed the costs of implementing the program.

However, it is not yet clear whether CBP anticipates, or expects, that the 

IAP will pay for itself through its government and air carrier cost savings, 

as it previously asserted.16

CBP officials said that they have also expanded a related program for 

training air carrier staff to better identify fraudulent identity documents 

and placed this program within IAP. This program, known as the Carrier 

Liaison Program, officially began in February 2006. According to CBP 

officials, CLP’s purpose is to enhance border security by providing 

technical assistance and training to air carrier staff on the identification of

improperly documented passengers destined for the United States. 

To continue to strengthen and successfully expand the IAP, CBP is faced 

with concerns expressed by host government and IAP officials about the 

duration of its IAP officer rotations. CBP officials said that they were 

aware of these concerns and are taking steps to address the matter. 

Several other countries, such as the United Kingdom, Canada, Australia, 

and New Zealand, also operate programs similar to IAP. Known as airline 

liaison officer (ALO) programs, these programs have in some cases been

CBP’s IAP Is Similar to

Programs in Other Countries 

 14 CBP was directed in the Conference Report accompanying its FY 2007 Appropriations 

Act to report to the Congress on the performance of the IAP no later than January 23, 2007. 

According to CBP, they submitted the report to Congress prior to this deadline. 

15 We did not independently assess these costs estimates or other reported program 

benefits. 

16 IAP cost savings are derived from a CBP estimate based on the average costs to detain 

and remove an individual from the United States who is found not eligible to be admitted. 

Page 16 GAO-07-346 Aviation Security
operating since the late 1980s. Like IAP, these countries also generally

post officers overseas at airports in an attempt to intercept improperly 

documented passengers from traveling to their country. CBP officials are 

aware of these programs but believe that the IAP is different in some key 

respects. Most notably, CBP officials stated that IAP’s focus is on 

terrorism, while ALO programs focus primarily on illegal immigration. 

However, valuable lessons can be gained from the experiences of these 

other countries in implementing similar programs as CBP continues to 

develop its IAP pilot. For example, officials from one ALO program stated 

that their country incorporated a Web-based system that allows its ALO 

officers to record improperly documented and other suspect travelers. 

These data can then be instantly accessed and analyzed at headquarters so 

that the information can be used to make changes to improve all of the 

country’s ALO locations. Another ALO program utilizes PNR data to 

identify trends in document fraud, allowing its ALO network to quickly 

transmit alert information into its passenger screening system so that 

identified passengers can be screened further at check in prior to boarding 

an aircraft. CBP, however, relies upon each IAP site to send aggregate 

reporting statistics to CBP headquarters—potentially limiting the 

program’s ability to rapidly analyze and act on trends in document fraud 

since there is a time delay in CBP headquarters receiving the data. 

Additionally, a United Kingdom official stated that their ALO program 

benefited from expanding the program slowly during the initial stages of

the program to allow the United Kingdom government to learn important 

lessons from its early ALO sites. Appendix II contains a summary of 

information and potential lessons to be learned from the ALO programs of 

other countries. 

CBP has not taken all of the steps necessary to fully learn from its pilot 

sites in order to determine whether the program should be made 

permanent and the number of sites that should exist. These steps are part 

of a risk management approach to developing and evaluating homeland 

security programs. Risk management is a continuous process of assessing 

risks, determining the best available actions to mitigate these risks, 

implementing actions to reduce risks, and evaluating these actions to 

determine their level of benefit. Managing homeland security efforts on the 

basis of risk has received widespread support from Congress, the 

President, and others as a way to help set priorities effectively and to 

allocate limited resources. A risk management framework includes such 

elements as formally outlining the goals of the program, setting 

CBP Could More Fully 

Incorporate Risk Management 

Principles in the IAP Pilot 

Page 17 GAO-07-346 Aviation Security
measurable performance measures, and evaluating program 

effectiveness.17 

Although CBP is currently taking steps to make its IAP sites permanent 

and to expand the program to other foreign locations, CBP has not 

finalized a strategic plan for the program that delineates program goals, 

objectives, constraints, and evaluative criteria. We have reported in the 

past that high-performing organizations have a focus on achieving results

and outcomes and foster a results-oriented organizational culture to 

reinforce this focus. Key to developing this focus is strategic planning, 

which involves having a mission that employees, clients, customers, 

partners, and other stakeholders understand and find compelling; setting 

goals to achieve the mission; and aligning the organization’s activities, core

processes, and resources with those goals.18 CBP officials told us that they 

have drafted a strategic plan for the IAP, which contains program goals 

and performance measures, but CBP stated that the plan has not yet been

finalized. 

DHS Intends to Align 

International and 

Domestic Prescreening 

Programs, but DHS Has 

Not Yet Made All Key 

Policy Decisions 

A second effort that CBP has under way to strengthen the international 

passenger prescreening process involves the alignment of the U.S. 

government’s international and domestic aviation prescreening programs, 

which are being developed separately by CBP and TSA, respectively.

Aligning these two programs is particularly important because many 

passengers in the United States who are traveling to or from foreign 

destinations have a domestic flight in addition to their international flight. 

Passengers traveling on these types of flights are currently subjected to

two different prescreening processes. 

 17These steps are part of an overall risk management framework for developing and 

evaluating homeland security programs. In 2004, we developed a risk management 

framework that brought together recognized risk management practices from public and 

private sector reports, as well as through interviews with terrorism experts. This

framework was reviewed by academic experts in risk management, field-tested on several 

GAO reviews, and applied in analyzing a variety of homeland security applications. For 

further discussion of this risk management framework, see GAO, Risk Management: 

Further Refinements Needed to Assess Risks and Prioritize Protective Measures at Ports 

and Other Critical Infrastructure, GAO-06-91 (Washington, D.C.: Dec. 15, 2005). 

18GAO, Forum on High Performing Organizations: Metrics, Means, and Mechanisms for

Achieving High Performance in the 21st Century Public Management Environment, 

GAO-04-343SP (Washington, D.C.: Feb. 13, 2004). 

Page 18 GAO-07-346 Aviation Security
The air carrier community has asked CBP and TSA to coordinate their 

efforts to ensure that the programs are compatible and are developed as a

single approach to avoid the need for air carriers to implement two 

separate screening systems to meet CBP and TSA requirements. Without 

such coordination, air carriers might have to implement different 

information connections, communications, and programming for each

prescreening program, as well as ensure that their data are compatible 

with each program. In a joint letter to the Secretary of DHS, the Air 

Transport Association of America (ATA) and the Association of European

Airlines (AEA) urged DHS to coordinate international and domestic 

aviation passenger prescreening programs so that air carriers are not 

unduly burdened by the costs and inefficiencies posed by working with 

two different prescreening programs. The letter also stated that ATA and 

AEA believed that there had been a lack of full coordination between CBP 

and TSA in aligning their respective passenger prescreening programs. 

