September 2005 

NASA/CR—2005-213924 

Potential Interventions by Government and 

Industry to Minimize Violations of Temporary 

Flight Restrictions 

Michael Zuschlag 

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

 
September 2005 

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September 2005 

NASA/CR—2005-213924 

Potential Interventions by Government and 

Industry to Minimize Violations of Temporary 

Flight Restrictions 

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 also to Alan Yost and Drew Kendra of the Volpe Center, for assisting in developing the 

recommendations in this report, and to Mark Freeman, also of the Volpe Center, for his comments and suggestions. 

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 

In effort to oppose the use of aircraft by terrorists, the FAA has been establishing temporary flight 

restrictions (TFRs), air defense identification zones (ADIZs), and other restrictive airspace in 

effort to increase security around potential ground targets. Since this widespread application of 

these airspaces, which may be collectively called "security-supporting airspaces" (SSAs), the 

annual rate of violations of such airspace is over 30 times greater than in previous years 

(Government Accountability Office, 2004). This frequency of violations entails an economic cost, 

and potentially compromises safety and even security, the latter by inducing complacency and 

misallocation of resources. This paper enumerates interventions to reduce the frequency of 

violations by more effectively providing pilots with the information necessary to avoid such 

violations (Zuschlag, 2005). Short term interventions, some variants of which are already in 

progress, focus on improving the form and content of the Notices to Airmen (NOTAMs) 

currently used to inform pilots of SSAs. These interventions include: 

 Support of better sorting, filtering, or highlighting of such NOTAMs in the preflight briefing 

reports returned through electronic briefing services, so that the relevant SSA NOTAMs, 

which often are more important that other NOTAMs, are given higher priority. 

 Provide improved and standardized language and formatting of each NOTAMs in briefing 

reports, arranging and emphasizing information so that relevant SSA NOTAMs are easier to 

find, and key information within the NOTAM is easier to understand. 

 Provide detailed and readable maps with each NOTAM of a SSA in order to illustrate better 

the SSA's boundaries with respect to significant surface and navigation reference objects. 

Government agencies can also reduce violations of SSAs chiefly through: 

 Representing relatively static or recurrent SSAs on aeronautical charts so that their presence 

and boundaries are obvious to pilots. 

 Using weather information products and other information channels to more widely distribute 

alerts of SSAs. 

 Standardizing and simplifying the procedures for entering SSAs that permit entry (e.g., 

ADIZs) in order to reduce confusion on these procedures. 

 Formalizing, standardizing, naming, and documenting the levels of control a SSA may have 

to simplify training on SSAs and allow faster understanding of NOTAMs on SSAs. 

 Proceeding with fielding new technology, such as the Operational and Supportability 

Implementation System (OASIS), designed to improve the capabilities and performance of 

flight service station briefers. 

 Distributing SSA information in standardized machine-readable format for vendors of GPS 

databases and other users. 

A long-term technical intervention is for industry to develop an Integrated System for Airspace 

Requirements Compliance (ISARC), which would provide pilots with the following functions: 

 Ground and airborne presentation of information on any SSA, including display on an 

electronic moving map. 

 Fully mechanized execution from the cockpit of the procedures required for entry into SSAs 

that allow entry. 
iv 

 Alerting of the potential for SSA violations both during flight planning and while the aircraft 

is moving. 

Capitalizing on a future government-developed infrastructure for the Wide Area Augmentation 

System (WAAS), datalink, and intra-agency digital communication, ISARC could be 

implemented as a set of features integrated in a general-purpose GPS moving map device. For 

example, datalink can be used to upload the latest SSA information and to electronically get 

clearances from air traffic control into SSAs that allow entry. Knowing the position of the aircraft 

and the SSA, and the existence of a clearance (or lack thereof), ISARC can alert the pilot before a 

violation occurs. Within an acceptable development time horizon, ISARC is expected to 

substantially reduce violations while not compromising safety or security. The incorporating 

device is expected to be affordable to pilots and ISARC requires almost no additional effort to 

use, making for a desirable product. 
v

Contents 

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

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

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

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

1. Problem and Purpose................................................................................................................ 1 

2. Background .............................................................................................................................. 2 

2.1. Characteristics of and Nomenclature for SSAs................................................................. 2 

2.1.1. Stability of Activation............................................................................................................. 4 

2.2. Root Causes of Accidental Violations .............................................................................. 6 

2.3. Current Efforts to Improve SSA Awareness and Understanding...................................... 7 

3. Goals and Principles for Interventions................................................................................... 10 

4. Short-term Interventions ........................................................................................................ 12 

4.1. Improving Pilot Awareness of the Presence of SSAs ..................................................... 12 

4.1.1. Sorting, Filtering, or Highlighting Briefing Reports............................................................. 12 

4.1.2. Formatting of NOTAMs in Briefing Reports ....................................................................... 14 

4.1.3. Other Possible Improvements for Briefing Reports.............................................................. 15 

4.1.4. Charting Recurrent and Static SSAs..................................................................................... 15 

4.1.5. Weather Products and Other Channels ................................................................................. 16 

4.1.6. Specific Times and Places for All TFRs............................................................................... 17 

4.2. Improving Pilot Awareness of SSA Boundaries............................................................. 17 

4.2.1. Charting SSAs ...................................................................................................................... 18 

4.2.2. Optimally Detailed Maps...................................................................................................... 18 

4.2.3. Improved Map Readability and Understandability............................................................... 20 

4.2.4. Standardize and Improve Text Descriptions......................................................................... 21 

4.2.5. Additional Measures to Improve Boundary Understanding ................................................. 23 

4.3. Improving Pilot Understanding of SSA Procedures ....................................................... 24 

4.3.1. Standardize and Improve Descriptions of Restrictions......................................................... 24 

4.3.2. Standardize and Simplify the SSA Procedures..................................................................... 25 

4.3.3. Standardize SSA Control Levels .......................................................................................... 27 

4.3.4. Education and Training......................................................................................................... 28 

5. The Long Term: ISARC......................................................................................................... 29 

5.1. Functional Requirements ................................................................................................ 30 

5.1.1. SSA Presentation .................................................................................................................. 30 

5.1.2. Mechanized Filing and Activation of SSA Flight Plans ....................................................... 30 

5.1.3. Alerting of Potential for SSA Violation ............................................................................... 31

5.1.4. Additional Functions ............................................................................................................ 32 

5.2. Infrastructure Requirements............................................................................................ 33 

5.3. Performance Requirements............................................................................................. 34 

5.4. Technological Elements and Development Needs.......................................................... 34 

5.4.1. Current Technologies............................................................................................................ 35 

5.4.2. Developing Technologies ..................................................................................................... 36 

5.4.3. Future Developments............................................................................................................ 37 

5.5. Notional System.............................................................................................................. 37 

5.5.1. Components and Interfaces................................................................................................... 37 

5.5.2. Function Implementation...................................................................................................... 39 

5.6. Analysis .......................................................................................................................... 40 
vi 

5.6.1. Effectiveness and Timeliness ............................................................................................... 40 

5.6.2. Compliance and Security Impacts ........................................................................................ 41 

5.6.3. Safety Impacts ...................................................................................................................... 41 

5.6.4. Certification.......................................................................................................................... 43 

5.6.5. Cost and Acceptance ............................................................................................................ 43 

5.6.6. Alternatives........................................................................................................................... 45 

5.6.7. Realization............................................................................................................................ 45 

6. Additional Issues and Research.............................................................................................. 45 

7. Summary ................................................................................................................................ 47 

8. Abbreviations and Acronyms................................................................................................. 47 

9. References.............................................................................................................................. 50 

Appendices .................................................................................................................................... 54 

Consolidated Mockup of Formatted NOTAM 5/1953............................................................... 54 

Interventions and Actions to Perform........................................................................................ 57 

Figures 

Figure 1. NOTAM 5/1953, an example of Presidential TFR NOTAM. Note: While fairly typcial for a 

Presidential TFR NOTAM, most non-TFR NOTAMs are considerably shorter. Use of all-capital 

letters is from the orginal NOTAM. User of Courier font as above is typical of DUATS. .................... 7 

Figure 2. Default map of the SSAs described in NOTAM 5/1953 (see Figure 1) as provided on the FAA 

TFR web site (FAA, 2005e). Value contrast is intensified in this gray-scale reproduction. In the 

original image, water bodies (gray in above image) are light blue, and SSA boundaries (black in above 

image) are red......................................................................................................................................... 9 

Figure 3. SSAs described in NOTAM 5/1953 (see Figure 1) when superimposed on a raster-scanned map. 

This DUATS-provided screen capture is similar to other maps provided by the FAA and IMAPS for 

computer screen presentation. The resolution is inferior to the original paper sectional, making most of 

the text and many symbols at this level of zoom illegible. Zooming in improves legibility, but 

eliminates the context. The original screen image for this figure was full color, with the SSAs rendered 

as bright red circles, but when printed on a black and white printer, it would appear much like above.

.............................................................................................................................................................. 10 

Figure 4. Mockup of heading for NOTAM 5/1953 (see Figure 1) using variable font weight and size to aid 

scanning. This would be followed by the content of the NOTAM in smaller font using mixed case (see 

Appendix, Page 54). ............................................................................................................................. 14 

Figure 5. Mockup of a METAR with inclusion of a TFR alert, both in coded form and as it would appear in 

a DUATS plain-text “translation.” ....................................................................................................... 16 

Figure 6. Mockup of a map for NOTAM 5/1953 (see Figure 1, Figure 2, and Figure 3) attempting to 

optimize the level of detail necessary to communicate key SSA information. Labels for each SSA 

(Areas 1, 2, and 3) cross-reference the pilot to additional information (see Appendix, Page 54). ....... 19 

Figure 7. Mockup of SSA text boundary information in a tabular format for 5/1953 for better reference and 

readability (compare to Figure 1). ........................................................................................................ 23 

Figure 8. Mockup of restrictions information for 5/1953, formatted for better reference and readability 

(compare to Figure 1). .......................................................................................................................... 25 

Figure 9. Components and flows for GPS moving map device with ISARC. All components shown are 

within an on-board airborne device. ..................................................................................................... 38 

Tables 

Table 1. Probable causes of violations of SSAs (Zuschlag, 2005). ................................................................ 2 

Table 2. Summary of Levels of Control for SSAs.......................................................................................... 3 
vii

Table 3. Examples of SSAs and SUAs typed by activation degree of stability and control level. SUAs are 

shown in italics....................................................................................................................................... 5 

Table 4. Variations in Control Level 2 departure procedures for airports in the Washington DC ADIZ and 

FRZ (AOPA, 2004b). ........................................................................................................................... 26 

Table 5. Variations in Control Level 2a procedures for airports within the DC ADIZ (AOPA 2004b, 

2004c). Note that only two airports allow arrivals under standard transponder codes. For the others, 

arrivals follow Control Level 2 procedures. ......................................................................................... 28 

Table 6. ISARC alert conditions and levels.................................................................................................. 32 

Table 7. Existing and new technological elements that may be used to implement ISARC’s functional 

requirements. ........................................................................................................................................ 35 

Table 8. Extension of current GPS devices to ISARC functions.................................................................. 36 
1 

1. Problem and Purpose 

In effort to oppose the use of aircraft by terrorists, the Federal Aviation Administration (FAA) has 

been attempting to increase the control of airspace around potential ground targets by establishing 

what may collectively referred to as "security-supporting airspace" (SSA) over potential targets. 

SSAs include security and VIP temporary flight restrictions (TFRs), Flight Restricted Zones 

(FRZ) or Special Flight Rules Areas (SFRAs), and Air Defense Identification Zones (ADIZs) 

(e.g., FAA 2003a, b, c, 2004a, b c). This array of different SSAs have emerged from the FAA 

rapidly adapting existing rules and technical capabilities to the sudden new challenges manifested 

by the 9/11/2001 attacks. 

SSAs are on average larger, more numerous, and more enduring than before the attacks of 

9/11/2001, affording a much greater probability of accidental violation by pilots. Indeed, since the 

emergence of these new SSAs, the annual rate of violations of such airspace is over 30 times 

greater than in previous years (Government Accountability Office, 2004). At its peak, the rate of 

violations has been several per day nationwide (Zuschlag, 2005). 

This frequency of violations represents a risk to safety. Intervention by air traffic controllers is 

required to handle such violations, a task that may distract the controller from his or her chief task 

of ensuring safe separation of aircraft. About 15% of all violations result in an armed aircraft 

intercepting the violator (Zuschlag, 2005). For every scramble there is a chance that a sequence of 

errors may lead to an innocent aircraft being shot down. 

This frequency of violations also compromises security. Apparently, all the thousands of 

violations since 9/11 have been false alarms rather than actual terrorist attacks. Such a high level 

of false alarms may yield complacency that delays an appropriate response during a real attack. 

Furthermore, given limited resources to respond to violators, there is a chance that resources may 

not be available for an actual attack due to their being already committed to a false alarm. 

Finally, the current frequency of violations has an economic cost, as resources are spent to handle 

to false alarms. Each military scramble alone costs tens of thousands of dollars (Associated Press, 

2005). Also, pilots who violate a SSA typically have their pilot’s licenses suspended, which may 

ultimately impact the local economy. 

Clearly, there is a need to reduce the frequency of accidental violations of SSAs.1

 Developing 

interventions to reduce the frequency requires understanding of the nature of such accidental 

violations. In a statistical analysis of two years worth of violations (Zuschlag, 2005), it was found 

that about three quarters of the violations are associated with long-duration or re-occurring SSAs, 

with the remainder being associated with relatively transitory SSAs. Further study of pilots’ 

descriptions of their violations of SSAs revealed that the violations appear to be primarily due to 

pilots not understanding the details about the SSA (see Table 1). Specifically, pilots often were 

mistaken about the relative position of the boundaries of the airspace. For some of these cases, 

this was due to the pilot not knowing his or her own exact geographic position, but more often the 

absolute position of the boundaries themselves was not clearly understood. Accidental violators 

also frequently misunderstood the procedures for allowed penetration of the airspace, especially 

for the DC ADIZ. A secondary, but non-trivial, cause of violations was the pilot not being aware 

 

1

 Many of the proposed interventions in this paper would also reduce the frequency of violations of nonsecurity and non-VIP TFRs (e.g., TFRs for hazards and air shows). However, over 97% of all TFR and 

ADIZ violations in recent years were for SSAs (Zuschlag, 2005), so emphasis is placed on avoiding SSA 

violations. 
2

of the existence of the SSA, especially for SSAs other than the DC ADIZ. Occasionally pilot 

errors in transponder use also played a role in some violations. However, in summary, over 85% 

of all violations are due to a pilot’s lack of knowledge or understanding about the SSA and the 

aircraft’s relation to it. 

Table 1. Probable causes of violations of SSAs (Zuschlag, 2005). 

Probable Cause DC ADIZ2 Other SSAs Total

Relative distance to SSA not understood 40.0% 41.8% 40.9%

SSA not known about or recalled 12.0% 30.1% 21.2%

Procedures for allowed penetration of SSA not 

understood 

31.0% 8.7% 19.7%

Time or date of activations not understood 0.0% 5.8% 3.0%

Other or unspecific lack of detailed knowledge 

about the SSA 

3.0% 2.9% 3.0%

Control setting error 3.0% 1.0% 2.5%

Indeterminate / multiple / other 10.0% 9.7% 9.9%

If there is any chance of reducing the violation rate to something approaching pre-9/11 levels, 

substantial interventions may be in order. The purpose of this paper is to suggest possible 

interventions aimed specifically at the identified causes of the violations. The interventions 

include both short-term changes involving current processes, and long-term changes leveraging 

emerging technologies. The interventions represent both actions that may be carried out by 

government agencies like the FAA, and opportunities for businesses seeking to provide products 

and services to pilots. In the appendix, starting on Page 57, is a list of all interventions along with 

the actions necessary by researchers, government, and industry for each intervention's realization. 

2. Background 

2.1. Characteristics of and Nomenclature for SSAs 

The large-scale application of TFRs, ADIZs, FRZs and other measures in effort to increase the 

security of the national airspace has been mostly ad hoc largely applying existing authority to the 

urgent new demands to thwart airborne terrorist threats. These measures have evolved since 9/11 

and continue to evolve to more effectively maximize and balance security and other interests. As 

a result, however, a certain vagueness pervades terms like “temporary flight restrictions” (for 

example, they may or may not be particularly temporary), so, for the purpose of this paper, a 

nomenclature is established to describe and classify SSAs from the functional viewpoint of the 

pilot in order to aid discussion of the interventions. 

A SSA (Security Supporting Area), to begin with, is any contiguous airspace of specified spatial 

boundaries established with the intention of improving the security of people or objects within. A 

SSA is active when the flight restrictions, requirements, or recommendations associated with the 

SSA are in force. An inactive SSA imposes no restrictions on flight, other than those associated 

with any other overlapping airspace that happens to be present (e.g., Class B). 

 

2

 About half of all SSA violations are for the DC ADIZ (Zuschlag, 2005). 
3 

For this paper, a TFR (Temporary Flight Restriction) refers to a particular instance of one or more 

SSAs becoming active. In this usage, a single TFR may concern the activation of multiple SSAs, 

and a single SSA may be activated multiple times through as many TFRs.3

To fulfill the intent of improving security, an active SSA is associated with a collection of 

restrictions, requirements, or recommendations for pilots. The possible collections can be loosely 

classified in one of four functional control levels identified here as 1, 2, 2a, and 3, and 

summarized in Table 2. 

Table 2. Summary of Levels of Control for SSAs. 

Control 

Level 

Summary 

1 Flight generally prohibited in airspace. 

2 Flight in airspace requires an active flight plan, a discrete transponder code, and twoway radio communications. 

2a Flight permitted along standard paths using standard transponder codes. 

3 Recommended that airspace be avoided. 

At Control Level 1, flight is generally prohibited in the SSA. Often however, there are 

exceptions. Aircraft associated with security and law enforcement are permitted, as typically are 

aircraft associated with medical emergencies (e.g., FAA 2005d). The FRZ around Washington, 

DC, along with some TFRs may permit regularly scheduled commercial flights. Individual 

operators or pilots may often also apply for waiver of the restrictions. Within the FRZ, for 

example, vetted and approved pilots may fly provided they follow certain procedures (FAA, 

2005c, Grady, 2005) 

At Control Level 2, flight is permitted but the identity and declared intent of the aircraft must be 

readily available to those monitoring the airspace. This is accomplished by the pilot: 

 Filing and activating a standard flight plan, which provides information about the aircraft and 

its intended route. 

 Continuously transmitting (or “squawking”) a discrete identifying transponder code assigned 

by air traffic control (ATC). 

 Maintaining two-way radio contact with ATC. 

ATC must verbally clear (i.e., authorize) the pilot to enter the airspace whether the aircraft is 

taking off from an airport within the airspace or entering the airspace from outside. In addition to 

the above requirements, Control Level 2 airspace may prohibit certain other kinds of flight, such 

as flight training, aerobatic flight, parachuting, crop dusting, animal population control flight, and 

banner towing. 

Control Level 2a is a variation on Control Level 2 in that flight is permitted as long as the intent 

of the aircraft is available to those monitoring the airspace. As in Control Level 2, flight is 

allowed if the pilot files and activates a flight plan, squawks a discrete transponder code, and 

maintains two-way radio communication with ATC. In addition to this, pilots may fly certain 

standard paths without filing a flight plan or contacting ATC as long as they squawk a standard 

 

3

 Technically, declaring a TFR is just one means by which the FAA can activate and SSA. A SSA can be 

activated in other ways, such as by establishing a Special Federal Aviation Regulation, as done for the FRZ 

(FAA, 2002). 
4

transponder code that represents the intent to fly a particular path. Typically, Control Level 2a has 

been applied around airports on the fringe of the Washington DC ADIZ where the standard paths 

take the aircraft out of the ADIZ by the shortest route (FAA, 2005b). There are also a couple 

fringe airports that include approved standard paths to the airport from outside the ADIZ (FAA, 

2005b). 

At Control Level 3, pilots are advised to but not required to avoid the airspace. If pilots do enter 

the airspace, it is recommended they proceed directly through the airspace without circling or 

loitering. 

The above four control levels comprise the SSAs currently imposed, although it should be noted 

there are variations within each control level. Other control levels are also possible. For example, 

during the Winter Olympics in 2002, all aircraft entering the airspace around Salt Lake City had 

to be physically inspected. Aircraft departing from airports within the airspace were inspected at 

their point of origin, while aircraft arriving from outside the airspace were required to land for 

inspection at a “gateway” airport on the fringe before being allowed to proceed (Aircraft Owners 

and Pilots Association (AOPA), 2002a; FAA, 2002a). This level of control has not been imposed 

since the Olympics. 

For a given potential target, a number of SSAs may be combined, typically to provide layers of 

protection by having smaller SSAs with a relatively strict control level surrounded by a larger 

SSA with a more liberal control level. For example, Washington DC is protected by the FRZ, a 

Control Level 1 SSA about 15 nm in radius. It is surrounded by the much larger ADIZ, a Control 

Level 2 SSA extending over 40 nm from the Capitol in places (FAA, 2003a). A few airports on 

the fringe of the ADIZ are functionally in Control Level 2a airspace (FAA, 2005a, b). Similarly, 

VIP TFRs intended to protect the President during visits to locations outside the DC area 

typically include a large (up to 30 nm radius) Control Level 2 SSA surrounding one or more 

relatively small Control Level 1 SSAs that correspond to specific locations the President will be 

(AOPA, 2003a; e.g., FAA, 2005d). This layered architecture seeks to balance security for the 

potential target with freedom of access to the airspace. 

The significance of control level to the causes of violations can be seen in Table 1. The DC ADIZ 

is a mostly Control Level 2 SSA, with parts at Control Level 2a, while most other SSAs are at 

Control Level 1. The result is a different distribution of cause for violations for the DC ADIZ 

than other SSAs, with the DC ADIZ being more likely that other SSAs to be violated due to 

misunderstandings of the procedures for allowed penetration. In contrast to Control Level 1 

SSAs, in order to reduce violations of Control Level 2 SSAs, it is nearly as important to improve 

pilots' understandings of the SSAs' procedures as to improve pilots' understanding of the 

boundaries of the SSAs. 

2.1.1. Stability of Activation 

In addition to control level, SSAs vary on their stability of activation. The activation of a SSA can 

be categorized as having roughly the following degrees of stability: 

 Transitory. Airspace is active for hours or days, with no recurrence over the next year or so. 

