A I R T R A F F I C O R G A N I Z A T I O N

ATO En Route Services 

Surveillance and Broadcast Services 

Benefits Basis of Estimate

August 2007 

This document describes the analyses used to estimate benefits for the Surveillance 

and Broadcast Services (SBS) program. The primary goal of the program is to use 

Automatic Dependent Surveillance-Broadcast (ADS-B) as a surveillance source and 

to broadcast aeronautical information. The National Airspace System (NAS) 

deployment of this system will support numerous operational applications. Benefits 

estimates for the program were derived directly from these applications. The 

results from these analyses were used in the business justification presented to the 

Joint Resources Council (JRC) on August 27, 2007 for a final investment decision on 

the program.

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N • A I R T R A F F I C O R G A N I Z A T I O N 
EXECUTIVE SUMMARY 

The SBS program will provide a number of FAA and user benefits. This document 

describes the analyses for each benefit element submitted as part of the business 

justification at the August 2007 investment decision of the SBS program. The following 

two tables present a summary of the total benefits and the benefits organized by location, 

application, and desired outcome for the current total program. The remainder of the 

document details the analyses that produced these results. 

Summary benefits for the SBS program 

Segment Benefits 2007-2035 

(BY 07 M$) 

Benefits 2007-2035 

(Risk-Adjusted PV M$) 

SBS Program $18,498.1 M $5,043.2 M 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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SBS program benefits by location, application, and desired outcome

Location Application Outcome Benefit 

(BY7 $M) 

Benefit 

(PV $M) 

CONUS, 

Hawaii, and 

Caribbean 

Surveillance 

Radar Airspace ATC 

Surveillance 

Surveillance cost avoidance $1,263.2 $371.1 

More efficient en route conflict resolution $3,258.1 $801.8 

More efficient en route metering to the arrival 

fix 

$1,746.6 $417.0 

Increased safety on the surface by controllers $11.6 $3.2 

More efficient ATC management of surface 

movement 

$92.1 $26.9 

Reduction in FAA subscription charges due to 

value added services 

$232.0 $80.6 

CONUS, 

Hawaii, and 

Caribbean 

Broadcast 

Services 

Enhanced Visual Acquisition 

and Conflict Detection Fewer aircraft-to-aircraft conflicts 

$719.8 $203.6 

Weather and NAS Status 

Situational Awareness 

Fewer encounters with hazardous weather $792.3 $232.5 

More efficient routes in adverse weather $18.4 $4.9 

Reduction in user costs to obtain weather info $88.9 $26.1 

Fewer controlled flights into terrain $1,015.6 $284.3 

CONUS, 

Hawaii, and 

Caribbean 

Aircraft 

Applications 

Enhanced Visual Approach - 

Initial Application More efficient spacing on approach in VMC $1,247.8 $300.4 

Enhanced Visual Approach - 

CAVS 

Continuation of Visual Approaches in 

marginal conditions 

$803.7 $196.4 

Enhanced Visual Approach - 

Merging and Spacing Increased ability to allow continuous descent 

approaches 

$2,876.7 $796.0 

ADS-B ATC Automation 

Integration 

Airport Surface Situational 

Awareness 

Increased safety on the surface by pilots 

$299.5 $70.5 

Final Approach and Runway 

Occupancy Awareness 

Gulf of Mexico 

Surveillance 

Non-radar Airspace ATC 

Surveillance (includes weather 

and comm as needed) 

High Altitude - Increased Capacity $2,064.7 $459.3 

High Altitude - Optimal Routing $256.5 $86.5 

Low Altitude - Increased Capacity $238.3 $84.2 

Fewer encounters with hazardous weatherlow altitude Gulf 

$13.1 $5.0 

Alaska 

Surveillance and 

Broadcast 

Services 

Weather and NAS Status 

Situational Awareness and 

Enhanced Visual Acquisition 

and Conflict Detection 

Fewer aviation accidents in Alaska 

$760.2 $300.1 

Non-Radar Airspace ATC 

Surveillance 

Access to lower altitude routes in Alaska $53.1 $19.5 

Increased IFR capacity (JNU) $3.0 $1.1 

Fewer aircraft-to-aircraft conflicts (JNU) $0.0 $0.0 

Improved search and rescue services in 

Alaska 

$15.8 $7.0 

Alaska Airport 

IFR Upgrade 

Services 

Weather Automation upgrade 

and IFR Approach 

Development 

Increased access to remote villages in Alaska 

$215.3 $90.0 

Increased Medevac access to remote villages 

in Alaska 

$411.8 $175.4 

Total $18,498.1 $5,043.2 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Table of Contents 

Executive Summary ............................................................................................................ ii 

1 Introduction ................................................................................................................. 1 

1.1 SBS Services ....................................................................................................... 2 