Further, as we have previously reported, since both agencies are 

developing and implementing passenger prescreening programs, CBP and 

TSA could mutually benefit from the sharing of technical testing results 

and the coordination of other developmental efforts.19 Coordination and 

planning in the development of these two programs would also enhance 

program integration and interoperability and potentially limit

redundancies. 

In 2004, CBP and TSA officials stated that they recognized the similarities 

between the international passenger prescreening and the proposed 

domestic prescreening programs, and acknowledged the need to 

coordinate the two programs. According to CBP officials, DHS has 

expressed its intention to align international and domestic passenger 

prescreening efforts, and decided to develop one “portal” through which 

carriers will transmit passenger data to the government for domestic and 

international flights. CBP officials further stated that interagency 

discussions with TSA have resulted in a decision to create a single 

communication point for the submission of the passenger data for both 

domestic and international flights, one of the main concerns of air carriers. 

Despite these coordination efforts and DHS’s commitment to align the 

processes, CBP and TSA have not yet made all of the policy decisions to 

complete the alignment between the CBP international prescreening 

program and the prospective Secure Flight program, including the use of 

 19 GAO-06-374T and GAO-05-356. 

Page 19 GAO-07-346 Aviation Security
different data elements, documentation, and identity matching

technologies to conduct prescreening.20 CBP officials stated that many of 

these policy and technical decisions have not been made because TSA is in 

a process of “rebaselining” its Secure Flight program, which involves TSA

reassessing program goals, requirements, and capabilities. In discussions 

with us, CBP and TSA officials stated that these coordination efforts were 

continuing, but they did not provide any documentation of how such 

matters were being resolved or when they planned for the programs to be 

aligned. 

One additional issue requires consideration, as well, in the context of 

DHS’s efforts to strengthen the passenger prescreening process. Despite 

recent efforts by CBP to provide more detailed information to the public 

about its use of passenger data during the international passenger 

prescreening process, CBP has not fully disclosed or assessed the privacy 

impacts of its use of personal information during international passenger 

prescreening as required by law. The Privacy Act of 1974 and the EGovernment Act of 2002 require federal agencies to protect personal 

privacy by, among other things, limiting the disclosure of personal 

information and informing the public about how personal data are being 

used and protected. Federal agencies inform the public of their use of 

personal information by issuing two types of documents: 

CBP Has Not Fully 

Disclosed its Use of 

Personal Information 

during the 

Prescreening Process 

System of records notices: The Privacy Act requires that agencies 

publish a notification in the Federal Register that informs the public when 

they establish or make changes to a system of records. 

Privacy impact assessment: The E-Government Act requires that 

agencies analyze how information is handled to (1) ensure handling 

conforms to applicable legal, regulatory, and policy requirements 

regarding privacy; (2) determine the risks and effects of collecting, 

maintaining, and disseminating information in identifiable form in an 

electronic information system; and (3) examine and evaluate protections 

 20 GAO-06-374T. 

Page 20 GAO-07-346 Aviation Security
and alternative processes for handling information to mitigate potential 

privacy risks.21

Although CBP has taken certain actions to meet the requirements of the 

Privacy and E-Government Acts, including the recent publication of 

additional privacy disclosures, these actions have not fully informed the 

public about how personal information is being used, as required by law. 

Specifically, CBP has published public notices and reports that describe 

certain elements of its international prescreening process, but these 

documents do not fully or accurately describe CBP’s use of personal data

throughout the passenger prescreening process. It is important for CBP’s 

documentation to describe all of the steps of the prescreening process 

because the interrelationship of various steps of the process allows data to 

be transferred and used in ways that have not been fully disclosed. 

CBP’s international prescreening process involves a wide range of 

procedures and data sources that CBP utilizes to determine passenger risk 

levels. According to a CBP official, to help make these prescreening 

decisions, CBP collects personal data from multiple sources (including 

passengers and government databases), and uses the data for several 

purposes, including identity matching against the government watch list, 

risk targeting, and passenger document validation. According to CBP, its 

officers also use commercial data, to a limited degree, to assist them in 

confirming a passenger’s identity when needed. CBP’s public disclosures 

about APIS and ATS do not describe all of the data inputs or the extent to

which the data are combined and used in making prescreening decisions.

22

 21 The Privacy Act places limitations on agencies’ collection, use, and disclosure of personal

information maintained in systems of records, which are groups of personal information

that are maintained by an agency from which personal information is retrieved by an 

individual’s name or identifier. Among the act’s provisions are requirements for agencies to 

give notice to the public about the use of their personal information. Also, when agencies

establish or make changes to a system of records, they must notify the public by a notice in 

the Federal Register about the type of data collected; the types of individuals about whom

information is collected; the intended “routine” uses of the data; the policies and practices

regarding data storage, retrievability, access controls, retention, and disposal; and 

procedures that individuals can use to review and correct personal information. The EGovernment Act of 2002 requires agencies to conduct a privacy impact assessment when 

using information technology to process personal information. 

22 The degree to which an agency must disclose its use of personal information may be 

limited by exemptions permitted by the Privacy Act. To claim such exemptions, an agency

must issue a rule, with an opportunity for public comment, identifying their exemptions 

and the reasons for taking the exemptions. 69 Fed. Reg. 41543, July 9, 2004 and 68 Fed. Reg. 

69412, 69413, Dec. 12, 2003. 

Page 21 GAO-07-346 Aviation Security
As shown in Figure 4, CBP’s passenger prescreening involves more data 

inputs and uses of data than are described in CBP’s current privacy 

disclosures. 

Figure 4: The interaction between CBP Prescreening Systems and Data Usage 

Source: GAO. 

Passenger Name 

Record Data (PNR data)

 Commercial Data

Advanced Targeting

System-Passenger (ATS-P)

PURPOSE: identity matching

and risk targeting

CBP Officers

 Conduct passenger inspections

 Validate authenticity of 

 travel documents

 Make screening decisions

 Create "lookout" alert flags on 

 passengers of interest

 Add information to government

 databases (e.g. TECS)

Passenger Passport 

Data (APIS data)

 

Watch list names from 

Terrorist Screening 

Database (TSDB) 

Data from other 

government 

databases (such as 

FBI’s NCIC database)

Data from government

databases

DATA CBP SYSTEMS CBP DECISION-MAKING

c

d

Continual data flow

Occasional data flow

a

Treasury Enforcement 

Communications

System (TECS)

PURPOSE: identity matching

b

a CBP officers can utilize TECS and ATS-P databases to enter “lookout” alert flags. Not all CBP 

officers have access to all of the databases listed. 

b

 In the APIS privacy impact assessment, CBP defined APIS as a system. However, CBP officials 

later stated that APIS is not a system but rather data that are sent to the TECS to conduct identity

matching. 

c CBP officials stated that commercial data are only used in rare situations when a passenger’s

identity cannot be verified against other information. 

d CBP officers use data from the TSC as needed to help confirm a passenger’s identity. 

