September 2005 

NASA/CR—2005-213923 

Violations of Temporary Flight Restrictions and 

Air Defense Identification Zones: An Analysis of 

Airspace Violations and Pilot Report Data 

Michael Zuschlag 

John A. Volpe National Transportation Systems Center, Cambridge, Massachusetts 

 

https://ntrs.nasa.gov/search.jsp?R=20050223553 2018-05-17T08:59:33+00:00Z
September 2005 

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September 2005 

NASA/CR—2005-213923 

Violations of Temporary Flight Restrictions and 

Air Defense Identification Zones: An Analysis of 

Airspace Violations and Pilot Report Data 

Michael Zuschlag 

John A. Volpe National Transportation Systems Center, Cambridge, Massachusetts 

National Aeronautics and 

Space Administration 

 Prepared for Langley Research Center 

Langley Research Center under Intragovernmental Transaction 

Hampton, VA 23681-2199 NNL04AA72I 
4 

Acknowledgments 

The investigator wishes to thank Susan Wilz and Eddie Norris of the Aviation Safety and Security Program, 

Protected Asset Flight System at NASA Langley Research Center for supporting this work and providing feedback 

on this report. Thanks to Cathy Welsh of FSOSC, FAA Air Traffic Special Operations Security, and to Jorge Moya 

and Vincent Mellone of ASRS, NASA Ames Research Center for providing the data for these analyses. Thanks 

also to Drew Kendra, Divya Chandra, and Michelle Yeh of the Volpe Center for assistance in developing the 

narrative categorization scheme and evaluating its reliability, and to Bob Lyons, Alan Yost, and Kevin Harnett, 

also of the Volpe Center for suggestions and corrections for this paper. 

Available from: 

NASA Center for AeroSpace Information National Technical Information Service 

7121 Standard Drive 5285 Port Royal Road 

Hanover, MD 21076-1320 Springfield, VA 22161 

301-621-0390 703-605-6000 

This report is also available in electronic form at http://ntrs.nasa.gov and 

http://www.volpe.dot.gov/opsad/pubs.html
iii

Executive Summary 

The purpose of this study is to determine the apparent factors and causes of violations of 

restricted airspace, particularly temporary flight restrictions (TFRs) and air defense identification 

zones (ADIZs). After the terrorist attacks on 9/11/2001, the Federal Aviation Administration 

(FAA) has greatly expanded the use of TFRs and ADIZs to more securely control the airspace 

around potential terrorist targets. Since then, there have been a substantial number of accidental 

violations of restricted airspace with over 2900 violations in the two years between June 2002 and 

June 2004 alone. This frequency of violations incurs security and safety risks plus economic 

costs. By illuminating the reasons for these violations, this study aims to take the first step 

towards reducing them. 

To provide an initial assessment of the basic characteristics of restricted airspace violations, the 

records for all 2910 violations from a two-year period were obtained from the FAA Flight Service 

Operations Support Center (FSOSC). These data indicated that most violations of restricted 

airspace are associated with relatively static or re-occurring restricted airspace, with half of all 

violations concerning just the ADIZ around Washington DC or restricted airspaces within it. This 

implies that most violations are not due a TFR “popping up” in unpredictable locations. 

While the FSOSC data indicated the locations of violations of restricted airspace, it provided 

limited insight into the reasons. Why are most violations at places where airspace restrictions 

ought to be predicable? To address this, the study next examined the narratives of 203 records 

from NASA’s Aviation Safety Reporting System (ASRS) in order to determine the probable 

causes and factors contributing to violations of restricted airspace. 

Based on a systematic categorization of the narratives in the ASRS data, the probable cause of 

most violations was the pilot having incorrect or a lack of detailed information about the airspace. 

Most violations were not due to the pilot being simply unaware of the airspace at the time of 

violation. In most violations, pilots are aware of the presence of the airspace but have incorrect 

information about it, namely, its exact boundaries or procedures for authorized penetration. 

Apparent violations of the DC ADIZ are especially likely to be due to such incorrect detailed 

information, and quite rarely due to the airspace being outright not known or recalled. With its 

relatively complex penetration procedures, the DC ADIZ frequently had the violations due to 

misunderstanding these procedures. 

The narratives frequently related cases where pilots tried to get information about a TFR or 

ADIZ, but ultimately developed misconceptions about the airspace. A substantial number of 

narratives explicitly reported that the pilots got the Notices to Airmen (NOTAMs) relevant to the 

flight or a preflight briefing, where NOTAMs and briefings are the chief means today of 

disseminating TFR and ADIZ information to pilots. Nonetheless these pilots allegedly violated a 

TFR or ADIZ. Indeed, about half of all the narratives explicitly cite communication problems 

concerning the airspace as a factor contributing to violating the airspace. This may be a 

miscommunication with an official Flight Service Station briefer or a communication failure 

concerning the NOTAMs themselves. The lack of depiction of TFRs and the DC ADIZ on 

standard aviation navigation charts has also been identified as a contributing factor in many 

narratives (the DC ADIZ and certain recurrent TFRs began appearing on charts in February 2004, 

after the period comprising the ASRS records analyzed for this study). 

These results imply that the best means to reduce violations of restricted airspace is to improve 

the effectiveness of informing pilots of the details about the restricted airspace. Better pilot 
iv 

awareness of the existence of TFRs and ADIZs should prevent some violations but cannot 

eliminate most of them. While the FAA has made graphic representations of TFRs available to 

pilots, this practice does not appear to have effectively conveyed the boundaries of restricted 

airspace. Furthermore, knowing the boundaries of the airspace is only part of the problem. For 

ADIZs and ADIZ-like TFRs, where penetration is allowed, the detailed procedures to be followed 

while in the airspace do not appear to be making it to pilots in an effective manner. 
v

Contents 

Executive Summary ....................................................................................................................... iii 

Contents........................................................................................................................................... v 

Figures............................................................................................................................................ vi 

Tables ............................................................................................................................................. vi 

1. Background .............................................................................................................................. 1 

1.1. TFRs.................................................................................................................................. 1 

1.2. ADIZ................................................................................................................................. 1 

1.3. Avoiding of Violations ..................................................................................................... 2 

1.4. Handling of Violations...................................................................................................... 2 

2. Purpose..................................................................................................................................... 3 

3. Basic Characteristics of Violations .......................................................................................... 4 

4. Method ..................................................................................................................................... 8 

4.1. Source of Data................................................................................................................... 8 

4.2. Biases within ASRS Records............................................................................................ 8 

4.3. Record Selection ............................................................................................................... 9 

4.4. Record Categorization .................................................................................................... 10 

4.4.1. Got NOTAMs/Briefing......................................................................................................... 10 

4.4.2. Violation of Concern ............................................................................................................ 11 

4.4.3. Probable Cause ..................................................................................................................... 11 

4.4.4. Reporter-identified Factors................................................................................................... 12 

4.4.5. Other Categorization Dimensions......................................................................................... 13 

4.5. Inter-rater Reliability ...................................................................................................... 13 

5. Analysis.................................................................................................................................. 15 

5.1. Violation Type ................................................................................................................ 15 

5.2. Pilot Preparation for Airspace......................................................................................... 16 

5.3. Probable Cause ............................................................................................................... 16 

5.3.1. Incorrect or Lack of Detailed Information............................................................................ 17 

5.3.2. Control Setting Error and Other Causes ............................................................................... 22 

5.4. Relationship between Probable Cause and Violation ..................................................... 23 

5.5. Reporter-Identified Factors............................................................................................. 24

5.5.1. Airspace Communication ..................................................................................................... 25 

5.5.2. Underuse of Optional ATC................................................................................................... 27 

5.5.3. Violation Handling Error...................................................................................................... 29 

5.5.4. Pilotage Limitations.............................................................................................................. 31 

5.5.5. Remaining Factors................................................................................................................ 32 

6. Conclusion.............................................................................................................................. 32 

6.1. Implications of the Basic Characteristics of Violations.................................................. 32 

6.2. Pilots Need the Details.................................................................................................... 33 

6.3. ATC and FSS Performance............................................................................................. 34 

6.4. Interception and Communication.................................................................................... 34 

7. Abbreviations and Acronyms................................................................................................. 35 

8. References.............................................................................................................................. 37 

Appendix: Documentation for Categorization of Narratives ........................................................ 39 
vi 

Airspace ..................................................................................................................................... 39 

Violation of Concern ................................................................................................................. 40 

Pilot Caught/Interception........................................................................................................... 42 

Got NOTAMs/Briefing.............................................................................................................. 43 

Probable Cause .......................................................................................................................... 51 

Reporter Identified Factors ........................................................................................................ 59 

Figures 

Figure 1. Number of violations for each hour of local time of day. ............................................................... 6 

Figure 2. Number of violations for each day of week. ................................................................................... 6 

Figure 3. Number of violations for each month of the year............................................................................ 7 

Figure 4. Model for assigning probable cause.............................................................................................. 12 

Figure 5. DC ADIZ and Class B outer limit correspondence. Note that while most of the ADIZ coincides 

with Class B, the ADIZ extends beyond it in the south. Several violations are associated with pilots 

not being aware of this detail................................................................................................................ 19 

Tables 

Table 1. Airspace related to violation............................................................................................................. 4 

Table 2. Aircraft classification involved in violation. .................................................................................... 5 

Table 3. Percent of violations involving an interception. ............................................................................... 5 

Table 4. Dimensions for categorizing ASRS records. .................................................................................. 11 

Table 5. Categories of Violation of Concern................................................................................................ 11 

Table 6. Reporter-identified Factors............................................................................................................. 13 

Table 7. Reliability of categorization dimensions. ....................................................................................... 14 

Table 8. Violation of concern....................................................................................................................... 15 

Table 9. Probable cause of violation of concern........................................................................................... 16 

Table 10. Breakdown of incorrect or lack of information. Percentages are of all cases............................... 17 

Table 11. Percent of each violation of concern associated with each probable cause. ................................. 24 

Table 12. Percent of cases including each Report-identified Factor............................................................ 24 
1

1. Background 

In the wake of the use of civil aircraft to carry out terrorist attacks on 9/11/2001, the Federal 

Aviation Administration (FAA) sought to combat future attacks of this kind by restricting or 

better controlling the airspace around potential targets. The FAA used two existing mechanisms 

for this: temporary flight restrictions (TFRs) and air defense identification zones (ADIZs). 

1.1. TFRs 

Historically, the FAA imposes TFRs over an area for a specific event whenever anticipated air 

traffic is deemed to be dangerous or threatening either to people or property on the surface or to 

the pilots and aircraft themselves. This includes events such as forest fires and other natural 

disasters (where sightseeing flights may interfere with disaster mitigation and rescue efforts), 

shuttle launches and air shows (to reduce the chances of mid-air collisions), and visits by the 

President or other VIPs (FAA, 2004d). TFRs may prohibit all air traffic in an airspace or may 

place other restrictions on aircraft that operate in the airspace. 

After 9/11, the FAA greatly increased the number TFRs imposed for security reasons 

(Government Accountability Office, 2004). In addition to visiting VIPs, TFRs have been imposed 

around military installations, large public gatherings and attractions, nuclear power stations, and, 

occasionally, entire cities. TFRs are regularly imposed as an "expansion" of an existing fixed 

Prohibited Area (e.g., about Camp David) as events within the area warrant (e.g., the actual 

presence of the President). The size of these new TFRs also may be quite large. Where a rescue 

TFR typically has a 3 nautical mile (nm) radius and extends up to an altitude of 2000 feet 

(Jeppesen Sanderson, 1998), security TFRs may be as much as 30 nm in radius and up to 18000 

feet (FAA, 2005a). Some of these "temporary" flight restricts have been in place for over a year 

and are expected to remain in force indefinitely. By the shear number, size, and duration of 

present TFRs, the raw opportunity to violate one has greatly increased since 9/11. 

1.2. ADIZ 

The ADIZ is a boundary surrounding the United States airspace originally intended to provide 

security from attacking foreign aircraft. All aircraft that cross the ADIZ are required to have a 

flight plan filed with air traffic control (ATC), to transmit or "squawk" an ATC-assigned discrete 

transponder code, and to maintain two-way radio communications with ATC. Following these 

procedures allows authorities to recognize such aircraft as non-hostile (Jeppesen, 1998). As the 

attacks of 9/11 illustrated that a hostile aircraft can come from within domestic airspace, a new 

ADIZ was established around the Baltimore and Washington DC region, extending over 40 nm 

from the Capitol in places. For a time there was also an ADIZ around greater New York City. 

Analogous to the original US ADIZ, aircraft entering or operating within the DC ADIZ must have 

a flight plan, a transponder code, and two-way communication. The aircraft must be transmitting 

the transponder code and be explicitly cleared into the ADIZ before entering. Aircraft that takeoff 

from airports within the ADIZ must be cleared by ATC and transmitting the code before they are 

airborne. Within the DC ADIZ, the FAA has erected a Flight Restricted Zone (FRZ). General 

Aviation flight is banned from this approximately 13 nm radius circle centered on the Capitol, 

except for specially vetted or approved cases (FAA, 2003a). 

While flights that cross the US ADIZ are relatively rare for most pilots, the BaltimoreWashington region is a heavily populated area, with abundant aircraft activity, including aircraft 

that normally operate under Visual Flight Rules (VFR), where a flight plan and ATC 
2 

communication are not required. As with the latest security TFRs, the establishment of the DC 

ADIZ provides much greater opportunity for restricted airspace violations than before 9/11 by 

simply having far more aircraft within the vicinity of restricted airspace. 

1.3. Avoiding of Violations 

Legally, pilots are solely responsible for gathering the necessary information to comply with 

TFRs and the ADIZ. Failure to comply with the requirements of a TFR or ADIZ can result in 

disciplinary action by the FAA (e.g., license suspension). Pilots can learn of the existence and 

details of a TFR through Notices to Airmen (NOTAMs) (Jeppesen, 1998). NOTAMs may be 

obtained from a Flight Service Station (FSS), typically as part of a standard preflight briefing, and 

from various government and commercial electronic sources. Details for complying with the 

requirements of the DC ADIZ were also published in a series of NOTAMs (FAA 2003a, b, c, 

2004a, b, c, 2005). 

To avoid a violation of restricted airspace, a pilot must gather information from the NOTAMs and 

operate the aircraft such that the pilot: 

 Is aware that the restricted airspace exists. 

 Understands the horizontal and vertical boundaries of the airspace. 

 Knows the effective dates and times in the case of a TFR. 

 Understands the procedures for legal penetration of the airspace, if they exist. 

 Navigates correctly so that one knows when the airspace is proximal. 

 Correctly carries out the necessary control settings or inputs to the aircraft to comply with the 

requirements of the airspace. 

A failure by the pilot to complete any of the above steps can result in a violation. 

1.4. Handling of Violations 

Violations are typically detected by air traffic controllers by monitoring their radar displays. If an 

unauthorized aircraft is detected within the restricted airspace, the controller may attempt to 

contact the pilot by radio and inform him or her directly of the violation. However, VFR traffic is 

not always required to be in radio contact with ATC, and this may not be successful. Also, VFR 

traffic typically is not required to transmit a discrete transponder code that distinguishes one 

aircraft from another, so the violator may be unidentified as well. In most such cases, the 

controller tracks the violating aircraft until it disappears near an airport. The aircraft is assumed to 

have landed there and the controller calls the airport to give the pilot a message. In any case, once 

on the ground, the pilot contacts ATC by phone where particulars are collected to file the 

violation. The typical disciplinary action is a one or two month suspension of the pilot's license. 

The pilot may also be interrogated in person by law enforcement. 

In certain cases, if the aircraft appears especially threatening, a military aircraft will be sent to 

intercept it. The interceptor and aircraft may communicate using emergency radio frequencies 

such as 121.5 megahertz (MHz). They may also communicate without radio though a set of 

standard aircraft maneuvers (FAA 2004d). In this way, the interceptor can order the aircraft to 

land at a specific airport, where law enforcement can conduct an interrogation. 
3

If the aircraft fails to comply with the orders of the intercepting aircraft, contingency procedures 

exist that ultimately may result in the aircraft being shot down if the threat is sufficient. 

2. Purpose 

Since 9/11, there has been a great increase in the number of violations of restricted airspace. The 

total number of violations for 1999 and 2000 was 71, while the total for 2002 and 2003 was 1655, 

a more than 20-fold increase (Government Accountability Office, 2004). Possibly, this number of 

violations is purely the result of the greater opportunities for violations presented by 

contemporary TFRs and the DC ADIZ. Nonetheless, this frequency of violations is unacceptable 

as it represents a risk to safety and security and an economic cost far beyond that witnessed for 

restricted airspace violations in previous years. 

 The handling of violations may distract air traffic controllers from their primary task of 

ensuring safe separation of aircraft. 

 All violations since 9/11 have been false alarms rather than actual terrorist attacks. A high 

frequency of false alarms breeds complacency that may result in a delayed or incomplete 

response in the event of an actual attack. 

 Every time an interceptor is scrambled, there is a chance that through some sequence of 

errors a pilot with innocent intentions may be shot down. Reducing the number of false 

alarms, and thus the number of scrambles, reduces the chance of this. 

 With violations occurring almost every day, there is a chance that an interceptor scrambled 

for a false alarm will not be available for an actual contemporaneous attack 

 Each false alarm scramble also carries an economic cost to the government for flying, 

maintaining, and ultimately replacing the interceptor. 

It is in the interests of air traffic controllers, defense and security agencies, pilots, and the general 

public to reduce the number of violations. However, there does not appear to be any solid 

understanding of why such violations occur. Some government officials have expressed 

frustration over the limited effectiveness of their efforts to educate pilots on the presence and 

procedures for the new restricted airspaces (Grady, 2004). Some agencies have even sought to 

criminalize such violations (Niles, 2003), implying that the violations are primarily due to 

careless pilots. Pilots, for their part have expressed frustration and anxiety over what they regard 

as the government's slowness to make compliance with TFRs and the ADIZ less burdensome 

(Charles, 2002, 2004). 

Missing from the debate is any data on why the violations occur. Any attempt to reduce violations 

must address the reasons for the violations. The purpose of this study is to determine apparent 

factors and causes of the violations of restricted airspace. To accomplish this, data provided by 

the FAA Flight Service Operations Support Center (FSOSC) regarding all restricted airspace 

violations over a two year period was analyzed to determine the basic characteristics of violations 

–where they occur, when they occur, and by what type of aircraft. To determine why violations 

occur, the study next determined the probable causes of violations as described in over 200 

narratives within NASA's Aviation Safety Reporting System (ASRS) records. For the purpose of 

this study, "restricted airspace" is defined as airspace associated with an ADIZ or a TFR, along 

with associated Restricted Areas and Prohibited Areas. Because of the databases and selection 

methods used, the vast majority of cases underlying the statistics involve ADIZs or TFRs. 
4 

3. Basic Characteristics of Violations 

To provide an initial assessment of the basic characteristics of restricted airspace violations, the 

records for all violations over a two-year period were obtained from the FAA Flight Service 

Operations Support Center (FSOSC). All records from June 2002 to June 2004 were obtained 

with the exception of records for 7/10 to 9/28 2002, which were missing. The 2910 FSOSC 

records include such attributes as the time, place, and aircraft type.1

 The statistics on these 

dimensions are presented in Table 1 through Table 3, and Figure 1 through Figure 3. 

Table 1. Airspace related to violation. 

Airspace Violations

DC ADIZ 49.0%

Presidential 22.0%

NY ADIZ 8.0%

Crawford / P-49 6.4%

Camp David / Thurmont / P-40 3.9%

Newport Chemical Depot 2.2%

Disney (either) 1.8%

US ADIZ 1.0%

Other 6.8%

Over 97% of all violations were for restricted airspace imposed for security reasons including 

VIP protection, with the remaining portion including TFRs imposed for rescue efforts, sporting 

events and air shows, hazards, and space operations.2

 About half of all violations are associated 

with the DC ADIZ (see Table 1). Violations of Presidential TFRs are the second most common, 

actually representing multiple locations spread across 39 states. This figure excludes violations of 

TFRs around the presidential residences in Washington, Camp David, Crawford, TX, and 

Kenebunkport, ME. The NY ADIZ, which was only in effect for 29 days, is also associated with 

a substantial number of violations. Its number of violations per month is comparable to the DC 

ADIZ for the same period. Specific locations comprising the largest portions of the Other 

category include violations of TFRs for space operations (0.7%), Blue Grass Chemical facility 

(Richmond, KY, 0.7%), and Kenebunkport (0.7%). As such, nearly three-quarters of all 

violations are associated with only 11 specific geographic locations. With the notable exception 

of Presidential TFR violations, nearly all violations involved restricted airspace that is relatively 

static or recurrent for a particular location. 

Most of the aircraft associated with violations of restricted airspace are small general-aviation 

(GA) airplanes (see Table 2). This is consistent with flights by GA aircraft constituting the bulk 

of the aircraft-hours for a given period of time (FAA 1994). Probably even more significantly, the 

 

1

 The number of violations for this time period as indicated by the FSOSC data is different than reported by 

the Government Accountability Office (2004) due to the use of different databases. The FSOSC database 

tracked number of detected violations, while the Government Accountability Office apparently used the 

FAA's database of violation enforcements. 