1.2 SBS Applications ................................................................................................ 3 

1.3 Benefits Estimates Segmentation ........................................................................ 5 

2 Operational Benefits ................................................................................................... 7 

2.1 Benefit Identification .......................................................................................... 7 

2.2 General Benefits Estimation Methodology ....................................................... 13 

2.3 Economic Values: Safety and Efficiency ........................................................ 14 

2.4 Equipage and Infrastructure assumptions ......................................................... 15 

2.4.1 Voluntary and Mandatory Equipage ......................................................... 15 

2.4.2 Mixed Equipage Considerations ............................................................... 16 

2.4.3 Infrastructure phasing ............................................................................... 18 

2.5 Flight Safety Benefits ....................................................................................... 19 

2.5.1 Fewer-aircraft-to-aircraft conflicts ............................................................ 19 

2.5.2 Fewer encounters with hazardous weather ............................................... 21 

2.5.3 More efficient weather deviations ............................................................ 23 

2.5.4 Fewer controlled flights into terrain (CFIT) ............................................. 24 

2.5.5 Fewer aviation accidents in Alaska ........................................................... 26 

2.6 Surface Benefits ................................................................................................ 32 

2.6.1 Increased safety on the surface by ATC ................................................... 32 

2.6.2 More efficient ATC management of surface movement .......................... 33 

2.6.3 Increased safety on the surface by pilots .................................................. 35 

2.7 Terminal and En Route Benefits ....................................................................... 37 

2.7.1 Continuing visual approaches in marginal conditions .............................. 37 

2.7.2 More efficient spacing during visual approaches ..................................... 39 

2.7.3 Increased ability to allow Continuous Descent Approaches ..................... 42 

2.7.4 More efficient en route metering to the arrival fix ................................... 45 

2.7.5 More efficient en route conflict resolution ............................................... 47 

2.8 Non-radar Benefits ............................................................................................ 50 

2.8.1 More efficient separation en route (non-radar) ......................................... 50 

2.8.2 Optimal routing ......................................................................................... 60 

2.8.3 Increased ability to fly Part 135 operations .............................................. 63 

2.8.4 Fewer encounters with hazardous weather ............................................... 66 

2.8.5 More efficient separation on approach ..................................................... 67 

2.8.6 Increased access to lower altitude routes .................................................. 68 

2.8.7 Improved search and rescue services ........................................................ 72 

2.8.8 Increased access to remote villages .......................................................... 75 

2.8.9 Increased Medevac access to remote villages ........................................... 78 

3 Cost Avoidance Benefits........................................................................................... 81 

3.1 Surveillance Cost Avoidance ............................................................................ 81 

3.2 Reduction in FAA subscription charges due to value added services .............. 81 

3.3 Reduction in costs to obtain weather info ......................................................... 82 

4 Summary of Program Benefits .................................................................................. 83 

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5 References ................................................................................................................. 85 

6 Acronyms .................................................................................................................. 88 

7 Appendix A: Equipage .............................................................................................. 91 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Table of Figures 

Figure 2-1. ADS-B Flight Safety Benefits Flow ................................................................ 9 

Figure 2-2. ADS-B Surface Benefits Flow ....................................................................... 10 

Figure 2-3. ADS-B Terminal and En Route Benefits Flow .............................................. 11 

Figure 2-4. ADS-B Non-radar Benefits Flow ................................................................... 12 

Figure 2-5. ADS-B Out and In Equipage for Air Carrier & Commuter Operators .......... 15 

Figure 2-6. Dependent Equipage Curves – Example Air Carrier .................................... 17 

Figure 2-7. CDA regimes as a function of the ratio between demand and capacity ........ 44 

Figure 2-8. Hourly demand profile for different demand bins ......................................... 53 

Figure 2-9. Hourly demand profile for low estimate ........................................................ 54 

Figure 2-10. Airspace and routes in the Gulf of Mexico .................................................. 61 

Figure 2-11. IFR En Route Grid System in low-altitude Gulf of Mexico ........................ 64 

Figure 2-12. Trimodal distribution of casulty death[22] .................................................. 79 

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Table of Tables 

Table 2-1. Safety Benefits – Economic Values (BY07 $) ............................................... 14 

Table 2-2. Efficiency Benefits – Economic Values for TAF user groups (BY07 $) ....... 14 

Table 2-3. Efficiency Benefits – Economic Values for SBS user groups (BY07 $) ....... 14 

Table 2-3. Fewer aircraft-to-aircraft conflict benefits ..................................................... 20 

Table 2-4: Fewer encounters with hazardous weather benefits ........................................ 22 

Table 2-5. More efficient routes in adverse weather benefits .......................................... 23 

Table 2-6. Fewer controlled flights into terrain benefits ................................................. 25 

Table 2-7. Capstone risk descriptions .............................................................................. 27 