Page 22 GAO-07-346 Aviation Security
CBP has stated that its public reporting on its use of APIS data complies 

with the Privacy Act through references to previously published Privacy 

Act notices about systems used during the prescreening process. However, 

these references are not sufficient because they do not fully disclose 

CBP’s use of personal information during the prescreening process. 

Specifically, CBP stated that because APIS is a system within the Treasury 

Enforcement Communications System, it is described in the TECS system 

of records notice, which was published in October 2001. CBP also 

referenced a 2003 system of records notice for the DHS Arrival and 

Departure Information System (ADIS), which interfaces with TECS, but 

which CBP officials stated separately is not used by CBP in the passenger 

prescreening process. However, neither of these notices specifically 

describes CBP’s passenger prescreening or the use of APIS or PNR data. 

Although CBP has stated that its previous privacy disclosures sufficiently 

complied with federal privacy law, on November 2, 2006, DHS published a 

Privacy Act system of records notice for ATS. In addition, on November 

22, 2006, DHS published a privacy impact assessment for ATS. Both of 

these documents refer to the ATS-P system used in CBP’s aviation 

passenger prescreening process. These disclosures —released after CBP 

received an earlier version of this report—provide much more detailed

information on ATS-P as compared with prior privacy disclosures. 

Nevertheless, CBP has still not published a system of records notice or a 

privacy impact assessment that comprehensively describes the entire 

prescreening process. For example, although CBP has published a privacy 

impact assessment for APIS and ATS, neither disclosure describes the 

combined use of APIS and PNR data in passenger prescreening decisionmaking. The disclosures also do not describe that during the prescreening 

process CBP officers are able to access personal data obtained from 

commercial providers. 

Because CBP’s development and operation of its international passenger

prescreening process has not been accompanied by the publication of 

Privacy Act notices or E-Government Act privacy impact assessments that 

fully describe the use of personal data and the steps taken to protect 

privacy, the public may not be aware of the different ways that their 

information is being used or protected, as required by law. Although 

maintaining that their prior privacy disclosures were fully compliant with 

federal privacy law, CBP stated in May 2006, and DHS reiterated in its 

official comments to this report in January 2007, that CBP plans to revise 

the APIS privacy impact assessment and issue a system of records notice 

for APIS. However, no deadline has been given for when these steps will 

be completed. As CBP moves forward with future modifications to its 

Page 23 GAO-07-346 Aviation Security
prescreening process, it will be important for CBP to fully assess and 

disclose data privacy protections used in these prescreening programs as 

well. 

Since the terrorist hijackings of aircraft on September 11, the United 

States and the rest of the world have uncovered new attempts to threaten 

the security of the commercial aviation system. These threats underscore 

the importance of continually reassessing the numerous security measures 

put into place to secure commercial aviation. One key security measure is 

the prescreening of passengers on international flights—an important step 

to ensure that high-risk passengers do not board international flights 

traveling to or from the United States. Another important effort involves 

ensuring that international and domestic prescreening programs are fully 

aligned to maximize their effectiveness and cost efficiency for the 

government, airline industry and passengers. In conjunction with 

conducting these important prescreening activities, DHS must also be 

vigilant about ensuring that it is in full compliance with public privacy 

requirements. 

Conclusions 

CBP is currently taking various and important steps to strengthen the 

international aviation passenger prescreening process. CBP’s recent 

publication of a proposed rule for changing the procedures and timing for 

conducting passenger identity matching is an important step. Another 

important effort to strengthen the international aviation passenger 

prescreening process is aligning the process with TSA’s new domestic 

prescreening program. Efforts to significantly expand the IAP may also 

strengthen the prescreening process, although CBP will need to ensure 

that sufficient data are collected to allow for appropriate risk assessments 

and evaluations. 

While CBP recognizes and is taking steps to address many of the 

challenges it faces in implementing its various planned prescreening 

programs, there are three areas, in particular, that require further planning 

and monitoring. These areas include:

• More fully incorporating risk management principles in the IAP

pilot. CBP is not benefiting from all of the information that could be 

learned from the pilot program and remains at risk of expanding the 

program or making IAP sites permanent without establishing a clear 

vision of what the program is intended to accomplish and how its 

success will be evaluated and measured. Without completing a 

strategic plan for the IAP, the program may not realize its full potential 

Page 24 GAO-07-346 Aviation Security
security benefits and could require substantial revisions after 

implementation. 

• Aligning international and domestic passenger prescreening 

programs. If these two prescreening efforts are not effectively 

coordinated with each other, air carriers and other stakeholders could 

be unnecessarily inconvenienced and experience potentially avoidable

costs. The U.S. government could incur avoidable costs as well, if the 

programs are not properly coordinated and aligned. So far, CBP and 

TSA have taken some steps to coordinate their efforts—for example, 

they have announced their intention to develop a single portal for 

prescreening passengers on domestic and international flights. 

However, CBP and TSA have not yet made all of the key decisions 

necessary to align the two processes nor have they completed a 

timetable for completing this process. 

• Attaining full compliance with privacy laws. It is important that 

CBP completes reports that fully describe the agency’s use and 

protection of personal data during the international passenger 

prescreening process to ensure that it is complying with all applicable

privacy laws. CBP’s current disclosures do not fully inform the public 

about all of its systems for prescreening aviation passenger information 

nor do they explain how CBP combines data in the prescreening 

process, as required by law. As a result, passengers are not assured that 

their privacy is protected during the international passenger 

prescreening process. 

To strengthen CBP’s international aviation passenger prescreening 

process, in our November 2006 report we recommended that the Secretary 

of the Department of Homeland Security take or direct the Commissioner 

of Customs and Border Protection to take the following three actions: 

Recommendations for 

Executive Action 

• To more fully incorporate risk management principles into the

planning, implementation, and evaluation of the IAP pilot, CBP should 

(1) prepare a strategic plan that identifies the risks, goals, objectives, 

and performance measures for the IAP pilot, and (2) conduct program 

evaluations that measure the performance of the pilot IAP sites against 

predetermined goals and performance measures. 

• To more fully align CBP’s international aviation passenger prescreening 

program with TSA’s prospective domestic aviation passenger 

prescreening program, take additional steps necessary to identify the 

remaining impediments to alignment, make the key policy and 

Page 25 GAO-07-346 Aviation Security
technical decisions needed to more fully coordinate these programs 

(including a determination of the data and identity matching 

technologies that will be used), and set time frames for when these 

efforts will be completed. 

• To fully inform the public of possible uses of their personal 

information, ensure that all required public data privacy disclosures, 

including system of record notices and privacy impact assessments, are 

completed to adequately cover each element of the international 

passenger prescreening process. The privacy disclosures should fully 

describe the use and handling of personal information within the 

prescreening process and all of CBP’s systems for conducting 

international passenger prescreening. 