2

 There were no space shuttle flights for about two-thirds of the sampled period due to the grounding of the 

shuttle fleet following the destruction of the Columbia on February 1, 2003. However, there were numerous 

unmanned rocket launches in the US through out the entire sampled period (National Aeronautics and 

Space Administration, 2004). 
5

use of VFR is very rare among transport aircraft while being common for GA. Transports almost 

always operate under Instrument Flight Rules (IFR), where they rely on electronic means of 

navigation and are positively controlled by an air traffic controller, typically following explicit 

vectors by ATC when at low altitudes where restricted airspace is present. With two independent 

parties (aircrew and ATC) monitoring the aircraft's position electronically, these aircraft are 

apparently relatively unlikely violate restricted airspace. ATC may monitor a VFR flight, 

especially if requested by the pilot, and alert him or her if the flight strays towards restricted 

airspace, but ATC is not required to do so, and the workload associated with controlling IFR 

flights may prohibit such service. An additional possible benefit of IFR flight is that compliance 

with IFR flight is nearly synonymous with compliance with ADIZ penetration: the pilot has filed 

and activated a flight plan, is transmitting a discrete transponder code, and is in radio contact with 

ATC. For pilots such as those of air transports that habitually fly IFR, the ADIZ represents a 

smaller adjustment. Familiarity with and use of IFR may effectively prevent ADIZ violations as 

well. Not all private pilots are certified or even equipped to fly IFR, however. 

Table 2. Aircraft classification involved in violation. 

Aircraft Violations

GA Airplane, Single Piston 72.7%

GA Airplane, Multi Piston 9.5%

GA Airplane, Turboprop 2.8%

GA Airplane, Jet 1.1%

Civil Rotorcraft 5.8%

Experimental 1.7%

Civil Transport 1.2%

Military 5.2%

The FSOSC data did not include pilot name or identity. However it did include the tail number of 

the aircraft. With the caveat that a single aircraft may be rented or shared among multiple pilots, 

tail number can be used to crudely estimate the frequency that a pilot repeatedly violates 

restricted airspace. Examining the 2043 FSOSC records that included tail numbers, only six 

percent of all tail numbers are associated with two or more violations. Without an estimate of the 

number of aircraft “exposed” to restricted airspace, it is not possible to determine if this 6% 

indicates that certain pilots are characteristically prone to violations (i.e., that a repeat violation is 

not merely a chance event). Indeed, depending on the actual number of exposed aircraft, this 6% 

may indicate that previous violators are less likely to violate again than those who have never 

violated. In any case, the 6% statistic is not consistent with a hypothesis that a few incorrigible 

pilots are responsible for a large portion of the violations. Ninety-three percent of all violations 

involve a single appearance of a tail number. 

Table 3. Percent of violations involving an interception. 

Intercepted Violations

Yes 14.6%

No 85.4%

Approximately 1 in 6 or 7 of all violations are associated with an interception (see Table 3). The 

probability of interception is not significantly related to aircraft classification. 
6 

Most violations occur during daytime hours, in particular, the afternoon, although there appears to 

be a small dip around lunch time (see Figure 1), and there is a tendency for more violations 

around the weekend (see Figure 2). This might be expected given most violations are associated 

with small GA airplanes. 

0

50

100

150

200

250

300

AMAMAMAMAMAMAMAMAMAMAMPMPMPMPMPMPMPMPMPMPMPMPMAM

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12

Figure 1. Number of violations for each hour of local time of day. 

0 100 200 300 400 500 600

Mon

Tue

Wed

Thu

Fri

Sat

Sun

Figure 2. Number of violations for each day of week. 

Only two years were included in the FSOSC sample so any relationship of violations to month of 

year can be only tenuously asserted. Nonetheless, there may be an increase in violations in the 

spring months (see Figure 3), perhaps associated with a general increase in GA activity for those 

months. However, it should be noted that March 2003 corresponds to the US invasion of Iraq 
7

with its heightened level of alert at home, which resulted in more TFRs and thus more violations. 

The New York ADIZ, which only existed from 3/18/2003 to 4/17/20033

, is alone responsible for 

232 of the 818 violations for March and April of both 2003 and 2004. On the other hand, the DC 

ADIZ was imposed in the beginning of February 2003, yet a sharp increase in violations does not 

occur until March, consistent with a general spring increase in GA activity bringing more pilots 

into conflict with the ADIZ. Furthermore, March of 2004 witnessed a doubling of violations 

compared to February 2004. While not as dramatic as the change from February 2003 to March 

2003 (a six-fold increase), this still represents a substantial increase that is not associated with any 

heightened level of alert. Indeed, February 2004 marks the beginning of depicting the DC ADIZ 

and certain recurring TFRs on aeronautical charts, so one might have predicted a decrease in 

violations as these charts are obtained and used by pilots. 

0 50 100 150 200 250 300 350 400 450

January

February

March

April

May

June

July

August

Septem ber

October

Novem ber

December

Figure 3. Number of violations for each month of the year. 

While the FSOSC data indicated when, where, and what sort of aircraft were violating restricted 

airspace, it provided limited insight into why. Why are most violations for restricted airspace, 

such as the DC ADIZ, that would be predicted to be well known? To answer this, one needs much 

greater detail about the sequence of events leading up to each violation. This can be found in the 

narratives in the records of NASA’s Aviation Safety Reporting System (ASRS). These records 

provide sufficient detail to reliably determine the probable cause and factors contributing to 

violations of restricted airspace. 

 

3

 The NY ADIZ was imposed a couple days before the invasion of Iraq on March 20, 2003 and rescinded 

on April 17 after major hostilities in Iraq ceased and the National Threat Advisory Level returned to 

Yellow (Aircraft Owners and Pilots Association, 2003a, 2003b); 
8 

4. Method 

4.1. Source of Data 

The Aviation Safety Reporting System (ASRS) was established in 1975 by NASA with the 

cooperation of the FAA in order to collect voluntarily submitted aviation safety incident reports 

with the goal to lessen the likelihood of aviation accidents. Reports are solicited from pilots, air 

traffic controllers, cabin crew, flight dispatchers, mechanics, and other airport personnel, although 

over 90% of the reports are from pilots (Aviation Safety Reporting System, 1996). In addition to 

recording the conditions of the incident (e.g., visibility, aircraft type, pilot experience), the 

reporter provides a narrative of the incident where she or he describes what happened, why it 

happened, and what can be done to reduce the chance of a re-occurrence4

. These narratives are 

the primary item of interest for this study as they provide the details necessary to categorize the 

probable cause of a violation of restricted airspace, as well as the reporter’s perspective of the 

factors that led to the violation. 

4.2. Biases within ASRS Records 

To encourage reporters to record an honest assessment of the incident, all submissions are 

confidential and the records are void of potentially identifying details (e.g., aircraft tail number, 

discrete transponder codes used, exact time and date of the incident). Furthermore, the FAA is 

prohibited by law from using any ASRS records for disciplinary actions. 

The contents of an ASRS record thus cannot be used for or against a pilot who is charged with 

violation. However, as an incentive for pilots to make ASRS reports, such pilots gain certain 

advantages with regard to FAA disciplinary actions (ASRS provides a reporter with a means to 

prove she/he submitted a report without revealing its contents). In the case of violation of 

restricted airspace, pilots whose licenses are suspended are not required to physically mail the 

license to the FAA.5

 It also appears, based on the narrative of the ASRS reports themselves, that 

during the phone interviews to collect the particulars of an alleged violation of restricted airspace, 

air traffic controllers are encouraging pilots to file ASRS reports. The result of these incentives 

and encouragement is a substantial and broad corpus of cases of restricted airspace violations in 

ASRS even though it was originally instituted for compiling safety issues. 

While the ASRS process is designed to encourage reporters to make reports and to make the 

reports honestly, ASRS records are still open to certain biases. As a voluntary reporting system, 

the records within ASRS do not constitute a random sample of incidents. As a result, the 

proportion of incidents of one class among ASRS records may not be the same as the proportion 

of incidents of that class within the National Airspace as a whole. For example, pilots who are 

most likely to enter restricted airspace for one particular reason may be disproportionately likely 

to file an ASRS report simply because they are the type of pilot who is familiar with ASRS. 

While this study reports the proportion of restricted airspace violations attributable to various 

causes, the proportions should be considered only rough approximations of the actual proportion. 

A high proportion of an incident class in ASRS records is a relatively reliable indicator that the 

class is important, but the true proportion might be different. 

 

4

 The ASRS reporting forms are available at http://asrs.arc.nasa.gov/forms_nf.htm. 5

 For other violations, filing an ASRS report would result in no suspension or other civil penalty at all, 

assuming certain criteria are met (e.g., violation did not result in an accident) (FAA, 1987). 
9

The records submitted to ASRS are a single person's perspective of an incident at the time it is 

reported. Even if the person is reporting honestly, the report may be distorted by lack of 

knowledge about, misunderstandings of, or failure to accurately recall the actual events that led to 

the incident. The vast majority of the reporters of the ASRS records used in this study were pilots 

whose flight was somehow related to a violation of restricted airspace. As such, the results of this 

study should be regarded as the violations from the pilots' point of view. 

4.3. Record Selection 

The investigator was supplied with a total of 784 ASRS records from October 2001 to December 

2003, selected because they referenced “temporary flight restriction” or “TFR.” From this total, 

records were selected to create a sample that meets two criteria: 

 The sample represents the more recent incidents. This was done so that the sample reflected 

the latest efforts by the FAA and other organizations to minimize the frequency of violations 

For example, in June 2003, the FAA made graphical TFR notices available to pilots. This 

sampling was also done to reflect violations of the most recent kinds of restricted airspace. 

For example, the DC ADIZ did not exist prior to February, 2003. 

 The sample matches proportions on various dimensions found in the FSOSC records. 

Specifically, the ASRS sample should match the FSOSC data for each time of day and day of 

week of the apparent violation, airspace associated with the violation, aircraft classification, 

and inclusion of an interception. This was done to minimize potential bias due to the ASRS 

records being voluntary submissions. For example, if pilots of air transports are especially 

likely to file an ASRS report, then the observed distribution of probable causes would be 

skewed to the degree that pilots of air transports tend to violate restricted airspace for 

different reasons than pilots of general aviation aircraft. This concern of bias is eliminated by 

matching the ASRS sample proportions to FSOSC proportions, which are the true statistics 

for nearly all restricted airspace violations over a two-year period. 

In practice, the proportions found in an exhaustive selection of all of the most recent ASRS 

records (from June 2003 on) were not significantly different than the proportions in the FSOSC 

data, with the following exceptions: 

 The ASRS data over-represented violations of the DC ADIZ, accounting for 65% of the 

records versus 49% for FSOSC. Also, violations in the NY ADIZ were not represented in 

most recent ASRS data, as it was rescinded in before June 2003. 

 Rotorcraft appear to be somewhat over-represented in ASRS data (10% of the records versus 

6% for FSOSC), while military aircraft are under-represented (less than 2% of the records 

versus 5% for FSOSC). 

With the most recent ASRS proportions nearly matching the FSOSC proportions, the two criteria 

were met by taking all the most recent records and then selecting a smaller number of somewhat 

less recent records to achieve the second criterion. Two hundred and nineteen records were 

selected from April 2002 to December 2003, with the majority (81%) being nearly all records 

from June 2003 to December 20036

, leaving 19% specifically selected to adjust the proportions in 

the sample to not differ significantly from the FSOSC proportions. For example, the NY ADIZ 

 

6

 There were a total of 1484 violations for the same time period according to the FSOSC data. Note that an 

incident reported in ASRS does not necessary appear in FSOSC; the ASRS data include incidents that are 

not associated with an actual accusation of violation of restricted airspace. 
10

only existed for a few weeks in March and April 2003, so records concerning the NY ADIZ from 

that time were selected in order for the sample’s proportion of records related to the NY ADIZ to 

match that found in the FSOSC data. 

Because the ASRS records only represent one reporter's perspective of an incident at a given 

point in time, it is not possible to strictly determine if a violation of restricted airspace actually 

occurred or not. The best that can be determined is that the reported incident involves concern 

about the violation of restricted airspace. That is, according to the narrative, a party (not 

necessarily the reporter) is concerned about a past or future violation of restricted airspace. This 

includes incidents where: 

 All parties in the narrative apparently agree that the pilot violated restricted airspace. 

 An air traffic controller has cited the pilot for violating restricted airspace, but the pilot 

suspects this is an error. 

 The pilot has not been accused of any violation but the pilot nonetheless believes she or he 

may have violated restricted airspace. 

 No party in the narrative believes a violation occurred, but the reporter believes certain 

factors may make violations likely in the future and (apparently) felt it was worth reporting 

this to ASRS. 

Some of the selected records do not include a concern about a violation of restricted airspace. A 

TFR may have played a role in the incident, but the report may have been submitted to document 

a different concern for safety or security, such as an uncleared entry into Class B airspace, failure 

to hold an assigned altitude, or near mid-air collision. On examining the narratives, sixteen of the 

219 records were found to not concern a violation of restricted airspace, based on the 

classification system documented in the appendix. These records were excluded from this study, 

leaving 203 selected records. 

4.4. Record Categorization 

For this study, the key contribution of the ASRS data is the narrative included with each record, 

in which the reporter describes the event, the causes of the event, and efforts that may reduce the 

chance of future similar events. Being a free-form text description, a systematic means of 

categorizing the narratives based on their content is required to extract statistics from these 

narratives. Based on the contents of its narrative, each ASRS record was categorized on the 

dimensions given in Table 4. Documentation and rules for classifying ASRS records on all these 

dimensions is provided in the appendix, but key details of each dimension are provided in the 

following sections. 

4.4.1. Got NOTAMs/Briefing 

The Got NOTAMs/Briefing dimension was used to get a rough estimate of the presence of pilot 

preparation for encountering restricted airspace. For the this dimension, a "Yes" means the 

narrative explicitly says the pilot got at least some NOTAMs or a partial preflight briefing. It does 

not necessarily mean the pilot got the NOTAMs or briefing specifically regarding the airspace 

associated with the violation of concern. A "No" means the narrative explicitly says the pilot did 

not get any briefing or NOTAMs. A narrative may also be categorized as “Unknown,” indicating 

that the narrative did not explicitly and unambiguously state that the pilot received or failed to 

receive any NOTAMs or briefing. 
11

Table 4. Dimensions for categorizing ASRS records. 

Dimension Meaning 

Got NOTAMs/ 

Briefing 

Whether the pilot got any NOTAMs or a preflight briefing for the flight. 

Violation of 

concern 

The specific action required for the airspace that the pilot may not have 

followed. 

Probable Cause The most likely cause based on the information provided in the narrative. 

Reporter-identified 

Factors 

Factors the reporter indicated contributed to (or may contribute to) the 

violation of concern. 

Airspace The airspace associated with the violation of concern. 

Accusation Whether the narrative indicates that the pilot was accused of violating 

restricted airspace by a federal authority. 

Interception Whether the narrative indicates that an interceptor was dispatched for the 

apparently violating aircraft. 

4.4.2. Violation of Concern 

The dimension Violation of Concern has the categories of actions given in Table 5. 

Table 5. Categories of Violation of Concern. 

Category Meaning 

Entry into 

Restricted Airspace 

Narrative concerns an aircraft entering airspace when entry is not allowed. 

Activation or 

Clearance 

Narrative concerns failure to get proper authorization prior to entering 

restricted airspace, including activating a flight plan, getting a clearance, 

and getting a discrete transponder code. 

Transponder Use Narrative concerns failure to correctly use the transponder as required for 

the airspace. 

ATC 

Communications 

Narrative concerns failure to establish or maintain communication radio 

communications with the appropriate air traffic controller after entry into 

the restricted airspace. 

Flight Path or 

Procedure 

Narrative or synopsis concern a prohibited flight path or procedure for the 

restricted airspace that otherwise allows flight. 

No Violation of 

Concern 

No party in the narrative is concerned that a violation of restricted airspace 

occurred or might occur in the future. 

As described in 3.3, records classified to have No Violation of Concern are not included in the 

statistics given by this report. 

4.4.3. Probable Cause 

The categories for probable cause are derived from the model for avoiding a violation of 

restricted airspace as described in 1.3 and illustrated in Figure 4. For the purpose of assigning 

probable cause to a record, it is assumed that the violation of concern actually occurred as 

described, even though the narrative may not necessarily relate an actual violation. Because the 

records for this study were selected if they included any concern about a violation of restricted 
12

airspace, the events in a particular narrative may not be an actual violation. Instead, they may 

represent a near-violation, the potential for a future violation, or merely the belief by one party in 

the narrative (sometimes the pilot) that a violation occurred when apparently no violation actually 

occurred. 

Aware Restricted

Airspace Exists

Know Time Airspace

is in Effect

Know Spatial Position

Relative to Airspace

Understand Procedures

for Penetration

Complete Necessary

Control Settings

Yes

Yes

Yes

Yes

Yes

No Violation

No

Violation Probable

C

No

No

No

No

Presence of Airspace

not Known or Recalled

Incorrect Understanding

of Distance to Airspace

Time or Date of Effect

not Correctly Known

Procedures for Penetration

not Understood

Control Setting Error

Incorrect or Lack of

Detailed Information

Figure 4. Model for assigning probable cause. 

The category for Incorrect Understanding of Distance to Airspace includes both errors in 

navigation and errors in understanding the boundaries of the restricted airspace. It is often unclear 

from the narratives which error occurred. All a pilot can report is that she or he apparently entered 

restricted airspace when she or he thought it was farther away. As a result, these two errors are 

combined into one probable cause for this study. 

A category of Indeterminate / Multiple / Other was also included for records that could not be 

categorized on any of the causes given in Figure 4. 

Navigation charts were referred to for some records in order to reconstruct the flights in order to 

assign the probable cause. 

4.4.4. Reporter-identified Factors 

Reporter-identified Factors are items the reporter explicitly identifies as contributing to a 

potential violation. They are also derived from reported elements of the chain of events leading to 

a violation. In addition, they are established from statements on reporter-suggested remedial 

actions that may prevent future violations (implying that the lack of such actions is a factor in 

current violations). Reporter-identified Factors are in contrast to Probable Cause, in that while 
13

Probable cause follows the investigator's model for avoiding violations of restricted airspace, 

Reporter-identified Factors are the reporters' perspectives on the cause of the violations. As such, 

they provide a separate viewpoint or cross-check of the results concerning Probable Cause. 

Based on an initial sample of ASRS records, eight Report-identified Factors were derived and 

each record was categorized as to whether it included each factor or not. The factors are detailed 

in Table 6. 

Table 6. Reporter-identified Factors. 

Factor Description 

Airspace Communication Problem in communicating restricted airspace information (e.g., 

through FSS or NOTAMs) and recommendations to improve its 

communication. 

ATC/Clearance Problem Problem in required communication with ATC. Does not include 

technical problems with the aircraft radio. 

Underuse of Optional ATC Lack of use of ATC services such as flight following or 

recommendations to use them in the future. 

Pilotage Limitations Imprecision in navigation due to reliance on pilotage (i.e., 

navigation by visual reference without electronic aids). 

General Human Factors 

Antecedents 

Miscellaneous human factors not specific to restricted airspace 

(e.g., fatigue, distraction). 

Equipment Failure Failure of aircraft or on-board equipment leading directly to 

possible violation. 

Violation Handling Error Apparent error in procedure or execution of the handling of an 

alleged violation of restricted airspace, including disputes about 

the existence of the violation. 

Overly Restrictive Rules Rules regarding airspace restrictions are regarded as 

unnecessarily strict or extreme. 

4.4.5. Other Categorization Dimensions 

The categories for Airspace were derived from the most frequently reported airspaces in the 

FSOSC data. 

A narrative was categorized as “Yes” for Accusation and Interception if it indicated the presence 

of an accusation or interception respectively, and “No” otherwise. There was no provision for 

categorizing narratives as “Unknown” on these dimensions. 

4.5. Inter-rater Reliability 

Because categorizing the ASRS reports on these dimensions requires a human rater, all 

categorization dimensions documented in the appendix were subjected to tests for inter-rater 

reliability. Twenty records were coded independently by two raters, and the categorizations 

compared. The results of the comparisons are presented in Table 7, where the percent agreement 

between the two raters is a measure of the inter-rater reliability. The reliability of binary 

dimensions, such as the Reporter-identified Factors, can also be indicated by the product-moment 

correlation (φ) of the ratings of the two judges, for which a value of 1.00 represents perfect 

agreement, and 0.00 represents no agreement. 
14

Table 7. Reliability of categorization dimensions. 