Table 2-8. Capstone risk frequencies ............................................................................... 28 

Table 2-9. Capstone risk mitigation descriptions ............................................................ 28 

Table 2-10. Capstone risk mitigations by phase of flight and user type in GBT coverage

........................................................................................................................................... 29 

Table 2-11. Capstone risk mitigations inside and outside GBT coverage for Part 91 en 

route flights ....................................................................................................................... 29 

Table 2-12. Fewer aviation accidents in Alaska benefits ................................................ 31 

Table 2-13. Increased safety on the surface by ATC benefits ......................................... 33 

Table 2-14. More efficient ATC management of surface movement benefits ................ 35 

Table 2-15. Increased safety on the surface by pilots benefits ........................................ 36 

Table 2-16. Continuation of Visual Approaches in marginal conditions benefits ........... 38 

Table 2-17. More efficient spacing during visual approaches benefit ............................. 40 

Table 2-18. More efficient merging and spacing en route benefits ................................. 45 

Table 2-19. Meter Fix Uncertainty from NASA study ..................................................... 46 

Table 2-20. Meter Fix Uncertainty with increased accuracy ............................................ 46 

Table 2-21. More efficient en route metering to the arrival fix benefits ......................... 47 

Table 2-22. More efficient en route conflict resolution benefits ..................................... 49 

Table 2-23. More efficient en route separation (non-radar) benefits ................................ 51 

Table 2-24. Capacity estimates for Gulf of Mexico before and after Surveillance .......... 51 

Table 2-25. Unconstrained Gulf of Mexico flight demand in daily bins .......................... 52 

Table 2-26. Average queuing delay results per aircraft for different demand bins .......... 55 

Table 2-27. Gulf of Mexico flight demand in daily bins constrained by delay cap ......... 56 

Table 2-28. Example of annual delay calculation for 2025 (most likely case) ................. 56 

Table 2-29. Average queuing delay results per aircraft using constrained demand ......... 57 

Table 2-30. Annual delay results for all three methods .................................................... 58 

Table 2-31. Additional flights accommodated by surveillance capacity (most likely case)

........................................................................................................................................... 59 

Table 2-32. Optimal routing benefits ................................................................................ 60 

Table 2-33. Optimal route savings between selected city pairs ........................................ 62 

Table 2-34. Increased ability to fly Part 135 operations benefits ..................................... 65 

Table 2-35. Capacity and service time by scenario .......................................................... 65 

Table 2-36. Fewer encounters with hazardous weather benefits ...................................... 66 

Table 2-37. More efficient spacing on approach (non-radar) benefits by segment .......... 67 

Table 2-38. Proposed FIXES for Lowering MEAs .......................................................... 69 

Table 2-39. Alaska cancellation costs ............................................................................... 70 

Table 2-40. Increased access to lower altitude routes benefits ......................................... 72 

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F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Table 2-41. Improved search and rescue services benefits ............................................... 73 

Table 2-42. Search and Rescue Time Savings by Stage ................................................... 74 

Table 2-43. Remote airport increased access and operations counts ................................ 77 

Table 2-44. Increased commercial access to remote villages benefits ............................. 78 

Table 2-45. Assumptions used in medical access benefit ................................................. 80 

Table 2-46. Increased Medevac access to remote villages benefits .................................. 81 

Table 3-1. Surveillance cost avoidance benefits ............................................................... 81 

Table 3-2. Reduction in FAA subscription charges due to value added services benefits

........................................................................................................................................... 82 

Table 3-3. Reduction in costs to obtain weather info benefits .......................................... 82 

Table 4-1. Summary benefits for the SBS program .......................................................... 83 

Table 4-2. SBS program benefits by location, application, and desired outcome ............ 84 

Table 7-1. ADS-B broadcast out equipage in CONUS ..................................................... 91 

Table 7-2. ADS-B In equipage in CONUS ....................................................................... 92 

Table 7-3. Additional CFIT eligible equipage in CONUS ............................................... 93 

Table 7-4. Gulf of Mexico equipage assumptions ............................................................ 94 

Table 7-5. UPS CDTI equipage ........................................................................................ 95 

Table 7-6. Alaska Capstone avionics equipage ................................................................ 96 

Table 7-7. Alaska Capstone additional CFIT eligible equipage ....................................... 97 
1 INTRODUCTION 

The Surveillance and Broadcast Services (SBS) program offers the FAA an opportunity 

to upgrade surveillance capabilities and services through currently available satelliteenabled technology. The primary tool for these improvements is Automatic Dependent 