In this case, a SSA is imposed to enhance security for a specific event at an arbitrary location. 

 Recurrent. Airspace is active for hours to weeks at a time interspersed with similar periods of 

inactivity. In this case, the security for a given area periodically needs to be enhanced under 

certain conditions such as due to the performance of vulnerable activities on the ground or 

due to an increase in apparent threat. 
5 

 Static. Airspace remains active for months to years, with no set date of expiration. In this 

case, a potential target on the ground is considered to require long-term security from the air. 

The significance of the degree of stability of activation can also be seen in the distribution of 

probable cause among the DC ADIZ and other SSAs as shown in Table 1. While the degree of 

stability of DC ADIZ is static, approximately half of the other SSAs are transitory. Compared to 

violations of the DC ADIZ, these violations of other SSAs are more likely to be due the pilot not 

knowing about or recalling the presence of the SSA. Thus, drastically reducing violations of 

transitory SSAs requires that one ensure that pilots are, first of all, aware that they exist. 

Crossing activation stability with control level yields a typology that can be applied to many of 

the new SSAs as well as other established security-related special use airspace (SUA) (FAA, 

2004d). This is shown in Table 3. 

Table 3. Examples of SSAs and SUAs typed by activation degree of stability and control 

level. SUAs are shown in italics. 

Control Degree of Stability 

Level Transitory Recurrent Static 

1 "Classic" TFR 

Core of VIP TFR 

Restricted Areas 

Newport TFR 

Stadium TFR 

Prohibited Areas 

FRZ 

Disney TFR 

2 Outer ring of VIP TFR Outer ring of Crawford TFR DC ADIZ 

2a -- -- Fringe airports in DC ADIZ 

3 -- -- National Security Area 

Industrial/Military TFR 

A transitory Control Level 1 SSA is much like the “classic” TFR, where effectively flight is 

briefly prohibited over an area where it would compromise with security or safety (e.g., during 

rescue operations or space flight) (FAA, 2004d). As discussed before, it also serves as the core of 

presidential VIP TFRs, which is surrounded by a transitory Control Level 2 SSA. Transitory 

Control Level 2 SSAs may also be imposed over major metropolitan areas in response to an acute 

threat. For example, an ADIZ was placed around New York City for four weeks in March and 

April 2003 while major hostilities transpired between US and Iraqi armed forces. 

A recurrent Control Level 1 SSA is much like many Restricted Area SUAs that periodically “go 

hot.” Certain TFRs also functionally represent recurrent Control Level 1 SSAs. For example, 

TFRs come and go around the chemical weapons depots in Newport, IN, and Pueblo, CO, 

dependent on the agent disposal operations being carried out there. A “blanket” TFR effectively 

places over all large stadiums (seating 30,000 or more) a recurrent Control Level 1 SSA that 

activates whenever an event is held at the stadium. Recurrent Control Level 1 SSAs also 

comprised the TFRs periodically imposed for places the President regularly visits, such as Camp 

David in Maryland and Crawford, TX. The Crawford airspace also includes a recurrent Control 

Level 2 SSA ringing the Control Level 1 core, as is typical for presidential VIP TFRs. 

A static Control Level 1 SSA is similar to a Prohibited Area SUA, where flight through that 

airspace is effectively banned indefinitely. Several “temporary” flight restrictions remained 

continuously in effect over a year, such as the TFRs for Disney World, Disneyland, and the 

ballistic missile submarine bases at St. Marys, GA, and Bangor, WA. The US Navy has sought to 
6

convert the latter two of these into full-fledged Prohibited Areas. The FRZ at DC is also a static 

Control Level 1 SSA, surrounded by the static Control Level 2 DC ADIZ. The fringe airports of 

the DC ADIZ comprise the only Control Level 2a SSAs currently present. 

A static Control Level 3 SSA is very similar to a National Security Area (NSA) SUA. A 

“blanket” TFR also effectively places static Control Level 3 SSAs over all military installations 

and various industrial facilities that are considered vulnerable or attractive terrorist targets (e.g., 

power plants, dams, and refineries). So far, there have been no examples of transitory or recurrent 

Control Level 3 SSAs. 

The degrees of stability can characterize a particular control level of a SSA, as well as its pattern 

of activation. In particular, a SSA may be transitorily or recurrently moved to more strict level of 

control in response to an increase in threat or vulnerability. For example, in the hours around the 

2005 State of the Union Address, the entire DC ADIZ was moved to Control Level 1. Static 

Control Level 3 SSAs likewise may become Level 1 with an increase in the level of threat. 

2.2. Root Causes of Accidental Violations 

The vast majority of violations of SSAs are due to lack of awareness and understanding of the 

SSAs. To correct this condition one must understand the reasons for this inadequate awareness 

and understanding. The reasons appear to be the traditional method used for disseminating 

information about SSAs. This information is primarily disseminated to pilots by Notices to 

Airmen (NOTAMs). NOTAMS are a means of distributing information of interest to pilots more 

quickly than through new editions of other publications such as aeronautical charts and 

directories. Typically these are free-text descriptions of such things as changes to procedures, 

outages of electronic aids to navigation or lights, runway and taxiway closures, and amendments 

to charts, along with declarations of TFRs (see Figure 1). 

While adequate when SSAs were rare, short-lived, and small, the NOTAM systems possess 

features that make reception of SSA information by the pilot prone to human error (Zuschlag, 

2005). As seen in Figure 1, it is difficult to picture and interpret from a free text description the 

geometric and temporal dimensions of a SSA. To see NOTAMs, a pilot preparing for flight 

typically downloads them from an electronic preflight briefing service such as the Direct User 

Access Terminal (DUAT) or the Direct User Access Terminal System (DUATS). These services 

provide very limited filtering and no pilot-selected sorting of the NOTAMs. Instead, the pilot 

scans the downloaded report of NOTAMs to find the ones specifically relevant to his or her 

flight. The NOTAMs for a single flight may fill 20 printed pages or more. Most NOTAMs are 

irrelevant for a given flight, involving airports the pilot will not stop at, routes she or he will not 

traverse, aircraft types she or he is not flying (e.g., jets), and procedures she or he will not follow 

(e.g., flying by instrument flight rules, or IFR). Within such a paper mass, a key SSA NOTAM is 

easy to miss. Alternatively, a pilot may get NOTAM information through a verbal preflight 

briefing from a Flight Service Station (FSS) controller. With such briefings typically done by 

phone, it is now the FSS controller who must peruse the NOTAMs to determine the ones relevant 

to the pilot, and verbally transmit them to the pilot, who, presumably, jots down the details on 

paper. The potential for error, from the FSS controller selecting and describing the SSA details to 

the pilot hearing and noting the SSA, are legion. 
7 

FDC 5/1953 ZJX PART 1 OF 4 FLIGHT RESTRICTIONS PENSACOLA, FLORIDA, MARCH 18, 2005 LOCAL.

PURSUANT TO TITLE 14, SECTION 91.141, OF THE CODE OF FEDERAL REGULATIONS (CFR), AIRCRAFT

FLIGHT OPERATIONS ARE PROHIBITED: WITHIN 30 NMR UP TO BUT NOT INCLUDING FL180 OF

302824N/0871115W OR THE CEW228033.7 FROM 0503181350 (0750 LOCAL 03/18/05) UNTIL

0503181805 (1205 LOCAL 03/18/05). WITHIN 10 NMR UP TO BUT NOT INCLUDING FL180 OF

302110N/0871901W OR THE BFM108041.3 FROM 0503181350 (0750 LOCAL 03/18/05) UNTIL

0503181455 (0855 LOCAL 03/18/05). WITHIN 10 NMR UP TO BUT NOT INCLUDING FL180 OF

302824N/0871115W OR THE CEW228033.7 FROM 0503181415 (0815 LOCAL 03/18/05) UNTIL

0503181640 (1040 LOCAL 03/18/05). WITHIN 10 NMR UP TO BUT NOT INCLUDING FL180 OF

302110N/0871901W OR THE BFM108041.3 FROM 0503181600 (1000 LOCAL 03/18/05) UNTIL

0503181805 (1205 LOCAL 03/18/05). END PART 1 OF 4

FDC 5/1953 ZJX PART 2 OF 4 FLIGHT RESTRICTIONS PENSACOLA, FLORIDA, MARCH 18, 2005 LOCAL.

EXCEPT AS SPECIFIED BELOW AND/OR UNLESS AUTHORIZED BY ATC: A. ALL AIRCRAFT OPERATIONS

WITHIN A 10 NMR AREA LISTED ABOVE ARE PROHIBITED EXCEPT FOR: 1. LAW ENFORCEMENT, MILITARY

AIRCRAFT DIRECTLY SUPPORTING THE UNITED STATES SECRET SERVICE (USSS) AND THE OFFICE OF

THE PRESIDENT OF THE UNITED STATES, EMERGENCY MEDICAL FLIGHTS, AND REGULARLY SCHEDULED

COMMERCIAL PASSENGER AND ALL-CARGO CARRIERS OPERATING UNDER ONE OF THE FOLLOWING TSAAPPROVED STANDARD SECURITY PROGRAMS/PROCEDURES: AIRCRAFT OPERATOR STANDARD SECURITY

PROGRAM (AOSSP), DOMESTIC SECURITY INTEGRATION PROGRAM (DSIP), TWELVE FIVE STANDARD

SECURITY PROGRAM (TFSSP), OR ALL-CARGO INTERNATIONAL SECURITY PROCEDURE (ACISP) AND ARE

ARRIVING INTO AND/OR DEPARTING FROM 14 CFR PART 139 AIRPORTS. 2. FOR OPERATIONS WITHIN

THE TFR, ALL MEDICAL FLIGHT OPERATION COMPANIES SHALL COORDINATE OPERATIONS IN ADVANCE

WITH THE END PART 2 OF 4

FDC 5/1953 ZJX PART 3 OF 4 FLIGHT RESTRICTIONS PENSACOLA, FLORIDA, MARCH 18, 2005 LOCAL.

USSS AT 850-444-5646 TO AVOID POTENTIAL DELAYS. B. WITHIN THE AIRSPACE BETWEEN 10 NMR AND

30 NMR LISTED ABOVE: 1. ALL AIRCRAFT ENTERING OR EXITING THE 30 NMR TFR SHALL BE ON AN

ACTIVE IFR OR VFR FLIGHT PLAN WITH A DISCRETE CODE ASSIGNED BY AN ATC FACILITY. AIRCRAFT

SHALL BE SQUAWKING THE DISCRETE CODE PRIOR TO DEPARTURE AND AT ALL TIMES WHILE IN THE

TFR. 2. ALL AIRCRAFT ENTERING OR EXITING THE 30 NMR TFR MUST REMAIN IN TWO-WAY RADIO

COMMUNICATIONS WITH ATC. 3. ALL AIRCRAFT OPERATING WITHIN THE 10 NMR TO 30 NMR TFR AND

OPERATING AT ALTITUDES OF UP TO BUT NOT INCLUDING FL180 ARE LIMITED TO AIRCRAFT ARRIVING

OR DEPARTING LOCAL AIRFIELDS AND ATC MAY AUTHORIZE TRANSIT OPERATIONS. AIRCRAFT MAY NOT

LOITER. 4. FLIGHT TRAINING, PRACTICE INSTRUMENT APPROACHES, AEROBATIC END PART 3 OF 4

FDC 5/1953 ZJX PART 4 OF 4 FLIGHT RESTRICTIONS PENSACOLA, FLORIDA, MARCH 18, 2005 LOCAL.

FLIGHT, GLIDER OPERATIONS, PARACHUTE OPERATIONS, ULTRALIGHT, HANG GLIDING, BALLOON,

AGRICULTURE/CROP DUSTING, ANIMAL POPULATION CONTROL FLIGHT OPERATIONS, AND BANNER TOWING

OPERATIONS ARE NOT AUTHORIZED. 5. ALL USSS CLEARED AIRCRAFT OPERATORS BASED IN THE AREA

SHOULD NOTIFY THE USSS PRIOR TO THEIR DEPARTURE. 6. FOR OPERATIONS WITHIN THE TFR, ALL

MEDICAL FLIGHT OPERATION COMPANIES SHALL COORDINATE OPERATIONS IN ADVANCE WITH THE USSS

AT 850-444-5646 TO AVOID POTENTIAL DELAYS. C. IT IS RECOMMENDED THAT ALL AIRCRAFT

OPERATORS CHECK NOTAMS FREQUENTLY FOR POSSIBLE REQUIRED CHANGES TO THIS TFR PRIOR TO

OPERATIONS WITHIN THIS REGION. END PART 4 OF 4

Figure 1. NOTAM 5/1953, an example of Presidential TFR NOTAM. Note: While fairly typcial 

for a Presidential TFR NOTAM, most non-TFR NOTAMs are considerably shorter. Use of allcapital letters is from the orginal NOTAM. User of Courier font as above is typical of DUATS. 

2.3. Current Efforts to Improve SSA Awareness and Understanding 

Recognizing that improved knowledge and understanding of SSAs is key to reducing accidental 

violations of them, the FAA has taken significant steps to improve the dissemination of SSA 

information, relying less on NOTAMs. Developed and maintained through NAS Aeronautical 

Information Management Enterprise System (NAIMES) program, the FAA now has a web site 

that lists all active and upcoming SSA activations (and non-SSA TFRs as well), providing links 

to the associated NOTAM, and, more significantly, a map illustrating the SSA (AOPA, 2003b; 

FAA, 2005e). The NOTAM gives the times of effect in both universal coordinate time and more 

convenient local time. Some information within the NOTAM is broken out into a column of 

fields for easier reading. This web site undergoes periodic improvements to provide better and 

easier to access information on SSAs (e.g., AOPA, 2003c). Meanwhile NAIMES has 
8

supplemented this web site with another with more detailed maps and more powerful map 

manipulation tools for pilots (currently at https://www.tfrfaa.naimes.faa.gov/TfrFAA2/start.do). 

The FAA has also updated its paper publications. Some recurrent and static SSAs, such as the DC 

ADIZ and FRZ and the SSA for the presidential residence in Kennebunkport, ME, now appear on 

charts. In the official Airport/Facility Directory (AFD) (FAA, 2004d) the entries for airports in 

the FRZ now warn that "compliance with SFAR 94 is required," SFAR 94 being the regulations 

governing flight in the FRZ. 

Other efforts to keep pilots informed of SSAs have been attempted. A review of Aviation Safety 

Reporting System reports on SSA violations4

 indicates that sometimes (but not always) SSAs are 

announced over the local airport's Automatic Terminal Information Service (ATIS), which 

otherwise provides key weather information for airborne pilots. Local FAA officials held for 

pilots in the DC area informative seminars on the DC ADIZ, a large static Control Level 2 SSA 

that alone has been responsible for half of all violations (AOPA, 2004a). As a long term 

intervention, the FAA continues to develop and deploy the Operational and Supportability 

Implementation System (OASIS), a sophisticated tool for FSS briefers that supports easier 

sorting, reviewing, and alerting of SSAs relevant to a particular flight. 

Other organizations, including private companies, have also attempted to make relevant SSA 

information more accessible and understandable to pilots. Internet Marine and Aviation Planning 

Services (IMAPS), DUATS, and the Aircraft Owners and Pilots Association (AOPA) each 

maintain a web site with maps of SSAs that supplement those provided by the FAA5

. DUATS 

and DUAT provide NOTAM "highlights" in easier-to-read tabular format. The AOPA’s web site 

provides extensive SSA information and training materials, along with a formatted plain-language 

"translation" of complex NOTAMs (AOPA, 2005a). AOPA also provides a service that emails 

pilots if a SSA is activated in their region and IMAPS provides a similar service. In addition to 

web sites, dedicated personal computer clients are available for purchase, including DUATS 

Golden Eagle, Jeppesen FliteStar, and IMAPS AeroPlanner, that each graphically show SSAs on 

flight planning maps. 

The combined efforts appear to be having an effect. After peaking at 231 violations of SSAs per 

month in the third quarter of 2003, the frequency of violations has progressively declined to 87 

violations per month in the second quarter of 2004. However the current rate of violations is still 

over 30 times higher than in the years prior to 9/11/01 (Government Accountability Office, 2004). 

While the above interventions were crucial, they also had limitations, although with updates and 

improvements being continuously applied, some limitations are perhaps being addressed. 

Airport/Facility Directory entries for airports within the DC ADIZ do not mention that special 

procedures are necessary to fly to them. There has been substantial delay in updating charts. The 

DC ADIZ did not appear on charts until 12 months after it was imposed (charts are normally reissued about every 6 months), resulting in charts showing the FRZ but not the ADIZ. In some 

cases during that period, a pilot, who knew the ADIZ existed, confused the smaller FRZ shown 

on the charts with the much larger ADIZ, resulting in a violation. The current sectional charts 

depict a 5 nm radius SSA around Camp David, apparently based on a canceled NOTAM from 

2002 (AOPA, 2002b; FAA, 2004e). More recently, the SSA for Camp David has been 10 nm 

radius. Reports indicate that some pilots accidentally violated this SSA because they assumed the 

chart depiction was for 10 nm, not 5 nm (Zuschlag, 2005). 

 

4

 This is the same corpus of reports used in Zuschlag (2005). 

5

 The federal National Interagency Fire Center uses IMAPS's products to also provide SSA maps in 

addition to maps for forest fire TFRs and other concerns 
9 

As for more transitory SSAs, the FAA web site does not provide a map for all of them, and when 

there are maps, they may not have all the details necessary to interpret the map (see Figure 2), 

although recently the FAA has incorporated the capacity to layer additional information through a 

separate link. This includes ATC center boundaries, highways (unlabeled), a widely spaced 

graticule, cities and metro areas and SUAs, along with airports and certain navigation aids shown 

in Figure 2. The web site has some information from the related NOTAM in an easier to read 

tabular format, it is not the most critical information: position, boundaries, and control level. 

Figure 2. Default map of the SSAs described in NOTAM 5/1953 (see Figure 1) as provided 

on the FAA TFR web site (FAA, 2005e). Value contrast is intensified in this gray-scale 

reproduction. In the original image, water bodies (gray in above image) are light blue, and SSA 

boundaries (black in above image) are red. 

Alternatively, the FAA web sites (including the newest NAIMES site) represent the SSAs 

superimposed on a raster scanned sectional aeronautical chart, similar to that seen in Figure 3. 

This practice also followed by private pilot information services such as DUATS and IMAPS, 
10

and appears superior to the sparse map format shown in Figure 2. Such maps provide nearly all 

the necessary details using standard symbology and ease cross-referencing to standard 

aeronautical charts. Such maps also have limitations, largely due sectionals being designed for 

high-resolution color printing on a large sheet of paper. When scanned into a computer, the result 

is too much information: a cluttered map that is difficult to read, especially when viewed on a 

computer screen or printed on a standard-sized paper in black-and-white. 

Figure 3. SSAs described in NOTAM 5/1953 (see Figure 1) when superimposed on a rasterscanned map. This DUATS-provided screen capture is similar to other maps provided by the 

FAA and IMAPS for computer screen presentation. The resolution is inferior to the original paper 

sectional, making most of the text and many symbols at this level of zoom illegible. Zooming in 

improves legibility, but eliminates the context. The original screen image for this figure was full 

color, with the SSAs rendered as three bright red circles, but when printed on a black and white 

printer, it would appear much like above. 

3. Goals and Principles for Interventions 

This paper aims to propose the most realistic, feasible, and effective interventions to reducing 

accidental violations of SSAs. Reducing the frequency of violations by an order of magnitude is 

an ambitious goal. Violations need to be vastly reduced for static and recurrent SSAs to decrease 

the frequency by 75% of the current rate. Decreasing it down to about 10% requires that 

interventions substantially reduce the violations of presidential TFRs (e.g., Figure 1), which 

account for nearly a quarter of all violations. These TFRs represent a particular challenge: 

 They usually cover a large populated area, typically being 30 nm in radius with altitudes 

extending to 18,000 feet, and thus confront a large population of pilots when activated. 

 They have complex structures, typically including two or more nested SSAs each with 

different control levels or activation periods. 
11

 They have complex procedures, usually including a variation of Control Level 2, which, as 

observed with the DC and NY ADIZ, can be difficult to understand when first imposed. 

 They can occur anywhere and anytime on short notice, making it more likely that pilots will 

not be expecting or preparing for them, and will be unfamiliar with the requirements. 

Achieving an order of magnitude reduction in the frequency of violations is only likely by 

adopting the pragmatic approach of acknowledging that accidental violations are a problem with 

the system and seeking the solutions that will work best in the real world wherever SSAs may be 

implemented. It is not productive to attempt to assign blame for this problem and to shift 

responsibility for solving it on one party or another. The ultimate solutions will require efforts by 

government service and regulatory agencies, the research community, industry, and pilots 

themselves. 

The interventions proposed here are derived from a working knowledge of the aviation domain 

and an understanding of the probable causes for SSA violations as found by Zuschlag (2005). No 

attempt has been made to evaluate the present or alternative approaches to securing potential 

terrorist targets from attacks from the air. It is conceivable that equal security can be effected 

through alternatives to applying the current types of SSAs –alternatives that may be associated 

with a substantially lower cost to the aviation community and the nation as a whole. However, the 

search for such alternatives, if they exist, is beyond the scope of this report. The interventions for 

this report assume that the national interest is best served by applying SSAs of the current type, 

size, frequency, and duration. 

The vast majority of violations of SSAs are made in small aircraft, usually a piston-powered 

single (Zuschlag, 2005). This implies that the most effective interventions are those that target the 

low-end general aviation private pilot, presumably flying under Visual Flying Rules (VFR). Such 

pilots do not have the resources to support his or her flying that a commercial or military pilot 

has. This implies that for an intervention to be most effective, it should, from the pilot's point of 

view, have the following attributes: 

 Low cost. 

 Low training requirements. 

 Not reliant on instrument flying skills. 

 Low workload. 

Low workload is especially important while airborne as typically such aircraft are operated by a 

single pilot. As an additional consideration of available resources, while advanced graphicscapable multi-function displays are making their way into the general aviation cockpit, such 

technology cannot be assumed to be available to all pilots in the next decade or so. Indeed, it 

should be assumed that there will always be a population of aircraft that do not have in-panel 

digital cockpit systems, or even electrical systems. Interventions should not depend on such 

systems. 