We provided a draft of the security sensitive version of this report, and 

related updates, to DHS and DOJ. On January 31, 2007, we received 

written comments from DHS which are reproduced in full in Appendix IV. 

DHS generally concurred with the three report recommendations and 

provided technical comments, which we incorporated where appropriate. 

DOJ also provided technical comments, which we incorporated where 

appropriate.

Agency Comments 

and Our Evaluation 

Regarding the actions DHS reported taking to address the 

recommendations, DHS stated that it has completed an IAP Strategic Plan 

and that the plan has been sent for Departmental review. DHS provided a 

copy of the draft IAP Strategic Plan to GAO. While DHS stated that the 

draft strategic plan outlines the measures that CBP intends to use to 

assess the IAP’s performance, it is not yet clear from the draft strategic 

plan how challenges as well as successes of the program will be measured 

at each IAP site. This appears to be the case since all of the performance 

measures outlined in the draft strategic plan are likely to improve 

following the deployment of IAP officers, without addressing program 

impediments. DHS also noted that CBP is developing system

enhancements that will permit simple input, extraction, and analysis of 

empirical data necessary for baseline and current data. We are encouraged 

by these efforts and believe that they will help CBP to better evaluate the 

effectiveness of this pilot program. Moreover, given CBP’s intention to 

Page 26 GAO-07-346 Aviation Security
transition this pilot program into a permanent one and expand the 

program to additional locations, it is important that IAP officers and those 

managing the IAP have the sufficient data necessary to make sound 

decisions. 

Regarding the recommendation that steps be taken to more fully align

CBP’s international passenger prescreening program with TSA’s domestic 

passenger prescreening program, DHS stated that its Screening 

Coordination Office has directed CBP and TSA to align these programs. 

DHS further stated that CBP has been working with TSA to align 

procedures and systems and functional requirements, and that both CBP 

and TSA will work with the Centers for Disease Control and Prevention to 

harmonize data requirements and present a single face to the travel 

industry. DHS also noted that CBP recognizes that air carriers have 

invested significant resources to reprogram systems to comply with CBP’s 

regulations, and that CBP will continue to work to allow for the 

submission of various passenger data through one transmission process. 

Given the potential costs to air carriers and the government of having 

prescreening procedures and requirements that are not aligned, we 

encourage DHS to complete these efforts and make associated policy 

decisions in a timely manner. 

Regarding the recommendation that the public be fully informed of the 

possible uses of its personal information and that all required public data 

privacy disclosures are completed to adequately address each element of 

the international passenger prescreening process, DHS responded with 

several statements. CBP stated in its comments on the draft report that it 

is and has been in compliance with both the Privacy Act regarding System

of Records Notices (SORNs) and section 208 of the E-Government Act of 

2002 regarding Privacy Impact Assessments (PIAs). CBP bases its 

compliance with the Privacy Act on the 2001 publication of a SORN for the 

Treasury Enforcement Communications System (TECS). To the extent 

that all uses of personal information in CBP international passenger 

prescreening can be associated with the statements made in that notice,

we would agree that CBP is in compliance with the law. That notice, 

however, states that TECS contains “[e]very possible type of information 

from a variety of Federal, state, and local sources, which contribute to 

effective law enforcement.” This statement does not identify the categories

of records maintained in the system, as required by the Act, 

Page 27 GAO-07-346 Aviation Security
let alone APIS and ATS, which CBP now describes as separate systems. It

also does not disclose that the system includes personal information 

collected directly from individuals (i.e., passport data) and indirectly 

through air carriers (i.e., PNR data). The TECS SORN does not “facilitate 

the exercise of the rights of individuals” under the Act, as required by 

OMB’s Privacy Act guidance.23 While OMB guidance states that agencies 

are granted considerable discretion in preparing SORNS, the guidance

stresses the importance of appropriately identifying the purpose(s) of a 

system and ensuring that any associated notices have “information value

to the public.” According to OMB, a major purpose of the Act is “the 

publicizing of what those systems are and how they are used.” The TECS 

SORN has virtually no information value to the public and cannot be said

to meet the requirements of the Act. 

CBP also stated in its comments that no PIA is required for its 

prescreening process because the March 2005 APIS PIA addressed 

changes to APIS, and there have been no changes to ATS since the EGovernment Act went into effect.24 This is incorrect for at least two 

reasons. First, CBP’s handling of personal information was significantly 

altered on the basis of its July 2004 agreement with the EU regarding 

handling PNR data from flights between the US and EU member 

countries.25 The DHS Privacy Office’s September 2005 report on the 

handling of EU PNR describes a number of changes made to CBP systems 

and processes to better safeguard such data. These changes are not 

addressed in any new or revised PIA or SORN. Second, the privacy 

documents that CBP has published do not fully describe the use of 

personal information in the CBP international passenger prescreening 

 23 40 Fed. Reg. 28948, 28952, July 9, 1975. 

24CBP states that the ATS PIA was conducted merely to satisfy a DHS requirement that new

SORNs be accompanied by PIAs, again, not because of any change to ATS that would 

require a PIA under the terms of the E-Gov Act. 

25 69 Fed. Reg. 41543, July 9, 2004. 

Page 28 GAO-07-346 Aviation Security
process, even accepting CBP’s statutory authority to limit public 

disclosures under certain circumstances.26 Contrary to CBP’s 

characterization of CBP officers as merely conducting an “act of physical 

inspection,” the CBP international passenger prescreening process 

involves decisions made by CBP officers on the basis of information 

obtained from multiple sources. As described in our report, CBP officers 

can retrieve identity matching information conducted with APIS data, 

identity matching and risk targeting information performed by ATS with 

PNR and APIS data, as well as information from other government 

databases. They can also access commercial data sources, although 

reportedly on a limited basis for confirming passenger identities. Finally, 

they can also enter information about individuals back into a number of 

government systems.27 These multiple uses of information are not 

described in any CBP privacy documents. Despite CBP’s statement to the

contrary, there are no legal limitations to the Privacy Act or the EGovernment Act that constrain the agency’s ability to provide the public 

with meaningful notice on the use and protection of personal 

information.28 Furthermore, given that the handling of personal 

information in the CBP prescreening process has been significantly 

changed multiple times in the last several years, including changes to 

address the EU PNR agreement and changes to the collection of passenger 

manifest information via APIS, the separate publication of APIS and ATS 

privacy documents satisfy the requirements of neither the Privacy Act nor 

the E-Government Act. 

Upon its issuance, we will provide copies of this report to the Secretary of 

the Department of Homeland Security, the Commissioner of Customs and 

Border Protection, the Administrator of the Transportation Security 

Administration, and interested congressional committees. 

 26The extent of an agency’s public description of a system of records can be limited by 

exemptions permitted by the Privacy Act, e.g., an agency can claim an exemption from the 

requirement to describe the categories of sources of records for investigative material 

compiled for law enforcement purposes. 5 U.S.C. § 552a(k). 