Surveillance-Broadcast (ADS-B). The SBS program also offers a bundling of supporting 

technologies directed at lowering agency, operator and the NAS user operating costs, 

while enhancing safety, capacity, productivity, and efficiency. ADS-B technology, in 

conjunction with the Global Positioning System (GPS), provides a highly accurate, 

timely (once per second), all weather, NAS-wide system of broadcasting geographical 

position, altitude and thrust vector from properly equipped aircraft and/or surface 

vehicles. Aviation applications employ ADS-B data-link technology to provide distinct 

aircraft or vehicle-specific identification, and operational data in the air-to-air, air-toground, ground-to-air, and/or ground-to-ground mode in all NAS domains (Terminal, 

Surface, En Route and Oceanic). These digital ADS-B position reports can be received 

by and used throughout the aviation community to enhance NAS operations, while 

reducing overall operating costs. With ADS-B as the “cornerstone,” enabling 

technologies such as Traffic Information Service-Broadcast (TIS-B) and Flight 

Information Service-Broadcast (FIS-B) will be bundled to enhance air traffic procedures 

to provide significant improvements to the NAS. 

Aircraft Operations: Using an ADS-B data link radio, equipped aircraft broadcast their 

own GPS-derived position once per second. This information is received by other ADSB equipped aircraft within reception range and presented on a multi-function display in 

the aircraft (also known as Cockpit Display of Traffic Information (CDTI)). To augment 

this air-to-air traffic display, ADS-B ground stations broadcast radar-derived aircraft 

position information of aircraft not broadcasting ADS-B data. These non-equipped 

aircraft are also displayed on the CDTI. To further supplement pilot situational 

awareness, text and graphical weather products (observations and forecasts) and digital 

NAS status information (Temporary Flight Restrictions (TFRs), Special Use Airspace 

(SUA), etc.), are broadcast on the same data link frequency and provided to pilots on the 

cockpit display. 

Aircraft Equipage: Many aircraft currently have the ability to broadcast ADS-B 

messages or have onboard equipment (i.e. GPS) that can be easily modified to broadcast 

ADS-B (latent-broadcast). All aircraft currently in production by both Boeing and 

Airbus have ADS-B latent-broadcast or broadcast capabilities. 

A key assumption of the program is that equipage of a broadcast (squit-only) capability 

will be mandated for all aircraft flying in certain classes of airspace. 

Air Traffic Control and Airspace Operational Management: ADS-B broadcast 

positional information will be combined with radar-derived surveillance positions and 

displayed for air traffic control, airline operations centers (AOCs), Regional Airport 

Authorities (RAA’s,) etc. for common/shared situational awareness and airspace 

management. Additionally, this ADS-B positional data will provide enhancements to 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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automated airspace flow prediction, airport surface operations, shared conflict awareness, 

and warning while offering a lower-cost alternative for radar-like coverage to areas not 

currently within radar surveillance. 

 

The SBS program office also concentrated on the opportunity to reduce FAA costs by 

eliminating legacy surveillance systems that provide redundant capabilities. The 

following analyses span the timeframe of 2007 through 2035 to allow for the completion 

of the on-going surveillance replacement programs as well as a complete cycle of next 

generation radar replacements in the future. Removal of legacy surveillance occurs in 

later years of the program and depends on ADS-B broadcast mandates. 

1.1 SBS Services 

The Surveillance and Broadcast Services program provides four fundamental services: 

ADS-B, ADS-R, TIS-B, and FIS-B. These services currently support seven initial 

program applications. 

Automatic Dependent Surveillance-Broadcast (ADS-B) - ADS-B equipped aircraft 

and vehicles periodically broadcast their state vector (horizontal and vertical position, 

horizontal and vertical velocity) and other information over either a 978 Universal Access 

Transponder (UAT) or a 1090 Extended Squitter (ES) data link. The ADS-B message 

broadcasts are received by other aircraft in the vicinity and by the SBS Data Link 

Processor. These ADS-B Messages are processed and formatted into ADS-B Reports. 

The Data Link Processor provides these reports to the Broadcast Server and ATC 

Automation system for use by ATC in providing separation assurance and other services. 

ADS-B is automatic because no external stimulus is required; it is dependent because it 

relies on an on-board navigation source to broadcast the information to other users. The 

aircraft or vehicle originating the broadcast may or may not have knowledge of which 

users are receiving its broadcast; any user, either aircraft or ground-based, within range of 

this broadcast, may choose to receive and process the ADS-B surveillance information. 

ADS-B has the potential to provide surveillance data at a higher update rate and with 

improved accuracy over today’s NAS radar systems. All four ADS-B functions, 

Aircraft/Vehicle, Data Link Processor, Broadcast Server, and ATC Automation are 

necessary to provide the ADS-B Service. 