 Agreement Correlation Significance 

Dimension % φ χ2 df p

Violation of concern 85% -- 40.30 12 < 0.001

Airspace violated 95% -- 8.84 1 < 0.005

Got NOTAMs/ Briefing 80% -- 18.50 4 < 0.001

Accusation 100% 1.00 12.93 1 < 0.001

Interception 100% 1.00 10.43 1 < 0.005

Probable Cause 

Grouped together Incorrect or 

Lack of Detailed Information 

85% -- 32.67 9 < 0.001

Subdivided Incorrect or Lack 

of Detailed Information 

75% -- 61.03 20 < 0.001

Reporter-Identified Factors 

Airspace Communication 75% 0.60 4.84 1 < 0.05

ATC/Clearance Problem 70% 0.36 1.06 1 > 0.1

Underuse of Optional ATC 95% 0.84 8.45 1 < 0.005

Pilotage Limitations 85% 0.49 1.98 1 > 0.1

General Human Factors 

Antecedents 

90% 0.80 9.53 1 < 0.005

Equipment Failure 100% 1.00 4.49 1 < 0.05

Violation Handling Error 80% 0.54 3.59 1 < 0.10

Overly Restrictive Rules 95% 0.69 1.87 1 > 0.1

The chi-square (χ

2

) tests of independence were used to determine the statistical significance of the 

inter-rater agreement for each dimension (at a bare minimum, the apparent agreement between 

the two raters must not be attributable to chance). The resulting p-values are shown, with the 

associated chi-square values and degrees of freedom (df). Cells with zero expected values were 

deleted from the analysis and the degrees of freedom adjusted accordingly. Yates correction was 

used when the degrees of freedom were 1. 

Reliability was consistently sufficient for all dimensions except for certain Reporter-identified 

Factors. Inter-rater reliability was calculated for Probable Cause both as a four-category 

dimension, with all subcategories of Incorrect or Lack of Detailed Information grouped together, 

and as a seven-category dimension, with each subcategory treated individually. The reliability is 

fairly low when the subcategories are treated separately, comparable to the reliability of the 

Airspace Communication Reporter-identified Factor. The impact of such levels of reliability is 

greater uncertainty regarding the observed proportions among the categories. The actual 

proportions for the entire population of cases may be substantially different.7

 

7

 Statistically, one impact of low reliability is that relationships among dimensions becomes diluted by the 

"noise" that low reliability brings. However, it will be seen later that there is a significant relationship 
15

Among the Reporter-identified Factors, ATC/Clearance Problem, Pilotage Limitations, and 

Overly Restrictive Rules (shaded gray in Table 7) all had inter-rater reliabilities that approached 

chance (p > 0.1), and Violation Handling Error has marginally acceptable inter-rater reliability. 

For Pilotage Limitations and Overly Restrictive Rules, the intuitively odd combination of high 

percentage agreement and nearing-chance performance is due to the very low frequency of these 

factors. For example, according to one rater, only one narrative out of 20 was classified as 

including Overly Restrictive Rules as a factor. Probabilistically, two unrelated but low frequency 

events are likely to fail to occur together (i.e., to apparently "agree") simply because they are 

unlikely to occur at all. The p-values for these factors reflect this. Due to their low reliability, 

ATC/Clearance Problem, Pilotage Limitations, and Overly Restrictive Rules are not statistically 

analyzed in this study, although Pilotage Limitations and Overly Restrictive Rules are discussed 

qualitatively. 

5. Analysis 

5.1. Violation Type 

Of all the ASRS reports selected for this study, 15% of the respective narratives did not explicitly 

indicate that the pilot was actually accused by a federal authority of any violation, but the reporter 

was nonetheless concerned about a potential violation. This necessarily includes both cases where 

there was no accusation and cases where the reporter simply neglected to mention there was an 

accusation. The specific violations of concern are given in Table 8. As the DC ADIZ constitutes 

airspace quite different from the others in this study while accounting for nearly half of the cases, 

the statistics for violation of concern and other dimensions are broken down for the DC ADIZ 

versus other airspace. 

Table 8. Violation of concern. 

Category DC ADIZ Other Airspace Total

Entry into Restricted Airspace 57.0% 90.3% 73.9%

Activation or Clearance 21.0% 5.8% 13.3%

Transponder Use 18.0% 3.9% 10.8%

ATC Communications 1.0% 0.0% 0.5%

Flight Path or Procedure 3.0% 0.0% 1.5%

Category of violation of concern varied depending on the airspace. Unauthorized entry into 

restricted airspace accounted for the vast majority of cases involving airspace other than the DC 

ADIZ. For the DC ADIZ, about half of the cases involved violations other than simple 

unauthorized entry (χ

2

(4) = 29.84, p < 0.001). This is probably simply due to the other violation 

categories concerning proper penetration of airspace (e.g., activating a flight plan and getting a 

clearance from ATC). While pilots are generally allowed into DC ADIZ, many if not most TFRs 

effectively do not allow any penetration –there is no procedure for pilots to become confused 

about. These TFRs afford no opportunity to make any violation other than simple entry into 

restricted airspace. 

 

between Airspace Communication and Airspace Violated, implying that the observed reliability is adequate 

for the purposes of this study. 
16

5.2. Pilot Preparation for Airspace 

Most of the narratives (53%) did not indicate if the pilot did or did not get any NOTAMs or a 

briefing prior to flight, while 39% explicitly said the pilot got at least some NOTAMs or a partial 

briefing, and 7% explicitly said the pilot did not get any briefing or NOTAMs. Compared to 

narratives involving other airspace, narratives involving the DC ADIZ are somewhat less likely to 

mention getting or nor getting NOTAMs or a briefing (62% versus 46%, χ

2

(2) = 6.82, p < 0.05). 

In any case, there is a substantial proportion of pilots in these reports who made at least some 

effort to be aware of the airspace they would be transiting but nonetheless became concerned 

about a violation. The following narrative from the ASRS reports is a case where the pilot 

apparently received both an electronic and personal briefing on the airspace, yet still incurred an 

apparent violation. 

I was told I entered a TFR that was placed over Chicago on [a day in June 2003]. This 

was due to a visit from government official. I was aware of the TFR from reading the 

notice on internet weather service, when I checked my weather and TFRs. Internet 

weather service I thought has about the best format for checking a pilot's preflight 

weather and en route conditions. I understood that there was a 30 mi restriction from 

ORD (O'Hare). I was told by the agency I talked with that it was 30 mi from the center 

of downtown Chicago. Then another person said from the center of Midway Airport. 

My route is outside the 30 mi Mode C ring south of Chicago's Class B airspace. I 

assumed I was well clear of the TFR. Later I downloaded my track from my GPS 

[(Global Positioning System] to DeLorme Topo [software]. It showed me between 36-

39 mi south of O'Hare, 28 mi south of downtown, 24-26 mi south of Midway. As our 

company check pilot I stress checking TFRs on a daily, flight bases. The government 

employee that I had to speak with made the comment that this TFR was confusing to 

him also. [ACN 584256]8

5.3. Probable Cause 

Statistics for the probable cause of the violation of concern are given in Table 9. Overall, the 

probable cause of most violations was incorrect or a lack of detailed information about the 

airspace. Most violations were not due to the pilot being simply unaware of the airspace at the 

time of violation. Probable cause varied significantly with airspace (χ

2

(3) = 11.41, p < 0.01), with 

apparent violations of the DC ADIZ being more likely to be due to incorrect or lack of detailed 

information, and less likely to be due to the airspace being outright not known or recalled. While 

the establishment of the ADIZ was relatively well publicized, airspace other than the DC ADIZ 

includes Presidential and other TFRs that may be imposed with little notification, making it 

relatively more likely to escape a pilot's awareness. 

Table 9. Probable cause of violation of concern. 

Category DC ADIZ Other Airspace Total

Airspace not known or recalled 12.0% 30.1% 21.2%

Incorrect or lack of detailed information 74.0% 59.2% 66.5%

Control setting error 3.0% 1.0% 2.5%

 

8

 ACN (Ascension Number) is the uniquely identifying ASRS report number. All ASRS narratives quoted 

in this report were converted from all capitals in the original to sentence case. Abbreviations in the 

originals have been spelled out. The original ASRS records may be accessed through their ascension 

numbers at the National Aviation Safety Data Analysis Center website (www.nasdac.faa.gov). 
17

Category DC ADIZ Other Airspace Total

Indeterminate / Multiple / Other 10.0% 9.7% 9.9%

The following narrative from the analyzed ASRS records is an example of such a case where the 

pilot appears to have been completely unaware of a TFR. 

Called Altoona, PA, FSS (1-800-WX-BRIEF). Told controller I was flying to Sarasota/ 

Bradenton International Airport [FL] at 8500 ft MSL [(mean sea level)], VFR. He said 

it was low clouds around North Carolina, but I should be fine. I should have asked for 

any NOTAMs.... [While reporter was flying over Florida, an] FA-18 [interceptor] told 

me to turn [to] heading of 270 degrees. Complied, told to call control tower upon 

reaching Sarasota. Asked to spell name, was told to fly back to Jacksonville 

International Airport. Security put us under arrest. Bomb dogs sniffed airplane. 

Jacksonville security very apologetic and professional. Four hours later interviewed by 

secret service. After 10 minutes he let my wife and I go. Told us we got too close to 

temporary restricted flight zone. Took us back to airplane and said good-bye. 1) I failed 

to ask FSS for NOTAMs. 2) [unrelated mechanical problem]. 3) Should have done flight 

following. 4) 27 years of United States military service, should prepare better.... [ACN 

593733] 

5.3.1. Incorrect or Lack of Detailed Information. 

For most cases, however, pilots are aware of the restricted airspace, but lack certain correct 

information that would have prevented the violation. The specific correct information that pilots 

were lacking is shown in Table 10. Compared to apparent violations of other restricted airspace, 

apparent violations of the DC ADIZ are significantly more likely to involve lack of correct 

knowledge for the procedures for allowed penetration, and less likely to involve lack of correct 

knowledge of the date when the airspace is restricted (χ

2

(3) = 17.11, p < 0.001). 

Table 10. Breakdown of incorrect or lack of information. Percentages are of all cases. 

Category DC ADIZ Other Airspace Total

Distance to airspace 40.0% 41.8% 40.9%

Time or date of effect 0.0% 5.8% 3.0%

Procedures for allowed penetration 31.0% 8.7% 19.7%

Unspecific 3.0% 2.9% 3.0%

Total 74.0% 59.2% 66.5%

This stands to reason as most TFRs effectively do not have procedures for allowed penetration, 

but often have effective dates and times. Even for TFRs, however, incorrect knowledge about the 

time or date of the TFR is not associated with a large proportion of the violations. 

As shown in Table 10, for both the ADIZ and other airspace, the most common lack of detailed 

information is that the pilot does not correctly know his or her distance to the restricted airspace. 

This may be a result of either incorrect understanding of the boundaries of the airspace (e.g., it 

being larger or extending further in one direction than expected), or it may be due to a navigation 

error. For some cases, the distinction cannot be determined from the ASRS record, as in this case 

which may have involved imprecise knowledge of the reporter’s own position or of the southern 

boundary of the DC ADIZ, or a little of both. 
18

I filed an ADIZ flight plan with Leesburg FSS. Flight plan for VFR flight from 

Manassas Regional Airport [VA] to Cambridge-Dorchester Airport, for [a morning] 

departure and return [six hours later]. I received an ADIZ clearance from Manassas 

tower, a squawk and departure frequency. Departed from runway 16R and proceeded 

southwest to Casanova VOR [ground-based radio navigation aid]. Called Potomac 

Approach. Controller was busy due to high traffic on weekend VFR day. No 

acknowledgement of radar contact. After heading to Casanova for approximately 7 

minutes, requested a turn to Brooke VOR. Was given a standby. A few minutes later, 

controller called and said, 'clear of ADIZ, squawk 1200 proceed on course.' I turned to 

heading of 090 degrees to Brooke. I continued 'on course' via Brooke to Cumberland 

[MD] VOR. In doing so, I entered the edge of the southern limit of the ADIZ. I 

continued flight as planned to Cambridge. At Cambridge, I was requested to call 

Potomac TRACON [(Terminal Radar Approach Control)]. I was advised that I had 

flown through the ADIZ without a discrete code. Suggestions: I should have queried the 

controller as to route of flight since it was questionable as to the procedure for a flight 

through the ADIZ. I should have requested flight following which would have required 

a discrete code. On the return trip, I contacted Patuxent Approach and requested flight 

following and activation of my flight plan. The return flight was essentially the same 

route with several handoffs. I will use this experience to assist other pilots in the use 

and procedures of the TFR/ADIZ. [ACN 597741] 

It appears that misunderstanding of the vertical dimensions of the airspace rarely causes 

problems. More commonly, pilots are unclear on the lateral dimensions of the airspace, and may 

attempt to use existing well-known or well-mapped boundaries as a guide. 

I had not flown my Piper Cherokee for over a month. I was at the service center with 

my company's Gulfstream IV and Gulfstream V. Upon my return to the Washington, DC 

area, opportunity was presented to fly my Cherokee. I departed Shannon Airport, 

Fredericksburg, VA approximately [10 minutes pass the hour] with the intention of 

flying a local VFR flight.... I was aware of the 30 mile Washington ADIZ, but thought 

that the ADIZ did not extend far enough south that it would conflict with the GPS 

Runway 24 approach [I use for practice]. Additionally, I mistakenly assumed that the 

ADIZ would conform to the 30 mile Class B outer ring of Dulles/Washington. 

Furthermore, I never contacted flight service, which is normally my practice, in order 

to discuss the area NOTAMs. The basis for not contacting flight service was that my 

primary mission intention was to fly within the immediate airport area, get the oil temp 

up on the engine and boil off the moisture and land. However, as the flight progressed, 

I decided to do a little training. I attempted to contact Potomac and Quantico Approach 

without success on both my #1 and #2 receiver. In my experience this is not unusual. 

Generally it is more effective to fly to the Richmond area and attempt to get into the 

[ATC] system. [Conducted various training maneuvers around Fredericksburg]. 

Approximately 3 miles from [a fix for an approach to Shannon], I was intercepted by a 

customs helicopter and ordered to land. After landing, I was informed that I had 

violated, by a mile or more the Washington ADIZ. It could probably be argued whether 

or not I actually penetrated the ADIZ. It doesn't matter, I was too close. Pilots don't like 

to make mistakes. I've been flying for forty-five years, all over the world, and never had 

an incident or violation. I got complacent, I assumed, when you should assume nothing 

in this business. [ACN 575606] 

At the time of the above incident, the DC ADIZ was not depicted on charts. While in most places 

the DC ADIZ does in fact coincide with the Class B outer ring (which is shown on charts), this is 
19

not so along the southern edge of the ADIZ (see Figure 5). Several pilots in the analyzed ASRS 

reports missed this detail. 

Figure 5. DC ADIZ and Class B outer limit correspondence. Note that while most of the ADIZ 

coincides with Class B, the ADIZ extends beyond it in the south. Several violations are associated 

with pilots not being aware of this detail. 

Even having the latest most sophisticated navigation equipment is no guarantee, as the 

information on restricted airspace in the databases of such equipment can only be as good as that 

available through official sources. Pilots appear to be finding such information confusing in 

certain cases. 

The event(s) involved the possibility of infringement in the expanded P-40 airspace 

surrounding Camp David. The problem arose as I have had recent cause to question 

the course that I have taken around the airspace. I regularly obtain a flight briefing 

prior to flying. I have been aware of the frequent NOTAMs involving the expansion of 

the airspace since inception. I fly the area weekly and usually file ADIZ transition, or 

file IFR through the Class B airspace. I also fly VFR without radar coverage for local 

flights. I... have an IFR certified approach and en route GPS. I have a current 

commercial database supplier database that I subscribe to and receive monthly 

updates. I have used the GPS for guidance assuming that the special airspace for P-40 

is depicted accurately. P-40 is depicted with 2 concentric circles surrounding it. I 

assumed that the inner circle was 4 nm and the outer circle was 10 nm from the P-40 

site. This would allow the pilot-in-command to navigate with reference to these 

delineations. The pilot could thus navigate around the larger circle when the expanded 

airspace is in effect. After contacting commercial database supplier, I discovered that 

the circles on the map were not 4 nm and 10 nm as I surmised, but 3 nm and 5 nm. 

There are no size labels on the map to indicate this. This ambiguity may mislead the 

user. Commercial database supplier offered no reason as to why the markings were at 3 
20

and 5 nm as the reference made no particular sense to the present airspace situation.... 

[ACN 595198] 

While the reporter above suspects an error in the database, the depiction is actually consistent 

with the official government navigation charts. The inner circle is P-40 itself; the outer circle is 

not the 10 nm TFR expansion of P-40, but a 5 nm ring whose meaning is not apparent. The 

symbology does not correspond to any established airspace representation and its definition is not 

given in the map legend (FAA, 2004).9

Alternatively, the pilot understands the boundaries of the restricted airspace but, due to a 

navigation problem, the pilot does not know his or her own precise position. 

Incursion into Newport, in TFR ([NOTAM #] FDC 1/0661). I was on a VFR flight at 

4500 ft MSL en route from Monroe County Airport, Bloomington, IN to Terre Haute 

VORTAC [ground-based radio navigation aid], directly to Rantoul Airport, IL. The 

beginning of the Newport TFR was no less than 5 nm from my intended route of flight. 

Weather conditions were VFR, but grey and moderately hazy due to extensive cloud 

cover at 7000-8000 ft. Visibility was 6+ nm. I had received a weather briefing and 

relevant NOTAMs from St. Louis FSS and through DUAT [electronic briefing service] 

prior to my initial flight from Rantoul to Bloomington earlier. I flew from Bloomington 

toward the Terre Haute VORTAC without incident. Upon departing the Terre Haute 

VOR checkpoint toward Rantoul, I believed I was on the proper route, however, I 

apparently ended up off-course and traversed the Newport, IN, TFR at 4500 ft MSL or 

about 1000 ft to 1100 ft below the TFR's AGL [(above ground level)] altitude limit of 

5000 ft. I believe that I was off course because of stronger than anticipated westerly 

winds.... I simply became disoriented as a new pilot in an unfamiliar area and did not 

reorient to multiple VORTACs fast enough. As this was my first flight in the vicinity of a 

TFR, I believe corrective actions would include the following: 1) If lost or off-course in 

the vicinity of a TFR, seek advisory services or vectoring from ATC/FSS immediately to 

avoid such an incursion. 2) Plan VFR flight routes well enough away from any TFR. 3) 

plan flight altitudes substantially in excess of TFR minimums (in this case, ceilings were 

lower than preferred and may have compromised safety). [ACN 599483] 

As shown in Table 10, the second most common lack of correct information was for the 

procedures that allow penetration of the restricted airspace, which, as mentioned above, is 

particularly common for the DC ADIZ. Specifically, pilots appear to often have difficulty with 

the procedure to get clearance into the DC ADIZ, which involves activating a flight plan, 

establishing contact with ATC, and getting a discrete transponder code. One common error is to 

attempt to get a clearance and transponder code after takeoff from an airport within an ADIZ. 

While it is common practice for a pilot to takeoff in VMC then initiate IFR flight or use other 

ATC services in this manner, it is a violation for the ADIZ; pilots must be cleared and squawking 

before the wheels leave the ground. 

I called Leesburg flight service to file an ADIZ flight plan from Leesburg Executive 

[inside the DC ADIZ] to Chester Company Airport. After the flight plan was filed, I 

asked the briefer for my transponder code. The briefer informed me that after takeoff, 

Potomac Approach will give me a squawk code. I contacted Potomac Approach as soon 

as possible after takeoff. Potomac Approach informed me that flight service should 

 

9

 The 5 nm ring could be an attempt to represent a static TFR placed around Camp David in April 2002 as 

described by NOTAM 2/3251 (Aircraft Owners and Pilots Association, 2002). This NOTAM was 

apparently canceled some time later, being replaced by a recurrent 10 nm TFR. 
21

have given me a code. I then turned back and landed at Leesburg executive to contact 

the office. The person I spoke with at Potomac Approach listened to the event and 

contacted Leesburg flight service. He said he was sorry about the mix-up, but he had to 

file the report, because the squawk code is necessary for takeoff. [ACN 595615]

In addition to misunderstandings concerning getting a clearance into restricted airspace, many 

violations can be traced to misunderstandings concerning the use of the transponder while flying 

in restricted airspace. This can be seen in this following example concerning the New York 

ADIZ, a restricted airspace that was only in effect for a few weeks, allowing pilots and ATC alike 

little time for education and adjustment. 

We are now approaching the north New Jersey shoreline well inside the ADIZ and we 

are told “radar service terminated, squawk 1200 and frequency change approved, 

unable to make a hand off New York”.... I questioned them about maintaining contact 

with ATC and asked for a frequency for New York. She gave us one to try and I made 

immediate contact with them. They identified us and the flight up the corridor was 

uneventful. Just before we were transferred to Newark Tower as we progressed up the 

river, we were told to call New York approach by telephone when we got on the 

ground.... I called the New York TRACON when I got on the ground. I was informed 

that I had penetrated the NY ADIZ on a 1200 code.... ATC needs to be better trained in 

the procedures involving the TFRs for national security. I did everything as the 

procedure stated. I briefed myself that morning on the procedures as well. I called FSS, 

filed a flight plan, called McGuire Approach to activate it, and stayed in radio contact. 