27As noted in DHS Privacy Office’s PIA guidance, privacy concerns can be raised where 

technology may only collect personal information for a moment. 

28For example, under these laws and their implementing guidance, CBP’s modification of

its systems and processes to comply with the 2004 EU agreement on the use of European 

PNR data should have led CBP to issue a revised SORN and conduct a PIA. 

Page 29 GAO-07-346 Aviation Security
If you have any questions about this report, please contact me at 

BerrickC@gao.gov or (202) 512-3404. Key contributors to this report are 

listed in appendix V. 

Cathleen A. Berrick 

Director, Homeland Security and Justice Issues 

Page 30 GAO-07-346 Aviation Security
Appendix I: Objectives, Scope, and Appendix I: Objectives, Scope, and Methodology 

Methodology 

The information contained in this public report is narrower in scope and 

detail than the original report and examines only limited aspects of 

international passenger prescreening procedures. It focuses on only 

certain elements of the current international aviation passenger 

prescreening process as well as only some of the actions that DHS is 

taking or has planned to strengthen prescreening procedures. More 

specifically the report’s content is limited to certain issues related to: 

• the implementation of the Immigration Advisory Program (IAP), a CBP 

program that assesses risk levels for certain passengers in overseas 

locations; 

• aligning international and domestic passenger prescreening programs; 

• ensuring that compliance with privacy laws is fully achieved with 

respect to information collected to conduct international passenger 

prescreening. 

Although the information provided in this report is more limited in scope,

the overall methodology used for our initial report is relevant to this report 

as well because the information contained in this report was derived from

the initial sensitive report. We addressed the following objectives in our 

initial November 2006 report: 

• the main factors affecting the international passenger prescreening 

process, and the potential impact of these factors, and 

• the status of efforts to address these factors, and the issues, if any, that

could affect efforts to strengthen the international prescreening 

process. 

To address our first objective from the November 2006 report—the factors 

that affect the international passenger prescreening process and their 

potential impacts—we interviewed officials from Customs and Border 

Protection (CBP), including staff at CBP’s National Targeting Center 

(NTC); the Terrorist Screening Center (TSC); and the Transportation 

Security Administration (TSA) to understand the current international 

passenger prescreening process and the data that are used during this 

process. We obtained and analyzed relevant documents from these 

agencies including statistics from the Immigration Advisory Program pilot, 

documentation on CBP’s use of data systems to conduct international 

passenger prescreening, and a CBP summary memorandum documenting 

the agency’s decision not to pursue the Advanced Passenger Prescreening 

Page 31 GAO-07-346 Aviation Security
Appendix I: Objectives, Scope, and 

Methodology 

(APP) system that currently operates in other countries such as Australia 

and New Zealand. To obtain a cross section of air carriers’ views about the 

process, we selected air carriers that fly large, medium, and small numbers 

of passengers annually into the United States. For the purposes of this 

review, we defined the transport of a large number of passengers as more 

than 1 million passengers annually, we defined a medium number as 

between 500,000 and 1 million passengers annually, and a small number as 

less than 500,000 passengers annually. These criteria generally reflect the 

distribution of the incoming passenger volume being flown into the United 

States between 2000 and 2004 as shown in Department of Transportation 

statistical reports. Using these criteria, we interviewed officials from seven 

large air carriers, four medium air carriers, and two small air carriers, both 

domestic and foreign, that conduct international flights into and out of the 

United States to discuss the impact of current U.S. international passenger 

prescreening requirements on their operations. We also spoke with 

officials from two domestic air carrier and passenger travel associations 

and three international air carrier associations to discuss the impact on 

their members of current international passenger prescreening 

requirements. We also reviewed documents from an international aviation 

association that evaluated the potential impact on its membership of 

CBP’s proposed passenger prescreening reforms. To determine the 

number of No Fly and improperly prescreened Selectee passengers who 

traveled on flights to or from the United States during 2005, we obtained

and analyzed TSA security incident reports from January 1, 2005 to 

December 31, 2005.1

To address our second objective from the November 2006 report— the 

status of CBP’s efforts to address these factors and the issues, if any, that 

could affect efforts to strengthen the prescreening process—we 

interviewed officials from CBP and reviewed relevant documents. We also

interviewed officials from the seven large air carriers, three medium air 

carriers, and two small air carriers, both domestic and foreign, that 

conduct international flights into and out of the United States to obtain 

their views on the potential impact of future U.S. international 

prescreening requirements. We also spoke with officials from two 

domestic air carrier and passenger travel associations, three international

air carrier associations, and a travel association that represent the 

interests of air carriers and travelers to obtain their views on the potential

 1

 We did not report on the details of this passenger information as it is sensitive security 

information.

Page 32 GAO-07-346 Aviation Security
Appendix I: Objectives, Scope, and 

Methodology 

impact of future U.S. international prescreening requirements including 

APIS- 60 and AQQ. We visited two Immigration Advisory Program (IAP) 

pilot sites and met with the IAP teams to discuss the current status of the 

program and observe the prescreening process at their respective 

locations. We discussed potential benefits and challenges of the program 

with the IAP teams. We also reviewed and assessed CBP’s evaluations of 

IAP pilot sites. Furthermore, we met with government officials from the 

United Kingdom and Canada to learn details about their respective airline 

liaison officer (ALO) programs and to obtain their views on how the IAP 

pilot compares with their ALO programs. One foreign government 

provided documents that summarize the functions of its ALO program. We 

also met with foreign government officials in the Netherlands, Poland, the 

United Kingdom, Australia, and New Zealand to discuss U.S. efforts to 

strengthen international passenger prescreening and the potential impact 

of these programs. Officials from Australia and New Zealand also provided 

documents related to their respective APP prescreening systems. We met 

with officials from the European Union to discuss the impact of U.S. 

international prescreening requirements (including the advanced 

transmission of passenger name record data) on air carriers originating 

from Europe. Additionally, we interviewed and obtained documents from 

private companies that facilitate the electronic transmission of passenger

data between air carriers and government agencies, including CBP, to 

determine their role, if any, in future international aviation passenger 

prescreening initiatives. To assess CBP’s July 2006 Notice of Proposed 

Rulemaking (NPRM), we obtained and analyzed documents associated 

with the NPRM, including CBP’s regulatory assessment for the rulemaking. 

To assess whether CBP disclosed, as required by law, its use of passenger

information during the prescreening process, we reviewed CBP’s 

published privacy impact assessments and system of records notices. We 

also met with CBP and DHS officials regarding their current and draft 

privacy documents related to passenger prescreening. To determine the 

extent to which CBP has utilized risk management principles to guide 

decisions on passenger prescreening, we used a risk management 

framework developed and tested by GAO over several years.2

 The risk 

management framework was developed by GAO after a review of 

 2

 GAO, Homeland Security: Summary of Challenges Faced in Targeting Oceangoing 

Cargo Containers for Inspection, GAO-04-557T (Washington, D.C.: Mar. 31, 2004). 