Automatic Dependent Surveillance-Rebroadcast (ADS-R) - Equipped aircraft receive 

broadcast ADS-B Messages directly from other aircraft equipped with the same data link 

technology. An aircraft equipped with a particular data link will have surveillance 

information only on like-equipped aircraft. As aircraft equip with either 978 UAT or 

1090 ES data link technologies, ADS-R provides a service to rebroadcast ADS-B 

messages received down one link and back up the other link. In this way, ADS-R service 

provides traffic information for interoperability between both data links. The 

Aircraft/Vehicle and Data Link Processor are necessary to provide the ADS-R Service. 

Traffic Information Service-Broadcast (TIS-B) - During NAS-wide deployment of 

ADS-B, aircraft will begin equipping with ADS-B avionics. During this transition, ADSB-equipped aircraft will lack surveillance information on aircraft that are not ADS-B 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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equipped. The Surveillance and Broadcast Services ground infrastructure will support 

air-to-air operations by broadcasting TIS-B Messages on both the 978 UAT and 1090 ES 

data links for targets detected and reported by radar or other surveillance systems. This, 

in conjunction with the ADS-R service, will provide equipped aircraft the information 

needed for a more complete picture of the traffic situation. TIS-B service will be 

decommissioned in the end state when all aircraft are ADS-B-equipped. The 

Aircraft/Vehicle, Data Link Processor, and Broadcast Server are necessary to provide the 

TIS-B service. 

 

Flight Information Service-Broadcast (FIS-B) - FIS-B provides the broadcast of 

weather and non-control advisory information providing users aeronautical information 

supporting safe and efficient operations. FIS-B products include, but are not limited to, 

graphical and textual weather reports and forecasts, Next Generation of Radar 

(NEXRAD) precipitation information, Special Use Airspace (SUA) information, Notices 

to Airmen (NOTAMs), electronic pilot reports (E-PIREPS), and other similar 

meteorological and aeronautical information. FIS-B products will be uplinked using the 

978 UAT from the Data Link Processor and will not be available on the 1090 ES link. 

There are many potential future FIS-B products that may be provided as their concepts 

mature. Therefore, the FIS-B service and data link capacity should allow for growth to 

accommodate additional products. The uplinked products will come from both 

government and commercial sources. The Aircraft/ Vehicle, Data Link Processor, and 

Broadcast Server are necessary to provide the FIS-B service. 

 

1.2 SBS Applications 

The following are the abbreviated descriptions of the seven initial SBS applications 

selected for near-term NAS implementation. These seven applications were chosen 

based on their maturity, cost and operational benefits, and an understanding of the 

performance requirements necessary for implementation. 

ATC Surveillance - The goal of this application is to use ADS-B information as a 

qualified surveillance source to provide ATC services throughout the NAS. The ADS-B 

surveillance information will also be used to enhance the quality of existing radar-based 

surveillance information for ATC automation system functions. The improved accuracy 

of ADS-B information will be used in advanced automation tools to allow more accurate 

spacing in the terminal area and for advanced procedures such as Continuous Descent 

Approach. The targeted implementation areas include surface, terminal, en route, offshore, and oceanic domains. ADS-B surveillance will allow ATC to apply separation 

between ADS-B-to-ADS-B and ADS-B-to-radar based targets. Within this document, 

this application is divided into Non-radar Airspace ATC Surveillance and Radar 

Airspace ATC Surveillance. 

- To support the continued development of increased surveillance services in nonradar airspace, the SBS program is also assisting with upgrading IFR 

infrastructure including some airport upgrades in Alaska. In the tables and charts, 

this activity is referred to under the application Weather Automation Upgrade 

and IFR Approach Development. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Airport Surface Situational Awareness - The objective of this application is to reduce 

the potential for deviations, errors, and collisions through an increase in flight crew 

situational awareness while operating an aircraft on the airport movement area. Flight 

crews will use a cockpit display to increase awareness of other traffic positions on the 

airport movement area. Additionally, the display may be used to determine the position 

of ground vehicles, e.g., snow plows, emergency vehicles, tugs, follow-me vehicles, and 

airport maintenance vehicles. 

Final Approach Runway Occupancy Awareness - The objective of this application is 

to reduce the likelihood of flight crew errors associated with runway occupancy and to 

improve the capability of the flight crew to detect ATC errors. The application involves 

the use of a cockpit display that depicts the runway environment and displays traffic from 

the surface up to approximately 1,000 feet above ground level on final approach and will 

be used by the flight crew to help determine runway occupancy. 

Enhanced Visual Acquisition - The objective of this application is to provide the flight 

crew enhanced traffic situational awareness in controlled and uncontrolled 

airspace/airports. The application uses a cockpit display to enhance out-of-the-window 

visual acquisition of air traffic. Flight crews will refer to the display during the 

instrument scan to supplement visual observations. The display can be used to either 

initially detect an aircraft or to receive further information on an aircraft that has been 

reported by ATC. The application provides the flight crew with the relative range, 

altitude, and bearing of other aircraft. 