Yet I am still being told I had a violation. I believe ATC, McGuire Approach made an 

error when they terminated us without a frequency change. The only [thing] I am not 

100 percent sure of is if they told us to change to 1200 code. My copilot and passenger 

both said they did.... [ACN 579443] 

Outside restricted airspace, it is common to switch the transponder to 1200, the standard VFR 

code, when radar services are terminated. However, when in ADIZ-like restricted airspace, 1200 

must never be squawked, even briefly. Especially when new restricted airspace is imposed, it is 

easy to imagine local pilots and even controllers missing differences from the usual procedures. 

Other violations were concerned with misunderstandings about radio communications and 

allowed flight paths. Operating within the DC ADIZ is particularly complicated, where individual 

airports vary on the procedure for getting a clearance and transponder code, for contacting ATC, 

and allowed and prohibit paths or procedures (Aircraft Owners and Pilots Association, 2004). For 

example, for a time at some airports just inside the ADIZ, pilots were not required to get a 

discrete transponder code if they are leaving the ADIZ by a "direct" route. 

New procedures were implemented for Washington ADIZ for special airports [inside 

the ADIZ] including Martin State, which includes the following: pilots shall fly the most 

direct route out of the ADIZ. Our training flight departed Martin following the 

prescribed procedures. As the NOTAM says, we flew directly to Westminster VOR [to 

the northwest outside the ADIZ]. Upon reaching our destination of Carroll County 

airport, we were informed by ground personnel to contact Potomac [Approach]. We 

were told by Potomac that we're in violation for not flying the quickest route out of the 

ADIZ, meaning to fly directly north of Martin state, or directly southeast. However, as a 

pilot, the definition of direct is to fly the shortest distance between 2 points, without 

deviating from that course, so as interpreted by many pilots, we flew the most direct 

route to Westminster. Problems with the current sys include: 1) The ambiguity of the 

wording 'most direct.' 2) No statements are made on what is the most direct route out of 
22

the ADIZ. 3) The same route was completed the night before, and was never told that a 

deviation had occurred. 4) We monitored the appropriate Potomac frequency, but was 

never advised that we were deviating from the intent of the NOTAM. To conclude, I feel 

that future violations can be minimized if the wording of the NOTAM is changed, so 

that there leaves no room for interpretation. I understand that these current procedures 

are a test, and as a pilot operating from within the ADIZ, I want them to be successful. I 

hope my statement shows that NOTAMS of this magnitude should be worded very clear, 

so that mistakes will not be made. [ACN 599020] 

By January 2005, the NOTAM associated with these procedures were changed to instruct pilots 

to take "the shortest route" out of the ADIZ (FAA, 2005b). 

5.3.2. Control Setting Error and Other Causes 

Errors in setting controls appears to relatively rarely cause violations of restricted airspace. For 

some cases of this class, the pilot by habit made an input that normally would be correct, but 

resulted in a violation when done within restricted airspace. For example, as described earlier, 

after radar services are terminated or IFR flight is canceled, pilots are supposed to change their 

transponders to 1200 --unless they are operating in the DC ADIZ for which they must continue to 

squawk the assigned discrete code until either they leave the ADIZ or land. However, the habit to 

switch to 1200 can be so strong that pilots may do it without even thinking. 

I was on an IFR flight plan landing at Leesburg Executive Airport [inside the ADIZ]. 

Controller told me to switch to UNICOM [airport communication] frequency when I 

canceled IFR flight plan but to remain on discrete IFR squawk. Because of distraction 

with other aircraft in landing pattern and because of training, I inadvertently squawked 

'1200' which I know was incorrect. Homeland security spoke with me about the 

incident. [ACN 601541] 

The Indeterminate / Multiple / Other category of probable cause mostly contains cases where a 

single cause cannot be determined, often due to insufficient information. In the following 

narrative, it is not clear what may have caused the violation, if, in fact, there was a violation. 

While on an air medical helicopter flight from [one location to a] hospital, I learned 

that a TFR was in effect for the area while inbound northeast of [a] city. I contacted 

approach control west of [another] city, and requested clearance to [the] hospital. I 

was told to hold my position and to squawk an assigned code. I was also advised of 

traffic which was at my altitude and not talking to approach. I was also advised that the 

aircraft was on the edge of the TFR and would be intercepted. I was then given 

clearance to [the] hospital and given a phone number to call when on the ground. I 

called and talked to a supervisor who asked for my name, address, phone number, and 

pilot certificate number. I asked if I had violated the TFR airspace and was told that he 

knew nothing about it and that he was just taking my information. I don't believe I was 

in the TFR airspace. [ACN 593019] 

This probable cause category also includes causes that cannot be linked to human error, such as 

an apparent equipment malfunction. 

...Certified flight instructor (pilot-flying) receiving instruction for initial multi-engine 

rating from certified flight instructor/ pilot-in-command (pilot-not-flying). Filed two 

ADIZ VFR plans with Leesburg FSS to depart ADIZ Leesburg Executive Airport 

(Leesburg, VA) direct to Winchester Regional Airport (Winchester, VA) and return. 
23

Departed Leesburg. Contacted Potomac Departure, direct Winchester. Exited ADIZ, 

squawked 1200. Airwork performed as prebriefed. Gear extended several times during 

lesson. Upon retraction, gear exhibited in transit light and low voltage bus warning 

light flashed on/off several times.... Contacted ATC on 125.05. Received [transponder] 

code [number] and pilot-in-command entered code with read back to ATC. Pilot-incommand (pilot-not-flying) and student (also certified flight instructor) visually verified 

[discrete code] Mode C displayed on transponder. Aircraft entered ADIZ [five minutes 

after that]. Approximately 5 minutes later, ATC requested our position and heading. 

Pilot-in-command (pilot-not-flying) advised location and heading. ATC requested 

squawk identification, pilot-in-command complied. ATC advised transponder 

transmitting code 1200 and advised 'squawk [discrete code] quickly.' Pilot-in-command 

verbally confirmed transponder set to [discrete code] and recycled as precaution.... 

Next day, Potomac Approach quality assurance advised ATC tapes showed aircraft 

entered ADIZ at [a certain time], displaying code 1200, despite cockpit display of [the 

discrete code]. [ACN 602516] 

Very rarely, there is an apparently deliberate violation of the restricted airspace. 

Our Homeland Security Act has established new aviation rules and regulations. 

Apparently there are abundant funds to investigate unintentional infractions, but no 

funds available for an updated communication systems to assist general aviation pilots. 

A telephone system which puts general aviation pilots in line 'to be answered by the 

next available operator' similar to the preflight weather briefing system and more 

available [radio] frequencies to contact Potomac Approach would be viable solutions 

to alleviate unfortunate and unintentional incidents such as the one I find myself faced 

with. On a routine, round trip, 20 nm flight from Glenair Airport [inside DC ADIZ] to 

Carroll County Regional Airport [outside ADIZ], 2 ADIZ flight plans were filed. We 

contacted Potomac Approach by cell phone, received our clearance and departed. An 

hour later, in preparation for the return flight, while trying to contact TRACON, we 

received only busy signals for in excess of 10 minutes. Unfortunately, Saturday 

afternoon became a very busy time and we were not able to make contact. The boys 

with the big transmitters continuously overpowered us for the entire 10-min flight to the 

ADIZ. We penetrated the ADIZ at 1600 ft MSL for 2 1/2 minutes -- the time it took to 

traverse the outer limits and land at Glenair.... [ACN 600552] 

While the reporter quoted above describes the violation as “unintentional,” she or he obviously 

knew Glenair was in the ADIZ, and therefore surely would have understood that proceeding to 

and landing there would constitute breaching the ADIZ boundaries. 

5.4. Relationship between Probable Cause and Violation 

Probable cause is strongly related to the violation of concern (χ

2

(24) = 130.24, p < 0.001). This 

relationship is shown Table 11. Entry into Restricted Airspace is usually due to either the pilot 

not being aware of the restricted airspace (or forgetting about it), or due to the pilot having 

incorrect information about the aircraft's distance to the restricted airspace. In contrast, all other 

violations are evidently most often due to the pilot having incorrect information about the 

procedures for allowed penetration of the airspace. This is consistent as the other violations all 

involve the procedures for allowed penetration (i.e., getting a clearance, maintaining radio 

communications, and squawking the correct transponder code). In contrast, when the pilot is 

concerned with simply staying out of the airspace altogether, the key information to understand is 

the presence of that airspace and the relative position of its boundaries. 
24

Table 11. Percent of each violation of concern associated with each probable cause. 

Violation of Concern

Probable Cause 

Entry into 

Restricted 

Airspace

Activation or 

Clearance

Transponder 

Use 

ATC 

Communications 

Flight Path or 

Procedure

Airspace not known 

or recalled 

28.0% 3.7% 0.0% 0.0% 0.0%

Incorrect or lack of 

detailed information 

(unspecific) 

4.0% 0.0% 0.0% 0.0% 0.0%

Distance to 

airspace 

50.0% 25.9% 0.0% 0.0% 33.3%

Time or date of 

effect 

4.0% 0.0% 0.0% 0.0% 0.0%

Procedures for 

allowed 

penetration 

2.7% 63.0% 72.7% 100.0% 66.7%

Control setting error 1.3% 0.0% 13.6% 0.0% 0.0%

Indeterminate / 

Multiple / Other 

10.0% 7.4% 13.6% 0.0% 0.0%

Total 100.0% 100.0% 100.0% 100.0% 100.0%

Control setting errors appear to be most closely associated with transponder use violations, 

suggesting that slips in the use of the transponder is the most common control setting error 

associated with violations of restricted airspace. 

5.5. Reporter-Identified Factors 

For each reporter-identified factor (omitting the unreliable ones), Table 12 shows the percent of 

cases that had that factor. There was no significant differences between the DC ADIZ and other 

airspace on the factors, except that reporters were more likely to point to Airspace 

Communication for other airspace (59.2%) than for the DC ADIZ (42.0%, χ

2

(1) = 5.35, p < 

0.025). 

Table 12. Percent of cases including each Reportidentified Factor. 

Factor Total

Airspace Communication 50.7%

Underuse of Optional ATC 16.7%

General Human Factors Antecedents 27.1%

Equipment Failure 6.4%

Violation Handling Error 16.3%
25

5.5.1. Airspace Communication 

Consistent with the finding that a lack of correct detailed information frequently is the probable 

cause of violations of restricted airspace, reporters often point to communication problems 

concerning the airspace as a factor contributing to violating the airspace. While the relatively low 

inter-rater reliability of this factor lends some uncertainty to the actual frequency in the 

population, it is clearly the most common contributing factor identified. Such communication 

errors can involve any source of airspace information, including "official" sources such as FSS 

briefers. 

Called flight service station [in the morning], was told of temporary restriction area 

(TFR). As I understood, it was a 30 mi radius from the Ventura [CA] VOR. I took off 

from Long Beach at [an hour and half later], turned west through the Los Angeles 

Special Flight Rules airspace [a separate ADIZ-like airspace] to Santa Monica, then 

north. I had assumed that this would keep me well east of the TFR. While transitioning 

through the Special Flight Rules area I was squawking [a discrete transponder code] 

and monitoring 128.55 as directed by the Los Angeles terminal chart. At approximately 

7 miles south of the Van Nuys Airport, I called Southern California Approach for 

advisories to my destination at Mammoth Lakes, CA (MMH). I was told to turn east to 

clear me from the TFR and call an 800 number at Los Angeles Center Control. What I 

think I did wrong was to assume that all TFRs were to be a fixed distance from an 

established radio navigation aid, i.e., a VOR. When I heard the FAA weather briefer 

mention a fix from the Ventura VOR of a 037 degrees and 5.7 miles, I took this to mean 

that the TFR was to protect something from that location, not that the 30 mile radius 

was to originate from that position. This of course extended the restricted area more 

easterly than I had thought. Conclusion, I should have stopped the fast talking briefer to 

ask specific questions and not assume anything.... [ACN 590613] 

While the above narrative apparently involved a misunderstanding, in some cases, pilots claim 

the briefer gave them flat-out incorrect information. In the following example, it appears the 

briefer was unaware that the P-49 prohibited area over Crawford, TX, was expanded. 

I got an in-person briefing at the Casper [WY] FSS.... One hour later, left Casper 

Airport for West Houston Airport [TX], making a fuel stop at Liberal Municipal 

Airport, KS. Then about one hour later, proceeded direct for West Houston Airport, 

making deviations for several thunderstorms and for Military Operations Areas in the 

vicinity of Wichita Falls Municipal Airport, TX. Northeast of Waco, TX, at 9500 ft [over 

15 mi from Crawford], I was intercepted by two F-16's and when I contacted Waco 

Approach, was instructed to land at Waco Regional Airport. I did get a complete 

briefing at the Casper FSS for weather, NOTAMs, and the like. I had asked about 

restricted areas along the route of flight. I was told that a restricted area existed at 

Colorado Springs, but that I would be well to the east. I specifically asked about the 

Waco-Crawford area and was told that the area around Crawford was a 3 mi radius. I 

asked if I'd be okay to the east of Waco and I was told that I should be okay. My Waco 

chart (current issue) shows no restricted zone at all --though I thought one existed. At 

the time of the incident, I thought I was clear. I was listening to 122.8 on one radio and 

to 122.0 on the other and squawking 1200. I was at 9500 ft on a direct heading for west 

Houston Airport, and was VFR. In retrospect, had I been on a VFR flight plan, the en 

route controller would probably have kept me further to the east of Waco, TX. [ACN 

582776] 
26

Pilots have also pointed to the omission of information as a factor, although it may be difficult for 

a FSS briefer to anticipate what information is necessary for a particular case. 

I planned an instrument training flight with a student, from Essex Skypark (Essey, MD), 

to Eastern WV Regional Airport (Martinsburg, WV). The student filed an instrument 

flight plan and asked the briefer what frequency to pick up the IFR clearance on. The 

briefer told my student 119.0. We departed Essex with a [a transponder code for local 

pattern work] and contacted Potomac Approach around 800 ft AGL. After a minute or 

two, Potomac gave us our IFR clearance. We were then given an 800 number to call. I 

had wrongly assumed that, because Essex lies within MTN (Martin State [Airport], 

Baltimore, MD) Class D airspace, that we could depart Essex on a [pattern-work] 

squawk and contact approach for our IFR clearance once airborne. At the time, it was 

not clear to me how to pick up an IFR clearance from Essex (other than on the ground), 

since the ADIZ was surrounding the Baltimore and Washington area. When the student 

asked the briefer for the frequency to pick up an IFR flight plan, the briefer said 119.0, 

but did not mention that you first have to at least get a squawk on the ground to enter 

the ADIZ, (which both the student and I should have realized). This further led to our 

confusion. According to my student (who got the briefing), the briefer did ask if he was 

familiar with the ADIZ, which he said he was.... [ACN 602933]

Another potential source of confusion is the written NOTAMs. For some, the large number of 

NOTAMs to peruse before flight, plus their low readability, can make determining the relevant 

NOTAM difficult. 

Overflying the Los Angeles International Airport Class B [airspace] at 13500 ft, I 

noticed a fighter jet fly by.... Shortly before my departure I printed out a full DUATS 

[electronic] briefing and flight plan (35 pages) for the direct route to Montgomery 

Field Airport [San Diego, CA]. Eleven of those pages were NOTAMs. I later found the 

Los Angeles TFR on the sixth NOTAM page, (the fifth FDC NOTAM) but I missed 

seeing it during my preflight reading.... There are a few things I think DUATS could do 

better which might help prevent similar incursions. First, government TFRs, because of 

their high profile should be listed first before all other NOTAMs (if it was even listed 

first among the FDC NOTAMs, I think I would have noticed it.) The regular NOTAMs 

are listed cleanly in upper and lower case with their headings in bold face type so it is 

easy to scan them to pick out any relevant items. However, the FDC NOTAMs are 

shown in all capital letters with no headings causing ones eyes to glaze over after a 

while.... Now if DUATS was as smart as an FSS briefer, it might even have noticed that 

my proposed route and altitude went smack through the middle of an active government 

TFR. If so it could display this fact right before or after the flight plan printout. While 

this would be impractical to do for all NOTAMs, I think it would be justified for popup 

TFRs. Certainly I was responsible for looking through all the NOTAMs to determine 

which ones were relevant, but with such a large number of NOTAMs, the chance of 

human error grows.... [ACN 585771] 

While all other restricted airspace (e.g., Prohibited Areas) appears on standard navigation charts, 

TFRs usually do not and, until February 2004, neither did the DC ADIZ. Many pilots see the lack 

of such an integrated graphic representation of restricted airspace to be a factor. 

...I received an in-flight briefing from Dayton FSS after departing from my first fuel 

stop. The specialist gave me 5 separate areas to be cautious of for the flight. 1) R-4501, 

2) Crane TFR off of Hoosier VOR, 3) an air show north of Indianapolis, 4) one on the 

Pine Bluff VOR and one off of the Terra Haute VOR [(over the town of Montezuma)]. I 
27

did not know I flew through the TFR over Montezuma, IN, until I was briefed by 

TRACON supervisor. Mitigating circumstances: I received the proper information on 

the TFRs from the Dayton FSS, but I wrote it down incorrectly, which is partly to blame 

because I was flying, trying to write down the info at the same time.... I wrote down that 

the TFR for the Terra Haute VOR was on the 223 degree radial, when it was actually 

on the 335 degree radial. It was actually the Hoosier VOR that was using the 223 

degree radial.... Contributing factors: 1) Pilot in a hurry to fly as far west as possible. 

2) Should have gotten briefing on the ground, not in the air. 3) Weather was very good, 

so I didn't bother with a full briefing, and only asked for TFR info. 4) This TFR has 

been in existence for a 1 1/2 years, why can't it be made into a restricted area and put 

on the chart? [ACN 588615] 

Maps of TFRs have become available from a FAA web site, which represents a substantial 

improvement, but, as implemented, these are not always adequate to prevent violations. 

I was on a flight to check out my new Mode S transponder, a test flight. After flying up 

towards Danbury [CT] area I headed south, down Route 7 and Norwalk River which is 

where I thought the [NY] ADIZ was west of. I mistook the Mode C/ADIZ as west of the 

Norwalk River/Route 7 instead of west of the Westport River. I was told upon my 

entrance into Sikorsky Memorial Airport airspace [Bridgeport, CT] to squawk on 1200 

VFR, and then told by ground control after landing to call NY TRACON. I called as 

soon as I got to my house. I inadvertently entered the ADIZ by mistake. Better charting 

on the internet would have helped me in my preflight planning in this instance. [ACN 

579571] 

Pilot also suggested other media for transmitting TFR and ADIZ information, such as the airport's 

electronic information systems (e.g., ATIS, the Automatic Terminal Information Service, or 

AWOS, Automated Weather Observing System), postings within the airport, and notes in the 

Airport Facilities Directory. 

5.5.2. Underuse of Optional ATC 

Many reporters suggested that the violation could have been avoided if the pilot had made better 

use of ATC services, such as flight following or even filing IFR for all flights. As discussed 

previously, IFR flights rarely experience airspace violations probably due to having two parties 

(pilot and ATC) monitoring the aircraft position relative to restricted airspace. A similar effect 

can be achieved for VFR pilots by securing "flight following" services from ATC. However, it 

appears that sometimes this is not possible, as ATC is unable to provide this service. 

I departed, VFR, from Capital City Airport [Harrisburg, PA] to Hagerstown Regional 

Airport [about 13 nm west of P-40's center], in a Piper Navajo. Shortly after departure 

the local controller informed me I was leaving the Class B airspace. I asked that 

controller for the frequency to obtain flight following, I was given a frequency for DC 

Center Control. I called and stated my position and requested flight following to 

Hagerstown, the controller replied that he was unable to provide assistance. (I made 

this request knowing that P-40 was expanded, and hoped for assistance to remain 

outside of its boundaries.) When I had a visual on Hagerstown, I was northeast of the 

field between Chambersburg and Green Castle [PA]. I called tower over Green Castle 

and reported my position. I was given entry and landing instructions. Upon landing I 

was instructed to contact approach control. It was at this time that I was informed that I 

had entered the 'expanded P-40 restricted area. Upon examination of my VFR chart I 

determined that I misread the dimensions of the P-40 airspace. I noticed the circular 
28

restriction area R-4009, followed by a space, then a dashed circular area marked in 

green on the accompanying chart. I assumed that the dashed line was the 10 mi, 

'expanded area' when in fact it was not. [It's 5 nm.] I did measure a 10-mi circle from 

the center of P-40. I now know the parameters of the 'expanded P-40 airspace.' I assure 

you that this incursion was entirely unintentional, and that I will not violate this 

airspace again. [ACN 597714] 

The presence of an ADIZ or TFR represents a significant increase in workload for controllers. 