There are also human factors considerations to any intervention. The intervention should be 

consistent with current flight concepts and practices so that existing knowledge and ingrained 

habits result in fewer violations rather than more. The intervention should be readily integrated 

into normal procedures and routines. The easier it is for pilots to include actions to avoid 

violations, the more likely they will take those actions. The more such actions disrupt flight tasks 

or conflict with flight goals, the less likely pilots will take them. Relatedly, the intervention 

should avoid requiring pilot actions that must be done specifically to avoid SSAs (e.g., checking 

an information source dedicated to SSAs before each flight). While pilots who are flying near 
12

static or frequently recurrent SSAs may be motivated to perform such actions, other pilots may 

not because a SSA is not expected. The intervention should be designed such that pilots naturally 

develop awareness and understanding of a SSA through their pursuit of the normal goals and 

tasks associated with flight (e.g., preflight preparation, navigating, avoiding weather, 

communicating). This is not to imply that pilots should not be responsible for being fully aware 

of the airspace they transit. It does, however, recognize that realistically many pilots are going to 

be less motivated to regularly carry out any extra work necessary for checking for SSAs given the 

low probability of a transitory SSA for a particular region at a particular time. Finally, the 

information provided through the intervention should be functionally trustworthy and useful. If 

the information source is found to be inaccurate (e.g., frequently causing false alarms) or not 

useful for avoiding SSAs, pilots will soon ignore it. 

4. Short-term Interventions 

Short-term interventions are those that can be accomplished without the development and 

deployment of new hardware, either to cockpits or to ground facilities such as air traffic control 

centers. In other words, these interventions are limited to procedure and policy changes, changes 

to information content, format, or medium, or, at most, software changes. Some of these 

interventions could be carried out by private industry using materials as it is currently distributed 

by the FAA, while other interventions may be better carried out by the FAA itself, perhaps as part 

of current programs to improve information dissemination, such as NAIMES. 

As shown in Table 1, most violations of SSAs can be attributed to lack of information about 

SSAs, the chief information being (1) the relative distance to SSA, (2) the simple presence of the 

SSA, and (3) the procedures for allowed penetration of SSA. Short-term solutions are broken 

down by the primary information deficiency they address, beginning with knowing the presence 

of the SSA. 

4.1. Improving Pilot Awareness of the Presence of SSAs 

Failure to recognize the existence of a SSA is not the single most important cause of SSA 

violations, but maximizing the number of pilots in an area that recognize the presence of a SSA is 

still the first step to reducing violations of it, thus interventions to maximize awareness are 

discussed first. 

Currently, the activation of a transitory and recurrent SSA is announced through a NOTAM. 

Thus, knowledge of the presence of such a SSA activation can be improved by increasing the 

likelihood of the pilot seeing the associated NOTAM. A typical preflight task includes using 

electronic preflight briefing services such as DUATS to receive a report on the weather and 

NOTAMs in the vicinity of the flight path as indicated by the flight plan provided by the pilot. An 

intervention to improve awareness of the SSA's NOTAM would best focus on improving this 

briefing report, rather than, say, developing other SSA-specific sources of the NOTAM, which 

would require pilot action specific to avoiding SSAs. 

4.1.1. Sorting, Filtering, or Highlighting Briefing Reports 

The briefing report can be improved to increase SSA awareness without sacrificing awareness of 

other important information through better sorting, filtering, or highlighting of its contents. 

Currently, NOTAMs appear at the end of the report, sorted broadly by source; SSA NOTAMs are 

at the end intermixed with numerous other NOTAMs from the National Flight Data Center. The 

FAA can support better sorting, filtering, and highlighting by including in each NOTAM standard 
13

keywords that allow software to identify the type and relevance of the NOTAM. Keywords can 

be used to encode: 

 Class and identity of object NOTAM relates to (e.g., runway, navaid, airspace). 

 Class of action related to object (e.g., name change, frequency change, restriction). 

 Type of flight or aircraft that the NOTAM is most relevant to. 

Further research by a government agency is necessary to determine the information to encode and 

the keywords to be used. Ultimately or alternatively to the keyword approach, the FAA could 

encode and transmit NOTAM information as named database fields, although this would require 

addition government research and development to convert the system to support formatting or 

markup. 

By using such keywords, or by using its own methods for categorizing NOTAMs, services such 

as DUATS can then provide more sophisticated filtering, sorting, or highlighting of NOTAMs 

within briefing reports for the given flight path or region to reflect the priority and proximity of 

the NOTAM. For many pilots, NOTAMs of proximal SSAs are the single most important type of 

NOTAM, so these should be listed first or highlighted (e.g., with additional delimiters such as a 

border of asterisks). The lowest priority is NOTAMs that simply announce the cancellation of 

other NOTAMs. These can be filtered out and presented separately, perhaps only with explicit 

pilot request. Apparently, it is technically feasible for a computer program to successfully extract 

the SSA shape and location from most NOTAMs. With this done, the briefing report can display 

a prominent alert at the top of briefing if the pilot-entered flight plan directly conflicts with a 

SSA. 

With sufficient information encoded in the NOTAMs, perhaps all NOTAMs may be sorted by 

likelihood that the pilot will encounter the element related to the NOTAM given the flight plan 

submitted by the pilot. Top priority for the pilot to view would be applied to NOTAMs for 

airports the aircraft lands at or takes off from, airways on the path, and airspace the given path 

passes through, the latter including any relevant SSA NOTAMs. Possibly the entire briefing 

report can be sorted by such criteria, with weather conditions, forecasts, and NOTAMs likely to 

be encountered all intermixed and sorted in the geographic order of the flight. Other weather and 

NOTAMs (the bulk of the report) would be presented separately. Currently the briefing report is 

sorted by the source of the information –first all Meteorological Reports (surface observations) 

presented together, then all airborne pilot reports, then radar summaries, then terminal forecasts, 

(etc.). 

NOTAMs could also be categorized and subsequently filtered by characteristics of the flight. For 

example, NOTAMs primarily relevant to IFR flight can be separated from those primarily 

relevant to VFR flight. Additional study of NOTAMs and how they affect flight may identify 

other dimensions for categorization that discriminate the NOTAMs' relevance for different pilots, 

aircraft, or types of flights. NOTAMS for Control Level 1 SSAs would be relevant to all aircraft 

and always have high priority, but with other irrelevant NOTAMs separated, they will be easier to 

spot. 

While most recommendations here focused on printed or electronic briefings, many pilots are 

briefed through FSS. FSS controllers as a rule are highly professional and competent, but there 

are nonetheless cases of pilots failing to be aware of active SSAs after being briefed by FSS 

(Zuschlag, 2005). Such failures to communicate may be due to the antiquated technology used by 

FSSs. At the very least, all FSS stations should have technology to detect a potential SSA conflict 

based on the flight plan supplied by the pilot. Better sorting and filtering of NOTAMs for the FSS 

controller will have similar benefits as it can have for pilots. Ideally, to assist cases when FSS is 
14

contacted by an airborne pilot, FSS workstations could display the current position of the aircraft 

on maps depicting the SSA, perhaps based on a feed from ATC, allowing the briefer to give more 

precise advice for avoiding the SSA. The FAA has most of these capabilities in the form of 

OASIS and the Special Use Airspace/Inflight Service Enhancement (SUA/ISE) system, but their 

availability has been limited (Reauthorization of the Federal Aviation Administration and the 

Aviation Programs, 2003), suggesting that funding and the application of policy is the primary 

obstacle. Considering the high frequency of SSA violations, the availability of these technologies, 

if anything, should be accelerated. 

4.1.2. Formatting of NOTAMs in Briefing Reports 

Spotting relevant NOTAMs such as those for SSAs is inhibited by the single-styled free-text 

format of the NOTAMs. Text is shown in all capital letters (as shown in Figure 1), making it 

difficult for the pilot to skim for key words. Use of proper sentence case would substantially 

improve matters. The FAA could make formatted NOTAMs available to briefing services, 

perhaps utilizing HTML for easy distribution and cross-platform compatibility. Varying text 

weight and size can be used to highlight and distinguish information key to help pilots determine 

the type and relevance of the NOTAM. Other details within the NOTAM should remain in 

normal font. Paragraph breaks for long NOTAMs should be by blocks of related content 

(currently, breaks appear to be arbitrary, possibly by the number of characters). A mockup of the 

heading of such a NOTAM is shown in Figure 4. As shown in Figure 4 and in contrast with the 

beginning text in Figure 1, the basic type of NOTAM, along with basic location and activation 

date of the SSAs should be prominently shown to catch immediate attention. Other fields in the 

header (e.g., miles from flight plan) could represent the NOTAMs relevance as determined 

dynamically from the flight information provided by the pilot. 

Even better would be to break down each NOTAM of any appreciable complexity (such as a SSA 

NOTAM) into tabular or form fields arranged in a standard geometry for each kind of NOTAM. 

AOPA and DUATS do this to SSA NOTAMs, but separately from the briefing report, requiring 

pilots to anticipate the potential for a SSA activation and seek that information elsewhere. Such 

formatting should be applied to all complex NOTAMs within the briefing report to aid the pilot in 

skimming the report for relevant NOTAMs. With practice, the very geometry of the NOTAM 

fields will cue the pilot to the type of NOTAM. The DUATS and AOPA formats may be studied 

as possible alternatives. Another alternative is discussed in Section 4.2.4. The ultimate format 

should be subjected to study with actual pilot populations to validate its effectiveness. 

Formatted and arranged text can be supplemented by including icons or graphics to redundantly 

identify the NOTAM’s attributes, where graphics are easier to recognize at a glance than words. 

It is not necessary for the icons to be immediately interpretable in isolation because attribute 

labels are also provided. Rather, the icons merely have to be easy to learn and remember, and, 

more importantly, easy to distinguish from one another as the pilot scans the report. IMAPS 

AeroPlanner makes limited use of icons in this capacity. 

FDC 5/1953. Located 8 nm from flight plan. High relevance for Any Flight. 

Flight Restrictions 

Pensacola, FL, March 18 2005, 7:50 – 12:05 local

Figure 4. Mockup of heading for NOTAM 5/1953 (see Figure 1) using variable font weight 

and size to aid scanning. This would be followed by the content of the NOTAM in smaller font 

using mixed case (see Appendix, Page 54). 
15

4.1.3. Other Possible Improvements for Briefing Reports 

There are a number of other possible improvements one could make to briefing reports. The exact 

format and effectiveness of each may be subjects of future research. 

In addition to improving sorting and formatting of NOTAMs within an electronic preflight 

briefing report, the electronic briefing service could include at the beginning a flight plan specific 

summary of the most critical information. This may be a dynamically generated map of the flight 

plan prominently displaying active SSAs as well as threatening weather, laser activity, moored 

balloons, smoke, and other hazards. Less critical information (e.g., frequency changes) may be 

more discretely represented. Links or cross references from the map access additional details 

(e.g., the associated NOTAM). As pilots get into the habit of first quickly checking the summary 

for any hazards, those who may not be expecting the activation of a SSA will nonetheless become 

informed. 

The briefing or the NOTAM itself can also indicate when a NOTAM for an object such as a SSA 

has been updated or corrected, including the date and time of the updating and highlighting the 

changes. This will cover cases of pilots erroneously dismissing certain NOTAMs as being 

functionally the same as prior familiar NOTAMs. 

For Restricted Area SUA that do not have a regular schedule that can be documented on charts 

(as is done now), the FAA could begin supplying NOTAMs to announce their activation. The 

same can be done for when the control level of a NSA is raised. This will help get pilots in the 

habit of referring to the NOTAMs in a briefing report for all recurrent or transitory airspace 

restrictions. Regularly checking for a SUA activation, the pilot is more likely to see a transitory 

SSA activation. 

Electronic briefing services or the FAA can develop a feature to support personalized update 

briefings. When delivering a standard briefing to a pilot, the username, timestamp, and flight plan 

is stored until some time after the pilot-provided end time of the flight. Pilots calling up the same 

flight plan (and possibly editing it) are then supplied with only new weather and NOTAMs given 

the current time and any flight plan changes. This will encourage pilots to check back with 

briefing services, perhaps while airborne, to see if anything significant has changed (e.g., a 

change in SSA activation) 6. The system may even automatically phone the pilot if there are 

significant changes from original standard briefing. 

4.1.4. Charting Recurrent and Static SSAs 

Along with various weather information products, navigation charts are a key source of 

aeronautical information that is frequently used by pilots. It is natural to map static and recurrent 

SSAs on charts such as sectionals, terminal area charts, and IFR en route charts, which already 

show SUAs, the cousins to SSAs. By placing SSAs on such regularly referenced charts, pilots are 

much more likely to be aware of the presence. For a recurrent SSA, this awareness will encourage 

pilots to regularly scan for a NOTAM indicating the SSA’s activation. To maximize the chance of 

this behavior, static SSAs need to be distinct from recurrent SSAs (parallel to what is done for 

Prohibited and Restricted SUAs), and the SSA needs to be clearly and consistently identified on 

both the chart and the header of the NOTAM. 

As mentioned earlier, some efforts have already been made to chart such SSAs. However, up-todate representations of these SSAs have been delayed, leading to confusion. If charts are to be 

 

6

 Presidential TFRs typically warn pilots to “check NOTAMs frequently for possible required changes” 

(see Figure 1) 
16

effectively used to raise pilots’ awareness of SSAs, then the process for adding and changing 

SSAs on charts needs to be streamlined. Otherwise, pilots may soon fail to trust and to use such 

information. Possibly, an agency can assist the FAA in studying the current process and 

proposing affordable improvements. Among the first steps to address this is to formalize the 

definition of “recurrent” or “static” SSA (e.g., by anticipated number of activations per year or 

activation duration) in order to identify the sort of SSAs that are candidates for charting and set 

the requirements for a revised system for charting SSAs. 

4.1.5. Weather Products and Other Channels 

While much can be done to increase awareness of SSAs by improving the current primary means 

of disseminating SSA information, awareness can also be improved by opening new channels to 

communicate the presence of SSAs. The task of determining the actual implementation (e.g., how 

to feed the data) requires further study. 

For the VFR pilot, perhaps the most important and frequently needed information from outside 

sources is weather. If a pilot does any preflight preparation at all, chances are it involves a check 

of the weather. The preflight briefing provides extensive weather information along with 

NOTAMs. However, a less than fully conscientious pilot may forgo a full standard briefing for 

short or simple flights (e.g., pattern work around the airport), and instead gather only key weather 

information. Accidental violations by such pilots can be reduced by including recurrent and 

transitory SSA activation alerts with local weather information products. As an alerting 

mechanism, it is not necessary to include any details about the SSA. It can merely serve to get the 

pilot’s attention and direct him or her to an appropriate source of the details. 

Automated Flight Service Station (AFSS) weather summaries can include SSA activation alerts, 

as can the pre-recorded weather summaries accessible through the Telephone Information 

Briefing Service (TIBS). Meteorological Reports (METARs) and Terminal Aerodrome Forecasts 

(TAFs) in particular make good products to include SSA activation alerts. METARs include a 

Remarks portion that may be suited for this. In keeping with the terse system of abbreviations 

found in such products, the key text “TFR” followed by the associated NOTAM number may be 

sufficient (see Figure 5). Consistent with the functions of METARs and TAFs, a METAR may be 

used if the SSA is currently active at that location, while a TAF may be used if a SSA 

encompassing that location will activate in the next 24 hours. 

METAR KPNS 181353Z VRB05KT 10SM FEW011 SCT043 09/06 A3004 RMK 

AO2 SLP177 T00890056 TFR5/1953 

Pensacola FL [KPNS] hourly observation on the 18th at 8:53am EST (1353Z) 

Wind variable at 5 knots, visibility 10 miles, 1,100 feet few, 4,300 feet scattered, temperature 

9°C (48°F), dewpoint 6°C (43°F), altimeter 30.04, automated station with precipitation 

discriminator, sea level pressure 30.05" Hg (1017.7 hPa), temperature 8.9°C (48.0°F), 

dewpoint 5.6°C (42.1°F), TFR in effect see NOTAM 5/1953. 

Figure 5. Mockup of a METAR with inclusion of a TFR alert, both in coded form and as it 

would appear in a DUATS plain-text “translation.” 

Some airports are already putting SSA activation alerts on their ATIS broadcasts, which are 

frequently checked by pilots before takeoff and as they approach their destination. Including such 

alerts make it possible for even airborne pilots to learn of the presence of an active SSA, 

including a SSA that changed after takeoff. This practice should be extended and standardized to 
17

all airports providing ATIS broadcasts. The Automated Weather Observing System (AWOS) may 

also be reprogrammed to allow the inclusion of such alerts. Alerts may also be included in other 

airborne weather information services such as Transcribed Weather Broadcasts (TWEB) and the 

Hazardous In-flight Weather Advisory Service (HIWAS). The frequency of local FSS can be 

included in the alert to allow the airborne pilot to get the details of the SSA activation. 

The FAA could provide fixed-based operators (FBOs) at airports and even individual pilots with 

alerts of the activation of SSAs through automatic faxes or email, similar to the services provided 

by private organizations. FBOs may be allowed to sign up for receiving standard-formatted largeprint notice that may be posted for pilots to see before flight. 

4.1.6. Specific Times and Places for All TFRs 

Historically, the FAA has imposed multiple SSAs through a single “blanket” NOTAM, which 

declare SSAs over all instances of a particular class of potential targets, rather than over an 

individual location. One such NOTAM currently in effect (FAA, 2003d), declares Control Level 

1 SSAs over any major populated stadium and sporting event. It is left to the pilot to determine 

where these events occur and when they are scheduled. Another NOTAM (FAA, 2004f) 

essentially declares Control Level 3 SSAs over all "military facilities" and "industrial 

complexes," among other structures, without defining these terms or the size or shape of the 

respective SSAs. While these are "only" at Control Level 3, it is nonetheless important for pilots 

to avoid these areas. This is especially so for nuclear power stations given a plane deemed 

threatening might be shot down (AOPA, 2005b). Few violations are associated with the SSAs 

covered by blanket NOTAMs. However, it remains a questionable expectation for pilots to keep 

clear of such SSAs while not providing sufficient information to do so. 

At a minimum, all such SSAs should be charted so the locations are known to pilots. There are 

then two alternatives to handle the time element, where different stadiums or sports events may 

use one or the other alternative dependent on the threat and vulnerability. Firstly, if it affords an 

acceptable level of security, a static Control Level 3 SSA could be placed over the stadium. Text 

(perhaps on the chart itself) should tell pilots that it is especially important to remain clear of the 

stadium when they are populated. Pilots may still stray over stadium events, but at least they will 

usually see that the stadium is populated (by the cars in the parking lot, if nothing else), and can 

promptly leave the area. 

Secondly, the FAA can establish recurrent Control Level 1 SSAs over certain high-risk stadiums, 

and announce each SSA activation through the usual channels. Given that events are scheduled 

well in advanced, a single NOTAM can cover a month or even a season's worth of activations for 

a particular stadium. The goal is to be able to provide in a briefing all the information necessary 

for the pilot to definitively determine if the airspace may or may not be flown. This alternative 

implies that event organizers should be required by law to inform federal authorities of their 

schedules. This would seem to be an appropriate obligation if such a level of control is truly 

necessary. In addition to providing the FAA with the information necessary to distribute an 

appropriate NOTAM, other federal agencies need the schedule in order to provided adequate 

security (e.g., having interceptors ready to stop an actual terrorist attack). 

4.2. Improving Pilot Awareness of SSA Boundaries 

The single most important cause of violations of SSAs is the pilot not being aware of the SSA’s 

position relative to the pilot’s aircraft. All interventions to this cause of violations focus on better 

communicating the boundaries of the SSA to the pilot. 
18

4.2.1. Charting SSAs 

Through NOTAMs and FSS briefings, SSA boundary information is currently represented in 

words, usually as a radius from geographic coordinates or a radial and distance from a navigation 

aid (see Figure 1). However, a pilot cannot take these words alone and form an accurate mental 

representation of the airspace. Only by taking the words and plotting the SSA on a map can any 

reliable sense of the boundaries by understood. Forcing pilots to manually plot a SSA from a text 

description provides an opportunity for errors in transcription and interpretation of the NOTAM. 

Furthermore, a pilot may elect to not do the extra labor to plot a certain SSA, believing it is not 

relevant, only for it to become relevant due to changes in plans after airborne (e.g., due to 

unpredicted weather). 

It thus makes sense to plot the SSA for the pilot, and it has already been recommended that static 

and recurrent SSAs be on all appropriate charts. This process appears to be already underway, but 

the efficiency of the process needs to be improved to ensure the SSA representations are timely 

and accurate. The goal should be to have the capacity to add or remove a SSA within a single 

update cycle of the chart. Ideally, unless there is an especially urgent security consideration, a 

recurrent or static SSA should not be imposed until it can appear on charts. 

The charting of the boundaries of static and recurrent SSAs should include SSAs associated with 

military facilities, industrial infrastructure, stadiums and other areas currently covered by 

“blanket” NOTAMs (the former two currently being Control Level 3 SSAs). Even transitory 

SSAs could be mapped if they are known with sufficient lead time and will be active for a 

substantial portion of the chart edition’s lifetime (e.g., that associated with a major event such as 

the Olympics). When possible, the FAA should use existing SUA types and associated 

symbology (e.g., Prohibited Areas, Restricted Areas, and NSAs) since these are already relatively 

familiar to pilots and well documented. However, it may be necessary to define new types of 

airspace corresponding to certain control levels and degrees of stability, and develop associated 

symbology. This is a topic for additional research. It is probably a good practice to state the SSA 

identity and boundaries on the chart (i.e., providing its name, diameter, and ceiling) so the pilot 

can cross-check it against notices concerning other SSAs. This will reduce the chance of a pilot 

confusing a NOTAM instantiating a new SSA with an existing SSA depicted on the chart, as has 

occurred in the past (Zuschlag, 2005). 

4.2.2. Optimally Detailed Maps 

For maps of transitory SSAs, the best solution is to provide them through electronic distribution, 

as is done by the FAA on their TFR web site, but, as discussed earlier, not all SSAs are mapped, 

and, if they are, often the maps lack the optimal level of detail (see Figure 2). Private 

organizations such as DUATS, AOPA, and IMAPS likewise use maps that are not optimized for 

the purpose of communicating the position and boundaries of a SSA. The map should be 

sufficiently detailed to allow a pilot unfamiliar with the area to precisely identify each SSA and 

draw each on a sectional or other chart, but not so detailed that text or symbols are difficult to 

read when printed in black and white or viewed at the level of zoom necessary to show the entire 

SSA. A proposed map design should be experimentally tested on pilots to verify that the design 

meets this criterion. 