 

Enhanced Visual Approach - This application is intended to enhance successive 

approaches for aircraft cleared to maintain visual separation from another aircraft on the 

approach. The goal is to maintain visual approach procedure operation arrival rates even 

during periods of reduced visibility or obstructions to vision (haze, fog, sunlight, etc). To 

achieve this objective, flight crews will be supported by a cockpit display of nearby 

traffic. This will provide continually updated identity and position information to assist 

the flight crew with achieving and maintaining visual contact with relevant traffic. 

Additional information such as range and speed will be provided to assist flight crews in 

monitoring their distance from the preceding aircraft. Enhanced Visual Approach has 

three sub-applications: 

-VMC situational awareness (Initial EVA) – application to assist with more 

efficient spacing for Visual approaches during Visual Meteorological Conditions 

(VMC) 

-CDTI Assisted Visual Separation (CAVS) – application to allow continuation 

of Visual Approaches during reduced meteorological conditions 

-Merging and Spacing (M&S) – application to allow optimization of approach 

trajectory while still in en route airspace. This application assisted by controller 

automation should allow multiple aircraft in high demand periods the ability to 

plan and perform advanced approach procedures, such as Continuous Descent 

Approach. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Conflict Detection - The objective of this application is to provide alerting and relevant 

traffic information to help the flight crew identify conflicts with other aircraft based on 

current flight states and intentions. Aircraft equipped with a cockpit display have the 

capability to display aircraft location and intent. More than simply displaying traffic, the 

application will alert pilots of developing conflicts. Also, the long surveillance range 

afforded by ADS-B will enable alerts to be issued in time to solve the conflict with 

minimum disruption to the flight path. NOTE: The Conflict Detection application is an 

ADS-B-enabled capability for properly equipped aircraft and is not intended as a Traffic 

Alert and Collision Avoidance System (TCAS) replacement. 

Weather and NAS Status Situational Awareness - The primary objective of this 

application is to provide the flight crew with improved access to weather information and 

aeronautical data. Many types of information are not suitable for conveyance by voice, 

such as graphical weather products. In the transfer of this information by voice, 

considerable detail is lost and the time and attention devoted to conveying the 

information is lengthy and diverts the pilot from primary flight duties. The application 

will improve access to textual and graphical weather and other aeronautical information 

(i.e., Aviation Routine Weather Reports (METARs), Terminal Area Forecasts (TAFs), 

Significant Meteorological Advisory (SIGMETs), PIREPs, NOTAMs, NEXRAD, SUA 

status, etc) by use of a cockpit-based display. 

1.3 Benefits Estimates Segmentation 

This document has two major sections: Operational Benefits and Cost Avoidance 

Benefits. The SBS program will provide the applications described in Section 1.2 to 

FAA and aviation users; these benefits are detailed in the Operational Benefits section. 

The SBS program will also provide currently available air traffic surveillance and 

communication services at lower cost to the FAA; these are outlined in the Cost 

Avoidance section. 

The benefits are further subdivided by location and application outcome. Some benefits 

are limited to specific areas of deployment in early years and represent further 

deployment areas and include NAS-wide deployment. The areas of early deployment 

were chosen to demonstrate early benefits in the program. The early years of the SBS 

program will: 

1. Provide ADS-B surveillance for flights in the Gulf of Mexico high-altitude (above 

FL240) non-radar region 

2. Provide ADS-B surveillance, upgraded communications, and additional weather 

reporting stations in the low-altitude Gulf of Mexico non-radar region 

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3. Integrate current ADS-B infrastructure with a Multilateration system in the Juneau, 

Alaska area to provide surveillance for the en route center and Juneau air traffic 

control tower (ATCT). 

4. Expand FIS-B/TIS-B services from current legacy deployment along the East 

Coast to cover an area that includes approximately 60 percent of General Aviation 

flights NAS-wide, and 

5. Implement the Enhanced Visual Approach and safety applications for CDTIequipped aircraft owned by United Parcel Service (UPS) and operated at three 

major hubs: Louisville International Airport (SDF), Philadelphia International 

Airport (PHL), and Ontario International Airport (ONT). By 2004, UPS had 

equipped 107 of their aircraft for ADS-B CDTI operations. They have been 

instrumental in the development of many CDTI applications and will continue to 

provide a test bed for advanced air-to-air and air-to-ground applications. These 

applications (and the associated benefits) should expand to other airlines and 

locations NAS-wide in Segment 2. 

The summary tables in the executive summary and Section 4 isolate the benefits by 

location, application, and benefit outcome in both Base Year 2007 and risk-adjusted 

Present Value dollars. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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2 OPERATIONAL BENEFITS 

2.1 Benefit Identification 

The initial step of the ADS-B operational benefits analysis was to develop a complete list 

of safety and efficiency benefits and the associated metrics. The benefit outcome metrics 

defined as part of the Phase I Safe Flight 21 cost benefit analysis [1] were used to draft 

the initial list. This list was then augmented based on inputs from the SBS program. 