GAO, Risk Management: Further Refinements Needed to Asses Risks and Prioritize 

Protective Measures at Ports and Other Critical Infrastructure, GAO-06-91 (Washington,

D.C.: Dec. 15, 2005). 

Page 33 GAO-07-346 Aviation Security
Appendix I: Objectives, Scope, and 

Methodology 

government and private sector documents on risk management and 

interviews with recognized experts in risk management and terrorism

prevention. We used elements of the risk management framework as 

criteria to analyze CBP’s actions in developing and implementing its 

existing international passenger prescreening process, as well as CBP’s 

proposed and planned actions to modify the international passenger 

prescreening process. We conducted our work, which included updates to

our version of the report that contains sensitive security information, from 

April 2005 through November 2006 in accordance with generally accepted 

government auditing standards. 

Page 34 GAO-07-346 Aviation Security
Appendix II: Airline Liaison Officer Programs Appendix II: Airline Liaison Officer Programs Implemented In Other Countries 

Implemented In Other Countries 

Several countries have created airline liaison officer (ALO) programs and 

placed officers in foreign countries to reduce the number of improperly 

documented passengers traveling into their respective countries. These 

officers also assist air carrier staff in establishing whether individual 

passengers who may appear to be improperly documented are actually 

eligible to fly without resulting in fines to the air carrier. According to the 

International Air Transport Association Code of Conduct for Immigration

Liaison Officers, the liaison officers’ primary responsibilities include: 

• Establishing and maintaining a good working relationship with the 

airlines, local immigration, police, other appropriate authorities, and 

other liaison officers posted to that country and with consular staff of 

other missions. Additionally, liaison officers assist local immigration 

and police authorities in gathering and sharing information related to 

the movement of improperly documented passengers. 

• Training airline staff in the general principles of passport and visa 

requirements, passenger assessment, and awareness of fraud and 

forgery, and advising airline staff on whether travel documents and 

visas are genuine, forged or fraudulently obtained. 

Table 1 shows a side-by-side comparison of the characteristics of ALO 

programs from four countries. 

Page 35 GAO-07-346 Aviation Security
Appendix II: Airline Liaison Officer Programs

Implemented In Other Countries 

Table 1: The Characteristics of Selected ALO Programs 

Characteristics

U.K. Airline 

Liaison Officer 

Program

Canadian 

Migration 

Integrity 

Program 

Australian 

Airline Liaison 

Officer 

Program

New Zealand 

Airline Liaison 

Officer 

Program

Initiation date 1993 1989 1989 1991

Number of 

locations 

32 39 14 9

Approximate 

number of staff 

34 45 20 9

Number of 

officers at each

location 

1-2 1-2 1-2 1

Physical location 

of staff 

At nearest 

embassy

At nearest 

embassy 

At airport At nearest 

embassy or with 

an air carrier

Mission Reduce travel

document fraud 

Reduce travel 

document fraud 

Reduce travel 

document 

fraud

Reduce number 

of refugee cases

Source: GAO analysis of ALO programs. 

These ALO programs have incorporated various approaches regarding 

data collection, program expansion, and staffing to allow for continuous 

improvement and measurement of their liaison programs. For example, 

the Canadian Migration Integrity Officers (MIO) program developed a

system that regularly collects data on improperly documented arrivals in 

Canada and other suspect travelers and records this information in a Web 

database to develop trend and other analyses. These data are also used to 

measure the success of the Canadian MIO program. Canadian officials 

stated that this web-based database allows Canada to immediately inform

air carriers of violations, has assisted in reducing the number of violations 

and fines, and has allowed air carriers to take corrective action in a timely

manner. Similarly, officials from the United Kingdom ALO program stated 

that they also collect statistics and intelligence to develop profiles and 

trends on particular flights for use in their program. The New Zealand ALO 

program utilizes passenger name record (PNR) data to identify the trends 

of travelers utilizing fraudulent passports to travel to their country. New 

Zealand officials stated that accessing and using PNR data in real time has 

allowed their ALO network to immediately load alert or referral 

information into its passenger-screening system so that identified 

passengers can be screened further at check-in prior to boarding. New 

Zealand officials also stated that they utilize data to conduct assessments 

and intensive reviews of the highest risk countries and passengers, which 

Page 36 GAO-07-346 Aviation Security
Appendix II: Airline Liaison Officer Programs

Implemented In Other Countries 

they then use to determine the location of airline liaison sites. Some New 

Zealand ALO sites also have direct access to the immigration application 

system, which allows their liaison officers to directly input alerts as 

necessary. The New Zealand government is also currently considering 

providing ALO officers with handheld computers to facilitate more 

efficient communications. Australian officials stated that at several of their 

ALO sites the liaison officers work under a particular air carrier versus 

going through the typical approval process needed to establish an 

overseas program, which may take a long time to complete. According to 

these officials, this type of arrangement provides them with the advantage 

of being able to quickly move liaison officers from location to location 

when needed to keep up with trends in illegal passenger travel. Both the 

United Kingdom and the Canadian ALO programs expanded gradually. A 

United Kingdom ALO program official validated this approach by 

suggesting that limited growth of ALO programs during the initial stages 

allowed countries to fully learn from the pilot program before expanding 

to other countries. 

Page 37 GAO-07-346 Aviation Security
Appendix III: APIS Quic

A

k Query (AQQ) and

PIS Minus 60 Minutes (APIS-60) 

Page 38 GAO-07-346

Appendix III: APIS Quick Query (AQQ) and 

APIS Minus 60 Minutes (APIS-60) 

In July 2006, CBP released a notice of proposed rulemaking that would 

require air carriers to transmit APIS data to CBP prior to the departure of

all international flights departing from or bound for the United States. The 

notice of proposed rulemaking provided air carriers with two main options 

for prescreening passengers on international flights prior to departure. 

One option under the proposed rule would require air carriers to send 

APIS data on all passengers to CBP 60 minutes before a flight’s departure.

The other option would allow air carriers to transmit APIS data on a 

passenger-by-passenger basis, up to 15 minutes prior to a flight’s 

departure. The two options are designed to accommodate air carriers with 

different types of operations.1

 

Under both options, CBP has broadly outlined the procedures for air 

carriers to receive a “not-cleared” response which would identify that a 

passenger is prohibited from boarding an aircraft. CBP would provide this 

response to the air carrier prior to the passenger boarding the aircraft. In

addition to satisfying requirements under the Intelligence Reform and 

Terrorism Prevention Act, both options would strengthen the prescreening 

process. 