In general, this means the details should be at a level comparable to that found on a sectional, 

using symbology consistent with a sectional chart. At the same time a simple unmodified scan of 

a sectional or other chart is not necessarily desirable. The details of such a scan may not be 

readable in a computer image at certain levels of scale and may produce difficult to read printouts 
19

in any case (see Figure 3). Also, information on the scanned sectional can conflict with NOTAM. 

For example, superimposing the current Disney World Control Level 1 SSA (2003e) on a 

sectional places it proximal to an existing legend advising pilots to "avoid" flying over Disney 

World, suggesting the SSA is only at Control Level 3. 

Figure 6. Mockup of a map for NOTAM 5/1953 (see Figure 1, Figure 2, and Figure 3) 

attempting to optimize the level of detail necessary to communicate key SSA information.

Labels for each SSA (Areas 1, 2, and 3) cross-reference the pilot to additional information (see 

Appendix, Page 54). 

Research involving actual pilots should ultimately determine the selection of details to be 

incorporated on such maps. Among the potential details that a map of a SSA should include are 

the following (see example in Figure 6): 

 Ground references such as those found on a sectional chart. In addition to airports and bodies 

of water shown in most existing SSA maps, this should include cities and towns, major roads, 

rail lines, power lines, bridges, and other landmarks. In addition to the coastline, Figure 6 

depicts and labels four cities and three major highways, along with an unlabeled rail line. 

Such ground references allows the pilot to visualize the SSA boundary in the view out the 

aircraft window, so she or he can use pilotage to avoid the SSA. Like FAA maps, AOPA 

maps (which appear to be using Jeppesen products) are short on such surface details. 
20

 All fixes useful for locating the SSA boundaries. This includes, but is generally not limited to, 

the navigation aid referenced in the NOTAM to locate the center of the SSA. Including 

multiple fixes helps the pilot plan the use of electronic navigation to avoid the SSA (e.g., by 

flying a particular radial, or heading to a fix stored in the aircraft’s GPS database). Figure 6 

depicts VHF omnidirectional ranges (VORs) and non-directional beacons (NDBs), along with 

reporting points using nearly standard symbols. Most DUATS and some AeroPlanner maps at 

least show navigation aids, but only AOPA shows additional fixes that may be useful to 

pilots. 

 Other airspace, especially Class B and C, and certain SUAs, along with any Mode C veil. 

Figure 6, for example, shows the Class C airspace around the three major airports in the 

center of the map, along with the US ADIZ along the south edge (numerous SUAs are not 

shown). Pilots are already used to avoiding such airspace. Being able to reference the SSA to 

such airspace allows the pilot to better understand its boundaries and may guide a strategy to 

avoid the airspace (e.g., stay out of the Mode C veil, which encompasses the entire SSA). 

Many GPS moving map displays display this airspace, allowing the pilot to monitor his or her 

position to the SSA while in flight. Showing Class E airspace boundaries, in contrast, will not 

provide this function and should be suppressed to minimize clutter. 

 Latitude and longitude graticule. Figure 6, for example, shows latitude and longitude in 20-

minute increments. In addition to providing general cartographic orientation and sense of 

scale, a graticule allows pilots with GPS hardware to create waypoints to navigate around the 

SSA. 

 State and national borders. Figure 6, for example, depicts the Florida-Alabama border. Like 

coastlines, this provides a general orientation and a sense of scale. 

It is probably better to not show terrain, as can happen when raster scanned maps are used, 

especially if the terrain altitude is color-coded as done on sectionals. This will tend to add 

excessive clutter and reduce the contrast of other map elements (especially when printed on a 

black and white printer), while providing little benefit. Stylized representations of significant 

terrain features (e.g., significant mountains and ridges as done on some approach charts) may be 

considered as these may help the pilot understand the boundaries of the SSA. 

In addition to surface references, the map should display the ceiling of each SSA shown, perhaps 

in the same manner as used for Class D airspace on sectionals. Figure 6 provides an alternative 

means to show this information that avoids the clutter that is often found at the center of a SSA 

(which are typically over urban and airport areas). Effective times of the SSA’s activation should 

also be indicated (as shown in Figure 6) so that the map provides the temporal as well as 

geographic boundaries of the SSA activation. Text or symbology should be used to distinguish 

the general level of control of the SSA. In Figure 6, for example, symbology based on that for 

charting Restricted Areas is used for the two smaller Control Level 1 SSAs in 5/1953, while 

symbology based on that for the ADIZ is used for the larger Control Level 2 SSA. In other words, 

all the key information from the NOTAM should be represented in the map. The map may even 

include a text caption summarizing the airspace with sufficient detail to allow it to be precisely 

drawn (i.e., radius and center position). A reference or hypertext link should exist between the 

map and the associated NOTAM or other SSA text representation, perhaps between map and the 

correct location in the preflight briefing. 

4.2.3. Improved Map Readability and Understandability 

Related to optimizing the map details is maximizing map readability and understandability. As 

discussed above, excessive information can clutter a map. However, even with a fixed amount of 
21

information to place on a map, the choice of scale and symbology impacts the capacity of the 

pilot to read and correctly understand the information on the map. SSA maps from AOPA ’s web 

site, for example, eschew the use of raster scanned sectionals to provide a less cluttered map. 

However, the map size and scale selected nonetheless tends to make the map difficult to read. 

A map scale of miles (bottom right of Figure 6) is often lacking on current SSA maps but is 

important for judging the size of the SSA and choosing references for navigating around the SSA 

(i.e., ones that are not too close to the boundary). Dynamically scaled maps, such as those shown 

on the computer screen should always show a scale of miles. Map orientation should always be 

with true north at the top to allow easier cross-referencing with charts. The FAA maps sometimes 

have direction of north at less than perfectly vertical (true north is approximately 6 degrees 

counterclockwise from vertical in Figure 2). 

It may be necessary to adjust map characteristics for the medium of display. For display on a 

computer monitor display, map images must be created with the consideration that computer 

monitors have substantially smaller sizes and lower resolutions (dots per inch) than a printed 

sectional. Very large scaling is necessary to read a scanned aeronautical chart, making it difficult 

to appraise the overall boundaries of the SSA. Electronic maps can be more effective through 

application of different font size, symbol representation, and color usage from printed maps, 

while still remaining generally consistent aeronautical charting conventions (e.g., Society of 

Automotive Engineers, 1997; International Civil Aviation Organization, 2001; Radio Technical 

Commission for Aeronautics (RTCA), 2003). Private organizations currently display electronic 

SSA maps only at a small “lowest common denominator” size, generally less than 640x380 

pixels, but most users have larger monitors than can ease the resolution problem. Thus, in 

addition to allowing the user to select the scale of such dynamic maps, the user should be able to 

set the map size to make best use of his or her display’s capability. 

The same map image used for display on the monitor may not be adequate for a printout. Most 

printers can print at resolution approaching a sectional, and printing a low-resolution map for 

monitors will fail to capitalize on this. With their higher resolution, printed maps can be made 

easier to read and more faithful to charting conventions for symbol shape. However, unlike for 

monitors, it cannot be assumed that the user has access to a color printer. Printed maps should 

work well in black and white, and color should not be the sole source of coding information. 

Printouts of the map are best printed at one of the standard scales used by aeronautical charts 

(e.g.,1:500,000, 1:250,000), making it easy for pilots to cross reference the map to official charts. 

Ultimately, it may be advantageous to supply two sources of maps, as done by AeroPlanner, 

dynamic maps for screen display and fixed-scale documents (e.g., as PDF (Portable Document 

Format) files) for printing. 

4.2.4. Standardize and Improve Text Descriptions 

While a map of the SSA is the best way to communicate the location and boundaries of the SSA, 

benefits can also be had by improving the text descriptions of the boundaries as provided in the 

NOTAM for the SSA. As discussed in Section 4.1.2, breaking up the SSA NOTAM and 

reformatting it will make it easier for pilots to recognize the relevance of a NOTAM when 

scanning through a preflight briefing report. Such restructuring can also make the NOTAM easier 

to understand once it is identified as relevant by representing the configuration of the SSA in the 

use of emphasis and the geometric arrangement of the information. This also makes it easier to 

pick out the boundary information at a glance when the pilot references the NOTAM. The 

arrangement of information should be such that the pilot can quickly draw the SSA on a chart, or 

enter it into a GPS moving map system. It should be recognized that the reading conditions may 
22

be substantially suboptimal (e.g., done while in flight with poor lighting, turbulence, and other 

tasks competing for attention). 

The FAA could help this process by considering standardizing and simplifying the shapes of 

transitory SSAs, so that a standard format of boundary information can be adhered to. Because 

recurrent and static SSAs should be charted as recommended in Sections 4.1.4 and 4.2.1 

(preferably before the SSA becomes active), these SSAs may have a more irregular shape that 

better balances airspace access and security concerns. Transitory SSAs, being by definition shortlived can afford less optimized boundaries for the sake of easier understanding by pilots, although 

exceptions from a standard shape must also be allowed for. For example, the US cannot legally 

impose a SSA over foreign airspace. A SSA centered on a point near the Mexican or Canadian 

border will need a “cutout.” The most convenient shape for pilots may be a circle of a given 

radius centered on a specified point, which describes most transitory SSAs currently imposed, but 

not necessarily all (Burnside, 2004). If a circular SSA happens to be centered on a distance 

measure equipment (DME) facility, a pilot can use the DME to keep clear of the SSA. For a more 

arbitrary point, many GPS systems will provide pilots with a continuous in-flight readout of the 

distance to a pilot-entered point. 

As stated earlier, the ultimate format of a NOTAM should be determined through systematic 

study with actual pilot populations. However, one approach to structuring SSA text information 

for pilots is illustrated in Figure 7. This can be compared with the approaches taken by private 

organizations such as DUATS and AOPA. 

As shown in Figure 7, each SSA activation within the NOTAM is presented tabularly as a 

separate column, arranged chronologically from left to right. Reference numbers for each SSA 

are provided in the top row to match the text to a mapped depiction of the SSAs (as in Figure 6; 

see Page 54 in the appendix for a consolidated mockup), which, for a hypertext medium, may be 

linked (represented by underlining in Figure 7). A Restrictions field includes a number that would 

refer the pilot (possibly by linking) to the basic rules for operating within the SSA. As is done in 

current NOTAMs, the position of each SSA is given both as latitude and longitude and as a 

position relative to a proximal navigation fix in order to maximize the ease and accuracy of 

manual entry of the position into various vendors’ GPS units. 

Additional characteristics of the NOTAM text can also improve a pilot’s ability to avoid 

accidentally crossing the boundaries of a SSA. The position of a SSA should always be given 

relative to a major navigation fix identifiable on nearly all charts, (e.g., using a radial and distance 

to indicate the center of a circular SSA). It should never be a location that cannot be relied on to 

be on charts or in a GPS database (e.g., the actual building or place the SSA is intended to 

protect). 

The SSA’s ceiling should always be provided as altitude above mean sea level (MSL), since even 

aircraft with minimal instrumentation will feature a barometric altimeter. Currently some SSA 

ceilings are specified in MSL, while others in height above ground, the latter which may lead to 

confusion as well as difficulty translating it into usable dimension (most single-engine piston 

aircraft do not have a radar altimeter). 

“Legalese” language and other text that is not relevant to understanding the functional impact of 

the NOTAM should be eliminated or de-emphasized. Referencing the federal regulation that 

justifies the imposition of the SSA (as in Figure 1) does not help a pilot understand it. 
23

Map Reference Area 1 Area 2 Area 3 Area 2

Restrictions 2 1

Location Lat 

Long 

30 28 24 N 

087 11 15 W 

30 21 10 N 

087 19 01W 

30 28 24 N 

087 11 15 W 

30 21 10 N 

087 19 01W 

 Fix CEW 228 033.7 BFM 108 041.3 CEW 228 033.7 BFM 108 041.3 

Radius 30 nm* 10 nm 

Ceiling MSL FL 180 

Time Zulu 05 03 18 1350 

05 03 18 1805 

05 03 18 1350 

05 03 18 1455 

05 03 18 1415 

05 03 18 1640 

05 03 18 1600 

05 03 18 1805 

 Local 0750 03/18/05 

1205 03/18/05 

0750 03/18/05 

0855 03/18/05 

0815 03/18/05 

1040 03/18/05 

1000 03/18/05 

1205 03/18/05 

Duration 4:15 hrs 1:05 hrs 2:25 hrs 2:05 hrs 

Public Airports within 1J9 

2R4 

5R4 

82J 

83J 

JKA 

NPA 

NSE 

PNS 

82J 

83J 

NPA 

82J 

83J 

NPA 

PNS 

82J 

83J 

NPA 

*Excluding airspace overlapping with Areas 2 and 3 during their respective active times. 

Figure 7. Mockup of SSA text boundary information in a tabular format for 5/1953 for better 

reference and readability (compare to Figure 1). 

IMAPS’s AeroPlanner and the AOPA web site for SSAs include with each NOTAM an 

alphabetized list all airports affected by the NOTAM, although not all specify which SSA affects 

each airport for NOTAMs that declare multiple SSAs (as done in Figure 7). In any case, such a 

list is useful to pilots. While airports are shown on the map depictions of SSAs, pilots looking for 

the impact on a specific airport can more quickly find this information in this tabular format. 

However the NOTAM text is formatted, electronic text representations should be suited for 

printing. Currently for some printers, the right margin gets cropped on the NOTAMs given on the 

FAA’s web site, and the tabular “highlights” summary on the DUATS web site. 

4.2.5. Additional Measures to Improve Boundary Understanding 

The above changes will help pilots who gather preflight briefing information from electronic 

sources. However, pilots may also use FSS for a briefing, where essentially visual information 

(the position and shape of a SSA) is once again transmitted verbally. FSS briefer should have the 

ability to easily fax or email SSA information (e.g., directly from the briefer's computer 

workstation), especially the map depiction, to pilots on request to aid pilots in understanding the 

controllers’ recommendations and possibly to prompt pilots on questions to ask. This actually 

would be a valuable capability for any NOTAM, cutting down the potential for transcription 

errors. 

Vendors of GPS navigate system software can build on the existing capability to allow pilotdefined fixes, as discussed earlier, and develop a feature that helps alert pilots of an approaching 
24

transitory SSA. After the pilot enters a fix and distance (and possibly a time interval as well), the 

GPS will alert the pilot with visual and/or auditory singal if the aircraft comes close to the given 

distance from the fix. It can even cue the pilot on which turn would best avoid the airspace. A 

more advanced variation of this feature is discussed in Section 5. It may be desirable for a 

government research agency to prototype such a feature in order to spur industry to develop and 

market it. 

The recommendations given in 4.2.4 focused on maximizing the readability of SSA information 

by humans. The FAA can ultimately reduce the number of violations of SSAs by also providing a 

version of SSA information that is easily readable by machines. This is a separate source of 

electronically distributed SSA activation information from NOTAMs, and is far beyond including 

keywords, as detailed as a stopgap measure in Section 4.1.1. Rather, this is a source of 

information intended solely for mechanized digital processing by electronic briefing services and 

vendors of GPS databases (although the direct use by properly equipped private individuals is 

also a definite possibility). Developing such a standardized format requires research by 

government, perhaps aided by industry standards organizations, to ensure the resulting format is 

usable by current and future vendors of such services and products. 

In distributing SSA information in an appropriate standardized machine-readable file format, 

requesting agencies can automatically plot any SSA on electronic and dynamically generated 

maps. GPS database vendors can alert their customers of updates that include new SSAs, 

allowing them to download the update to their cockpit GPS systems. With this feature, even 

transitory SSAs can be displayed on a moving map display, and an automated alert system can 

notify pilots if they are approaching a SSA. Ideally, the transfer of SSA information should be 

fast and compatible with automated downloading and processing in order to maximize the chance 

of information reaching pilots in a timely matter. 

4.3. Improving Pilot Understanding of SSA Procedures 

For the DC ADIZ, a Control Level 2 SSA, failure to understand the procedures for allowed 

penetration of the SSA is the second most common cause of violations, accounting for a 

substantial number of all SSA violations (see Table 1). Over the course of a year and half after 

the DC ADIZ was imposed, pilots continued to misunderstand these procedures, accounting for 

about 15% of all SSA violations in the entire country (Zuschlag, 2005). With time, such errors 

should diminish as the local pilots become fully educated on the ADIZ. However, Control Level 

2 SSAs of similar size as the DC ADIZ are being imposed throughout the country, usually as part 

of a presidential TFR. One can also imagine transitory or recurrent Control Level 2 SSAs being 

imposed in various places in response to changes in the terrorism threat level, as happened for 

New York City during the invasion of Iraq in March, 2003. In either case, pilots in these regions, 

often near major metropolitan areas, are unacquainted with the procedures, and, barring 

intervention, can be expected to make the same errors observed in the early months after the DC 

ADIZ was imposed. For the four weeks that the New York Control Level 2 SSA was active, the 

frequency of violations was comparable to that for the DC ADIZ during the same period (the DC 

ADIZ had been imposed a mere two months earlier), suggesting the experience of the DC ADIZ 

is typical for any new Control Level 2 SSA (Zuschlag, 2005). 

4.3.1. Standardize and Improve Descriptions of Restrictions 

Just as with the descriptions of the boundaries of SSAs, the descriptions of the entry requirements 

can also benefit from replacing the current stream of text with a standard formatting, arranging 

the information in fields, and using varying emphasis to communicate the structure of the 
25

restrictions. One possible approach is shown in Figure 8. Indenting and spacing are used to 

organize information, with headings and key information in bold print to catch the eye of a 

scanning pilot. As with the table in Figure 7, cross-references are provided to a mapped depiction 

of the SSAs (see Appendix, Page 54), which may be hyperlinked (represented by underlining in 

Figure 8). 

Restrictions 1 (see map reference Areas 2 and 3)

Prohibited: All aircraft operations.

Exceptions: 

Law enforcement and military aircraft directly supporting the United States Secret Service (USSS) 

and the Office of the President of the United States, 

Emergency medical flights in which the flight operations company coordinates operations in 

advance with the USSS at 850-444-5646 in order to avoid potential delays. 

Regularly scheduled commercial passenger and all-cargo carriers arriving into and/or departing 

from 14 CFR Part 139 airports and operating under any of the following: 

Aircraft Operator Standard Security Program (AOSSP), 

Domestic Security Integration Program (DSIP), 

Twelve Five Standard Security Program (TFSSP), 

All-Cargo International Security Procedure (ACISP) 

Restrictions 2 (see map reference Area 1)

Requirements: All aircraft shall 

Be on an active IFR or VFR flight plan. 

Squawk an ATC-assigned discrete transponder code prior to departure and at all times in the TFR. 

Remain in two-way radio communications with ATC. 

Exceptions: 

Emergency medical flights in which the flight operations company coordinates operations in 

advance with the USSS at 850-444-5646 in order to avoid potential delays. 

Prohibited: 

Loitering. 

Flight training. 

Practice instrument approaches. 

Aerobatic flight. 

Glider operations. 

Parachute operations. 

Ultralight flight. 

Hang gliding. 

Ballooning. 

Agriculture/crop dusting. 

Animal population control flight operations. 

Banner towing. 

Additional Information: All USSS cleared aircraft operators based in the area should notify the USSS at 850-

444-5646 prior to their departure. 

Notes 

It is recommended that all aircraft operators check NOTAMs frequently for possible required changes to this TFR prior to 

operations within this region. 

These flight restrictions are pursuant to title 14, section 91.141, of the Code of Federal Regulations (CFR). 

Figure 8. Mockup of restrictions information for 5/1953, formatted for better reference and 

readability (compare to Figure 1). 

4.3.2. Standardize and Simplify the SSA Procedures 

There are interventions that may decrease the number of violations due to not understanding SSA 

procedures, even procedures for transitory Control Level 2 SSAs. Among these is simplifying and 

standardizing the procedure for Control Level 2 penetration. Currently the procedure can vary 
26

even within a single SSA. For example, the procedure for getting a transponder code and 

clearance into the DC ADIZ varies by the airport of departure (see Table 4). 

Table 4. Variations in Control Level 2 departure procedures for airports in the Washington 

DC ADIZ and FRZ (AOPA, 2004b). 

Airport 

Abbreviation 

Phone Number to 

File Flight Plan 

Contact for 

Transponder Code 

Phone Number/ 

Frequency 

Airborne 

Frequency 

00B 800-WX-BRIEF Potomac TRACON24 866-429-5882 119.7 

0V5 800-WX-BRIEF Potomac TRACON2 866-709-4993 124.65 

2W5 800-WX-BRIEF Potomac TRACON2 866-599-3874 119.85 

ANP 800-WX-BRIEF Potomac TRACON2 866-429-5882 119.7 

BWI 800-WX-BRIEF Clearance Delivery 118.05 126.753

CGS1 866-225-7410 Potomac TRACON 866-599-3874 119.85 

FME 800-WX-BRIEF Potomac TRACON2 866-429-5882 119.7 

GAI 800-WX-BRIEF Clearance Delivery 121.60 128.7 

HEF 800-WX-BRIEF Clearance Delivery 120.20 124.65 

IAD 800-WX-BRIEF Clearance Delivery 135.70 126.65, 125.053

JYO 800-WX-BRIEF Clearance Delivery 118.55 126.1 

VKX1 866-225-7410 Potomac TRACON 866-599-3874 125.65 

W00 800-WX-BRIEF Potomac TRACON2 866-599-3874 119.3 

W18 800-WX-BRIEF Potomac TRACON2 866-429-5882 126.75 

W321 866-225-7410 Potomac TRACON 866-599-3874 125.65 

W48 800-WX-BRIEF Potomac TRACON2 866-429-5882 119.0 

W50 800-WX-BRIEF Potomac TRACON2 866-429-5882 128.7 

1

Located in the FRZ, pilots conducting flight operations must also be vetted. 2

Apparently, it is also sometimes possible to get the transponder code from 800-WX-BRIEF. 3

Or frequency assigned by clearance delivery. 