They must monitor the airspace and route traffic around it. They must detect and report 

violations, sometimes tracking violating aircraft for hours. In the case of an ADIZ, they must now 

give clearances and maintain radio communications not only with the normal IFR traffic but also 

with all VFR traffic now on ADIZ flight plans (or traffic that is normally VFR but filing IFR to 

reduce the chance of a violation). This inevitably includes some inexperienced pilots who do not 

use the radio or ATC services in the most standard or efficient manner. In the following narrative, 

the controller appears to express some frustration with the repeated request for help from a VFR 

pilot. Under flight following, ATC provides advisories and vectors to an aircraft only as the 

controller's time allows. 

On [a Friday afternoon in October], I received a transponder code for transition to the 

ADIZ at Intersection GOLDA on a flight from Summit Airport [Middletown, DL] to 

Montgomery County Airpark [Gaithersburg, MD, within the DC ADIZ]. I continued 

flying until I came to the Bay Bridge [Airport] and turned toward Tipton Airport [Fort 

Meade]. I was at 1200 ft. There was a wind 10 to 15 knots from southwest. I must have 

drifted toward the little piece of the Class B airspace. The controller reminded me to 

keep out of Class B airspace and told me to turn to 260 degrees. I complied and asked 

how many miles to fly this direction because I didn't want to get into the Washington 

[FRZ]. I was told to turn back to 330 degrees and I complied. He reminded me how 

much trouble I would be in if I entered the [FRZ]. By this time I am really concerned 

and asked him which direction would keep me out of trouble and on my way to 

Gaithersburg. He said he didn't have time to fool with me, advised me to submit a NASA 

[ASRS] form. He then told me he was turning me over to a trainee who would help me. I 

thanked him very much, but I felt like he was toying with me somewhat. [ACN 596899]

A proportion of cases cannot be determine (due to unreliability of the categorization scheme for 

the ATC Communication factor), but there appear to be cases of clearances into the DC ADIZ 

being delayed due to ATC workload. Some pilots end up violating the ADIZ as they loiter outside 

waiting for clearance to enter. 

...We departed Sky Manor [Pittstown, NJ, west of the NY ADIZ] en route to Linden 

Airport [inside the ADIZ].... We filed an ADIZ flight plan, and attempted to contact NY 

TRACON on 127.6. The controller asked us to call back in two minutes. We then began 

to circle over Spruce Run reservoir. We made contact again, and asked for clearance 

into the NY ADIZ. The controller said we were unreadable. We were now circling for 

15 minutes. We called the controller again on the same radio he then told us we were 

on the wrong frequency, and to try 132.8. We made contact with the controller on 132.8 

and he cleared us into the airspace with a [transponder] beacon code. We completed 

our circle to an on course heading of 95 degrees and then the controller told us we 

needed to call him when we got on the ground. He said we penetrated the ADIZ with 

out a beacon code.... Human performance consideration: we turned inbound as soon as 

we made contact, and when we did not receive a clearance we started circling again. 

This happened twice, and when we finally received a beacon code we were right on top 
29

of the NY ADIZ. We should have made contact with a less congested approach control 

such as Lehigh Valley International.... [ACN 579274]

An overworked controller is more likely to make mistakes, which may possibly account for pilotreported erroneous accusations of violations of restricted airspace (see 5.5.3). 

5.5.3. Violation Handling Error 

A small but not inconsiderable portion of pilots suspect an error in the handling of a violation, 

often suggesting that they are being incorrectly accused. Given that ATC often cannot positively 

identify a violating aircraft from the radar display, the potential exists for one aircraft to be 

confused with another. 

I called flight service filed an ADIZ flight plan and proceeded to call my TRACON for 

discrete [transponder] beacon code. Upon takeoff I circled the airport [outside the DC 

ADIZ] until I was in communication with ATC. At this point I informed the controller 

that I was airborne and squawking the appropriate code. It was an extremely busy day 

for ATC. The controller replied that he acknowledged my presence and that there would 

be no [flight following] radar services at that time. He also informed me to stay clear of 

Class B airspace.... [Transiting through the ADIZ,] I remained clear of the Class B at 

all times and monitored the ATC frequency. I did not hear my numbers called. When I 

arrived at my destination the ground controller said I was told to call TRACON. I 

phoned TRACON and was scolded by the man on the other end. I explained to him the 

chain of events and said I felt that I did not do anything wrong. At that point he said he 

would reprimand the controller.... [ACN 579606] 

However, it should be noted that these narratives almost always represent only the pilot's 

perspective, and the pilot's suspicions may merely be the result of an inability to determine his or 

her own error. 

Obtained weather briefing from Millville FSS, standard VFR briefing [(includes 

NOTAMs)] from Sussex Airport [NJ] to Orange County Airport [VA]. Asked about 

Washington area TFRs. Departed Sussex. Route of flight was direct, overflying 

[Frederick VOR?], then under the western outer Class B ring of Dulles at 3000 ft MSL 

direct Orange County. I squawked 1200 entire route, and did not contact ATC, because 

I was under Dulles Class B airspace on the west side. Aircraft is IFR GPS certified. My 

flight plan was well planned using web site to avoid P-40, R-4009 and ADIZ. My route 

was verified by the GPS and pilotage. I am IFR rated, but chose to fly VFR. My route 

was 20-24 nm west of the Washington ADIZ. Upon landing at Orange County, line 

personnel gave me a phone number to call. I called and spoke to the supervisor at 

Potomac TRACON. He informed me that I had flown through the Washington ADIZ.... 

A Cessna 172 landed just prior to me at Orange County. I do not know where his flight 

originated. Perhaps the line person was supposed to give the Cessna the phone number 

to call. I cannot see how TRACON had me in the ADIZ when I was at least 20-24 nm 

west of it. I would never purposely fly into an ADIZ without first obtaining a clearance. 

[ACN 600267] 

Despite the reporter's certainty of not violating the ADIZ, the narrative happens to provide 

enough details to determine the error. The pilot says the aircraft passed under the western portion 

of the outer Class B ring of Dulles. This is most definitely within the ADIZ. The position is 20-24 

nm west of the FRZ. It would seem this pilot confused the FRZ boundary with the ADIZ 
30

boundary. The very fact that pilots can be directly told that they violated the airspace but they 

cannot understand it is an indication of the confusion TFRs and ADIZs have fostered. 

Many narratives that suggested problems with the handling of a violation included concern about 

things other than an allegedly incorrect accusation. In particular, there are reports of 

communication problems between interceptors and the pilot. Intercepted pilots have complained 

of interceptors failing to respond on the standard emergency frequency of 121.5 MHz, which 

pilots expect from their training. 

...Prior to this flight, on this day I had checked the weather and flight information.... 

For MSP [(Minneapolis-St Paul International Airport)] one of the NOTAMs [according 

to Meteorologix, an electronic briefing system] was as follows: 'MSP 06/078 MSP see 

FDC 3/4756 ZMP 91.141 WEF 0306191655-0306191945.' I looked under the flight 

data center page for a description of the above mentioned FDC [NOTAM] but found 

nothing. My destination on both flights [of that day] was not MSP or around, so I didn't 

do further research.... At about 5 miles west-northwest of Lake Elmo Airport (21D) an 

F-16 aircraft initiated a right turn just in front of me. First I thought the pilot was just 

avoiding me. I realized on a second passage that I was being intercepted for an 

unknown reason. I started to turn eastbound then I followed him on his third passage 

and acknowledged by rocking my wings. Immediately I tried to contact him on 121.5 

MHz at least 5 times. I received no answer. Lake Elmo Airport was in front of me 

therefore I decided to land there. To my surprise, people on the ground informed me 

about the existence of the TFR for the government official.... Conclusion: Whilst not 

attempting to absolve myself of the responsibility of contacting FSS for additional info 

[about the missing FDC NOTAM], had the Meteorologix system, which I used as a 

legal source to obtain flight information, provided me all the information I needed, I 

would have avoided the situation of flying into the TFR altogether. [ACN 584989]

On the other side, there are reports of pilots failing to tune their radios to establish contact with 

interceptors. Sometimes, the pilot is not immediately aware they are being intercepted. 

On [a Monday in August], I was returning to Tucson. I was not aware of any 

restrictions. I was squawking 1200 on my transponder and listening to 122.9 on my 

radio. In this area I am unable to talk to [Albuquerque Center Control] below 8000 ft. 

When I was at approximately 7000 ft, an F-16 came up beside my plane. At first I didn't 

realize the F-16 was there because of me. The F-16 turned in front of my plane and then 

appeared on my left wing. It circled around me and dropped some flares. I then realized 

it didn't want me near Mount Lemon so I went north towards Winkleman and circled 

around to Marana and then to La Cholla Airpark. When I landed at La Cholla Airpark 

(57AZ), a gentleman from the military was on the telephone for me. He told me I had 

come within 20 miles of the center of the TFR. I gave him my name, address, telephone 

number, and address and identity of my airplane. He wanted to know why I didn't go to 

the air guard emergency channel so I could communicate with the F-16. I told him I 

didn't know it couldn't reach me. I only thought the F-16 wanted me to avoid the area 

so I turned around and headed north. I didn't know I was in a TFR.... I have learned 

from this incident that I should do everything I can to ensure there are no TFRs on my 

route of flight. [ACN 593033]

From other narratives, it appears that some occupants of interceptors have taken to holding signs 

up to their cabin windows in order to tell pilots to contact them by radio. There are standard 

communication signals for interception that do not depend on radios, involving the visual 

behavior of the aircraft (FAA, 2004d). However, as the narrative above illustrates, these do not 
31

always appear to be working. In other cases, the interceptor is perhaps too aggressive in drawing 

the attention of the pilot. 

...S of Waco, near Temple, TX, I was severely rattled by a fighter (hard enough to cause 

scrapes, bruises and contusions to my passenger and myself). He rocked his wings, 

meaning to follow, which I immediately did and I tried to contact him on 121.5. He sped 

off to the north until I could no longer see him and I never heard him respond to my 2 

or 3 calls. I was confused by the action and not having any direction, decided that I 

must have wandered into a Military Operations Area not shown on the GPS database, 

(it was current), so I returned to course. About 10-15 minutes later, I was rattled even 

harder. This rattle actually broke a hand held radio, caused some damage to the 

aircraft, additional injury and frighten my passenger. This time the fighter responded to 

my call on 121.5 and provided a contact frequency to Waco Approach. Approach 

requested I return and land at Waco Regional Airport for an interview. Being based in 

Georgetown (less than 75 miles s of Waco) and flying from Georgetown to Dallas 

Executive Airport frequently, I am very well aware of the P-49 TFR. After this call, I 

strongly suspected I had entered the TFR. After landing, I was asked to call the tower. 

It was confirmed by the tower controller that I had, in his words 'nicked the TFR.'... 

[ACN 588498]

Modern fighters like the F-16 are ill suited for intercepting the small piston-driven airplanes 

associated with most violations of restricted airspace. It is simply difficult to make a supersonic 

fighter fly slow enough to not run away from such an aircraft. Once flying relatively slowly (and 

closely, as necessary for interception), the wake turbulence of a 30,000-pound fighter can be 

hazardous. In some cases, agencies have taken to intercepting violators with passenger helicopters 

and business jets apparently due to their better low-speed capabilities. Such aircraft, however, 

may have limited capability to force an intercepted aircraft to comply with direction. 

5.5.4. Pilotage Limitations 

As airspace communication problems are consistent with violations being due to the lack of 

correct detailed knowledge of the airspace, then pilotage limitations is consistent with navigation 

imprecision causing violations. Pilotage is navigation by ground references using a detailed map, 

and is a simple and common means of navigating for VFR flight. However, as the ADIZ and 

TFRs are not defined by ground references, keeping the aircraft clear of the imaginary dividing 

line between restricted and normal airspace can be a challenge, even when augmented with some 

electronic aids. 

I was on a flight checking out a pilot in a new twin Comanche aircraft he had 

purchased. We were en route from Barstow (BOW) to Sanford (FL). No contact was 

made with ATC as it was his first flight in type and I didn't want to be concerned with 

altitude holding. I was aware of the Disney TFR. I dialed in the 030 degree radial from 

the Lakeland VOR to keep us clear of the TFR. I later moved it to 027 degrees. 

However, we were later informed that we had flown through it. I was sure we were 

clear. I have flown over Disney before on IFR plans. This time we were not in contact 

with ATC, so we were visually navigating. Unfamiliarity with the Disney area was a 

contributing factor. We relied on the Epcot ball [a large distinct building near Disney] 

and estimated we were 10 to 12 miles west of it. Next time I go anywhere near Disney I 

will be talking with ATC again. It is too easy to get distracted and fly into these TFRs. It 

is also easy to assure you are clear of 'Disney' by keeping a distance from a prominent 

'Disney' landmark and find that this is not sufficient. [ACN 579114] 
32

There are definitely cases where the reporter identifies pilotage limitations as contributing to the 

violation. However, due to the unreliability of the scheme for categorizing the presence of this 

factor in the narratives, the proportion of cases with this factor is unknown. It does not appear to 

be especially frequent, suggesting it may not be as important a factor as other factors. Widespread 

use of GPS in and of itself cannot be expected to significantly reduce the number of TFR 

violations. 

5.5.5. Remaining Factors 

Quite frequently, the reporter points to general human factors (e.g., fatigue, distraction) as a 

contributor to the violation. However, as such factors may contribute to human error in any 

situation, this provides little insight into interventions specifically concerning reduction of 

violations of restricted airspace. 

Pilots relatively rarely blame equipment failure for violations of restricted airspace. Likewise, 

there appears to be very few complaints about the TFRs or ADIZ being unnecessarily strict and 

very few calls to reduce the restrictions or responsibilities imposed on pilots. Such comments are 

so few that a reliable percentage of narratives including such statements cannot be determined. 

Pilots, even those who have been accused of violating TFRs or ADIZs, appear to accept the need 

for greater control over the airspace in the interests of improved security. 

6. Conclusion 

6.1. Implications of the Basic Characteristics of Violations 

Based on the records of nearly 3000 violations recorded by FSOSC, most violations are 

associated with small general aviation aircraft, namely single engine piston-powered airplanes. In 

other words, most violations are by the lowest cost and least well-equipped aircraft likely 

operated by a single pilot crew. The operation of these aircraft is an economic and practical 

necessity. However, such aircraft imply constraints on any solution to the problem of reducing 

violations of restricted airspace. To maximize its effectiveness, any technical solution should be: 

 Low cost for the pilots. 

 Simple to use with little training required. 

 Low workload, especially while in flight. 

 Adaptable to a large range of aircraft, including older aircraft without digital displays, 

and possibly without even electrical systems. 

Based on the FSOSC data, about three-quarters of all violations concern “static” or “recurrent” 

restricted airspace, where static restricted airspace remains in effect over a specific geographic 

location for a long and indefinite period (e.g., the DC ADIZ or the Disney TFR), and recurrent 

restricted airspace periodically goes into effect over the same specific geographic location (e.g., 

Newport Chemical Depot or the Camp David P-40 expansion). Pilots have expressed greatest 

concern about TFRs that are not so predictably associated with a specific location (Charles, 2002, 

2004). This includes, justifiably, the Presidential TFRs, which in principle can crop up anywhere 

anytime and account for nearly a quarter of the violations. However, pilots are also particularly 

concerned with the TFRs for nuclear power plants, large public gatherings, and such for which 

the associated NOTAMs do not give a specific geographic location or time. A “blanket” NOTAM 
33

covers each of these TFRs without listing where the locations might be or how a pilot can find out 

about them. It is understandable that pilots will feel anxious about being given a requirement to 

fulfill without the guidance needed to fulfill it. However, violations of these TFRs are statistically 

incidental, accounting for a few percent of the cases. Substantially reducing the number of 

violations means reducing the number of violations associated with static and recurrent restricted 

airspace. It cannot be assumed that because a TFR “should be well-known,” it is not subject to 

frequent violations. 

6.2. Pilots Need the Details 

This study analyzed over 200 ASRS reports involving a concern about a violation of restricted 

airspace. Converging evidence from analyses for probable cause and from reporter-identified 

factors suggests that most violations of restricted airspace observed in the ASRS data are due to 

pilots having inadequate specific information about the airspace, not due to lack of awareness 

about the airspace. Better awareness of the existence of TFRs and ADIZs should reduce the 

number of violations but these results imply it cannot eliminate most of them. Most of the time, 

the pilots lacked certain correct details about the airspace, details that were necessary to avoid a 

violation. 

It may be remembered that ASRS data is voluntarily submitted, and thus the actual proportions of 

probable cause among all violations may differ from those observed here. Efforts were made to 

minimize bias by statistically matching the ASRS sample to the FSOSC data. Nonetheless, it 

remains conceivable that, among all pilots, more violate restricted airspace due to lack of 

awareness than lack of correct details. However, barring compelling evidence that supports an 

enormous bias in probable cause of such violations reported to ASRS, it appears at the very least 

that lack of correct details is a very important reason –if not the most important reason –for 

violations of restricted airspace. Furthermore, these results from the ASRS data are consistent 

with the results from the FSOSC data, a sample of violations that does not have any volunteer 

bias. The FSOSC data showed that most violations concern static or recurrent restricted airspace, 

airspace whose existence should become widely known over time. It is more plausible that 

violations of such airspace would be due misunderstanding its details than simply not knowing it 

exists. 

Chief among the details that pilots lack, especially for TFRs, is a reliable, unambiguous, and 

usable representation of the lateral boundaries of the airspace. Text descriptions of the 

boundaries, as often found in a NOTAM for the TFR, are likely to be inadequate. In mid-2003, 

the FAA began making graphic representations of TFRs available to pilots (e.g., via tfr.faa.gov) 

(Aircraft Owners and Pilots Association, 2003c). This is a very significant step. However, it 

should be pointed out that most ASRS cases analyzed in this study occurred after these graphical 

TFRs became available. 

Furthermore, knowing the boundaries of the airspace is only part of the issue. For ADIZs and 

ADIZ-like TFRs, where penetration is allowed for pilots that follow certain procedures, the 

details for such procedures do not appear to be making it to all the pilots that need them, thus 

contributing to violations of such airspace. It does little good to tell a pilot he is at an airport in an 

ADIZ when the problem is the pilot thinks he can get a clearance after becoming airborne. 

Pilots conventionally receive such details through briefings, either by FSS professionals or by 

electronic means. However, there are many cases where pilots were briefed but nonetheless still 

failed to get the necessary information to avoid a violation. Perhaps there are difficulties in 

making up-to-date and correct information available to these sources. Perhaps it is difficult for 
34

pilots to acquire and interpret the information that is provided. TFR and ADIZ information is 

given primarily as text or spoken words. Perhaps there are limits to the effectiveness of 

transmitting information of this type verbally. 

While TFRs and ADIZs have been around for a long time, only recently have so many pilots had 

to confront them so often. Lacking adequate information, pilots naturally fall back on their 

training, experience, and the information they do have available. They extend the rules they know 

to the new experience of TFRs and ADIZs. They use the boundaries of other significant airspace 

to judge the boundaries of the restricted airspace. They attempt rely on published sectional maps 

for flight planning. They assume the rules for IFR flight are the same as for flight in an ADIZ. All 

these response have been associated with violations. 

Any solution that aims to reduce the frequency of TFR and ADIZ violations must address 

providing the right detailed information to the pilot. Pilots need to know where the airspace is, 

and what they must do to comply with it for whatever place they happen to be at the time. 

6.3. ATC and FSS Performance 

In many ASRS reports, a pilot claims that an FSS briefer or air traffic controller made an error, 

sometimes in providing information and sometimes (in the case of the controller) in accusing the 

pilot of a violation. As nearly all the analyzed cases provide strictly the pilot's point of view, it is 

not possible to assess the validity of these claims, and it should be pointed out that many pilots 

also find ATC and FSS personnel to be highly knowledgeable and professional (Daly, 2003). 

However, there may be reason to believe that ATC is being overloaded with the additional 

demands imposed by ADIZs and TFRs. 

An increase in ATC workload may itself be contributing to violations (as well as having safety 

implications; a couple of reviewed ASRS reports concerned near mid-air collisions in the DC 

ADIZ). Further study of this is warranted to determine if indeed ATC is being overworked, and 

whether some adjustments are necessary. Pilots are looking to more ATC services to avoid 

violations of restricted airspace, so the demands on ATC may be increasing. 

Even if the workload for ATC is adequately managed, it should be noted that increased reliance 

on ATC is not a strategy that will fit all pilots. IFR flight and radio communications are relatively 

advanced skills for some private pilots. Pilots must first master VFR flight before attempting to 

acquire these skills, otherwise the increased workload and distraction may disrupt the learning 

pilot's ability to conduct flight safely. Pilots, right up to the most experienced air transport pilot 

with tens of thousands of hours of IFR flight logged, typically started flying under VFR. Any 

solution that aims to reduce the frequency of TFR and ADIZ violations must allow for a 

population of pilots who fly without contact with ATC (i.e., VFR). 