First Prescreening Option: 

Transmitting APIS Data 60 

Minutes Prior to Departure 

The first option under the proposed rule would require air carriers to 

transmit APIS data to CBP for all passengers on a flight 60 minutes prior to 

the flight’s departure. This approach is known as APIS-60. The APIS-60 

option will require an air carrier to transmit a manifest to CBP with APIS 

information for all passengers on the flight 60 minutes before the flight 

departs. This option gives CBP staff approximately 60 minutes before 

flight departures to match the APIS information against the lists and notify 

the carrier if any passengers should not be allowed to travel. Under this 

option, a passenger would be issued a boarding pass, but if a “not cleared” 

response is later received from CBP, the air carrier would be responsible 

for denying boarding, or for removing the passenger and his or her 

 1

 Under the current international passenger prescreening process, CBP has identified some 

air carriers whose reservation systems do not allow them to send passenger APIS data to

CBP through a batched electronic transmission. These air carriers include seasonal 

charters, air taxis, and air ambulances. CBP allows these air carriers to transmit passenger 

data through other means, such as through e-mail, in a program called eAPIS. In its NPRM,

CBP noted that such air carriers are not likely to be able to adopt either the APIS-60 or 

AQQ prescreening options. Consequently, these air carriers will be permitted to continue to 

send passenger data through eAPIS, but they will still be bound by the requirement to 

transmit APIS data 60 minutes prior to departure and they must be able to receive CBP’s 

identity matching results through e-mail or telephone. 

Aviation Security
Appendix III: APIS Quick Query (AQQ) and

APIS Minus 60 Minutes (APIS-60) 

baggage from the aircraft, if the passenger had already boarded the 

aircraft. This option, according to CBP officials, is likely to be preferred by 

smaller air carriers that are not dependent on having passengers transfer 

from connecting flights (and therefore whose passengers would not likely 

have difficulty checking in at least 60 minutes before flight departure). 

According to CBP officials, these air carriers might prefer APIS-60 because

it would not require technical changes in how they transmit APIS data to 

CBP, although it would require that carriers develop the technical means 

to receive a screening response from CBP. In the fall of 2004, CBP initially 

proposed APIS-60 as the sole approach for conducting international 

prescreening. However, the International Air Transport Association 

(IATA), the Air Transport Association of America (ATA),2

 and individual

air carriers raised concerns about the economic impacts they believed 

would be associated with implementing APIS-60 across the industry. For 

example, they told CBP that network flight schedules would have to 

change to expand the minimum connection times between flights because

all passengers would be required to check in at the airport at least 1 hour 

in advance of the flight so that information could be collected and sent to

CBP on time. Air carriers that carry passengers arriving on connecting 

flights, which are known to operate on “hub-and spoke” networks,3

 said 

that they would be particularly affected because their passengers could 

arrive on a variety of connecting flights from many other airports, and 

some would not arrive 60 minutes in advance of their connecting flight, 

making them ineligible to board their scheduled flights. In addition, 

according to some air carriers, the trend in the air carrier industry of 

moving toward self-service check-in by some passengers has shortened 

the time between check-in and scheduled flight departure times, further 

exacerbating the impact of this type of approach. In response to industry 

concerns that the APIS-60 approach would create serious problems for 

some carriers’ operations, CBP offered a second option for air carriers to 

 2

 IATA represents the airline industry and comprises 260 passenger and cargo air carriers, 

representing 94 percent of international scheduled air traffic. ATA is the nation’s largest 

airline trade association and its stated purpose is to foster a business and regulatory 

environment that ensures safe and secure air transportation. 

3

 With a hub-and-spoke network, air carriers can combine local passengers (those 

passengers originating at or destined for the hub), with connecting passengers (those not

originating at or destined for the hub but traveling via the hub) on the same flight. In this 

manner, carriers can serve more cities and offer greater frequency of service with their 

fleet of aircraft than is possible with point-to-point service, which is service from one city

to another without this connecting network. 

Page 39 GAO-07-346 Aviation Security
Appendix III: APIS Quick Query (AQQ) and

APIS Minus 60 Minutes (APIS-60) 

consider adopting to conduct passenger prescreening in advance of flight

departures. 

Second Prescreening 

Option: Transmitting APIS 

Data as Each Passenger 

Checks In for a Flight 

The second option under the proposed rule would require air carriers to 

send APIS data to CBP as each passenger checks in for a flight. CBP would 

then complete its identity match against the No Fly and Selectee Lists and 

send a response to the air carrier—generally within 4 seconds—identifying 

that the passenger is either cleared or not-cleared for boarding. Since this 

approach would utilize a nearly instantaneous data transmission between 

air carriers and CBP, it is known as a real-time prescreening option.4

 For 

those passengers found to be eligible to board, the response message from 

CBP would identify that the air carrier is permitted to issue a boarding 

pass and receive checked-in luggage from the passenger.5

 Known as APIS 

Quick Query (AQQ), this approach would represent a significant change to

the current prescreening process in that CBP would complete its identity

matching for each passenger separately, instead of conducting identity 

matching for all passengers on a flight at the same time. 

CBP officials believe that larger carriers with hub-and-spoke operations 

are the most likely to choose the AQQ option, in part because larger 

carriers are more likely to have the communications infrastructure needed 

to develop and install the new interactive system. Some air carriers have 

expressed the desirability of receiving a real-time cleared/not cleared 

response from CBP earlier in the prescreening process such as what AQQ 

would provide. This timing would allow them to know almost immediately 

if an identified passenger represents a potential security risk.

CBP officials are already in the process of developing the AQQ system. 

Under this approach, the federal government would bear the costs 

associated with the actual prescreening of passengers. However, air 

carriers would be responsible for any changes needed to their internal 

information technology systems and the transmission of APIS data. This 

type of real-time interactive prescreening approach is currently in use in 

 4

 It is also known as an interactive approach, because CBP transmits a response message 

back to air carriers informing them whether a passenger can board or not board. 

5

 Passengers whose identities matched the No Fly List from this initial screening would not 

be issued a boarding pass by the air carrier until CBP and other agencies completed their 

identity vetting procedures and returned a message to the air carrier identifying that it was 

okay to board the passenger. If this identity verification process is not completed prior to

the flight’s departure, the passenger would not be permitted to travel on the flight. 

Page 40 GAO-07-346 Aviation Security
Appendix III: APIS Quick Query (AQQ) and

APIS Minus 60 Minutes (APIS-60) 

several countries, including Australia, New Zealand, and Bahrain, through 

a system called Advance Passenger Processing (APP). The APP system

was initially used by Australia’s Customs Service and Department of 

Immigration and Multicultural and Indigenous Affairs, and was first 

implemented in 1995. 