4

Terminal Radar Approach Control

Instead, there should be standard, specific, continuously available, nation-wide communication 

channels that support the entire Control Level 2 procedure: filing a flight plan, activating it, and 

receiving a transponder code and clearance. The principal is that pilots operating in or near static 

or recurrent Control Level 2 or 2a SSAs will get into the habit of using the same channel for all 

flights without concern for the airport of origin. Details specific to that airport (e.g., whether to 

follow Control Level 2 or 2a rules) can be handled in the course of the communication. 

For this to benefit transitory Control Level 2 SSAs, the access point should be a contact 

commonly used by pilots in the ordinary course of preparing for flights. One candidate is the tollfree number for briefings by FSS controllers (currently, 1-800-WX-BRIEF). The FSS controllers 

contacted through this number, in addition to briefing the pilot (including on the existence of the 

SSA) and taking the pilot’s flight plan as normal, can connect the pilot with the appropriate ATC 

facility for the pilot to receive his or her clearance, approach control frequency, and transponder 

code. By standardizing the process for all airports and SSAs, training of FSS controllers is 

simplified and the chance of error is reduced. NOTAMs for a transitory SSA can explicitly 
27

instruct pilots to call FSS before takeoff in order to comply with the Control Level 2 

requirements. Working through FSS can work for towered airports too, provided that standard 

language is used to emphasize that a clearance into a SSA does not constitute clearance to depart 

the airport or to enter other controlled airspace (e.g., Class D). 

In a more technically advanced system, the FSS controller can deliver the clearance and code 

directly to the pilot by communicating electronically with the ATC facility. Electronic flight plan 

activation with clearance delivery is discussed in greater detail in Section 5.4.3, but the capacity 

for it within the FAA and with selected other agencies opens additional candidates for singlecontact compliance with Control Level 2 requirements. The radio frequencies for FSSs can be 

used, so a single radio call from an airborne pilot approaching a SSA could yield a filed and 

activated flight plan, and the code and clearance for entry into the SSA. 

Another contact point that would benefit from electronic flight plan activation with clearance 

delivery would be electronic briefing services such as DUATS and DUAT. Having entered a 

flight plan previously or in the same session, a pilot can activate it and receive clearance and 

code. Electronic flight plan filing can already be done through DUATS and DUAT, but only for 

flights that do not enter Control Level 2 SSAs.. 

Barring electronic flight plan activation, the FSS controller contacted from the air should at least 

be able to hand off the pilot to ATC for clearance and code. NOTAMs for transitory SSA should 

include the ATC frequencies that may be used. 

4.3.3. Standardize SSA Control Levels 

SSA control levels have been gravitating to the levels given in Table 2. Confusion about the 

procedures for these control levels can be reduced by formalizing, standardizing, naming, and 

documenting the control levels. To minimize the training, memory burden, and confusion, the 

number of standard control levels should be kept to a bare minimum. Four is likely to be an 

acceptable number of levels. 

Once standardized, pilots can be taught about the required procedures as part of normal flight 

training. Reference manuals such as the Aeronautical Information Manual (AIM) (FAA, 2004d) 

can provide details in the event the exact procedures are forgotten. When a transitory SSA is 

imposed, pilots will at most need only a quick brush up. Standardization also simplifies training 

and minimizes the chance of error for ATC and FSS personnel. 

Procedures for each control level should be sufficiently standard and clear such that if a NOTAM 

states that a “Control Level 2 TFR” has been imposed, or that a static SSA is being temporarily 

upgraded from “Control Level 3” to “Control Level 1,” pilots can know or easily find out what is 

required without further reference to the NOTAM. With such standardization, the full formatted 

description of the requirements, as shown in Figure 8, will not need to be included with every 

NOTAM, reducing the information clutter a pilot must sift through when reviewing a preflight 

briefing report. The NOTAM can be limited to just information specific to a particular SSA, such 

as its boundaries in the case of a transitory SSA. With such terminology defined, the 

Airport/Facility Directory can note the control level for each airport in a static or recurrent SSA. 

For charts and maps associated with SSAs, each standard control level should have 

distinguishable symbology so that pilots looking at the chart or map can immediately recognize 

the required procedures. 

While standardization should be maximized as much as feasible, allowance should be provided 

for additional requirements or licenses for a given transitory SSA activation for very exceptional 

circumstances in response to a specific threat or vulnerability. Such exceptions should be 
28

prominently indicated in the associated NOTAMs, using formatting techniques discussed in 

Sections 4.1.2 and 4.2.4, and shown in Figure 8. 

Standardization and formalization of the control levels will be of particular benefit to Control 

Level 2 and 2a SSAs. Control Level 2 SSAs vary in their requirements, with transitory SSAs, 

such as those for presidential TFRs, tending to restrict more operations than static SSAs, such as 

the DC ADIZ (e.g., compare FAA 2003a with 2005b). The Control Level 2a SSAs within the DC 

ADIZ, meanwhile, are relatively vaguely and inconsistently defined. Sometimes both airport 

arrival and departure is allowed under standard codes, and sometimes only departure (see Table 

5). The allowed regions or paths are ill-defined for many airports, and there have been violations 

due to misunderstandings of the text descriptions provided in the NOTAMs (Zuschlag, 2005). 

As feasible for each SSA’s degree of stability, these regions should be specifically defined and 

placed on the maps provided with the associated NOTAMs, and on sectionals and other 

navigation maps, as well as in GPS displays. For static and recurrent SSAs, the standard 

transponder codes should be printed in the chart margins and be available in the AFD notes for 

the airport. 

Table 5. Variations in Control Level 2a procedures for airports within the DC ADIZ (AOPA 

2004b, 2004c). Note that only two airports allow arrivals under standard transponder codes. For 

the others, arrivals follow Control Level 2 procedures. 

Airport 

Abbreviation 

Departure 

Code 

Arrival 

Code 

Airborne Frequency1

1W5 1205 None Potomac TRACON 128.7 

2VG2 1205 None Potomac TRACON 124.65 

3VA1 1205 None Potomac TRACON 124.65 

3W3 1233 1233 Common Traffic Advisory Frequency 122.7 

4MD9 1205 None Potomac TRACON 126.75 

7MD9 1205 None Potomac TRACON 119.7 

AVA9 1205 None Potomac TRACON 124.65 

MD48 1205 None Potomac TRACON 119.0 

MD64 1205 None Potomac TRACON 119.7 

MD90 1205 None Potomac TRACON 119.7 

MD92 1205 None Potomac TRACON 119.0 

MTN 1205 None Potomac TRACON 119.0 

VA97 1205 None Potomac TRACON 124.65 

W29 1227 1227 Common Traffic Advisory Frequency 123.0 

1

Pilots are required to monitor the respective frequency, but do not have to contact with ATC. 

4.3.4. Education and Training 

Standardization of procedures and control levels will eventually reduce the frequency of SSA 

violations due to procedure misunderstanding, but until then pilots still must climb a learning 

curve regarding these new kinds of airspace. In the mean time, errors can be somewhat reduced 

by introducing new standard language for FSS and ATC controllers to emphasize the peculiar 
29

aspects about SSAs. For example, FSS briefers can remind pilots to “squawk discrete code before 

takeoff,” since a common error is for pilots to attempt to get a clearance and transponder code 

immediately after takeoff into a Control Level 2 SSA, this being a common practice in other 

analogous situations (Zuschlag, 2005). 

Another common error is setting the transponder to the standard VFR code (1200) when ATC 

services, such as IFR flight, are terminated within a Control Level 2 SSA. Again, this standard 

practice for flight outside a SSA, and pilots may find themselves doing this unthinkingly once 

ATC announces its services have ended. By changing the standard language for ending services 

in a SSA (e.g., “Maintain squawk <code>. Radar services now terminated.”), ATC can cue the 

pilot to follow the proper procedure, and prevent pilots from thinking or assuming they heard 

instructions to “squawk VFR.” 

The FAA can also continue its educational outreach to pilots in the interim before training on the 

standardized control levels becomes a normal part of ground school. The widespread application 

of SSAs over the past three years represent a substantial change in the airspace and warrants an 

aggressive educational campaign, probably on a scale similar to what has been done for runway 

incursions (FAA, 2002d) or the conversion of Terminal Control Areas (TCAs) to Class B 

airspace in 1992. Such an outreach may also be necessary for any future SSA that does not follow 

“standard” levels of control (e.g., a SSA that uses the gateway airport model of control described 

in Section 2.1). Possible avenues of outreach include: 

 Safety seminars normally held by the local Flight Standards District Office. 

 Biannual recurrent VFR ground instruction. 

 Incorporation in the educational materials shipped to flight instructors. 

 The FAASafety.gov electronic newsletter. 

Perhaps an annual educational push can be conducted each February, since there is some reason 

to believe that the frequency of SSA violations is especially high in March and April, as flying 

activity increases with the coming of spring (Zuschlag, 2005). 

5. The Long Term: ISARC 

With a long-term view, new technologies can be developed to attain a more dramatic reduction in 

the frequency of accidental violations of SSAs than can be achieved by just changing the content 

and form of SSA information. Such short-term changes to content and form are expected to 

reduce violations, but the present technical system would still require pilots to search effectively 

for the information prior to flight and to accurately recall and use the information once 

approaching an SSA. This will have an inherently limited impact. In pursuing long term 

technological interventions, it becomes possible to conceive of a system that "pushes" SSA 

information to the pilot with nominal initiation on his or her part. Furthermore, this information 

can be presented to the pilot not just during flight planning, but while airborne, including shortly 

before a potential violation. With the information presented temporally proximal to the potential 

violation, recall failures and errors are minimized. The system can select when, where, and how 

to present such information based on selected contextual information (e.g., aircraft location) from 

sources that are likely to be more accurate than those provided by the pilot. Finally, the system 

can automate various processes, or at least offer recommended actions for the pilot to approve, 

reducing the probability of pilot error in manually carrying out the procedures required by an 

SSA. 
30

Specifically, one can envision the future implementation of an Integrated System for Airspace 

Requirements Compliance (ISARC), a set of digital device features that supports the following 

root functions to be available to the pilot both while on the ground and while airborne: 

 Presentation of up-to-date information on any SSA of any degree of stability, including the 

display of the SSA on an electronic moving map. 

 Fully mechanized filing and activation of SSA flight plans and reception of SSA clearances 

and transponder codes. 

 Alerting of the potential for a SSA violation. 

For system to provide such functions in the air, it will almost certainly require that new devices 

be aboard aircraft. Given that an effective intervention requires that these devices be aboard the 

vast majority of all low-end general aviation aircraft (as well as other aircraft), such devices must 

be compatible with all principles given in Section 3, including low cost. For a more long term 

intervention, the need to follow these principles is likely to be even more important since future 

airspace is expected to include large numbers of light sport aircraft (AvWeb 2004; FAA, 2004g), 

pilots of which should have and use devices that include ISARC. Details for conforming to these 

principles are discussed further in Section 5.6. 

5.1. Functional Requirements 

The following sections detail the requirements for each root function of ISARC. Unless otherwise 

stated, all requirements apply both when the aircraft is airborne and when on the ground. 

5.1.1. SSA Presentation 

ISARC is capable of providing up-to-date information on any SSA. The information available to 

the pilot includes the SSA’s activation time, control level or compliance procedure, ceiling, 

special (e.g., SSA-specific) requirements, and other information relevant to complying with the 

SSA. Changes in a SSA's attributes, including its activation, are provided in real time from when 

the changes come into effect or earlier. This includes the establishment and activation of 

transitory SSAs. 

ISARC is capable of displaying the SSA information in several formats to best support the pilot's 

task of complying with the SSA. This includes a strategic map display of the SSA, showing its 

position and boundaries for a pilot-selected map view, and a tactical map display, showing the 

SSA relative to the aircraft's current position with an appropriate frequency of position updates 

(e.g., RTCA, 2003). Both map display types are capable of showing the SSA relative to other 

aeronautical objects as described in Section 4.2.2. The control level of the SSA is symbolically 

differentiated on the map displays. 

ISARC is also capable of displaying the SSA information as text, with the format and layout 

designed to maximize understandability and compliance (see Sections 4.2.4 and 4.3.1). 

5.1.2. Mechanized Filing and Activation of SSA Flight Plans 

ISARC is capable of receiving or retrieving a pilot-entered flight plan. The flight plan may be 

retrieved from a separate device or component, or a flight planning capability may incorporated 

with ISARC into a single device to allow the creating, updating, and deleting flight plans. ISARC 

is then capable of formally filing the retrieved flight plan by electronically sending it to a ground-
31

based FSS or ATC authority as appropriate. ISARC is capable of both initiating and updating a 

flight plan in this manner. Included with the flight plan is the following information: 

 Flight plan type: IFR, VFR, or VFR for SSA penetration (i.e., defense-VFR). 

 Aircraft identity and description. 

 Pilot identity and contact information. 

 Aircraft capabilities, as appropriate (e.g., if aircraft is equipped with digital radio). 

 Other information necessary to file a flight plan (e.g., occupant information). 

ISARC is capable of sending a request for clearance into a SSA and receiving clearance 

authorization in return. As the aircraft approaches entry into a SSA, this request may be 

transmitted automatically, or ISARC can prompt the pilot to transmit the request. 

Having received a SSA clearance, ISARC is capable of processing the information included with 

the clearance for use by the pilot and the ISARC alerting function. This information includes the 

transponder code and the necessary communication radio frequency for SSA penetration. As a 

minimum, ISARC is capable of displaying the code and radio frequency to the pilot (e.g., as a 

notice or as an item on an electronic checklist). Optionally, ISARC interfaces with the 

transponder and/or radios, setting the transponder code automatically, and tuning the standby 

radio to the appropriate frequency. ISARC is capable of verifying that the code transmitted by the 

transponder corresponds to the code received with the clearance. 

ISARC is capable of displaying the status of the clearance for a SSA, indicating if the pilot is 

cleared to enter the SSA or not. The pilot is able to determine from the device the reason for a 

lack of clearance (e.g., no filed flight plan, no activated flight plan, or ATC-rejected flight plan). 

ISARC is also capable of indicating if the flight plan has been closed or canceled and if the 

transponder code is no longer valid or required (e.g., due to the aircraft exiting the corresponding 

SSA under VFR). 

ISARC supports the electronic closing and canceling of flight plans. The pilot is able to manually 

close and cancel a flight plan filed with ATC with real time effect. ISARC is capable of 

automatically closing a flight plan on determination that the flight has been completed (e.g., 

aircraft arrives on the ground at the destination or alternative airport as entered in the flight plan). 

ISARC does not close the flight plan if there are indications of a mishap (e.g., sharp drop in 

ground speed to zero). ISARC notifies the pilot if it does not close a flight plan for this reason. 

Optionally, ISARC can take measures to alert the authorities in the event of such a mishap. 

The ISARC capacity to process flight plans includes conveniently supporting flight plans 

involving pattern work at an airport, being able to file, activate, monitor, and possibly close such 

plans. ISARC is designed such that it is not necessary to file and activate a new flight plan with 

every takeoff when using a flight plan involving pattern work. 

5.1.3. Alerting of Potential for SSA Violation 

ISARC is capable of alerting the pilot if there are indications of the potential for a violation of a 

SSA. An ISARC alert is presented at a level of attention-getting that corresponds to the urgency 

of pilot action to avoid a violation. At the lowest level of alert, potential for violation is on the 

order of hours away. At the highest level, pilots must respond in less than a minute to avoid a 

violation. The alert level may vary from the display of a small symbol or annunciator to a 

prominent alert message and aural, possibly speech, alarm. 
32

ISARC is capable of providing the appropriate level of alert for all the conditions given in Table 

6. High level alerts include an indication of the imminence of the violation and perhaps offer a 

course of action to avoid a violation (Stock, 2004). For example, as the aircraft is approaching a 

SSA, an alerting message on the display may give a countdown of tenths of nautical miles until 

anticipated penetration. If the SSA is at Control Level 2, and a valid unfiled flight plan is 

available to the device, ISARC can offer to file and activate it. If the SSA is at Control Level 1, 

ISARC may offer an alternative course that will best avoid penetration, possibly allowing for 

other considerations (e.g., terrain). 

ISARC is capable of determining if the aircraft is on the ground and not positioned for departure 

and thereby suppresses alerts. Alerts are triggered under the conditions in Table 6 on indication 

that the aircraft is preparing for takeoff at an airport in a SSA (e.g., positioned between ends of a 

runway and oriented on the runway's heading). 

Table 6. ISARC alert conditions and levels. 

Condition Alert Level 

An entered flight plan conflicts or is especially 

close to a SSA. 

Medium for Control Level 1. Low for Control 

Level 2, 2a, or 3. 

A new active SSA relevant to the flight plan or 

current general location has been imposed since 

the pilot filed the flight plan. 

Medium for Control Level 1 2, or 2a. Low for 

Control Level 3 

Current track and altitude or vertical speed will 

imminently bring the aircraft into a SSA. 

High for Control Level 1. High for 2 if no flight 

plan is activated. Low for Control Level 3. 

Current speed, flight plan and/or track will cause 

the aircraft to become trapped in a SSA that is 

about to activate. 

High for Control Level 1. High for 2 if no flight 

plan is activated. Low for Control Level 3. 

Transponder is not squawking the appropriate 

code while approaching a Control Level 2 or 2a 

SSA. 

High 

Pilot attempts to change the transponder from 

the appropriate code while in a Control Level 2 or 

2a SSA. 

High. If ISARC can control the transponder, it 

requests pilot confirmation before the 

transponder code is actually changed. 

Pilot attempts to cancel the flight plan while in a 

Control Level 2 SSA.7

High. ISARC requests pilot confirmation 

before actually canceling the flight plan. 

The aircraft is deviating from an activated flight 

plan. 

High when in a Control Level 2 SSA. Medium 

otherwise. 

The aircraft is deviating from an acceptable path 

while in a Control Level 2a SSA. 

High 

5.1.4. Additional Functions 

The following functions are not related to ISARC's three root functions, nor are they intended to 

reduce the frequency of violations of SSAs. They are additional optional features whose value is 

to mitigate the possible repercussions of a violation. Depending on the implementation of the onboard device that incorporates ISARC and its relation to other devices, such functions can be 

supported by leveraging the ISARC components necessary for the root functions. 

 

7

 There is no alert if the pilot attempts to amend the flight plan. 
33

Among these additional functions is an ability for an authorized air traffic controller, law 

enforcement officer, or interceptor pilot to unilaterally extract flight plan information from the 

device incorporating ISARC (whether filed and activated or not), along with the aircraft identity 

and type. Another is a dedicated radio emergency communication channel that allows authorized 

personnel to contact the pilot irrespective of what the aircraft's communications radio is tuned to 

or even if the radio is on. ATC or interceptors may use this channel to contact a pilot who is 

violating a SSA when all normal channels fail. With the ability to extract information and 

establish communication with a violating aircraft, authorities can make a more accurate 

assessment of the risk presented by the aircraft, minimizing the chance of a misunderstanding 

resulting in targeting the aircraft as a high-level threat. 

5.2. Infrastructure Requirements 

ISARC will rely on various routine processes to exchange information between the on board 

device and ground agencies. Ground-to-ground versions of many of these processes already exist, 

but need to be revised to best suit ISARC. Chief among these is a means to transfer the latest SSA 

information to each instance of ISARC. This may involve various organizations in the FAA 

coordinating to distribute the information to the device's vendor for subsequent reformatting and 

distribution to the pilot (much as is now done for the databases for GPS moving map devices). 

Alternatively, the FAA can make the information directly available to the pilot for downloading 

into the device incorporating ISARC. In order to include information on transitory SSAs and 

recurrent SSA activation, this distribution will need to include information that is usually covered 

by NOTAMs. In order to meet the requirement for up-to-date information, the capability must 

exist to transmit such information to a moving aircraft. 

To be maximally effective at meeting its functional requirements and thereby reducing violations 

of SSAs, ISARC (as proposed) depends on an infrastructure that includes the implementation of 

many of the short-term interventions discussed in Section 4. ISARC, in this way, builds on more 

immediate interventions, and such short term intervention retain their value after ISARC has 

reached widespread deployment. Among the key short-term interventions that ISARC needs is 

the replacement of blanket NOTAMs with individual SSAs (Section 4.1.6). ISARC can no better 

than a pilot reliably keep track of all locations and events that may qualify under these NOTAMs. 

Instead, ISARC needs information on specific locations with specific boundaries and time for 

displaying them and alerting the pilot. 

Improving and standardizing the format and language of NOTAMs is equally important for 

deploying ISARC as it is for achieving short term impacts (Sections 4.1.2 and 4.2.4). A pilot 

using ISARC to display information about a SSA would benefit as much from better formatting 

as a pilot retrieving such information from the web. For ISARC, it is especially important for the 

FAA to offer a standardized machine-readable format for SSA information (Section 4.2.5), so that 

ISARC can correctly interpret the requirements of a SSA and alert the pilot accordingly. If 

ISARC has to extract requirements from free-form text NOTAMs, it may make errors in 

determining the requirements, and such errors will lead to pilots distrusting and ultimately not 

using ISARC. In line with this intervention is the standardization of SSAs into a few levels of 

control, each with standard names and symbology (Section 4.3.3). This will allow ISARC to 

present precise and accurate representations of the SSAs, using symbols consistent with paper 

charts. With standardized control levels, ISARC can minimize the number of alert false alarms. 

Electronic flight plan activation with clearance delivery requires a new capability on the ground 

to accept such electronic flight plans, pass them to appropriate personnel in the FAA, and 

transmit back a clearance and transponder code. This represents the most significant new 
34

infrastructure change needed for ISARC to realize its full potential, especially for minimizing 

violations of Control Level 2 SSAs. Electronic flight plan activation is defined as a fully 

automated process for filing and activating a flight plan via electronic links to an FSS/ATC 

system. For flights into a Control Level 2 SSA, the FSS/ATC system automatically reviews it, 

and, on approval, passes the information to the appropriate controller. The system then sends 

back to the pilot an approved clearance, transponder code, and radio frequency to contact ATC 

for when the aircraft enters the SSA. Approval of the flight plan would be based on an 

algorithmic review of the flight plan against any special security requirements of the SSA. In 

general, any reasonable flight plan would be routinely approved. 