6.4. Interception and Communication 

While it may not concern the reduction of the number violations of restricted airspace, it appears 

that there have been some issues involving the communication between violating aircraft and an 

interceptor. Standard procedures exist, even for communication without radio, but nonetheless 

confusion and even injury has apparently resulted. This warrants further study, as, following an 

accidental violation of an ADIZ or TFR, a failure of communication with an armed interceptor is 

the next error in the series that may result in an innocent pilot being shot down. 
35

7. Abbreviations and Acronyms 

ACN ............. Ascension Number 

ADIZ ............ Air Defense Identification Zone 

AGL.............. Above Ground Level 

AOPA........... Aircraft Owners and Pilots Association 

APP............... Approach 

ASRS............ Aviation Safety Reporting System 

ATC.............. Air Traffic Control 

ATIS............. Automatic Terminal Information Service 

AWOS .......... Automated Weather Observing System 

BOW............. Bartow Municipal Airport 

COM1........... Communications radio 1 

CRM............. Crew Resource Management 

CTAF............ Common Traffic Advisory Frequency 

DUAT........... Direct User Access Terminal 

DUATS......... Direct User Access Terminal System 

E ................... East 

FAA.............. Federal Aviation Administration 

FBO .............. Fixed Base Operator 

FDC .............. Flight Data Centers 

FRZ............... Flight Restricted Zone 

FSOSC.......... Flight Service Operations Support Center 

FSS ............... Flight Service Station 

GA ................ General Aviation 

GPS............... Global Positioning System 

HF................. Human Factors 

IFR................ Instrument Flight Rules 

LA................. Los Angeles 

LAX.............. Los Angeles International Airport 

Max............... Maximum 
36

MHz.............. Megahertz 

MMH............ Mammoth Yosemite Airport 

MOA............. Military Operations Area 

MSL.............. Mean Sea Level (i.e., the altitude above it) 

MSP.............. Minneapolis-St Paul International Airport 

MTN............. Martin State Airport 

N................... North 

NASA........... National Aeronautics and Space Administration 

NECD........... Newport Chemical Depot 

nm................. Nautical Mile 

NOTAM ....... Notice to Airmen 

ORD ............. Chicago O'Hare International Airport 

PCT............... Potomac TRACON 

PF ................. Pilot Flying 

PIC................ Pilot In Command 

PNF............... Pilot Not Flying 

SA................. Situation Awareness 

SFRA............ Special Flight Rules Area 

SW................ Southwest 

TFR............... Temporary Flight Restriction 

TIBS ............. Telephone Information Briefing Service 

TRACON ..... Terminal Radar Approach Control 

UNICOM......Aeronautical Advisory Station

Unk............... Unknown 

US................. United States 

VFR .............. Visual Flight Rules 

VHF.............. Very High Frequency 

VIP ............... Very Important Person 

VMC............. Visual Meteorological Conditions 

VOR ............. VHF Omnidirectional Range 
37

VORTAC ..... VOR and Tactical Air Navigation 

WX ............... Weather 

8. References 

Aircraft Owners and Pilots Association (2002). Reduction of P-40 TFR good news for Maryland pilots. 

New Items, April 25, 2002, http://www.aopa.org/whatsnew/newsitems/2002/02-2-074x.html. 

Aircraft Owners and Pilots Association (2003a). Code orange means "ADIZ creep" for New York and 

Washington, D.C. News Items, March 18, 2003, http://www.aopa.org/whatsnew/newsitems/2003/03-

1-128x.html. 

 Aircraft Owners and Pilots Association (2003b). TSA lifts NY ADIZ, Chicago TFR. News Items, April 17, 

2003, http://www.aopa.org/whatsnew/newsitems/2003/03-2-054x.html. 

Aircraft Owners and Pilots Association (2003c). AOPA Expo 2003 to kick off with visit from FAA 

administrator. News Items, June 27, 2003, http://www.aopa.org/whatsnew/newsitems/2003/03-2-

198.html. 

Aircraft Owners and Pilots Association (2004). Departure and Pattern Operations at Airports within the 

Washington Air Defense Identification Zone Including Clearance Delivery Frequencies and Potomac 

Landline Numbers. 

Aviation Safety Reporting System (1996). ASRS Database Statistics. DirectLine, 8, June 1995, p20-34. 

Available at http://asrs.arc.nasa.gov/directline.htm. 

Charles, M. M. (2002). As the Beacon Turns #53: Skipping Through the Mine Field. Avweb, July 24, 2002. 

http://www.avweb.com/news/columns/182359-1.html. 

Charles, M. M. (2004). As the Beacon Turns #83: TFRs Again & Again. Avweb, Nov. 14, 2004. 

http://www.avweb.com/news/columns/188505-1.html. 

Daly, S. G. (2003). Those Terrible TFR's. Pilot Journey. http://www.pilotjourney.com/article_138.php. 

Federal Aviation Administration (1987). Advisory Circular 00-46D: Aviation Safety Reporting Program. 

February 26, 1987. 

Federal Aviation Administration (1994). Census of U.S. Civil Aircraft (1994 edition). FAA Aviation 

Policy, Planning, and Environment (AEP). http://api.hq.faa.gov/cen/centoc94.htm. 

Federal Aviation Administration (2003a). Washington DC Metropolitan Area Air Defense Identification 

Zone (DC ADIZ) (FDC 3/2126). FAA Air Traffic Control Systems Command Center. 

http://tfr.faa.gov/tfr/jsp/save_pages/detail_3_2126.html. 

Federal Aviation Administration (2003b). Washington DC (FDC 3/0853). FAA Air Traffic Control 

Systems Command Center. http://tfr.faa.gov/tfr/jsp/save_pages/detail_3_0853.html. 

Federal Aviation Administration (2003c). VFR Traffic Pattern Operations (FDC 3/2943). FAA Air Traffic 

Control Systems Command Center. http://tfr.faa.gov/tfr/jsp/save_pages/detail_3_2943.html. 

Federal Aviation Administration (2004a). Ingress/Egress Procedures for Bay Bridge (W29) and Kentmorr 

(3W3) Airports in Maryland (FDC 4/0539). FAA Air Traffic Control Systems Command Center. 

http://tfr.faa.gov/tfr/jsp/save_pages/detail_4_0539.html. 

Federal Aviation Administration (2004b). Egress Procedures for Certain Airports within the Washington, 

DC Metropolitan Area Air Defense Identification Zone (DC ADIZ) (FDC 4/0540). FAA Air Traffic 

Control Systems Command Center. http://tfr.faa.gov/tfr/jsp/save_pages/detail_4_0540.html. 

Federal Aviation Administration (2004c). Washington, DC Metropolitan Area Air Defense Identification 

Zone (DC ADIZ) (FDC 4/5555). FAA Air Traffic Control Systems Command Center. 

http://tfr.faa.gov/tfr/jsp/save_pages/detail_4_5555.html. 
38

Federal Aviation Administration (2004d). Aeronautical Information Manual. 

http://www.faa.gov/ATpubs/AIM/. 

Federal Aviation Administration (2004e). Washington Sectional Aeronautical Chart, 75th Edition, February 

19, 2004. Product ID SWAS. Washington, DC: National Aeronautical Charting Office, Federal 

Aviation Administration. 

Federal Aviation Administration (2005a). TFR Data Elements. FAA Air Traffic Tactical Operations 

Program. http://tfr.faa.gov/tfr/jsp/list.jsp. 

Federal Aviation Administration (2005b). ADIZ Egress Procedures for Certain Airports within the 

Washington, DC Metropolitan Area Air Defense Identific... (FDC 5/0847). FAA Air Traffic Control 

Systems Command Center. http://tfr.faa.gov/tfr_save_pages/detail_5_0847.html. 

Government Accountability Office (2004). General Aviation Security: Increased Federal Oversight Is 

Needed, but Continued Partnership with the Private Sector Is Critical to Long-Term Success. GAO05-144, November, 2004. 

Grady, M. (2004). TFRs Are Here, They're Weird, Get Used To It. Avweb Newswire, Nov. 8, 2004. 

http://www.avweb.com/newswire/10_46a/briefs/188497-1.html. 

Jeppesen Sanderson (1998). Federal Aviation Regulations / Aeronautical Information Manual. Englewood, 

CO: Jeppesen Sanderson, Inc. 

National Aeronautics and Space Administration (2004) Office of Space Operations – Space Statistics. 

http://www.hq.nasa.gov/osf/spacestat.html. 

Niles, R. (2003). TFRs: Who Are They Really Stopping? Avweb Newswire Nov. 10, 2003. 

http://www.avweb.com/newswire/9_46a/briefs/186022-1.html. 
39

Appendix: Documentation for Categorization of Narratives 

Airspace 

Identify the restricted airspace of concern in the narrative. Pick choice that best fits based on 

narrative and synopsis. Chose the actual airspace pilot potentially violated (if pilot is accused of 

violating A while trying to avoid B, code for A). Use locations given in report to determine most 

likely airspace. 

 DC ADIZ / FRZ / P56 / P73. Includes any restricted airspace completely enclosed within the 

DC ADIZ. Includes restricted airspace related to "SFRA," "the White House," "the Capital," 

"the Capital," or "DC" if the state is VA, MD, or DC. 

 Crawford / P49. Includes restricted airspace around the President's ranch in Texas, both 

permanent (P49) and temporary (e.g., 30 nm TFR). 

 Camp David / Thurmont / P40. Includes restricted airspace around Camp David such as P40 and R4009. Includes restricted airspace related to "Thurmont" and "Hagerstown" if the 

state is WV, MD, or PA. Includes any TFR expansion of P40. 

 Kennebunkport / P67. Includes permanent and temporary restricted airspace around the 

Bush family home in Kennebunkport, ME. Includes restricted airspace related to 

"Kennebunk." 

 VIP (nonresidence). Includes any temporary restricted airspace related to the location of a 

VIP or government official (including foreign) other than those listed above. Includes any 

restricted airspace related to a visit by the President or Vice President. 

 NY ADIZ. ADIZ for NY that was in effect a while ago. Includes any TFR for the city of NY 

itself. Does not include separate TFRs for surrounding cities or states. 

 US ADIZ. Contiguous US ADIZ offshore. Includes any ADIZ violation by an aircraft 

coming from overseas unless another specific ADIZ is given (e.g., DC or NY). 

 Newport Chemical Depot, IN. TFR for Army chemical weapons depot in Newport IN. 

Includes any restricted airspace related to "NECD," "Newport Chemical," or any military 

facility at Newport, IN. Includes any restricted airspace related to "Newport," "Chemical" if 

the state is IN or IL (unless other text makes it clear it does not refer to NECD). 

 Disney (either). TFR for Disneyland and Disneyworld. Includes any restricted airspace 

identified as "Anaheim" or "Orlando." Does not include restricted airspace identified at "LA," 

"LAX," or "Los Angeles." 

 NASA / Shuttle. TFR related to rocket launches at Cape Canaveral, FL. Includes any 

restricted airspace related to "NASA" or "Shuttle" if the state is FL. 

 Sports (anywhere). Any TFR related to any large public gatherings. Includes any TFR 

related to a stadium including stadiums identified by name (e.g., Commerica in MI). Includes 

any TFR for any public event identified by name (e.g., "Superbowl") or type (e.g., 

"Fireworks") other than airshows. 

 Airshow (anywhere). Any TFR related to an airshow, including airshows or events 

identified by name (e.g., "Oshkosh," or "Lakeland."). 
40

 Hazards (anywhere). Any TFR placed because flight represent a hazard to the pilot or others 

(excluding Airshows or NASA/Shuttle). Includes hazards identified by name or type (e.g., 

forest fire, crane). 

 Other / Unknown. Any other TFR. Generally these are security TFRs or specific R- and Pzones other than those given above (e.g., Bangor, St. Marys). Often these are associated with 

military facilities (other than Newport). Also use this code if the airspace is ambiguous (e.g., 

"Texas TFR"). Describe in the Details field. 

Violation of Concern 

Code for the violation or potential violation that the narrative and synopsis concern. 

 Code Rules 

0. No Concern of 

Violation of 

Restricted Airspace 

No party in the narrative is concerned that a violation of restricted 

airspace occurred or might occur in the future. Use this code if 

violation of concern involves airspace other than a TFR, ADIZ, Rzone, or P-zone (e.g., Class B airspace, MOA, Warning areas). The 

pilot may have done something wrong, illegal, or even dangerous, 

but it wasn’t violating restricted airspace. This includes the pilot 

doing did something questionable as a side effect of handling a TFR. 

Do not code 0 if: 

 Pilot cited or accused of a violation of restricted airspace, 

whether pilot believes s/he made a violation or not. 

 Pilot believes there may have been a violation (even though not 

cited), or otherwise felt confused about what was required. 

 Pilot believes current system may result in a violation in the 

future by him/herself or others. 

Examples of Code 0 include: 

 Pilot thought he was broadcasting on CTAF, but was actually 

broadcasting on the approach frequency still tuned from going 

through ADIZ. 

 To avoid WX and a TFR, pilot flew into Class C airspace 

without a radio. 

If Code 0 is applied, do not code for Cause and Factors. 
41

 Code Rules 

1. Entry into Restricted 

Airspace 

Narrative or synopsis concerns an aircraft entering airspace when 

entry is not allowed. Also, use this code if narrative explicitly says 

pilot may not have filed a flight plan as required before entered 

airspace. 

Do not code this if the aircraft is allowed in the airspace but the 

narrative or synopsis concerns failing to follow one of the 

requirements for doing so as classified in Codes 2 through 5. 

However, Code as 1 if the narrative or synopsis concern multiple 

violations as classified in Codes 3 through 5(e.g., 3 by terminating 

radio communications with ATC and 5 departing the flight plan). 

Use Code 2 if the pilot filed a flight plan, but did not do other steps 

required for penetrating the restricted airspace. Use Code 2 for 

failure to get a discrete transponder code, even though it could be 

argued that the pilot necessarily also use the transponder incorrectly 

(Code 4). Also use Code 2 for failure to get a clearance into the 

restricted airspace even though this may also involved a failure to 

establish communication with ATC (Code 3) in order to get that 

clearance. 

2. Activation or 

Clearance 

Narrative or synopsis concern failure to get proper authorization 

prior to entering restricted airspace. This includes activating 

("opening") a flight plan, getting a clearance into the airspace, and 

getting a discrete transponder ("squawk") code. 

If narrative or synopsis explicitly says the pilot may not have 

correctly filed a flight plan, use Code 1. If the narrative only 

concerns activating or "opening" the flight plan, assume a flight plan 

was filed and use this code. 

3. ATC 

Communications 

Narrative or synopsis concern failure to establish or maintain 

communication radio communications with the appropriate air traffic 

controller after entry into the restricted airspace. Does not include 

failure to get a clearance to enter the airspace in the first place (Code 

2). However, use this code if the pilot fails to contact ATC after

getting a discrete transponder code or otherwise getting cleared into 

the airspace (e.g., takes off from non-towered airport with FSSsupplied transponder code but does not contact Approach once 

leaving the pattern for the airport). 
42

 Code Rules 

4. Transponder Use Narrative or synopsis concerns failure to correctly use the 

transponder as required for the airspace. Includes failure to enter the 

proper standard (non-discrete) transponder code as required for 

certain situations. Does not include failing to get a discrete

transponder code prior to airspace entry (see Code 3). However it 

does include failure to enter or use the correct transponder code at 

the correct time or place, including failure to enter or use the right 

standard (non-discrete) codes for certain procedures or flight paths 

(e.g., departure or arrival at certain airports). 

Code 5 for incorrect flight path in response to a failed transponder. 

5. Flight Path or 

Procedure 

Narrative or synopsis concern a prohibited flight path or procedure 

for the restricted airspace that otherwise allows flight. For certain 

cases, pilots are prohibited from: 

 Departing the airspace by a less than shortest route. 

 “Loitering” within the airspace. 

 Departing from the filed flight plan while in the restricted 

airspace. 

 Leaving the pattern of an airport (as during flight training). 

 Conducting certain training exercises (e.g., touch and goes). 

 Continuing on a flight with a failed transponder. 

Code as 1 if pilot is simply not allowed in the airspace but flight path 

may have taken him/her there. Also Code as 1 for failure to correctly 

file a flight plan for entering prohibited airspace. 

6. Other Narrative or synopsis concern failure to meet a requirement for entry 

into the airspace other than above codes. Put details in Notes. 

Pilot Caught/Interception 

Pilot Caught. Pilot actually caught (check, no check) by federal officials. Check if contacted by 

ATC and accused of a violation, was asked to make a phone call or given a phone number on 

landing, was contacted by law enforcement, or was intercepted. Do not check if not explicitly 

stated in narrative or synopsis. 

Interception. Interception reported (check, no check). Check if any mention of an intercept being 

attempted. The actual intercept does not necessarily have to be completed. Check if ATC says a 

scramble was ordered. Check if an interceptor reaches the pilot's aircraft. Check if the an 

interceptor reaches the pilot's aircraft even after the latter lands. An interceptor is considered to be 

any tactical military aircraft (e.g., F-16 Fighting Falcon) or helicopter (e.g., H-60 Blackhawk) or 

any aircraft transporting military or law enforcement personnel (e.g., secret service, customs 

officials, local police). 
43

Do not check if no attempted intercept was reported. Do not check if reporter explicitly or 

quantifiably states the aircraft reached the pilot's aircraft more than 12 hours after the target 

aircraft landed. 

Got NOTAMs/Briefing 

This field is used to indicate if pilot says got or did not get any information in the form of 

NOTAMs or a briefing for the flight associated with the potential violation. This does not 

necessarily have to be information specifically about the restricted airspace itself. Code this based 

on information in the narrative and synopsis. 

Code Unknown if there is no indication that the pilot did or did not get NOTAMs or a briefing, 

code Unknown. 

Code No if the pilot is reported to have gotten no NOTAMS or no FSS briefing, code as No. 

Code Yes if the pilot is reported to have gotten any NOTAMs or any FSS briefing for the flight 

Narrative Code Rationale 

Not get briefing from FSS or check 

NOTAMs.10 

No Explicitly didn’t get briefing or check NOTAMs. 

I did not get briefing or read 

NOTAMs due good weather and 

being in a hurry. 

No Explicitly didn’t get briefing or check NOTAMs. 

I didn't check with FSS. No Explicitly didn’t get briefing. No mention 

(anywhere in narrative) of getting NOTAMs. 

No briefing since good WX. No Explicitly didn’t get briefing. No mention 

(anywhere in narrative) of getting NOTAMs. 

I checked for NOTAMs for flight Yes Expicitly says pilot got NOTAMs. 

Downloaded NOTAMs for flight Yes Expicitly says pilot got NOTAMs. 

FSS briefed me on the weather. Yes Expicitly says pilot got briefing, even though 

briefing may not have included TFRs. 

I only checked for NOTAMs going 

to XXX since I was not expecting to 

divert to into YYY. 

Yes Explicitly got at least some NOTAMs, even 

though may not have been all necessary 

NOTAMs. 

1. Code for getting or not getting NOTAMS/briefing, not for knowledge or understanding 

of restricted area. 

The narrative must explicitly refer to getting or not getting NOTAMs or briefing in order to code 

as Yes or No. Do not code based on statements indicating how much the pilot knows about the 

restricted airspace. Only statements showing that the pilot did or did not get NOTAMs or a 

briefing are used to fill this field. 

 

10 For all examples of Getting NOTAMS/Briefing, consider the example is the only text in the ASRS 

narrative concerning NOTAMs/briefing. All text in the narrative must be included in actual coding. 
44

Code Unknown if all the narrative says is “I was fully familiar with the restricted area,” with no 

statement on where this information came from (maybe the pilot read a NOTAM, or maybe they 

heard it from a flight instructor, a mechanic, or TV). Even if the pilot quotes the NOTAM 

verbatim, code as unknown unless there is explicit indication the pilot got the NOTAMs or 

briefing for that flight. Statements about knowledge of the airspace are not relevant for coding 

this field. 

Code No if narrative explicit refers to not getting any NOTAMs or a briefing. Note that the pilot 

may know everything about the restricted airspace but this field is still coded as No (e.g., the pilot 

knows the NOTAM from prior flight, so says he didn't check it again for the flight of concern).11 

Code Yes if narrative explicitly refers to getting any NOTAMs or a briefing. Note that this means 

a pilot may know nothing about the restricted airspace but this field is still coded as Yes (e.g., 

because the pilot was briefed, but the briefing apparently did not include information about the 

airspace). 

Narrative Code Rationale 

I knew there was a TFR in effect. Unk Does not explicitly refer to getting NOTAMs or 

a briefing. 

The NOTAM said I could do pattern 

work. 

Unk Does not explicitly refer to getting NOTAMs. 

I had no idea the ADIZ existed Unk Does not explicitly refer not getting NOTAMs or 

a briefing. 

I had no idea the ADIZ existed 

because I didn’t get a briefing 

No Explicitly states there was no briefing. 