While measuring a change in a particular metric is simple, interpreting the results is 

sometimes difficult. The most complex part of benefits analysis is attributing a change to 

the use of an application. We attempt to better understand the activity changes by 

outlining the mechanisms for benefit in a specific format, which we call a “benefits 

flow.” 

The benefits flow process begins with a meeting of potential users for the new 

application. Operators explain the direct impact of each application-driven capability and 

discuss the changes in airport or airspace operations that arise from these impacts. 

Subsequently, we develop concise descriptions of each operational change. The benefits 

flow is a diagram that serves as an outline for this narrative framework. It has four 

columns: application, direct impact, outcome, and benefit. For clarity, we define these 

words below for our context: 

Application – new or improved capability provided to the users (see Section 1.2) 

Direct Impact – how the new or improved capability enhances user operations 

Outcome – the result of the direct impacts on airport/airspace operations 

Benefit – how the outcomes improve airport/airspace operations in terms of quantifiable 

measures 

Because the SBS effort is considering different types of applications for different users, 

we divided the potential benefits into four separate categories. The Flight Safety flow 

involves benefits from the SBS program targeted at general aviation pilots. The Surface 

flow concerns applications available to pilots, air traffic controllers, and airlines on the 

airport surface. The Terminal and En Route flow involves ADS-B airborne efficiency 

applications for both pilots and controllers. Finally, the Non-radar flow focuses on ADSB applications specific to non-radar regions such as the Gulf of Mexico and Alaska. 

Figures 2-1, 2-2, 2-3, and 2-4 present diagrams of the benefits flows that trace 

applications to benefits for each of the four categories that we examine in this effort. The 

benefit details section is organized by the Outcomes seen in each flow. The major SBS 

Outcomes are listed on the next page organized by category. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

7
F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

8

Flight Safety (see Figure 2-1) 

• Fewer aircraft-to-aircraft conflicts 

• Fewer encounters with hazardous weather 

• More efficient weather deviations 

• Fewer controlled flights into terrain (CFIT) 

Surface (see Figure 2-2) 

• Increased safety on surface by ATC 

• More efficient ATC management of surface movement 

• Better communication between pilots, airlines, and ATC on surface 

• Increased safety on the surface by pilots 

• More efficient movement on airport surface by pilots 

Terminal and En Route (see Figure 2-3) 

• Continuation of visual approaches in marginal conditions 

• More efficient spacing during visual approaches 

• More efficient merging and spacing en route 

• More efficient en route metering to the arrival fix 

• More efficient release from en route circular holding 

• Increased ability to allow Continuous Descent Approaches 

• More efficient en route conflict resolution 

• Better communication between pilots and ATC 

Non-radar (see Figure 2-4) 

• More efficient separation on approach (non-radar) 

• More efficient separation en route (non-radar) 

• Optimal routing 

• Increased access to lower altitude routes 

• Increased ability to fly Part 135 operations 

• Fewer encounters with hazardous weather 

• Improved search and rescue services 

• Increased commercial access to remote villages in Alaska 

• Increased Medevac access to remote villages in Alaska 

In addition to the operational benefits there are some FAA cost avoidance benefits 

outlined in Section 3. The summary charts (Section 4) also mention many of these 

benefits. 
Figure 2-1. ADS-B Flight Safety Benefits Flow 

Application Direct Impact Outcome 

Technology 

Improved traffic situational 

awareness 

Improved terrain situational 

awareness 

Improved weather situational 

awareness 

Fewer encounters with 

hazardous weather 

Fewer controlled flights into 

terrain 

Fewer aircraft-to-aircraft 

conflicts 

More efficient deviations 

Multi-Function 

Display for pilots 

including access to 

CDTI, TIS-B, FIS-B, 

Terrain Map for 

pilots)

Enhanced Visual 

Acquisition, 

Conflict Detection 

and Weather and NAS 

Status Situational 

Awareness 

Flight Information 

Service - Broadcast 

(FIS-B) 

Traffic Information 

Service – Broadcast 

(TIS-B) 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

9
F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

10

Figure 2-2. ADS-B Surface Benefits Flow 

More efficient movement on 

airport surface by pilots 

Radar Airspace ATC 

Surveillance 

for ATC Tower 

Increased safety on the surface 

by pilots 

More efficient ATC 

management of surface 

Common situational 

awareness of 

aircraft/vehicle positions 

between ATC, Airlines, 

and pilots 

Increased ability to 

anticipate ETA and order 

of arrivals 

Better communication between 

airline, pilots, and ATC 

Airport Surface 

Situational 

Awareness 

and 

Final Approach and 

Runway Occupancy 

Awareness 

Increased ability to monitor 

runway queues 

Increased pilot airport 

surface and traffic 

situational awareness 

Increased safety on the surface 

by ATC 

Technology Application Direct Impact Outcome 

ASDE-X upgrade 

to remaining 

ASDE-3 only sites 

Multifunction 

Display for pilots 

Surface Moving 

Map Database 
F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

11

Figure 2-3. ADS-B Terminal and En Route Benefits Flow 

Enhanced Visual 

Acquisition 

and 

Enhanced Visual 

Approach 

(for pilots) 