Because the air traffic controller is not responsible for ensuring separation for an aircraft 

operating under VFR, such a clearance can be automated because the controller does not have to 

coordinate the aircraft’s entry into the airspace with other traffic. As such, this form of automated 

clearance delivery is limited to flights into SSAs. If the pilot intends to fly IFR or enter Class B 

(major terminal) airspace, an air traffic controller may likely have to become involved, although 

in the future the controller may deliver the clearance through the same electronic channel (Morse, 

2004). This is similar to the current process where clearance into a SSA does not necessarily 

constitute clearance into other airspace imbedded within. 

While electronic flight plan activation and clearance delivery represents a new capability, as 

discussed in Section 4.3.1, it may be valuable for reducing SSA violations even before ISARC is 

deployed. Once electronic flight plan activation is implemented for ground-based electronic 

briefing services, extending it to ISARC becomes a relatively small extension. 

5.3. Performance Requirements 

The requirements for ISARC regarding accuracy, reliability, and integrity are much the same as 

for any avionics (e.g., RTCA, 2003). In particular, it is necessary for ISARC to be sufficiently 

accurate and reliable to meet the FAA's criteria for a sole source of SSA information. In addition, 

like any avionics, a detectable failure of ISARC must not endanger the aircraft before the pilot 

can respond and an undetectable failure of ISARC must not endanger the aircraft in any case. For 

example, an implementation of ISARC must not fail in a manner that it displays hazardously 

misleading information. Furthermore, the operation of ISARC must not compromise the safe 

operation of the aircraft as a whole. For example, an ISARC-generated alert must not be so 

intense that it distracts pilots from more important information in the cockpit. Likewise, the 

workload associated with the correct use of ISARC must not interfere with safety-critical tasks of 

flight. Beyond these requirements, a certain level reliability, accuracy, effectiveness, and ease of 

use are necessary to maximize the probability of pilot acquisition and use of ISARC (see Section 

3). 

5.4. Technological Elements and Development Needs 

There are numerous ways to implement ISARC as defined above. However, a fast and affordable 

implementation can be expected to capitalize on existing and emerging technological elements. 

The fewer elements that need to be developed from scratch, the more rapidly ISARC can become 

available to a large proportion of pilots, and the larger impact it will have on reducing violations 

of SSAs. The elements, their relation to ISARC, and their current development status are 

summarized in Table 7. 
35

Table 7. Existing and new technological elements that may be used to implement ISARC’s 

functional requirements. 

Element Related Features Related Requirements Status 

GPS Moving Map 

Devices 

Platform for ISARC. See Table 8. Deployed 

Electronic Flight 

Bags (EFBs) 

Additional platform 

for ISARC. 

Same as GPS moving map 

devices. 

Prototyped 

Universal Access 

Transceiver (UAT) 

Aircraft-ground 

datalink protocol 

developed for 

general aviation. 

En route updating of SSA 

information. 

Electronic flight plan activation and 

automated reception of SSA 

clearances. 

Field testing 

Flight Information 

Service – Broadcast 

(FIS-B) 

General information 

service for datalink. 

En route updating of SSA 

information. 

Field testing 

Digital Radio Always-available 

emergency 

channels. 

Communication with violating 

aircraft. 

Under 

development

Wide Area 

Augmentation 

System (WAAS) 

Aircraft altitude and 

precise position. 

Suppression of false alerts when 

taxiing. 

Currently 

being 

deployed 

System Wide 

Information 

Management 

(SWIM) 

Infrastructure for 

inter-agency 

information transfer. 

SSA information transmission. 

Electronic flight plan activation and 

automated clearance delivery. 

Under 

development

FAA 

Telecommunications 

Infrastructure (FTI) 

Infrastructure for 

information transfer 

within the FAA. 

SSA information transmission. 

Electronic flight plan activation and 

automated clearance delivery. 

Under 

development

Electronic flight plan 

activation and SSA 

clearance. 

Infrastructure for 

automated flight 

plan processing. 

Electronic flight plan activation and 

automated clearance delivery. 

To be 

proposed 

5.4.1. Current Technologies 

A root requirement of ISARC is the on-board map display if SSAs relative to the aircraft. As 

such, it is functionally closest to existing cockpit GPS navigation and situation awareness moving 

map devices. Marketed at general aviation pilots, these moving map devices generally feature a 

GPS receiver, a database of aeronautical objects, a map generator to create an image of these 

objects in relation to the current position of the aircraft, and a graphic display to show the image. 

Typically, the vendor provides periodic updates for the database that the pilot manually uploads 

through a physical port or data storage device reader. 

Moving map devices provide basic functions related to ISARC. Many of these devices will show 

airspace (e.g., Class B, C, D, etc.) on their moving map displays (Aircraft Electronics Association 

(AEA), 2004). Other products, such as those provided by Weather Services International, already 

provide graphic depiction of TFRs on cockpit displays (AEA, 2004; see also Higdon, 2002). 

Built-in databases of moving map devices allow the pilot to access text information about various 
36

aeronautical objects and procedures. Today’s GPS moving map devices also provide functionality 

closely related to the requirement to support filing and activating of SSA flight plans. Even the 

cheaper versions of these devices allow pilots to create and edit complete flight plans, which may 

be saved and retrieved for later flights. The pilot can not file the flight plan from these devices, 

but electronic filing of flight plans is a feature of the ground-based DUATS and DUAT systems, 

so there is precedence for this capability. As for the requirement to alert of potential SSA 

violations, some cockpit GPS devices will alert the pilot if she or he approaches certain airspace 

(e.g., Class B). Finally, the more sophisticated devices include built-in navigation and 

communication radios, electronic checklists, and control of the transponder (AEA, 2004; Garmin, 

2004). 

ISARC is thus an extension of current GPS moving map devices to the new domain of SSAs. 

Table 8 summarizes these extensions. It can be assumed that a device incorporating ISARC will 

include all the more general functions in the "Current GPS Moving Map Device Capability" 

column of Table 8. As such, ISARC is not expected to be implemented as a separate SSA-specific 

device, but rather a set of features to be found in future GPS moving map devices designed to 

assist the pilot in avoiding violations of SSAs among other functions. With ISARC as an integral 

part of such a general-purpose product, pilots are more likely to include the device in all planning 

and flying, and thus ISARC will be available regardless of if the pilot is anticipating a SSA or 

not. SSA compliance will not be a separate task in future flight, but an integral element of flight 

planning, navigating, and communicating. 

Table 8. Extension of current GPS devices to ISARC functions. 

Current GPS Moving Map Device Capability Extension for ISARC’s Requirements 

Moving map display of airspace Moving map display of SSAs. 

Information on aeronautical objects and 

procedures 

Information on SSA attributes and required 

procedures 

Flight plan creation, editing, storage, and 

retrieval 

Flight plan filing, activation, updating, and 

closing 

Alerting of conflicts with airspace Alerting of conflicts with SSAs 

5.4.2. Developing Technologies 

For ISARC to be fully functional, some new technology will have to be available. Fortunately 

much of this technology is currently being developed and deployed for reasons other than 

security. 

While ISARC can obtain much of the information it displays by the conventional methods used 

by present day moving map devices, the ISARC requirements for up-to-date SSA information and 

electronic flight plan activation imply electronic communication between the ground 

infrastructure and the moving aircraft. Current work to develop datalink, including protocols such 

as Universal Access Transceiver (UAT) and services such as Flight Information Service - 

Broadcast (FIS-B), will make it possible for the latest information to be automatically transferred 

to and from ISARC, including information that today is only available through NOTAMs (Strain, 

2004). Flight plan activation requests and subsequent SSA clearances can also be transferred over 

such protocols. While still in the testing phase of development, UAT with FIS-B is undergoing 

rapid expansion and is currently available throughout the eastern US seaboard (FAA, 2005f; 

Strain, 2004). 
37

Digital radio will also offer new options for communication between the aircraft and the ground, 

including the possibility of an always-on emergency voice communication channel. The channel 

can even be design to be heard by the pilot even if the radio's microphone key is stuck (Morse, 

2004). While currently available GPS moving map devices is perhaps the most logical product to 

include ISARC, the new and more general purpose electronic flight bags (EFBs), with their own 

GPS modules and databases, is an additional possibility (Chandra, et, al., 2003) that may make 

ISARC available to an even wider range of pilots. 

Meanwhile, on the ground, deployment of the Wide Area Augmentation System (WAAS) is 

proceeding, which, in addition to allowing navigation with greater precision and integrity, can 

also be used to determine altitude in lieu of the traditional barometric altimeter. This will allow a 

self-contained device to determine if an aircraft is flying over an airport or merely taxiing on its 

surface, thus making it possible for ISARC to suppress false alerts of SSA penetration. National 

network interconnection initiatives, such as System Wide Information Management and the FAA 

Telecommunications Infrastructure wide-area network, will provide the infrastructure for faster, 

more widespread, and more automatic transfer of digital information among government 

agencies, including SSA declarations and activations. 

5.4.3. Future Developments 

The most significant all-new development needed to fulfill ISARC’s requirements is the 

infrastructure to support electronic flight plan activation and automated clearance delivery. While 

this may leverage the new FAA information infrastructure current under development (see 5.4.2 

above), certain dedicated automated processes will have to be implemented in order to actually 

receive an electronic flight plan (perhaps via datalink), review it for security requirements, route 

it to the appropriate ATC personnel, and select the proper transponder code and radio frequency 

to transmit back to the pilot. As a significant new process, electronic flight plan activation 

requires research and development largely by the government. Likely, a functioning proof-ofconcept demonstration may be the necessary first step in order to establish the feasibility to the 

FAA and to the aviation community. 

5.5. Notional System 

5.5.1. Components and Interfaces 

Figure 9 presents an example implementation of ISARC using the technological elements 

reviewed above in 5.4. Actual implementation may differ from this depending on research 

findings, the capabilities of future technology, and the details of the targeted operational 

environment and market. The notional device shown here integrates ISARC with many of the 

components found in current GPS moving map devices (shown black outline in Figure 9). Any of 

these components may be implemented as an integrated hardware, software, and network 

architecture. A database component includes flight plans that were entered through the user 

interface or uploaded through a port (if the flight plan was prepared on another device such as a 

personal computer). The database also includes all aeronautical information including 

information on all SSAs of all degrees of stability. Much of this information, including 

information on static and recurrent SSAs, may be updated through a port (e.g., from a storage unit 

shipped by the vendor). Pilots also have limited ability to create and edit information (e.g., pilotdefined waypoints). Clearance records are kept indicating if each entry into a SSA in the flight 

plan is approved. Aircraft and pilot identity and characteristics are entered by the pilot when the 

device was acquired. A WAAS-capable GPS receiver component determines the aircraft position 

and altitude. A moving map generation component takes all this information to create a map 
38

image. The user interface component includes a graphical display capable of presenting maps and 

text. SSA information, clearance statuses, and alerts may be represented as text or graphically by 

symbolic coding on the map. An aural display, possibly with synthesized voice, is used only for 

high level alerts. 

Figure 9. Components and flows for GPS moving map device with ISARC. All components 

shown are within an on-board airborne device. 

As a future GPS moving map device, the device also features a datalink component, allowing upto-the-minute information to be sent to and from the device, including SSA activation 

information, but also weather and other information that is distributed today by NOTAMs. 

Datalink is also used by the electronic flight plan activation component, which, on command 

from the pilot to activate the flight plan, sends the flight plan and aircraft identity information to 
39

ATC, receiving in return clearance approval and transponder codes, the latter which may be sent 

to the transponder. The SSA compliance monitor, part of a more general monitoring and alerting 

component, takes the aircraft and SSA positions, the clearance records, and other information and 

compares these to requirements for the SSAs as stored in the database. 

The device may interface with the transponder, as shown in Figure 9, to allow ISARC to 

automatically set the transponder to the code necessary for SSA penetration once clearance is 

received. Alternatively, perhaps to avoid the additional certification issues associated with 

interfacing with panel electronics, the device may instead include a 1190 MHz transponder 

receiver so that it can detect the aircraft's current transponder setting and provide alerts if the 

transponder code does not match the code received with the clearance. Ideally, such an 

implementation of ISARC would include a 1030 MHz receiver and low-powered transmitter so 

that if no ATC interrogations are detected, ISARC can interrogate the aircraft's transponder. This 

will provide an alerting functionality even when the aircraft is not in range of ATC radar (e.g., 

when on the ground at certain airports). 

In another variation, a totally self-contained handheld unit may be implemented with an 

integrated the transponder that encodes the WAAS altitude with its response signal. The use of 

WAAS altitude rather than barometric altitude for this purpose would need to be approved by the 

FAA, but it would make it allowable for aircraft without an electrical system to fly through 

Control Level 2 and 2a SSAs. If WAAS altitude is to be used for high altitude flight (above Flight 

Level 180), surface pressure readings would have to be datalinked to the device so it can correct 

the altitude to simulate the standard barometric altimeter setting of 29.92 inches. 

Not shown in Figure 9, but also possibly included are incorporated or interfaced communication 

radios (possibly with the future digital channels) and perhaps even navigation radios. 

5.5.2. Function Implementation 

To display information about SSAs to the pilot, SSA information is stored in the database with 

other geographic and aeronautical information. Information on the boundaries of static and 

recurrent SSAs is loaded into the database through routine updates. Information on recurrent SSA 

activations and transitory SSAs is loaded automatically by datalink when the device is on and 

new information is available. The SSAs are shown graphically on the map display, along with 

other geographic information, both when the pilot is graphically editing and reviewing a flight 

plan and when the pilot has selected the moving map display. Different symbology, consistent 

with that found on official paper charts, distinguishes different levels of control. The pilot can 

also call up as text additional information from the database on any SSA, just as she or he can for 

weather, hazards, and other information useful in flight planning. 

Using the datalink, the pilot can choose to electronically file a created or amended flight plan 

with the FAA, including for flight through a Control Level 2 SSA. An annunciation on the 

display acknowledges acceptance of the plan. For a simple VFR flight, this may mean little more 

than entering the identifier of the destination airport and selecting “Send Plan.” The current 

airport, as determined from the GPS position, is the default starting point, and a single course 

path is assumed and likely flight time is calculated; pilot and aircraft information are pulled from 

the database. 

The datalink is also used to activate the flight plan for VFR flight, which includes clearance 

delivery to the cockpit for entry into Control Level 2 SSAs. Ideally, a single pilot action activates 

(or amends) the flight plan with ATC and FSS or possibly, activation is automatically triggered 

by the aircraft arriving at the start point of the flight plan (e.g., the GPS receiver indicates that the 
40

aircraft is moving onto a runaway of an airport identified as the flight plan's origin). If this 

involves Control Level 2 SSA, the clearance and appropriate transponder code is received in real 

time. A status annunciator on the ISARC display informs the pilot if she or he is cleared or not, 

and the received transponder code and radio frequency is set or displayed to the pilot. The flight 

plan is automatically closed via the datalink when the aircraft arrives at its destination as 

indicated by the GPS receiver. The status annunciator also indicates if the aircraft has departed 

the SSA, although the transponder code may best be left unchanged (e.g., in case the aircraft is 

flying under IFR). 

The implementation supports ISARC’s SSA alerting functionality by continuously monitoring 

transponder setting or transmissions, along with aircraft altitude, position, and trend as 

determined from the GPS receiver, and combining this with information stored in the database on 

the SSA boundaries, aircraft flight plan, and clearances and codes in order to determine if an alert 

is warranted. For example, in general no alert is given if the WAAS altitude, current position, and 

ground speed indicate the aircraft is on the ground at an airport (where airport altitude is stored in 

the database). However if the aircraft moves towards the ends of any runway at the airport or 

otherwise enters a runway and aligns itself on the runway’s heading (where runaway end 

positions are also stored in the database), then a synthesized voice warns the pilot if a Control 

Level 1 SSA is in effect over the airport. 

In the event of certain alerts, the device displays recommended courses of action based on 

information in the database and capabilities provided by other components. For example, in 

recommending an alternative course to avoid a Control Level 1 SSA, The device may consider 

the current WAAS altitude and terrain information, the latter which may be stored in the 

database. If the incorporating GPS navigation device is currently coupled to the autopilot, the 

pilot may simply approve the course recommendation, and the device will execute it. 

5.6. Analysis 

5.6.1. Effectiveness and Timeliness 

Over eighty-five percent of violations of SSAs are due a pilot’s lack of correct knowledge or 

understanding of a SSA, specifically, the presence of the SSA, the boundaries of the SSA, and the 

procedures necessary for SSA penetration. By providing SSA presence, boundary, and procedure 

information in a most compelling representation (e.g., on a moving map), it is very improbable 

that a pilot who uses ISARC would violate a SSA due to lack of knowledge. For those that do, the 

alerting feature offers a backup to make violations even more remote. The main limit on the 

effectiveness of ISARC is the proportion of pilots that are equipped with ISARC. If nearly all 

pilots operating around static and recurrent SSAs were equipped with ISARC (these being the 

pilots most motivated to acquire ISARC), and ISARC were nearly 100% effective at preventing 

violations due lack of knowledge and understanding, then, given 75% of all violations occur in 

static and recurrent SSAs, the frequency of SSA violation can be expected to drop by 64%. If, in 

addition, half of all remaining pilots acquire ISARC (these being less motivated pilots), the 

frequency of SSA violation can be expected to drop by 75%. Given that ISARC is an integrated 

set of features of a GPS moving map device, many pilots will acquire ISARC not because they 

specifically sought it, but because it was part of a generally useful device. Indeed, in the future, as 

advanced digital electronics increase their penetration the general aviation cockpit, perhaps nearly 

all pilots will have a GPS moving map device, all which may include ISARC. In such a future, 

violations may be reduced by 85% or more. If this is achieved, the frequency of SSA violations 

will be returned to the same order of magnitude as observed before 9/11/2001. 
41

By building on technology that currently exists or is already under development, the development 

time for ISARC is probably on the order of 10 years. The primary limit on faster development is 

not the incorporating device itself. GPS moving map devices already exist, and moving map 

displays using datalink have already been demonstrated. Rather, the primary limit is the time 

necessary to implement the ground infrastructure. This includes providing nation-wide datalink 

coverage, improving information transmission within federal agencies, and developing and 

supporting electronic flight plan activation. While ISARC may be about 10 years away, it is 

likely the problem it addresses will still remain. The future of the current sources of terrorism is 

unpredictable, but, while it is conceivable that it will be greatly attenuated within the next 10 

years, it seems more likely that it will remain for a number of decades (United States, 2004). 

Even if the current source is attenuated, one can anticipate new organizations with new political 

agendas attempting to emulate the same tactics as seen on 9/11/2001. In other words, SSAs may 

remain part of the aviation landscape for many years come. There is a definite need for a longterm intervention to reduce accidental violations of SSAs. 

5.6.2. Compliance and Security Impacts 

ISARC is primarily intended to reduce accidental violations of SSAs. Given that its purpose is to 

increase compliance with flight regulations, one should consider the possibility that it could also 

unintentionally decrease compliance with regulations. With regard to automated clearance 

delivery via electronic flight plan activation, the possibility exists for pilots to confuse a SSA 

clearance for other traditional clearances (e.g., for takeoff or entry into Class B). Mitigating this 

issue is that non-SSA clearances will continue to be given through two-way radio communication 

for the near future, just as pilots are used to today. Only SSA clearances, that is, only the new 

airspace types will support automated clearance delivery. This is an improvement over the current 

system where clearance to nearly all airspace, including SSAs, is done by radio. The potential for 

a pilot to confuse clearance into a SSA to also include clearance into overlapping airspace of 

another type is higher now than it would be with ISARC, yet this does not appear to be a serious 

problem (Zuschlag, 2005). Pilots have long been acquainted with handling overlapping layers of 

airspace (e.g., Class D under Class B, or a restricted SUA in Class B). 

ISARC is not specifically designed to address a security threat, at least not directly. One may ask 

if, in seeking to reduce accidental SSA violations, ISARC will compromise security. Specifically, 

cannot a terrorist take an ISARC equipped aircraft and use the electronic flight plan activation 

component to gain access to a Control Level 2 SSA? The answer is yes, this will be possible, but 

it represents nothing different than what may be done today. There is nothing stopping a terrorist 

from using a phone or radio to file and activate a legitimate flight plan into a Control Level 2 

SSA. ISARC may offer a slightly greater security by its feature to automatically send pilot and 

aircraft identification information with the flight plan. For example, if the plane has been reported 

as stolen, the terrorist has declared its location by filing and activating a flight plan (although a 

savvy terrorist may have the knowledge and time to re-write the identifying information in the 

incorporating device’s database). It should also be remembered that reducing violations itself 

improves security by making more resources available for handling each violation. Adding 

improved communication as part of ISARC also allows any remaining accidental violations to be 

handled quickly and safely so that attention can be refocused on any other potential threats. 

5.6.3. Safety Impacts 

ISARC is also not specifically designed to directly improve safety, at least outside of minimizing 

accidents associated with interception. However, as when anything is introduced into the cockpit, 

the impact on safety must be considered for both normal and failure modes. Because ISARC is 
42

primarily an information presentation system and because the information is not safety related, 

the impact of an ISARC failure is minimal. That is, there is simply no information about a SSA 

that ISARC could incorrectly display that would be hazardously misleading. If ISARC displays 

the wrong information about a SSA, the likely impact is either (a) the pilot avoiding airspace 

when it is not necessary, or (b) the pilot violating a SSA. The former may cost the pilot time and 

money (e.g., additional fuel) and the latter results in an enforcement action against the pilot, but 

neither are themselves safety concerns. A failure to correctly depict a SSA or alert the pilot of a 

SSA is very unlikely to result in catastrophic consequences (e.g., aircraft destruction), at least not 

without other improbable errors also occurring (e.g., by an interceptor). Providing features to 

mitigate the impact of violations, such as including an always-available emergency radio channel, 

reduces the chance of catastrophe even further. In general, a sufficient level of reliability, 

integrity, and accuracy of the SSA depictions are primarily an issue for certification (Section 

5.6.4) and pilot acceptance (Section 5.6.5), not safety. 

Regarding normal functioning, concern may also be raised that ISARC represents greater 

workload and distraction for the pilot as discussed in Section 5.3 (e.g., from alerts and display of 

SSAs, which may mask more pressing information the pilot needs). GPS moving map devices, 

for example, are already complex, offering a myriad of features and information layers. 