I had no idea the ADIZ existed even 

though I got a briefing 

Yes Explicitly states there was a briefing. 

2. Yes if any indication that pilot got briefing or NOTAMs. 

If there are contradictory statements in the narrative, coding precedence is to statements that 

indicate the pilot got briefing/NOTAMs. 

Code Unknown if the narrative has no statements that meet the criteria for Yes of No for either

briefing or NOTAMs. 

Code No if all relevant statements in the narrative say the pilot did not get a briefing or 

NOTAMs. If the pilot is reported to have gotten no NOTAMs and there’s no mention of a 

briefing (or vice versa), code as No. 

Code Yes if anywhere in the narrative there is a statement that meets the criteria for getting 

briefing/NOTAM.. This includes the narrative stating that the pilot got either NOTAMs or an 

FSS briefing. If the pilot is reported to have gotten NOTAMs but no FSS briefing, or vice-versa, 

code as Yes. 

 

11 The Probable Cause field affords and opportunity to indicate that the pilot did not know about or did not 

fully understand a NOTAM or briefing regarding the restricted airspace. 
45

Narrative Code Rationale 

No briefing or check of the 

NOTAMs. 

No Explicitly got neither briefing nor NOTAMs. 

I couldn't get anyone to brief me. No Explicitly no briefing. No mention of NOTAMs 

one way or the other. 

I shouldn't have skipped checking the 

NOTAMs 

No Explicitly no NOTAMs. No mention of briefing 

one way or the other. 

Because I got a briefing from FSS, I 

didn’t bother to check the NOTAMs 

myself. 

Yes Explicitly did not check NOTAMs but explicitly 

got briefing. 

I didn't check for NOTAMs. Before I 

left I saw the TFR in the NOTAMs. 

Yes A statement in the narrative meets criteria for 

Yes (even though previous statement meets 

criteria for No). 

3. Yes for getting partial briefing or NOTAMs 

Code Unknown if the narrative does not mention getting or not getting NOTAMs, restricted 

airspace information, or a briefing. Code Unknown if pilot is reported to have only gotten an 

"outlook" from FSS or a source of NOTAMs (e.g., DUAT) with no mention of getting any actual 

NOTAMs. 

Code No if the narrative indicates the pilot failed to get any NOTAMs or any briefing. 

Code as Yes if the narrative states the pilot got any NOTAMs or any briefing or otherwise was 

successful in checking for NOTAMs or getting a briefing, even if the pilot did not get all 

NOTAMs s/he ultimately needed, or if the briefing was incomplete. Code Yes even if the pilot 

explicitly says the NOTAMs or briefing did not include information about the restricted airspace. 

Code Yes even if reporter characterizes briefing as only a "weather briefing." Code Yes even if 

method of extracting NOTAMs or a briefing was flawed, as long as access to the source was at 

least partially achieved. 

Narrative Code Rationale 

FSS gave me the outlook for the day. Unk "Outlook" does not count as a briefing. 

I tried to search for NOTAMs, but it 

wouldn't work. 

No Failed attempt to get any NOTAMs. 

I couldn't get through to get a 

briefing 

No Failed to get even a partial briefing. 

I searched for NOTAMs, and didn’t 

find any for my flight. 

Yes Pilot checked for NOTAMs, but there apparently 

weren't any. 

I loss my phone connection before he 

finished briefing. 

Yes Partial briefing (briefing had been started but not 

finished). 
46

Narrative Code Rationale 

The briefer asked if I was aware of 

the TFR, and I said “yes.” 

Yes A briefing was given, although it lacked 

important detail. 

The printer broke before all 

NOTAMs printed. 

Yes Got some NOTAMs, but not all. 

Got NOTAMs from DUATS but 

missed that one. 

Yes Pilot got at least some NOTAMs. 

When I checked after the flight, I 

discover I hadn't included that TFR 

with the NOTAMs I read. 

Yes Pilot got at least some NOTAMs. 

By going with an abbreviated 

briefing, I missed the TFR 

information. 

Yes Pilot got at least a partial briefing. 

4. FSS briefings versus other briefings. 

Code Unknown if all information about the restricted airspace came from sources other than FSS 

or written NOTAMs, regardless of the reliability of the source (e.g., instructor, FBO employee, 

ATC, other pilot). Also code Unknown if the “briefing” is clearly the type that would not concern 

restricted airspace (e.g., or pre-takeoff or approach briefing) or not by FSS personnel or from a 

aviation-related electronic source of NOTAMs (e.g., by DUATS). Code as Unknown if reporter 

explicitly says the briefing was only an "outlook briefing.". 

Code No if there is any statement about failing to get a “briefing” without further qualification. 

Assume the briefing is by FSS unless there is reason in the narrative not to. Code No if the 

narrative states the pilot failed to get an electronic “briefing” from an aviation-related source of 

NOTAMs such as DUATS. 

Code Yes if there is any statement about getting a “briefing” without further qualification. 

Assume the briefing is by FSS. Code Yes for an electronic “briefing” from an aviation-related 

source of NOTAMs (e.g., DUATS). Code Yes irrespective of the stated type or content of such a 

briefing (from FSS or an aviation-related source of NOTAMs), except for "outlook" briefings. 

Narrative Code Rationale 

We were busy doing the approach 

briefing. 

Unk Not a briefing on airspace by FSS. 

The flight instructor mentioned 

nothing about TFRs in his briefing. 

Unk Not a briefing by FSS personnel. 

I check the weather before leaving Unk No mention of a formal briefing or restricted 

airspace information. 

I skipped the briefing. No Briefing assumed to be by FSS. 

I didn’t check for any NOTAMs in 

my DUAT briefing. 

No Not a briefing by FSS personnel. Explicitly did 

not get any NOTAMs. 
47

Narrative Code Rationale 

I was briefed before flight. Yes Briefing assumed to be by FSS. 

The PIC gave me the NOTAMs to 

read. 

Yes Concerns getting written NOTAMs, not a verbal 

briefing. 

Got a WX briefing from FSS Yes Briefing by FSS. 

I didn’t ask about TFRs in my 

briefing. 

Yes Briefing assumed to be by FSS. 

I glanced at the briefing from DUAT. Yes Briefing from DUAT or DUATS. 

The briefing warned of 

thunderstorms to the North. 

Yes Briefing assumed to be by FSS. 

5. Code based on statements of access of sources of NOTAMs and briefings. 

Code Unknown if source of NOTAMs or the briefing is explicitly not a FSS or aviation-related 

electronic sources of NOTAMs or restricted airspace information, such as the TIBS, DUAT, 

DUATS, AOPA, and FAA web sites. Code Unknown if, in relation to accessing these sources, 

narrative does not explicitly mention NOTAMs, restricted airspace information, or a briefing of 

any kind. Code Unknown if the briefing or information is characterized as an "outlook." 

Code No if narrative explicitly states the pilot’s attempts to access sources of NOTAMs or 

briefings failed (assuming there is no statement indicating that the pilot got some NOTAMs or a 

briefing by other means). It is not necessary for the narrative to say the purpose was to get 

NOTAMs, a briefing, or restricted airspace information. 

Code Yes if narrative explicitly mentions accessing, checking, contacting, talking to, or listening 

to FSS or aviation-related electronic sources of NOTAMs or TFR information in order to get a 

“briefing,” NOTAMs, or information on restricted airspace. Narrative must explicitly mention 

that a ‘briefing,” NOTAMS, or restricted airspace information in relation to the information 

source. A "briefing" must not be characterized as an "outlook." Accessing the source must also be 

at least partially successful to be coded Yes. Assume any mention of contact was successful 

unless explicitly stated otherwise. Aviation-related electronic sources include TIBS, DUAT, 

DUATS, AOPA, and FAA web sites. 

Narrative Code Rationale 

I asked my instructor about any 

TFRs before leaving. 

Unk Not an FSS briefer. 

The news didn't say anything about 

the President visiting this weekend. 

Unk Not a source for NOTAMs. 

I called FSS before leaving. Unk Does not state purpose was to get a briefing or 

restricted airspace information. 

I checked the FAA web site before 

departure. 

Unk Does not state purpose was to get NOTAMs or 

restricted airspace information. 
48

Narrative Code Rationale 

I filed my flight plan with the local 

FSS 

Unk Does not state purpose was to get a briefing, 

NOTAMs, or restricted airspace information. 

I used DUATS for this flight. Unk Does not state purpose was to get a briefing, 

NOTAMs, or restricted airspace information. 

I verified with DUATS that the 

weather was fine. 

Unk Does not state purpose was to get, NOTAMs, or 

restricted airspace information. 

I got the outlook from DUATS. Unk No mention of NOTAMs or restricted airspace 

information. Not a "briefing." 

I called FSS before I left, but there 

was no answer. 

No Explicitly states that access to briefing source 

failed. 

I tried the AOPA website, but it was 

down 

No. Explicitly states that access to NOTAM source 

failed. 

I called FSS to check for TFRs 

before leaving. 

Yes Explicitly states attempt to access FSS for 

restricted airspace information. Assumes access 

was successful. 

I got a briefing from DUATS. Yes Explicitly states got standard briefing. 

I got all the NOTAMs I thought I’d 

need from DUATS. 

Yes Explicitly states got NOTAMs. 

I checked the FAA TFR site before 

departure. 

Yes Explicitly states got restricted airspace 

information from a source of NOTAMs. 

I didn’t see anything about this TFR 

on the FAA site. 

Yes Explicitly mentions restricted airspace 

information in connection to accessing a source 

of NOTAMS. 

The AOPA site was down, so I used 

the FAA site to check on TFRs. 

Yes Explicitly states got restricted airspace 

information from a source of NOTAMS. 

6. Coding of statements implying a pilot did/didn’t get briefing/NOTAMs 

Code Unknown statements concerning knowledge of the restricted airspace even if the detail of 

knowledge “must” mean the pilot read the NOTAM or got a briefing. Also code Unknown 

statements of plans or recommendations on the manner to access or read NOTAMs or get a 

briefing. 

Code as Yes any statements that logically or sequentially require that the pilot got some 

NOTAMs or a briefing. For example, “The FSS briefing never mentioned this TFR,” indicates 

the pilot got a briefing, even if it was possibly incomplete. Code as No if the narrative gives plans 

or recommendations to get a briefing or NOTAMs in the future, as this implies the pilot got no 

briefing or NOTAM for the reported flight. 
49

Narrative Code Rationale 

I assumed the NOTAM meant 5000 

feet MSL, not AGL. 

Unk Indicates knowledge of TFR, not whether pilot 

actually got a written copy or FSS briefing on it. 

Pilots should always read the 

NOTAMs carefully 

Unk Statement of manner to get NOTAMs. Does not 

necessarily imply the pilot got no NOTAMs for 

the flight. 

I should ask the briefer specifically 

about TFRs every time 

Unk Statement of manner in which to get a briefing. 

Does not necessarily pilot got no briefing at all. 

I'll rely on DUATS for NOTAMs 

from now on 

Unk Statement of manner in which to get NOTAMs. 

Does not necessarily imply the pilot got no 

NOTAMs for the flight. 

Next time, I’ll get a briefing no 

matter what the weather is like 

No Implies pilot did not get a briefing for the flight 

of concern. 

Always check NOTAMS. Always, 

always, always. 

 Implies pilot did not check NOTAMs for the 

flight of concern. 

When I read the NOTAM, I assumed 

5000 feet was MSL, not AGL. 

Yes Pilot must have had written copy of NOTAM in 

order to read it. 

I realize now that I missed that 

NOTAM 

Yes Implies pilot got some NOTAMs, although not 

all that were needed. 

It would have been worse if I didn’t 

read any of the NOTAMs for the 

ADIZ, but next time I’ll read every 

NOTAM 

Yes Implies pilot got some NOTAMs, although not 

all that were needed. 

7. Getting versus reading NOTAMs. 

Code Unknown if the narrative does not explicitly say the pilot accessed, got, learned about, saw, 

or read the NOTAMs. Also code as Unknown if the narrative explicitly says the pilot was 

informed verbally about the NOTAMs or restricted airspace information, unless it was by an FSS 

briefer. 

Code No if it is explicitly stated that the pilot did not read or look at the NOTAMs even if the 

pilot successfully accessed some NOTAMs. 

Code Yes if the pilot is reported to have access the NOTAMs without further qualification. It is 

assumed that s/he saw and read at least some of them. . 

Narrative Code Rationale 

The NOTAM clearly allows pattern 

work without a squawk code. 

Unk Does not say pilot actually got the NOTAM 

before flight. 
50

Narrative Code Rationale 

I heard that the TFR was going hot 

that afternoon. 

Unk Information about the restricted airspace was not 

from a written source or explicitly from an FSS 

briefer. 

There were so many NOTAMs I 

decided I didn’t have time to read 

any. 

No Got NOTAMs but explicitly states pilot did not 

read any of them. 

I printed out the NOTAMs, but 

didn’t read all of them. 

Yes Pilot read some NOTAMs 

I connected to DUATS for the 

NOTAMs. 

Yes Pilot accessed NOTAMs. It is assumed he read at 

least some of them. 

I heard from the FSS that the TFR 

was going hot that afternoon. 

Yes Restricted airspace information from FSS. 

8. Code Unknown if determined that NOTAM/briefing (or lack thereof) is old or for a 

different flight or occurred after violation of concern. 

A single "flight" has one takeoff. Treat multi-leg trips as multiple flights. 

Code Unknown if it can be quantitatively determined from the report that the pilot got the 

NOTAM was more than 36 hours before the start of the flight associated with the violation of 

concern. Also code Unknown if the NOTAM was explicitly gotten for a flight that occurred an 

indeterminate time before the flight associated with the violation of concern. Also code Unknown 

if explicitly determined that NOTAM or restricted airspace information was sought after the 

violation of concern occurred. 

Code No if the pilot is reported to have not gotten a briefing or NOTAMs without further 

qualification. Assume it was for the flight associated with the violation of concern. 

Code Yes if the pilot is reported to have gotten a briefing or NOTAMs without further 

qualification. Assume it was for the flight associated with the violation of concern. 

Narrative Code Rationale 

I checked the NOTAMs a couple 

days before I left. 

Unk Explicitly says got NOTAM more than 36 hours 

ago. Does not count as getting the NOTAM for 

flight associated with the violation of concern. 

I had read the NOTAMs for the 

ADIZ every time I flew last year, so 

I know it inside and out. 

Unk Explicitly says NOTAM was read for some other 

flight(s) that occurred some indeterminate time 

in the past. 

I still had the NOTAM for my trip 

into YYY. Potomac said I violated 

the ADIZ when I left YYY. 

Unk Explicitly says pilot got NOTAM some other 

flight that occurred an indeterminate time in the 

past. 
51

Narrative Code Rationale 

I checked the NOTAM after being 

interviewed by the customs officials 

and saw it was indeed for up to 5000 

feet. 

Unk NOTAM sought after occurrence of violation of 

concern. 

I had a chance to check DUATS the 

day before I left, but I didn't. 

No Pilot says he did not get NOTAM less than 36 

hours before departure. 

I never use FSS. No Pilot says he did not get briefing for any flights, 

including flight associated with the violation of 

concern. 

I didn't check the NOTAMs for my 

trip into YYY. Potomac said I 

violated the ADIZ when I left YYY 

in later that same day. 

No Pilot says he did not get NOTAM less than 36 

hours before departure. 

I had read the NOTAM about the 

TFR. 

Yes Assumes NOTAM was read for the reported 

flight. 

I still had the NOTAM for my trip 

into YYY . Potomac said I violated 

the ADIZ when I left YYY in later 

that same day. 

Yes Pilot determined to have gotten NOTAM less 

than 36 hours before departure of flight 

associated with violation of concern. 

I read the NOTAM for the TFR but it 

was a very long time ago 

Yes NOTAM was read. Time ago is cannot be 

quantitatively determined to be greater than 36 

hours. 

I got that NOTAM last month, and 

the briefing suggested no reason that 

it would be different. 

Yes NOTAM determined to be greater than 36 hours 

old, but pilot got a briefing, which is assumed to 

be for the reported flight. 

Probable Cause 

Applies Violation of Concern. This a code for the probable cause of the violation as represented 

in the Violation field. It may be an actual violation, alleged violation, or merely some concern 

about a possible or future violation by a party in the narrative. 

Code the probable cause of the violation of concern. That is, assuming the violation of concern 

did in fact occur (or will in fact occur) as described in the narrative, code for the most likely cause 

of the violation.12 If the narrative concerns the avoidance of a violation of restricted airspace, 

code for the element that prevented the violation, treating the lack of if as the probable cause if 

the violation were to occur. 

Only one code is allowed per ASRS report. 

 

12 While it is assumed that a violation occurred for the purposes of assigning probable cause, if the 

information provided in the narrative strongly indicates a mistaken concern for a violation (e.g., an error in 

accusation by ATC), indicate this in the Notes field. 
52

Unlike Pilot-reported Factors, Cause coding requires as certain amount of interpretation 

beyond what is actually stated by the pilot. The narrative synopsis (written by the ASRS staff) 

can be used to help make such interpretations. For example, if the synopsis states that the pilot 

was unaware of the TFR (apparently based on the fact that the pilot never mentions it in the 

narrative and says he can’t understand what he did wrong since he was clearly outside Class D 

airspace), then assume that is a correct judgment and code accordingly. 

Keep in mind this is a coding of probable causes of restricted airspace violations. A pilot may 

state they misunderstood something in a TFR NOTAM, but do not code anything other than 0 

unless, based on the facts as presented in the narrative, that misunderstanding probably led to a 

violation of a P-zone, R-zone, ADIZ, or TFR. 

While selecting the most probable cause requires an interpretation, the facts should not be open to 

interpretation. Instead, assume the facts of the case are as stated as the reporter even if it 

seems more reasonable that s/he is mistaken. If a pilot says his autopilot malfunctioned and 

carried him into a TFR, assume that is true, not the more likely interpretation that he incorrectly 

programmed the autopilot or GPS. Where there is a conflict on the facts in the narrative, assume 

the reporter is correct. For example, if the FSS briefer says she explain the NOTAM to the pilot, 

but the pilot says she didn’t, assume she did if the reporter is the briefer, and assume she didn’t if 

the reporter is the pilot. 

The Code 2’s are broken down into a hierarchy of subcategories of progressively greater 

specificity. Code with the most specific subcategory possible. If more than one sub-category 

applies (only one Cause may be assigned per ASRS report), or it’s not clear which of two subcategories apply, code as the next level up. 
Code Category Rules Examples 

0 Indeterminant / 

Multiple / Other 

The violation of concern was due to unspecific causes, or a combination of multiple causes below, or for causes not included below (e.g., equipment malfunction). 

Transponder mysteriously startwhile in the ADIZ. Pilot does nit. Pilot didn’t get NOTAMs for The says he would’ve flown into because of the emergency he ePilot violated TFR, but narrativno information on if pilot knew understood the details of the Tpilot correctly executed controthe TFR. 

1 Presence of 

airspace not known or recalled 

There was lack of knowledge of the restricted airspace or failure to recall of presence of the restricted airspace as the aircraft approached it. Code this only if the pilot does not even know the restricted airspace existed round the general region. Treat each airspace separately. A TFR may effectively be an “expanded” prohibited zone, but it is still considered different airspace. Use this code if the pilot was aware of the P-zone, but not aware of its temporary expansion. 

Pilot was unaware of ADIZ, anavoiding Class B airspace. Pilot didn’t notice the TFR NOprintouts. Pilot did not check with FSS foobviously good weather. Just plain forgot about it even tregularly in and out of ADIZ bRelied on local media to alert warea. Didn’t hear anything, so aaround. 
54

Code Category Rules Examples 

2 Incorrect or lack of 

information 

Aware that restricted airspace is in effect, but lack sufficient or correct knowledge to prevent a violation or potential violation. This code or any of the “2” subcategories should be selected if there is a conflict about the correct interpretation of a NOTAM. That is, if ATC thinks the pilot was inside the TFR bounds but the pilot is sure he was outside, or vice versa, still code a 2 or 2-subcategory. Whoever is right, someone has incorrect or lack of 

information that can cause a real violation or the accusation of a violation, both which are concerns. 

Chain of events lead to enterineven though pilot had reviewed 

2.1 Incorrect 

understanding distance to airspace 

Misunderstanding plane position relative to airspace boundaries. Code this if it’s not clear whether the plane may not be where thought, or the airspace boundaries may not be where thought. 

Pilot believed he was E of the Pilot was depending on unreliaestimate distance from TFR, suEpcot dome appeared to be. 
Code Category Rules Examples 

2.1.1 Navigation error / 

Aircraft position not correctly known 

The precise airplane geographic position is not correctly known. Aircraft believed to be at one point but may have been at another. Errors due to pilotage get this code, including the pilot thinking a feature on ground is one place, but learns it’s somewhere else. Also code this if pilot got lost, or just wasn’t tracking own position (lost of geographic SA). Also code this if the aircraft may have been at a different altitude than the pilot thought. Narrative or synopsis must explicitly refer to uncertainty or error as to geographic position/altitude of the aircraft in connection with possibly violating the restricted airspace. 