AQQ and APP are both real-time interactive concepts but are different 

systems. CBP officials stated that they considered APP when determining 

which prescreening options to pursue but, in an August 2005 

memorandum, identified a number of reasons for not adopting it.6

Nonetheless, the experience of these other countries with APP may be of 

value to CBP as it continues to develop the AQQ program. For example, 

Australian government officials told us that the successful deployment of 

the APP program was dependent upon working closely with air carriers to 

ensure system functionality upon implementation. This will be particularly 

important with regard to the AQQ given that almost 200 air carriers fly 

international routes into and out of the United States, assuming that a 

number of these air carriers decide to participate in AQQ.7

 Officials from

Australia and New Zealand said that they were willing to continue to share 

relevant lessons learned as CBP works to develop its AQQ program. 

 6

Some of the reasons CBP cited for not adopting APP included high infrastructure and 

transaction costs to both air carriers and government, and the system’s inability to 

adjudicate possible matches and allow for human intervention and response. Although 

CBP’s memo refers to an evaluation of APP conducted by its Office of Field Operations and

Office of Information Technology, CBP did not provide us with the supporting 

documentation of this evaluation despite a request for relevant documentation in its 

considerations of implementing APP. 

7

 CBP estimated that 1,280 foreign and domestic air carriers will be affected by its proposed 

rulemaking related to AQQ and APIS-60. 

Page 41 GAO-07-346 Aviation Security
Appendix IV: Comments from the Department Appendix IV of Homeland Security : Comments from the 

Department of Homeland Security 

Page 42 GAO-07-346 Aviation Security
Appendix IV: Comments from the Department 

of Homeland Security

Page 43 GAO-07-346 Aviation Security
Appendix IV: Comments from the Department 

of Homeland Security

Page 44 GAO-07-346 Aviation Security
A

A

ppendix V: GAO Contacts and Staff

cknowledgments 

Page 45 GAO-07-346

Appendix V: GAO Contacts and Staff 

Acknowledgments 

Cathleen A. Berrick, Director, Homeland Security and Justice Issues, 

(202) 512-3404 

In addition to the individual named above, key contributors to the report 

include Mark Abraham, Charles Bausell, Dawn Hoff, David Hooper, 

Michele Fejfar, James Madar, Jan Montgomery, Hugh Paquette, David 

Plocher, Neetha Rao, Brian Sklar, and Stan Stenersen. 

GAO Contacts 

Staff 

Acknowledgments 

Aviation Security
GAO Related Products GAO Related Products 

Aviation Security: Progress Made in Systematic Planning to Guide Key

Investment Decisions, but More Work Remains. GAO-07-448T. 

Washington, D.C.: February 13, 2007.

Homeland Security: Progress Has Been Made to Address the 

Vulnerabilities Exposed by 9/11, but Continued Federal Action Is Needed 

to Further Mitigate Security Risks. GAO-07-375. Washington, D.C.: 

January 2007. 

Transportation Security Administration’s Office of Intelligence: 

Responses to Post Hearing Questions on Secure Flight. GAO-06-1051R. 

Washington D.C.: August 4, 2006. 

Terrorist Watch List Screening: Efforts to Help Reduce Adverse Effects 

on the Public. GAO-06-1031. Washington, D.C.: Sept. 29, 2006.

Border Security: Stronger Actions Needed to Assess and Mitigate Risks 

of the Visa Waiver Program. GAO-06-1090T. Washington, D.C.: 

September 7, 2006. 

Border Security: Stronger Actions Needed to Assess and Mitigate Risks 

of the Visa Waiver Program. GAO-06-084. Washington, D.C.: July 2006. 

Process for Admitting Additional Countries into the Visa Waiver 

Program. GAO-06-835R Washington, D.C.: July 2006. 

Aviation Security: TSA Oversight of Checked Baggage Screening 

Procedures Could Be Strengthened. GAO-06-869.Washington, D.C.: 

July 28, 2006.

Aviation Security: Management Challenges Remain for the 

Transportation Security Administration’s Secure Flight Program. 

GAO-06-864T. Washington D.C.: June 14, 2006. 

Aviation Security: Significant Management Challenges May Adversely 

Affect Implementation of the Transportation Security Administration’s 

Secure Flight Program. GAO-06-374T. Washington, D.C.: Feb. 9, 2006. 

Aviation Security: Transportation Security Administration Did Not 

Fully Disclose Uses of Personal Information During Secure Flight 

Program Testing in Initial Privacy Notes, but Has Recently Taken Steps

to More Fully Inform the Public. GAO-05-864R. Washington, D.C.: 

July 22, 2005.

Page 46 GAO-07-346 Aviation Security
GAO Related Products 

Aviation Security: Secure Flight Development and Testing Under Way, 

but Risks Should Be Managed as System Is Further Developed. 

GAO-05-356. Washington, D.C.: March 28, 2005. 

Aviation Security: Measures for Testing the Effect of Using Commercial

Data for the Secure Flight Program. GAO-05-324. Washington, D.C.: 

Feb. 23, 2005. 

Transportation Security: Systematic Planning Needed to Prioritize 

Resources. GAO-05-357T. Washington, D.C.: February 15, 2005. 

General Aviation Security: Increased Federal Oversight is Needed, but 

Continued Partnership with the Private Sector is Critical to Long-Term 

Success. GAO-05-144. Washington, D.C.: November 10, 2004. 

Aviation Security: Challenges in Using Biometric Technologies. 

GAO-04-785T. Washington, D.C.: May 19, 2004. 

Aviation Security: Improvement Still Needed in Federal Aviation 

Security Efforts. GAO-04-592T. Washington, D.C.: March 30, 2004. 

Aviation Security: Challenges Delay Implementation of ComputerAssisted Passenger Prescreening System. GAO-04-504T. Washington, D.C.: 

March 17, 2004. 

Aviation Security: Computer-Assisted Passenger Prescreening System 

Faces Significant Implementation Challenges. GAO-04-385. 

Washington, D.C.: Feb. 13, 2004. 

Forum on High Performing Organizations: Metrics, Means, and 

Mechanisms for Achieving High Performance in the 21st Century Public 

Management Environment, GAO-04-343SP. Washington, D.C.: Feb. 13, 

2004. 

Aviation Security: Efforts to Measure Effectiveness and Strengthen 

Security Programs. GAO-04-285T. Washington, D.C.: Nov. 20, 2003. 

Aviation Security: Efforts to Measure Effectiveness and Address 

Challenges. GAO-04-232T. Washington, D.C.: Nov. 5, 2003. 

Aviation Security: Progress Since September 11, 2001, and the 

Challenges Ahead. GAO-03-1150T. Washington, D.C.: Sept. 9, 2003. 

Page 47 GAO-07-346 Aviation Security
GAO Related Products 

Airport Finance: Past Funding Levels May Not Be Sufficient to Cover 

Airports’ Planned Capital Development. GAO-03-497T. Washington, D.C.: 

Feb. 25, 2003. 

Commercial Aviation: Financial Condition and Industry Responses 

Affect Competition. GAO-03-171T. Washington, D.C.: Oct. 2, 2002. 

(440403) Page 48 GAO-07-346 Aviation Security
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