Accessing these features with limited controls and viewing this information on a small screen is 

already pushing the limits of acceptability in some cases. Adding ISARC increases the demands 

of the user interface. It is necessary that ISARC not interfere with other features, especially those 

related to safety of flight. The more ISARC can be integrated as part of the user interface of a 

multi-function on-board device (e.g., a general-purpose moving map display), the less impact it 

will have. On the other hand, the more ISARC is implemented as a separate device or a poorly 

integrated set of features within a multi-function device, the more workload it will likely 

represent. 

The incorporation of ISARC in large-screen state-of-the-art glass cockpits for general aviation 

aircraft is almost certainly feasible. It is believed to be also possible for a handheld unit to meet 

these requirements. For example, a decluttering feature to remove the display of SSAs from the 

moving map is likely to be a common characteristic of such devices, possibly integrated with a 

general “airspace” display mode. Only by evaluating actual implementations can it be 

demonstrated that a small device provides ISARC at acceptable levels of ease of use. Not all 

possible implementations are likely to be successful. With adequate research and attention to this 

issue, impacts can be minimized. Overall, ISARC should reduce pilot workload. Displaying the 

SSA on a moving map allows the pilot to monitor the SSA's relative position better than requiring 

the pilot to cross-reference a paper chart. Electronic flight plan activation with clearance delivery 

reduces the attention and actions necessary to obtain clearance into a Control Level 2 SSA, 

freeing pilot resources for safety concerns. 

There is also a safety issue related to displaying recommended pilot actions in the event of an 

alert of an approaching SSA. Research is need to study the possibility of the pilot blindly 

following a recommendation and possibly compromising safety for the sake of avoiding a 

violation (e.g., turning away from a SSA and into terrain or traffic). To some degree, this is 

mitigated by ISARC’s capacity to graphically display SSAs well before an alert condition is 

triggered (indeed, before the flight even begins). Thus, alerts prompting an immediate response 

by the pilot should be relatively rare. Nonetheless, the manufacturer needs to address in the 

design of this feature such a possibility. At a minimum, it needs to be made clear to the pilot what 

conditions are considered in providing the recommended action. Otherwise, this may be a feature 

that is best left out. 
43

A moving map device that incorporates ISARC may also have more direct safety benefits. With 

the capacity for convenient electronic flight plan filing and activation, VFR pilots may be more 

likely fly under flight plans even when no SSA is nearby. With more pilots flying with filed flight 

plans, search and rescue can respond more quickly to an overdue aircraft. One may also ask if 

more filed flight plan means more false alarms for search and rescue due to failure to close a 

flight plan or notify FSS of a change in plans. However, the former is minimized by ISARC 

automatically closing the flight plan on arrival. The latter is minimized by ISARC alerting the 

pilot of flight plan deviations (to which the pilot may respond by amending the flight plan, or, if 

outside a SSA, easily canceling the plan). It seems more likely that if electronic flight plan 

activation and closing is widely used in lieu of manual activation and closing, the frequency of 

such false alarms would decrease. 

Finally, it should be noted that the presence of ISARC in a GPS moving map device may 

encourage pilots (e.g., those flying around static SSAs) to use such a device when otherwise they 

would not. While their main reason for using the device may be to avoid SSA violations, the 

other features will likely provide them with greater overall situation awareness, increasing overall 

safety. 

5.6.4. Certification 

To be effective, an ISARC implementation must meet the FAA's criteria for a sole source of SSA 

information. Furthermore, being on board the aircraft and possibly interfacing with panelmounted avionics, it may also have to be certified as a cockpit device. Certification can add 

considerably to the development time and costs of such a system. However, given that ISARC 

does not provide information related to safety of flight (see Section 5.6.3), such implementations 

may be certified at a relatively low level, comparable to devices intended for situation awareness. 

At the lowest level, ISARC may be incorporated into a handheld moving map device with no 

other connection to the aircraft other than possibly a power supply and cradle. In such an 

implementation, no interface is provided to the transponder or communication radios, although 

ISARC should be able to monitor the aircraft's transponder signal for alerting purposes. This does 

not rule out a manufacturer from choosing a higher level of certification, consistent with the 

intended market and selling price (Chandra, Yeh, Riley, and Mangold, 2003), in which the 

incorporating device is panel mounted with interfaces with cockpit systems such as the altimeter, 

radios, transponder, and autopilot. This range of potential implementation is desirable because it 

makes ISARC more widely available for more pilots and more aircraft, allowing it to have a 

larger impact on reducing violations. 

Thus, the impact of certification is that the time and cost to develop and a device with ISARC is 

comparable to the time and costs of a general-purpose GPS moving map device. ISARC does not 

add much additional certification burden. Manufacturers intending to implement ISARC can 

reduce the cost and development time by organizing with the FAA to write minimum operational 

performance standards for ISARC, which the FAA can cite in a technical standard order (TSO). 

5.6.5. Cost and Acceptance 

Cost is another consideration when evaluating the viability of ISARC. By leveraging 

infrastructure technology that will be deployed anyway, additional costs to federal agencies is 

minimized. The electronic flight plan activation component, specifically automated clearance 

delivery capability is the only element that is specific to reducing SSA violations. While 

electronic flight plan activation with clearance delivery is key for the most effective 

implementation of ISARC and important for reducing SSA violations even in the absence of 
44

ISARC, it has other benefits as well. As discussed in Section 5.6.3, by making filing and 

activating a flight plan more convenient, pilots flying VFR are more likely to file flight plans in 

order to capitalize on the safety of having search and rescue promptly initiated in the event of a 

failure to complete the flight plan. While the automated clearance delivery feature is only initially 

suitable for SSAs, it may have a more general application in the future national airspace that 

implements the Next Generation Air Transportation System (NGATS) (Joint Planning and 

Development Office, 2004). In such an environment where the responsibility for traffic separation 

is shared between aircraft and ground, automated clearance delivery may have application for 

access to dense traffic areas. The application of automated clearance delivery to SSAs may thus 

serve as test bed for such concepts. The FAA may be motivated to pursue its implementation for 

these reasons of safety improvement and future airspace development, in addition to the reducing 

SSA violations. 

Pilots are expected to bear some of the cost by purchasing and maintaining the GPS moving map 

devices that incorporated ISARC. Many if not most pilots that habitually operate near static or 

recurrent SSAs (e.g., the Washington D.C. area) are likely to accept the cost of a moving map 

device with ISARC given the penalties for violating an SSA, commonly being a two month 

suspension of one's pilot's license (Zuschlag, 2005). However, for ISARC to reduce SSA 

violations by an order of magnitude, the majority of pilots throughout much of the US should be 

equipped with such devices. With a range of moving map products marketed, from situation 

awareness devices to those certified for navigation, nearly every pilot should be able to find a unit 

that is within budget. Furthermore, with ISARC being a set of features within a more general 

product, some of the cost may be absorbed into the larger system, providing the pilot with more 

value than would be achieved with a separate dedicated device. Pilots may purchase the 

incorporating device primary for its other features, believing ISARC itself will not be necessary. 

Nonetheless, ISARC will be available for them when it is needed. 

After purchase of a device with ISARC for whatever reason, the subsequent use of ISARC is a 

voluntary action for pilots. Success of ISARC thus depends on the wide acceptance and use of 

ISARC in the pilot community. Acceptance and use probably depends mostly on the degree 

ISARC provides tangible benefit with minimal additional effort. Thus, as discussed previously, a 

certain level of accuracy and reliability, along with ease of use of the user interface is key to the 

acceptance of an ISARC implementation. With the proper infrastructure in place (e.g., the FAA 

providing machine-readable SSA information available to aircraft by datalink to compare to the 

WAAS-determined aircraft position), accuracy and reliability should be very high. A certain level 

of integrity monitoring can also be built into the system in that it flags the pilot if, for example, a 

SSA declaration is received that for some reason ISARC cannot interpret. An easy-to-use user 

interface represents a greater challenge that warrants further research. If the device is difficult to 

use, pilots may respond by not using the device during periods of high workload, which is 

typically when operating at low altitude such as on approach, precisely where a SSA violation is 

most likely. 

Currently, pilots are deeply concerned about SSA violations and appear willing to take some 

responsibility to reduce the chances of a violation on their own (Charles, 2002, 2004), and thus 

ISARC is likely to be accepted, and even welcomed. Furthermore, ISARC represents few 

inconveniences for the pilot, integrating well with normal tasks. Indeed, electronic flight plan 

activation is likely to be seen as a significant benefit: a flight need only be entered once, not twice 

as is necessary for today (once for ATC or FSS, and once for the GPS map device). Pilots may 

recognize the safety benefits of this feature even when no known SSA is present. Finally, when 

ISARC is not needed, it remains unobtrusive. Assuming the user interface requirements are met, 
45

using a device with ISARC when no SSAs are present entails no more work than using a device 

that lacks ISARC. 

5.6.6. Alternatives 

ISARC nonetheless presents a nontrivial investment, and it is worth comparing its value to 

alternatives to reducing SSA violations. It may be argued that the short-term interventions listed 

in this paper are sufficient. However, the short-term interventions as a group have one major 

limitation that ISARC addresses: only ISARC helps the pilot avoid a SSA violation when it is 

about to occur. The short-term interventions provide help primarily during preflight. Violations 

do not occur until after the pilot is airborne, allowing time for the pilot to forget SSA information 

or become distracted while attempting to deal with SSAs. Furthermore, only ISARC addresses 

the scenario of a pilot who is simply lost (Zuschlag, 2005). Avoiding a SSA requires that pilots 

know the SSA boundaries relative to the aircraft. If the pilot is lost, knowing the absolute location 

of the boundaries by referring to a chart will not help. ISARC will display and alert the pilot to an 

approaching SSA even if the pilot does not know where she or he is. 

Within the context of long-term solutions, one should consider other technological interventions 

for reducing SSA violations. For example, one could develop portable radio beacons to mark the 

boundaries of SSAs. A system could monitor ATC radar data and detect an aircraft straying too 

close to a SSA and automatically send the pilot a warning such as by laser light (Associated 

Press, 2005; Avweb, 2005). Navigation aids could be modified to transmit a special signal when 

they are in a SSA. Any solution that relies on widespread ground-based and cockpit hardware 

specifically related to SSA will likely cost substantially more overall than ISARC, which uses 

only ground infrastructure and cockpit systems that are being developed anyway. Furthermore, 

only ISARC, being onboard the aircraft with access to its navigation and communication systems, 

is in the best position to evaluate the aircraft’s compliance with the SSA’s requirements –not only 

whether the aircraft is in or out of the SSA, but whether it has a clearance and is squawking the 

right code. Such other technological interventions can certainly be developed to reinforce the 

effectiveness of ISARC, but ISARC will likely provide the greatest impact on SSA violations for 

the amount of effort expended. 

5.6.7. Realization 

While it is expected that there is a market for ISARC, it may be necessary to encourage the 

private implementation of it through development and demonstrations by government aviation 

research agencies. Specifically, such an organization can work with the FAA to specify and even 

develop the infrastructure as described in Section 5.4.3. Work is necessary to determine the best 

means to implement the infrastructure, establishing ground communication links and new 

processes among FAA organizations. A research organization can also contribute by prototyping 

an ISARC-incorporating device. By studying ISARC use under realistic flight conditions, such an 

organization can provide a proof of the concept, flesh out the requirements beyond those given in 

5.1, and investigate promising avenues of implementation, as discussed in 5.5. Such preliminary 

work will do much to encourage ISARC development by industry. 

6. Additional Issues and Research 

This paper has focused on interventions to reduce violations of SSAs by focusing on providing 

pilots with better information on SSAs. There are other issues related to reducing violations or 

minimizing the impacts of violations, but further study is necessary before interventions can be 

formulated (Zuschlag, 2005). These issues include: 
46

 Effectiveness of SSA communication between pilots and FSS briefers. 

 Impact of the current frequency of SSAs on ATC workload and techniques to mitigate it. 

 Effectiveness of communication between violating pilot and interceptor pilot. 

 Interceptor requirements, current suitability, and alternatives. 

 Further study, including trend analysis, of SSA violation frequencies. 

Most of the proposed interventions in this paper seek to provide better SSA information to pilots 

by changing NOTAMs, maps, cockpit displays, and other artifacts used directly by pilots. 

However, pilots also received SSA information from through FSS personnel, and there are some 

indications of communication breakdown concerning SSAs between pilots and FSS briefers. 

Zuschlag (2005) provided only the pilot’s perspective on this problem. Specific study of FSS 

briefers is called for to better understand the characteristics and seriousness of this problem. The 

deployment of new systems such as OASIS is aimed at improving FSS quality of service, but it is 

not clear if these systems will specifically address the reasons for the apparent problems with 

SSA communication. 

There have also been some indications that SSAs represent a substantial increase in workload for 

ATC, and higher workload itself may be contributing to violations and other problems 

(Landsberg, 2003; Zuschlag, 2005). Further study is needed to specifically understand the impact 

of SSAs on ATC. If the workload has increased to the point that performance is compromised, 

interventions may be called for. For example, it may be necessary to break up the airspace around 

static SSAs. When a recurrent or transitory SSA is in effect, it may be helpful to subdivide tasks 

among more controllers (e.g., one controller may be charged with just giving SSA clearances). 

After a violation has occurred, there have been cases of difficulties of communication between 

the interceptor and violator (Zuschlag, 2005), even though procedures supposedly allow effective 

communication even when no radio contact is achieved. There may be a need for an educational 

outreach for general aviation and interceptor pilots, emphasizing the importance of knowing and 

following standard intercept procedures and monitoring the emergency radio channel, especially 

when a TFR is nearby. 

The interceptor aircraft itself also warrants more careful study. The current interceptors include 

full-capability supersonic fighters such as the F-16 and passenger-type aircraft such as Blackhawk 

helicopters and Citation business jets. These represent a poor compromise of the requirements 

and can even present dangers (Zuschlag, 2005). An interceptor for SSA violations should have 

low operating costs and be able to fly at low speed. It also should be able to dash across an SSA 

to the location of the violator, communicate with a violator, possibly without relying on radios, 

maneuver and target weapons on an adversary (which may be an acrobatics-capable airplane), 

and deliver ordinance capable of downing a large aircraft. 

Government study is needed to flesh out these requirements, and find an aircraft that best fits 

them. One option is to develop an all-new aircraft, but possibly there are currently active or 

mothballed aircraft (e.g., the A-4 or AT-38) that may serve, perhaps after some minor 

modifications. Alternatively, the fully detailed requirements and performance characteristics may 

imply that a system of multiple aircraft types is best. For example, possibly multiple uninhabited 

aerial vehicles (UAVs) can patrol the same airspace cheaper than a single manned aircraft. With 

several UAVs each responsible for a smaller portion of the SSA, they would not need especially 

high dash speed. A loitering unarmed UAV may be used to initially intercept, observe, 

communicate with, and direct a violating aircraft. A high-speed armed and manned tactical 
47

aircraft is scrambled only if the aircraft refuses to comply or attempts evasion. A third passengertype aircraft may also be available to promptly bring law enforcement personnel to the violator's 

aircraft after it has landed. 

Finally, it is important to continue to monitor the frequency of violations of SSAs. As stated 

earlier, the frequency appears to be decreasing but it may level off at an unacceptable rate if 

additional interventions are not implemented. As interventions to reduce accidental violations are 

implemented, it will be important to monitor their ultimate impact. It would be particularly 

interesting to monitor violations associated with presidential TFRs to evaluate the effectiveness of 

communication about them. Presidential TFRs include large Control Level 2 SSAs, which, based 

on the early experience of the DC and New York ADIZs, can be hypothesized to be associated 

with substantial numbers of violations. This hypothesis has yet to be tested, however. 

7. Summary 

This paper suggests interventions to reduce the violations of SSAs. As a rule, a pilot does not 

deliberately violate a SSA. Pilots in general feel strongly motivated to avoid such violations and 

take such violations and the general need for SSAs very seriously (Zuschlag, 2005). Violations 

are pilot errors mostly due to the pilot’s lack of knowledge or understanding of a SSA. The 

interventions in this paper seek to improve this knowledge and understanding. In the short-term, 

interventions are focused on improving the form and format of the information on SSAs 

contained in NOTAMs, along with providing additional channels for SSA information, such as on 

aeronautical charts. In many ways the past three years have been an experiment, with various 

kinds of SSAs tried to seek a good balance between security and free access to the skies. Now 

there should be enough experience to standardize SSAs, which itself should reduce violations. A 

proposed long-term intervention dovetails well with existing and emerging technologies to 

provide pilots with SSA situation awareness and alerts in the cockpit, where it is needed most. 

The philosophy behind these interventions is to acknowledge the problem SSAs present for pilots 

and to find feasible solutions that best address the problem, whether the cost of solution is 

initially borne by pilots, the government, or industry. The shear frequency of violations indicates 

that current means of addressing violations through sanctioning pilots is ineffective. The nation is 

not one ounce more secure by intercepting and punishing accidental violators. In fact, it is less 

secure. 

8. Abbreviations and Acronyms 

ADIZ ............ Air Defense Identification Zone 

ADS-B.......... Automatic Dependent Surveillance – Broadcast 

AEA.............. Aircraft Electronics Association 

AFD.............. Airport/Facility Directory 

AFSS ............ Automated Flight Service Station 

AIM .............. Aeronautical Information Manual 

AOPA........... Aircraft Owners and Pilots Association 

ARP .............. Aerospace Recommended Practice 
48

ATC.............. Air Traffic Control 

ATIS............. Automatic Terminal Information Service 

AWOS .......... Automated Weather Observing System 

BGAN........... Broadband Global Area Network 

CFR .............. Code of Federal Regulations 

CTAF............ Common Traffic Advisory Frequency 

DC ................ District of Columbia 

DME............. Distance Measuring Equipment 

DUAT........... Direct User Access Terminal 

DUATS......... Direct User Access Terminal System 

EFB............... Electronic Flight Bag 

FAA.............. Federal Aviation Administration 

FANS............ Future Air Navigation System 

FBO .............. Fixed Base Operator 

FDC .............. Flight Data Center 

FIS-B ............ Flight Information Service - Broadcast 

FRZ............... Flight Restricted Zone 

FSS ............... Flight Service Station 

FTI................ FAA Telecommunications Infrastructure 

GPS............... Global Positioning System 

HIWAS......... Hazardous In-flight Weather Advisory Service 

HTML........... Hypertext Mark-up Language 

ICNS............. Integrated Communications, Navigation and Surveillance 

IFR................ Instrument Flight Rules 

IMAPS.......... Internet Marine and Aviation Planning Services 

ISARC .......... Integrated System for Airspace Requirements Compliance 

METAR........ Meteorological Report 

MHz.............. MegaHertz 

MSL.............. Mean Sea Level 

NAIMES....... NAS Aeronautical Information Management Enterprise System 
49

NAS.............. National Airspace System 

NASA........... National Aeronautics and Space Administration 

NDB ............. Nondirectional Beacon 

NGATS......... Next Generation Air Transportation System 

nm................. Nautical Mile 

NORAD........ North American Aerospace Defense Command 

NOTAM ....... Notice to Airmen 

NSA.............. National Security Area 

NTSC............ National Transportation Systems Center 

OASIS .......... Operational and Supportability Implementation System 

PDF............... Portable Document Format 

RTCA ........... Radio Technical Commission for Aeronautics 

SFRA............ Special Flight Rules Area 

SSA............... Security-Supporting Airspaces 

STI................ Scientific and Technical Information 

SUA.............. Special Use Airspace 

SUA/ISE....... Special Use Airspace/Inflight Service Enhancement 

SWIM........... System Wide Information Management 

TAF .............. Terminal Aerodrome Forecast 

TCA.............. Terminal Control Area 

TFR............... Temporary Flight Restriction 

TIBS ............. Telephone Information Briefing Service 

TRACON ..... Terminal Radar Approach Control 

TSA .............. Transportation Security Administration 

TSO .............. Technical Standard Order 

TWEB........... Transcribed Weather Broadcast 

UAT.............. Universal Access Transceiver 

UAV ............. Uninhabited Aerial Vehicles 

US................. United States 

USSS ............ United States Secret Service 
50

VFR .............. Visual Flight Rules 

VHF.............. Very High Frequency 

VIP ............... Very Important Person 

VOR ............. VHF Omnidirectional Range 

WAAS .......... Wide Area Augmentation System 

9. References 

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http://www.aea.net/. 

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Winter Olympics. News Items, January 16, 2002. http://www.aopa.org/whatsnew/newsitems/2002/02-

1-021x.html. 

Aircraft Owners and Pilots Association (2002b). Reduction of P-40 TFR good news for Maryland pilots. 

News Items, April 25, 2002. http://www.aopa.org/whatsnew/newsitems/2002/02-2-074x.html. 

Aircraft Owners and Pilots Association (2003a). President Bush gets 30-nm TFR for Chicago visit 

Wednesday. News Items, June 10, 2003. http://www.aopa.org/whatsnew/newsitems/2003/03-2-

187x.html. 

Aircraft Owners and Pilots Association (2003b). 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 (2003c). AOPA, member input leads to improved FAA TFR Web 

site. News Items, November 6, 2003. http://www.aopa.org/whatsnew/newsitems/2003/03-4-

083x.html. 

Aircraft Owners and Pilots Association (2004a). FAA joins AOPA's efforts to educate D.C.-area pilots on 

flight restrictions. News Items, June 9, 2004. 

http://www.aopa.org/whatsnew/newsitems/2004/040609adiz.html. 

Aircraft Owners and Pilots Association (2004b). Departure and Pattern Operations at Airports within the 

Washington Air Defense Identification Zone Including Clearance Delivery Frequencies and Potomac 

Landline Numbers. http://www.aopa.org . 

Aircraft Owners and Pilots Association (2004c). Checklists for Operations within the Washington D.C. 

ADIZ Area. http://www.aopa.org . 

Aircraft Owners and Pilots Association (2005a). AOPA Online - Notices to airmen (NOTAMs, TFRs). 

http://www.aopa.org/whatsnew/notams.html. 

Aircraft Owners and Pilots Association (2005b). NORAD can shoot down aircraft threatening nuke plants. 

News Items, March 17, 2005. 

Associated Press (2005). Pentagon to use lasers to warn pilots. Washington, DC, April 12, 2005. At Cable 

News Network, http://www.cnn.com/2005/TRAVEL/04/12/lasers.planes.ap/index.html. 

AvWeb (2004). Predicting the Short-Term Future. Newswire, March 28, 2004. 

http://www.avweb.com/eletter/archives/avflash/216-full.html. 