Pilot got lost looking for airporand re-entered it. Pilot was not aware that vector Disneyland until he looked dowPilot reports undetected drift dfigure it out until too late. Progressed further E than anticplan en route due to WX. Had baroaltimeter mis-set resuand into TFR rather than just o

2.1.2 Airspace 

boundaries not correctly known 

Misunderstanding of the precise spatial location of airspace boundaries. Pilot knows where s/he is relative to points on ground (or on the sectional) and apparently knows his/her altitude correctly, but may not be correct where the restricted airspace begins and ends in absolute terms. Narrative or synopsis must explicitly refer to uncertainty or error as to boundaries of the restricted airspace in connection with possibly violating it. 

Did not know ADIZ was out to to the ground. Thought TFR was smaller and Knew where he was. Just didnTFR. 
56

Code Category Rules Examples 

2.1.2.1 Horizontal airspace 

boundaries not correctly known 

Misunderstanding of horizontal boundaries. Pilot may have thought the horizontal edge was farther from its actual geographic point. Narrative or synopsis must explicitly refer the horizontal trajectory or position relative to the restricted airspace (e.g., aircraft course, or bearing or nm to boundaries) or horizontal dimension of the restricted airspace (e.g., diameter, relative position of navaid or ground references to boundary). 

FSS gave bad advice on course Lateral boundaries of ADIZ asClass B. Flew too far S avoiding possibentered ADIZ. Thought destination was outsidAssumed “10nm TFR” referred radius. 

2.1.2.2 Vertical airspace 

boundaries not correctly known 

Misunderstanding of vertical boundaries. Pilot may have thought altitude ceiling for airspace was different than actual. Narrative or synopsis must explicitly refer the vertical trajectory or position relative to the restricted airspace (e.g., “over” or number of feet above) or vertical dimension of the restricted airspace (e.g., its height or altitude). 

Thought ADIZ vertical structuB, and tried to fly “under” it. TFR was always capped at 300was 5000 ft. 

2.2 Time or date of 

effect not correctly known 

Misunderstanding or failure to recall the time or day when restricted airspace would be in effect. Includes lack of awareness of current time or date relative to time or date when airspace would be in effect. Includes lack of awareness that a known restricted airspace is "hot" (must explicitly indicate airspace is known). 

Believed TFR would end at 3:0Thought the TFR would have b
Code Category Rules Examples 

2.3 Procedures for 

allowed penetration not understood 

Misunderstanding of the procedures for legally penetrating restricted airspace. There no reason to believe the pilot misunderstood the boundaries for the airspace, and aircraft are allowed in the airspace at that time but only if they follow certain procedures. There appears to be some question on whether the pilot followed the correct procedures. Includes pilot contacted ATC too late for both a clearance and a transponder code. 

Thought it would be okay to geafter takeoff from airport in ADATC and pilot confused on preneed for squawk. 

2.3.1 Flight plan 

submitting requirements not understood 

Misunderstanding submitting a flight plan. Pilot may have not submit a flight plan as may be required, or maybe submitted it to the wrong place, or at the wrong time or by contacting the wrong agency. Code this if any misunderstanding or human error (by 

pilot or anyone else) led to incorrect submission. 

Tried to air file flight plan afte

2.3.2 Transponder usage 

not understood 

Misunderstanding transponder usage. Pilot may not know how to get right code, or someone thought no special code was necessary, or there’s conflict on what the right code is. Confusion over the right procedure in the event of a broken transponder. Pilot may have misheard the transponder code. If pilot contacted ATC too late for both a clearance and a transponder code, code as 2.3. 

Safety concerns delay squawkiuntil after takeoff from airport that would be okay. Used transponder code from olcall FSS for discrete code. 
58

Code Category Rules Examples 

2.3.3 Radio usage or 

required clearances not understood 

Misunderstanding of required communications or clearances. Includes errors with opening (but not filing) a flight plan. Pilot may have made contact at the wrong place or time or with the wrong party. Pilot announces entry by radio into airspace but maybe should have requested clearance first. If pilot may have contacted ATC too late for both a clearance and a transponder code, code as 2.3. 

Not aware/ forgot to establish rrequired when leaving a pattern FSS said it was okay to open flbut when pilot tried, was told h

2.3.4 Allowed flight 

paths or procedure not understood 

Misunderstanding allowed flight paths. Particular path was believed to be allowed through restricted airspace, but this may be been wrong. Do not code this if someone thought path would avoid airspace but it may not have. Code that as 2.1.2. 

Was doing pattern work in ADbut ATC still accused them of Thought flights directly out of were allowed. 

3 Control setting 

error 

Tried but may not have executed appropriate actions even though requirements of the restricted airspace understood correctly. This includes “slips” or errors in using avionics. This includes not knowing how to properly operate avionics or other controls. Does not 

include incorrect or lack of inputs due to incorrect or inadequate knowledge about the restricted airspace or its requirements (see Code 2). Use this code only if the pilot was unable to make the correct entry despite the intention to do so. Forgetting to perform a certain action as required for the airspace is one of the codes under 2 (see). 

Failed to land to full stop as relanding. ATC may have thoughgo, which is not allowed at airpForgot to switch to COM1 for contact with approach. Possibly accidentally set wrong 
59

Reporter Identified Factors 

Applies to Real and Potential Violations. These codes are for factors the reporter has identified 

to have contributed to a violation or apparent violation, or may lead to future violations. 

Factors also include recommended remedial actions that may prevent future violations. This is 

a flip side of any factor code: if an action would prevent a violation, the failure to take such an 

action is a reported contributing factor to a violation. 

An ASRS report may have any number of factors. More than one factor may be coded per 

ASRS report. However, the same factor may only appear once regardless of how many statements 

qualify for that coding. A single sentence can result in two factors. A report may have zero 

factors coded. 

Unlike probable cause, pilot-reported factors are things that the pilot says may have lead to (or 

may lead to) a violation of restricted airspace. That is, it is the cause from the perspective of the 

pilot. As such, factors should be apparent from the content of the narrative with minimal 

interpretations. Pilot factors may be identified by any of the following: 

 Explicit statement of the reason for a violation ("It happen because I...", "The violation was due 

to...") 

 Intentions to change own behavior ("Next time, I'll be sure to...") 

 Recommendations for changes to the system ("NOTAMS on TFR should be...", "The FAA could...") 

 Recommendations to other individuals ("Pilots must never...", "Someone should...") 

 Statements of hypothetical or alternative actions in the past ("I should have...", "If they had told 

me...") 

However, such explicit language is not necessary to code for a factor. Include as a factor any event that 

the narrative places in the chain of events leading up to the concern for the violation. For example, if a 

pilot says "I had been up for 22 hours straight... [Later,] ATC said I violated a TFR," then being up for 22 

hours becomes a factor. Factors may also be identified by inferring the intent of the pilot in providing a 

statement. For example, if a pilot says " I flew into the TFR. I missed seeing that NOTAM in the briefing," 

then it is safe to infer the pilot believes he flew into the TFR because he missed the NOTAM. As long as it 

is evident that a statement in the narrative was included in order to explain the potential violation, the factor 

is be coded. 

Code only for factors that reportedly result directly in possible violation of restricted airspace. For 

example, if according to the narrative ATC incorrectly advises the pilot he is keeping clear of the restricted 

airspace, then that would be coded as 2. However, if ATC gives the pilot an incorrect radio frequency, 

causing confusion that distracts the pilot from keeping clear of the restricted airspace, then that is not coded 

as 2 (it would be coded as a 5 however). 

Do not code as factors simple statements of making, or failing to make, an action that is legally required in 

order to comply with the airspace. Factors are things to contribute to the violation occurring. They are 

not the violation itself. Compare the following examples: 

Statement Factor Statement Factor 

I violated the TFR because I 

flew into it 

None. Flying into the 

TFR is the violation itself. 

I violated the TFR because I didn’t 

understand the NOTAM for it. 

1 

Next time, I’ll call ATC for a 

clearance into the ADIZ. 

None. This is a 

requirement for the ADIZ. 

Next time, I’ll call ATC for flight 

following to make sure I don’t go 

into the ADIZ. 

3 
60

Statement Factor Statement Factor 

Pilots should be extra careful 

about avoiding these TFRs 

None. Pilots are required 

to avoid such TFR. 

Pilots should give the boundaries 

of these TFRs a 2 nm margin to be 

sure to avoid them. 

4 

1. Airspace Communication 

Any problem or remedy concerning correctly communicating information about the restricted airspace or 

the pilot's flight plans with respect to the airspace prior to the violation of concern. 

This includes communication though any of the following media: 

FSS personnel or an unspecified briefer. 

 Briefer provided apparently incorrect or insufficient information concerning the restricted 

airspace 

 Pilot misunderstood or failed to receive information supplied by briefer. 

 Wrong pilot apparently received information or instruction. 

 An incomplete or unclear briefing, or failure to ask clarifying questions in a briefing. 

 Suggestions to improve information clarity or accuracy, or to provide more information. 

Examples: 

FSS not alert pilot of ADIZ, 

FSS said it was okay to open flight plan after airborne. 

FSS gave bad advice on course to avoid P-40. 

FSS erroneously said that if clear of Class B, no need to file IFR. 

FSS said "10nm TFR"; thought it was diameter, not radius. 

NOTAMs or sources of NOTAMs. 

 NOTAM relevant to restricted airspace was not detected in the pilot's perusal of printed or 

electronic NOTAMs. 

 Pilot used wrong or obsolete NOTAM. 

 Any inability to access correct NOTAMs. 

 Information within a NOTAM was missed or misunderstood 

 General failure to thoroughly review a NOTAM. 

 Suggestions to search NOTAMs more carefully or make relevant NOTAMs easier to spot, or 

improve NOTAM distribution or access. 

 Suggestions to study relevant NOTAMs more carefully or make NOTAMs easier to read and 

understand. 

Exceptions: 

Do not use this code to indicate that the pilot failed to get any NOTAMs. On the contrary, 

this code often implies the pilot got at least some NOTAMs (but not necessarily related to 

the restricted airspace). The Got Briefing/ NOTAMS field is used to indicate a failure to 

get any NOTAMs at all. 

Examples: 

Too much info in DUATS to sort through. 

TFR NOTAMs should be first in list, 
61

Missed seeing NOTAM in 11 pages of DUATS. 

In on-line briefing, missed that TFR coming on later in day. 

Did not catch TFR in on-line briefing. 

Should have look at NOTAMs more closely. 

NOTAM not posted. 

DUATS should recognize and flag flight plan through/over TFRs. 

NOTAM followed obsolete. DUATS from same day did not have update. 

NOTAM should use mixed case and headings. 

More thorough examination of NOTAM and discussion among crew. 

NOTAM must be read carefully. 

No visual aids in ADIZ description to keep clear of it, 

Poor graphic of ADIZ from web. 

Charts or other maps. 

 Restricted airspace not present or not found on printed or electronic navigation charts or maps 

 Restricted airspace or shown in an incomplete, incorrect or confusing manner. 

 Misreading restricted airspace information from map. 

 Suggestions to print or mark restricted airspace on maps. 

Examples: 

ADIZ not shown on chart. 

Should show ADIZ on chart. 

TFR not on chart. 

Max P-40 boundary not on charts. 

Chart not show potential TFRs 

Other media. 

 Unspecified individuals or individuals other than ATC or FSS, 

 Written/printed material other than NOTAMs or charts. 

 Signs and notices. 

 Training materials or classes specific to restricted airspace. 

 Avionics. 

 Ground-based electronic systems. 

Exceptions: 

Does not include communication problems related to handling an alleged violation (e.g., 

during interrogation by law enforcement). See 7. 

Use this code if it is reported the pilot did not know how to correctly get a clearance or 

open a flight plan. However, do not use this code for communication problems related to 

ATC such as getting a clearance from them. See 2 and 3. 

Only training specific to restricted airspace is coded as 1. A need for general flight 

training is coded as 5. 

Examples: 

No mention of restrictions by ground personnel. 

PIF and dispatcher not say two-way radio necessary for pattern work. 
62

Someone should broadcast advisory over Unicom. 

Pilot not told where to get IFR clearance. 

Airport directory should say that airport is in ADIZ. 

Someone should organize a seminar to explain ADIZ. 

Pilot needs additional TFR training. 

2. ATC/Clearance Problem 

Prior to the violation of concern, there was a communication problem, breakdown, or error 

involving ATC controller, getting clearance into the restricted airspace, or opening (activating) a 

flight plan. 

 ATC controller provided pilot with apparently incorrect or incomplete information or 

instructions 

 Pilot misunderstood or failed to receive information or instructions. 

 Wrong pilot apparently received information or instruction. 

 Pilot draws incorrect inferences from information or guidance from ATC. 

 Difficulty or inability to contact or communicate with ATC when required due to congestion 

or ATC being too busy or having technical problems. 

 Difficulty or inability get a clearance or activate a flight plan due to congestion or federal 

authority being too busy or having technical problems. 

 Suggestions to cross-check information or to improve accuracy of information from ATC. 

Exceptions: 

Does not include errors in accusation of pilot of violating airspace (see 7). 

Only includes communication problems related to required contact or communication 

with ATC. For problems with optional ATC services, see 3. 

Only includes communication difficulties due frequency congestion or ATC/clearance 

authority being busy or having technical problems. Does not include difficulties due to 

pilot lack of knowledge of person, place, time, or procedure for making contact as 

required for the airspace (see 1). Does not include difficulties due to on-board equipment 

problems (see 6). 

Examples: 

Vectored by ATC into TFR. Not see it until over it. 

ATC comment that visual APP possible makes pilot think airport is outside ADIZ. 

ATC does not give squawk, but thought was due to military flight, as happened before. 

Mistook ATC advisory as upcoming incursion into ADIZ, and thus turned N right into TFR. 

No mention of restrictions by ATC. 

ATC cleared pilot into the ADIZ, but thought he was clearing someone else. 

3. Under-use of Optional ATC 

Lack of use of optional ATC services from a controller. 

 Inability or failure to request or receive information or guidance from ATC 

 Not filing IFR. 

 Not using flight following or advisory services. 
63

 Difficulties communicating with ATC in order to get optional service. 

 Failure or difficulties in monitoring ATC (when not required to do so). 

 Suggestions to use ATC optional services or IFR more, or to make them more readably 

available. 

Exceptions: 

Does not include pilot failure to contact ATC or get clearance as required for airspace or 

any other required actions. That's a violation, not a factor of the violation. 

Does not include difficulties in getting required communication or clearances from ATC 

or ATC providing apparently insufficient or incorrect information. See 2. 

Examples: 

Should file IFR 

Should have requested flight following. 

Should seek advisory services if lost. 

Should talk to ATC when near Disney. 

Contact PCT sooner for flight following. 

Monitor PCT freq to learn what’s going on. 

Not request clarification from ATC after hearing need for squawk on party line. 

4. Pilotage Limitations 

Imprecision in navigation due to reliance on pilotage. 

 Errors in navigation not evidently related to the use of electronics. 

 Errors due to winds. 

 Incorrect identification of or inability to identify ground references, or other incorrect reliance 

on ground references. 

 Suggestions to use more precise electronic navigation methods (e.g., GPS, navaids) or 

determine or define boundaries of restricted airspace based on electronic navigation methods. 

 Suggestions to allow for a greater margin of lateral error or higher altitude (unless navigation 

was explicitly not by pilotage). 

 Suggestions to use more reliable ground references. 

Examples: 

Mistake in position: not as far North as thought. Should fly with GPS. 

Ended up off course due to unanticipated winds. Simply became disoriented and not reorient fast 

enough. 

Winds from SW may have caused drift towards Class B. 

Should plan to give ADIZ wider berth, 

Plan routes with greater TFR clearance, plan altitude well above TFRs. 

Visual landmarks not sufficient. 

Flew too far S avoiding possible P-40 max limits and entered ADIZ. Not ensure flight free of 

restricted airspace. 

Not thinking of ADIZ because had over flown Bay Bridge, which is well outside. 

Training will now be done at an airport more distant from ADIZ. 
64

5. General HF Antecedents 

Miscellaneous human factors that may play a role in any incident, not just a violation of restricted 

airspace. 

 Fatigue. 

 Stress. 

 Distraction 

 Complacency 

 Rushing or falling being schedule. 

 Unfamiliarity with region. 

 General flight training. 

 CRM issues. 

 Physiological factors. 

Exceptions: 

Does not include training or training materials specifically concerning restricted airspace. 

See 1 

Examples: 

Possible hypoxia may have affected judgment. 

Should focus on responsibilities and guard against complacency. 

Thought PIC had taken care of everything and didn’t crosscheck. 

Flown same route without ADIZ last year, (habit) 

Rushed due to delays. 

Distractions and sun interfere with map reading. 

Entering ADIZ from unfamiliar angle. 

Unfamiliarity with Disney area. 

PNF handle radios and not communicating with PF. 

6. Equipment Failure 

Failure of aircraft or on-board equipment leads directly to possible violation. 

 Failure of navigation equipment leading to course error. 

 In-flight emergency requiring landing in restricted area. 

 Any loss of control of aircraft resulting in flight into restricted airspace. 

Exceptions: 

Code as 5 if equipment failure led to distractions rather than directly in a violation. 

Examples: 

Transponder mysteriously starts squawking 1200. 

Radio electrical problems prevent contacting ATC as required. 
65

7. Violation Handling Error 

Apparent error in procedure or execution of the handling an alleged violation of restricted 

airspace. 

 Apparent errors in determining the existence of a violation. 

 Apparent errors in providing information or instruction after the violation of concern 

 Suggestions to change or improve the handling of violations. 

Exceptions: 

Does not include errors by any personnel prior to the violation of concern. See 1 for 

apparent errors by FSS or within restricted airspace information media that lead to the 

violation. See 2 for apparent errors by ATC that lead to the violation. 

Examples: 

Pilot believes ATC is mistaken in accusing him of violating airspace. 

Customs officials get wrong tail number and interrogate wrong pilot. 

Interceptor closes on the wrong aircraft. 

FBO worker gave pilot a phone number to call, but it was meant for another pilot. 

Pilot was not a sufficient threat to warrant an interception. 

Interceptors should monitor 121.5. 

8. Overly Restrictive Rules 

Rules regarding airspace restrictions unnecessarily strict or extreme. 

 TFR being too large or unnecessary. 

 Suggestions for changes in rules for using airspace. 

Examples: 

If flight plan filed on ground, should be allowed to get transponder code in air. 

TFR too large. 

9. Other 

Other factors given by pilot that are worth capturing. 
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Contractor Report

 4. TITLE AND SUBTITLE

Violations of Temporary Flight Restrictions and Air Defense Identification

Zones: An Analysis of Airspace Violations and Pilot Report Data

5a. CONTRACT NUMBER

 6. AUTHOR(S)

Zuschlag, Michael

 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center John A. Volpe National Transportation

Hampton, VA 23681-2199 Systems Center

 Cambridge, MA 02142

 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

 8. PERFORMING ORGANIZATION

 REPORT NUMBER

10. SPONSOR/MONITOR'S ACRONYM(S)

NASA

13. SUPPLEMENTARY NOTES

Langley Technical Monitor: Eddie Norris

An electronic version can be found at http://ntrs.nasa.gov and http://volpe.dot.gov/opsad/pubs.html

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Category 03

Availability: NASA CASI (301) 621-0390

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email: help@sti.nasa.gov)

14. ABSTRACT

This document provides the results from a study into the apparent factors and causes of violations of restricted airspace,

particularly temporary flight restrictions (TFRs) and air defense identification zones (ADIZs). By illuminating the reasons for

these violations, this study aims to take the first step towards reducing them. The study assesses the basic characteristics of

restricted airspace violations as well as the probable causes and factors contributing to violations. Results from the study

imply most violations occur where the restriction has been in place for a significant amount of time prior to the violation.

Additionally, the study results imply most violations are not due to the pilot simply being unaware of the airspace at the time

of violation. In most violations, pilots are aware of the presence of the restricted airspace but have incorrect information about

it, namely, its exact boundaries or procedures for authorized penetration. These results imply that the best means to reduce

violations of restricted airspace is to improve the effectiveness of providing pilots the details required to avoid the airspace.

15. SUBJECT TERMS

Airpsace; Air defense; Aviation safety; ASRS; ADIZ; TFR

18. NUMBER

 OF 

 PAGES

74

19b. TELEPHONE NUMBER (Include area code)

(301) 621-0390

a. REPORT

U

c. THIS PAGE

U

b. ABSTRACT

U

17. LIMITATION OF 

 ABSTRACT

UU

Prescribed by ANSI Std. Z39.18

Standard Form 298 (Rev. 8-98)

3. DATES COVERED (From - To)

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

NNL04AA72I

5e. TASK NUMBER

5f. WORK UNIT NUMBER

23-723-51-A5

11. SPONSOR/MONITOR'S REPORT

 NUMBER(S)

NASA/CR-2005-213923

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PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

01- 09 - 2005