AvWeb (2005). Laser Tag, NORAD Style, Is No Game. Newswire. April 17, 2005. 

http://www.avweb.com/eletter/archives/avflash/388-full.html. 

Burnside , J. (2004). TSA Watch: AOPA And The "Dumbbell" TFR. AvWeb BizAv, July 21, 2004. 

http://www.avweb.com/bizav/10_30/news/187740-1.html. 
51

Chandra, Divya C., Yeh, M., Riley, V., & Mangold, S.J. (2003). Human factors considerations in the 

design and evaluation of Electronic Flight Bags (EFBs), Version 2. DOT-VNTSC-FAA-03-07. 

USDOT Volpe Center: Cambridge, MA. http://www.volpe.dot.gov/opsad/efb/pdf/efb_version2.pdf. 

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. 

Federal Aviation Administration (2002a). Enhanced Security Procedures for Operations at Certain Airports 

in the Washington, DC Metropolitan Area Special Flight Rules Area. Docket No. FAA-2002-11580, 

SFAR 94, RIN 2120-AH62, February 13, 2002. Washington, DC: Federal Aviation Administration. 

Federal Aviation Administration (2002b). Airspace and Flight Operations Requirements for the 2002 

Winter Olympic Games, Salt Lake City, UT (14 CFR Part 91, RIN No. 2120-AH61, Docket No. 

FAA-2002-11332; SFAR No. 95). 

Federal Aviation Administration (2002c). Runway Incursions Nationwide Decreased in 2001. Press release 

posted January 23, http://www.faa.gov/apa/pr/pr.cfm?id=1490. 

Federal Aviation Administration (2002d). Runway Safety Blueprint 2002-2004. FAA Office of Runway 

Safety, July 2002, http://www.faa.gov/runwaysafety/publications.cfm. 

Federal Aviation Administration (2003a). Washington DC Metropolitan Area Air Defense Identification 

Zone (DC ADIZ) (FDC 3/2126). FAA Air Traffic Control Systems Command Center. 

Federal Aviation Administration (2003b). Washington DC (FDC 3/0853). FAA Air Traffic Control 

Systems Command Center. 

Federal Aviation Administration (2003c). VFR Traffic Pattern Operations (FDC 3/2943). FAA Air Traffic 

Control Systems Command Center. 

Federal Aviation Administration (2003d). Proximity to Stadiums and Other Sporting Events (FDC 3/1862). 

FAA Air Traffic Control Systems Command Center. 

Federal Aviation Administration (2003e). Orlando, FL (FDC 3/2122). FAA Air Traffic Control Systems 

Command Center. 

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. 

Federal Aviation Administration (2004c). Washington, DC Metropolitan Area Air Defense Identification 

Zone (DC ADIZ) (FDC 4/5555). FAA Air Traffic Control Systems Command Center. 

Federal Aviation Administration (2004d). Aeronautical Information Manual. 

http://www.faa.gov/ATpubs/AIM/. 

Federal Aviation Administration (2004e). Washington Sectional Aeronautical Chart (75th Edition). National 

Aeronautical Charting Office (FAA Product ID SWAS). 

Federal Aviation Administration (2004f). Proximity to Power Plants, Dams, Refineries, Industrial 

Complexes, Military Facilities (FDC 4/0811). FAA Air Traffic Control Systems Command Center. 

Federal Aviation Administration (2004g). Certification of Aircraft and Airmen for the Operation of LightSport Aircraft. Docket No. FAA–2001–11133, SFAR 94, RIN 2120–AH19, September 1, 2004. 

Washington, DC: Federal Aviation Administration. 

Federal Aviation Administration (2005a). Special Notice, Ingress/Egress Procedures for Bay Bridge (W29) 

and Kentmorr (3W3) Airports in Maryland (FDC 5/0345). FAA Air Traffic Control Systems 

Command Center. 
52

Federal Aviation Administration (2005b). Special Notice. ADIZ Egress Procedures for Certain Airports 

within the Washington, DC Metropolitan Area Air Defense Identification Zone. (FDC 5/0847). FAA 

Air Traffic Control Systems Command Center. 

Federal Aviation Administration (2005c). Washington DC. (FDC 5/1254). FAA Air Traffic Control 

Systems Command Center. 

Federal Aviation Administration (2005d). Pensacola, Florida, March 18 2005 Local (FDC 5/1953). FAA 

Air Traffic Control Systems Command Center. 

Federal Aviation Administration (2005e). Federal Aviation Administration - Graphic TFR's. Federal 

Aviation Administration. http://tfr.faa.gov/tfr/list.jsp. 

Federal Aviation Administration (2005f). Automatic Dependent Surveillance - Broadcast (ADS-B) and 

other Broadcast Services--Initial Capabilities in the National Airspace System (NAS). Graphic 

Notices, General Information, GEN05002, 3/10/2005. 

http://www.faa.gov/ntap/NTAP05APR14/gen05002.htm. 

Garmin (2004). GNS 480 Color GPS/WAAS/NAV/COM Pilot’s Guide. Olathe, KS: Garmin International, 

Inc. 

Grady, M. (2005). New Rule Spells Out Procedures. AvWeb Newswire, February 14, 2005, 

http://www.avweb.com/newswire/11_07a/leadnews/189160-1.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.Higdon, D. (2002). AEA 2002: Avionics Advances Continue Unabated. 

AvWeb (April 2002), http://www.avweb.com/news/aea2002/181592-1.html. 

International Civil Aviation Organization (2001). Aeronautical Charts, Annex 4 to the Convention on 

International Civil Aviation (10th edition), July 2001. Montreal: International Civil Aviation 

Organization. 

Joint Planning and Development Office (2004). Next Generation Air Transportation System Integrated Plan 

http://www.jpdo.aero. 

Landsberg, B. (2003). Delayed and distracted. AOPA Pilot, September 2003. Also available at 

http://www.aopa.org/asf/asfarticles/2003/sp0309.html. 

Morse, D. (2004). Next Generation FANS over BGAN. Integrated Communications, Navigation, and 

Surveillance (ICNS) Conference and Workshop, April 2004. 

Radio Technical Commission for Aeronautics (2003). Minimum Operational Performance Standards for 

the Depiction of Navigation Information on Electronic Maps (DO-257A). Washington, DC: Radio 

Technical Commission for Aeronautics. 

Reauthorization Of The Federal Aviation Administration And The Aviation Programs (2003).108th 

Congress, 1st Session (testimony of Walter W. Pike). 

Society of Automotive Engineers (1997). Electronic Aeronautical Symbols (ARP 5289). Warrendale, PA: 

Society of Automotive Engineers. 

Stock, T. (2004). Data Link- Supported Low-Cost Airspace Alerting and Avoiding System. MITRE 

Eleventh Annual Technology Symposium. McLean, VA: MITRE Corporation, (April, 2004) 

http://www.mitre.org/news/events/tech04/5.html#1496. 

Strain, R. (2004). Safe Flight 21East Coast Implementation of Broadcast Services. Proceedings of the 

Fourth Integrated Communications, Navigation, and Surveillance (ICNS) Conference and Workshop. 

(August) (NASA/CP-2004-213308). Cleveland, OH: NASA Glenn Research Center. 

United States of America (2004). The 9-11 Commission Report: Final Report of the National Commission 

on Terrorist Attacks Upon the United States (9-11 Commission). Washington, DC: Government 

Printing Office. 
53

Zuschlag, M. K. (2005). Violations of Temporary Flight Restrictions and Air Defense Identification Zones: 

An Analysis of Airspace Violations and Pilot Report Data. NASA/CR—2005–213923, Hampton, VA: 

NASA Langley Research Center.
54

Appendices 

Consolidated Mockup of Formatted NOTAM 5/1953 

The following consolidation of Figure 4, Figure 6, Figure 7, and Figure 8 is a mockup of a 

complete NOTAM using formatting and graphic techniques discussed in Sections 4.1.2, 4.2.2, 

4.2.4, and 4.3.1 for improving pilot awareness of the presence, boundaries, and requirements for a 

SSA. This may be compared to that currently available from the FAA as shown in Figure 1 and 

Figure 2. Such a consolidated NOTAM may be included in or linked from a preflight briefing 

report. The last portion of text (labeled Restrictions 1 and Restrictions 2) are not necessary if SSA 

requirements are standardized, as described in 4.3.3. 

FDC 5/1953. Located 8 nm from flight plan. High relevance for Any Flight.

Flight Restrictions

Pensacola, FL, March 18 2005, 7:50 – 12:05 local
55

Map Reference Area 1 Area 2 Area 3 Area 2

Restrictions 2 1

Location Lat 

Long 

30 28 24 N 

087 11 15 W 

30 21 10 N 

087 19 01W 

30 28 24 N 

087 11 15 W 

30 21 10 N 

087 19 01W 

 Fix CEW 228 033.7 BFM 108 041.3 CEW 228 033.7 BFM 108 041.3 

Radius 30 nm* 10 nm 

Ceiling MSL FL 180 

Time Zulu 05 03 18 1350 

05 03 18 1805 

05 03 18 1350 

05 03 18 1455 

05 03 18 1415 

05 03 18 1640 

05 03 18 1600 

05 03 18 1805 

 Local 0750 03/18/05 

1205 03/18/05 

0750 03/18/05 

0855 03/18/05 

0815 03/18/05 

1040 03/18/05 

1000 03/18/05 

1205 03/18/05 

Duration 4:15 hrs 1:05 hrs 2:25 hrs 2:05 hrs 

Public Airports within 1J9 

2R4 

5R4 

82J 

83J 

JKA 

NPA 

NSE 

PNS 

82J 

83J 

NPA 

82J 

83J 

NPA 

PNS 

82J 

83J 

NPA 

*Excluding airspace overlapping with Areas 2 and 3 during their respective active times. 

Restrictions 1 (see map reference Areas 2 and 3)

Prohibited: All aircraft operations.

Exceptions: 

Law enforcement and military aircraft directly supporting the United States Secret Service 

(USSS) and the Office of the President of the United States, 

Emergency medical flights in which the flight operations company coordinates operations in 

advance with the USSS at 850-444-5646 in order to avoid potential delays. 

Regularly scheduled commercial passenger and all-cargo carriers arriving into and/or departing 

from 14 CFR Part 139 airports and operating under any of the following: 

Aircraft Operator Standard Security Program (AOSSP), 

Domestic Security Integration Program (DSIP), 

Twelve Five Standard Security Program (TFSSP), 

All-Cargo International Security Procedure (ACISP) 

Restrictions 2 (see map reference Area 1)

Requirements: All aircraft shall 

Be on an active IFR or VFR flight plan. 

Squawk an ATC-assigned discrete transponder code prior to departure and at all times in the TFR. 

Remain in two-way radio communications with ATC. 

Exceptions: 

Emergency medical flights in which the flight operations company coordinates operations in 

advance with the USSS at 850-444-5646 in order to avoid potential delays. 

Prohibited: 

Loitering. 

Flight training. 

Practice instrument approaches. 
56

Aerobatic flight. 

Glider operations. 

Parachute operations. 

Ultralight flight. 

Hang gliding. 

Ballooning. 

Agriculture/crop dusting. 

Animal population control flight operations. 

Banner towing. 

Additional Information: All USSS cleared aircraft operators based in the area should notify the USSS at 850-

444-5646 prior to their departure. 

Notes 

It is recommended that all aircraft operators check NOTAMs frequently for possible required changes to this TFR prior to 

operations within this region. 

These flight restrictions are pursuant to title 14, section 91.141, of the Code of Federal Regulations (CFR).
57

Interventions and Actions to Perform 

The following lists all recommended interventions in this document with cross-references to the 

document's body. Given with each intervention are the specific causes of SSA violations (see 

Table 1) that the intervention addresses. For each intervention, the necessary actions to realize it 

are given, broken down by actor: 

 Government research agencies, or research agencies sponsored by the government. 

 Government service and regulatory agencies or offices and their contractors. 

 Private industry, providing products and services directly to pilots or aircraft operators. 

Actions are listed in tabular format with each row specifying the actions that are contingent on 

each other. In general, the research should be conducted first, followed by actions regarding 

government services or regulations, followed by the actual development of products and services 

by industry, although industry may choose to conduct its own research, and develop a product in 

anticipation of supporting government regulations or services. 

Intervention: Support Sorting, Filtering, or Highlighting Briefing Reports (Section 4.1.1) 

Cause of Violations Addressed: SSA not known about or recalled. 

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Determine keywords or fields 

to best categorize NOTAMs. 

Add keywords to NOTAMs. Develop preflight briefing 

applications to sort/filter/ 

highlight NOTAMs based on 

keywords 

Study feasibility of distributing 

NOTAMs with as fields of 

database records. 

Format NOTAMs by database 

fields rather than free text. 

Develop preflight briefing 

applications to manipulate the 

appearance of NOTAMs 

based on the field values and 

flight plan. 

 Proceed with deployment of 

OASIS and SUA/ISE systems 

Intervention: Standardize, Format, and Improve Text Descriptions (Sections 4.1.2, 4.2.4, 

4.3.1) 

Cause of Violations Addressed: 

 Relative distance to SSA not understood. 

 SSA not known about or recalled. 

 Procedures for allowed penetration of SSA not understood. 
58

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Determine format for improved 

readability, scanability, and 

understandability of NOTAMs. 

Format or markup NOTAMs 

for easier scanning or reading. 

Display NOTAMs in markedup form in preflight briefing 

reports. 

 Standardize shapes of 

transitory SSAs. 

 Standardize boundary 

descriptions to always 

reference a navigation aid and 

always use MSL altitude. 

 List public airports affected by 

SSA 

Intervention: Provide interactive graphic summary in preflight briefing reports (Section 0). 

Cause of Violations Addressed: SSA not known about or recalled. 

Actions: 

Government Research Industry 

Study usefulness of an interactive graphic 

summary in preflight briefing reports. 

Implement summary, contingent on research 

findings. 

Intervention: Include SUA activations in NOTAMs (Section 0). 

Cause of Violations Addressed: SSA not known about or recalled. 

Actions: 

Government Services & Regulations 

Develop means to route SUA information into NOTAM system. 

Intervention: Support personalized updates in briefings (Section 0). 

Cause of Violations Addressed: SSA not known about or recalled. 

Actions: 

Government Services & Regulations Industry 

Support personalized updates in FSS briefings. Support personalized updates in electronic 

briefing services. 

Intervention: Chart Recurrent and Static SSAs (Sections 4.1.4, 4.2.1). 

Cause of Violations Addressed: 

 Relative distance to SSA not understood. 

 SSA not known about or recalled. 
59

Actions: 

Government Research Government Services & 

Regulations 

Industry 

 Formalize the definitions of 

static and recurrent SSAs. 

Study and provide 

recommendations on 

streamlining charting of SSAs. 

Streamline process for putting 

SSAs on charts. 

 Maximize use of existing SUA 

types for map representation. 

 Show charted SSAs on 

electronic map devices. 

Intervention: Use Weather Products and Other Channels to Announce SSA Activations

(Section 4.1.5) 

Cause of Violations Addressed: SSA not known about or recalled. 

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Determine implementations for 

including SSA information in 

weather products. 

Feed and include SSA 

activation information in 

weather products. 

Support plain-text translations 

of SSA information in weather 

product in preflight briefing 

reports 

 Implement electronic shipping 

of SSA activation notice 

posters to FBOs 

Intervention: Specific Times and Places for All TFRs (Section 4.1.6) 

Cause of Violations Addressed: SSA not known about or recalled. 

Actions: 

Government Services & Regulations 

Chart covered facilities. 

Instate regulation requiring event organizers to notify the federal authorities of events. 

Change blanket NOTAMs to NOTAMs listing discrete activations. 

Intervention: Optimize Detail and Improved Map Readability and Understandability

(Sections 4.2.2, 4.2.3) 

Cause of Violations Addressed: Relative distance to SSA not understood. 
60

Actions: 

Government Research Industry and Government Services & Regulations 

Determine critical information and 

details to include on maps of SSAs. 

Update map web sites to use new maps. 

 Indicate map scale on maps. 

 Adjust map format for electronic displays and black-andwhite printing. 

 Support user-selected map size for electronic displays 

Intervention: Support easy electronic transmission of maps from FSS briefers (Section 4.2.5). 

Cause of Violations Addressed: Relative distance to SSA not understood. 

Actions: 

Government Services & Regulations 

Supply FSS briefers with applications to transmit maps and other graphics by email and fax. 

Intervention: Develop pilot-defined airspace alerting feature in GPS map devices (Section 

4.2.5). 

Cause of Violations Addressed: Relative distance to SSA not understood. 

Actions: 

Government Research Industry 

Study means to implement pilot-defined 

airspace alerting feature in GPS map devices. 

Implement pilot-defined airspace alerting 

feature in GPS map devices. 

Intervention: Provide machine-readable format for SSA information (Section 4.2.5). 

Cause of Violations Addressed: Relative distance to SSA not understood. 

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Study best means of 

formatting SSA information for 

machine reading. 

Develop standards for 

formatting SSA information for 

machine reading. 

Develop and distribute 

machine-readable SSA 

information. 

Develop standards for 

formatting SSA information for 

machine reading. 

Develop applications to 

automatically read and map 

such distributed information. 

Intervention: Standardize and Simplify the SSA Procedures (Section 0) 

Cause of Violations Addressed: Procedures for allowed penetration of SSA not understood. 
61

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Study feasibility of FSS 

controllers delivering SSA 

clearances directly to pilots. 

Study means of implementing 

electronic flight plan activation 

and automated clearance 

delivery. 

Develop and standardize on 

single nation-wide 

communication channel for 

SSA clearances. 

In TFR NOTAMs, inform pilots 

of available channels. 

Provide applications to 

support electronic flight plan 

activation and automated 

clearance delivery. 

Intervention: Standardize SSA Control Levels (Sections 4.2.1, 4.3.3). 

Cause of Violations Addressed: Procedures for allowed penetration of SSA not understood. 

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Study consolidation of SSA 

requirement to a few standard 

categories, maintaining 

security while maximizing 

access to airspace. 

Define, standardize, and name 

control levels. 

Document and use standard 

control levels in NOTAMs and 

publications such as the AIM 

and AFD. 

Develop map symbology for 

SSA control levels. 

Print maps and charts using 

new symbology. 

Use new symbology on 

electronic map displays. 

Intervention: Provide educational outreach and support training on SSAs (Section 0) 

Cause of Violations Addressed: Procedures for allowed penetration of SSA not understood. 

Actions: 

Government Services & Regulations 

Adjust ATC and FSS phraseology to emphasize key requirements of SSAs 

Conduct educational outreach. 

Intervention: Research, develop, and deploy ISARC (Section 5) 

Cause of Violations Addressed: 

 Relative distance to SSA not understood. 

 SSA not known about or recalled. 

 Procedures for allowed penetration of SSA not understood. 
62

Actions: 

Government Research Government Services & 

Regulations 

Industry 

Validation of functional, 

infrastructure, and 

performance requirements. 

Use requirements to plan 

infrastructure development. 

Use requirements to plan 

development of devices with 

ISARC. 

Continuing testing and 

developing modern datalink 

capabilities. 

Deploy high bandwidth 

datalink nationwide. 

Develop services using 

datalink to transmit up-to-date 

SSA information to en route 

aircraft. 

Study means of distinguishing 

taxiing from imminent takeoff 

using WAAS data. 

Complete deployment of 

WAAS. 

Implement taxiing detection in 

air space alerting components 

of GPS moving map devices. 

Develop proof-of-concept 

prototype ISARC. 

Study user interface issues, 

developing guidelines for 

simplifying interaction, 

especially for challenging form 

factors. 

Study impact of providing 

recommended courses to 

avoid SSAs. 

Work with industry standards 

committees to define ISARC 

performance standards, then 

subsequent write a TSO citing 

them. 

Develop on-board devices with 

ISARC, possibly integrated 

with a GPS moving map 

device. 

Study means of implementing 

electronic flight plan activation 

with automated SSA clearance 

delivery. 

Investigate usefulness of 

automated clearance delivery 

for other applications such as 

NGATS. 

Continue to develop and 

deploy infrastructure for intraand inter-agency information 

transfer. 

Plan, develop, and deploy 

electronic flight plan activation 

with automated SSA clearance 

delivery. 

Develop devise with ISARC 

that support electronic flight 

plan activation with automated 

SSA clearance delivery 

Prototype demonstration of 

always-on emergency 

communication channel for 

digital radios. 

Working with industry 

standards committees, define 

and standardize an always-on 

emergency communication 

channel 

Develop digital radios 

including an always-on 

emergency communication 

channel. 

Other research questions (Section 6) 

 Effective SSA communication between pilots and FSS briefers. 

 Impact of the current frequency of SSAs on ATC workload and techniques to mitigate it. 

 Effectiveness of communication between violating pilot and interceptor pilot. 

 Interceptor requirements, current suitability, and alternatives. 

 Further study, including trend analysis, of SSA violation frequencies. 
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Contractor Report

 4. TITLE AND SUBTITLE

Potential Interventions by Government and Industry to Minimize

Violations of Temporary Flight Restrictions

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 enumerates interventions to reduce the frequency of restricted airspace violations, particularly those associated

with temporary flight restrictions (TFRs) and air defense identification zones (ADIZs), by more effectively providing pilots

with the information necessary to avoid such violations. Interventions are divided into both near term and far term groupings.

Short term interventions, some variants of which are already in progress focus on improving the form and content of the

textual Notices to Airmen (NOTAMs) as well as the graphical depiction of TFRs. A long-term technical intervention is

proposed which would provide pilots the following functionality: ground and airborne presentation of information on any

restricted airspace, including display on an electronic moving map, fully mechanized execution from the cockpit of the

procedures required for entry into restricted airspaces that allow for entry, and alerting of the potential for TFR violations both

during flight planning and while the aircraft is moving.

15. SUBJECT TERMS

Airpsace; Aviation safety; Security-Supporting Airspaces; ADIZ; TFR; SSA

18. NUMBER

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72

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(301) 621-0390

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3. DATES COVERED (From - To)

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5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

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5e. TASK NUMBER

5f. WORK UNIT NUMBER

23-723-51-A5

11. SPONSOR/MONITOR'S REPORT

 NUMBER(S)

NASA/CR-2005-213924

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1. REPORT DATE (DD-MM-YYYY)

01- 09 - 2005