Increased pilot ability to 

identify, visually acquire, 

and maintain ADS-B traffic

Increased pilot awareness 

of overall traffic flows

Improved ability to 

maintain efficient spacing 

with lead aircraft

Increased ability to allow 

Continuous Descent 

Approaches 

Better communication 

between ATC and 

pilot

Continuation of visual 

approaches in marginal 

conditions 

More efficient merging and 

spacing en route

Radar Airspace 

ATC Surveillance 

Common situational 

awareness of aircraft/vehicle 

positions between ATC, 

Airlines, and pilots 

More efficient spacing during 

visual approaches

Increased automation 

spacing accuracy and 

update rate 

More efficient release from 

en route circular holding 

More efficient en route 

conflict resolution 

Technology Application Direct Impact Outcome 

Multi-Function 

Display for pilots 

including access to 

CDTI, TIS-B for 

pilots) 

Traffic Information 

Service – Broadcast 

(TIS-B) 

More efficient en route 

metering to arrival fix 

ADS-B ATC 

Automation 

Integration 
F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

12

Figure 2-4. ADS-B Non-radar Benefits Flow 

Ability to use reduced 

separation standards 

Improved weather situational 

awareness for ATC 

Increased number of 

available routes 

Optimal routing 

Improved search and rescue 

services 

More efficient separation en 

route (non-radar) 

Fewer encounters with 

Hazardous weather 

Increased ability to fly Part 

135 IFR operations 

Non-Radar Airspace 

ATC Surveillance 

(for ATC) 

Improved traffic situational 

awareness for ATC 

Automated 

Weather 

Observations 

Improved 

Communications 

Services 

More efficient separation on 

approach (non-radar) 

Increased commercial 

access to remote villages 

Increased Medevac access 

to remote villages 

IFR Route and 

Approach 

Development 

Ability to perform IFR 

airport approaches 

Increased access to lower 

altitude routes 

Technology Application Direct Impact Outcome 

ADS-B ATC 

Automation 

Integration 

Upgrade IFR 

Infrastructure 
2.2 General Benefits Estimation Methodology 

The SBS operational benefits were estimated relative to the existing ATC system, with 

established procedures currently in effect. Historical data were combined with traffic 

projections to describe the baseline from which benefits could be measured. This 

reference point was modified, prior to estimating benefits, to reflect any approved future 

improvements to the baseline that are scheduled during the analysis time period. System 

effectiveness measures, the percent reduction in either accident rates or typical delay 

times, were applied to the estimated baseline level in order to derive expected benefits. 

Effectiveness was defined in terms of the improvement expected given the technology is 

adopted. The system effectiveness, the percent of the population equipped, and the 

percent of infrastructure installed are key drivers in all the benefit estimates. These 

factors combine to represent the level of benefits that are expected in the future. 

Benefits were estimated in terms of both safety and efficiency gains. Safety benefits are 

derived from the estimated reductions in accident rates and the potential economic 

savings in terms of avoided loss of life, injuries and aircraft damages. The efficiency 

benefits quantified refer to delay and fuel savings. The delay savings are valued in terms 

aircraft direct operating costs and passenger value of time. 

The historical baselines for the safety benefits were based on a careful review of National 

Transportation Safety Board (NTSB) aviation accident reports, a 16-year period 1989 

through 2004 was used. Appropriate database search methodologies were developed for 

each accident type for which reductions are expected. The sets of accidents identified for 

each category were compared to ensure that specific incidents were not counted more 

than once towards the potential benefits. The total historical number of accidents for 

each accident type was tabulated by region and compared with regional traffic counts 

over the same time period to estimate accident rates. 

Both the safety and efficiency historical baselines are functions of traffic density. The 

baselines are combined with traffic projections from the FAA Terminal Area Forecasts 

(TAF) to develop forecasts of potential benefits each year. In addition, the timeframe for 

which each benefit starts to accrue is based on when the specific application is to be 

operationally certified as well as on user equipage and the commissioning of the 

necessary ground equipment. 

The effectiveness percentages attributed to SBS applications and the percent of the 

population anticipated to equip are multiplied by the potential benefits each year to 

develop annual benefit estimates. The effectiveness assumptions are based on a 

combination of subject matter expert assessments and the results from previous studies. 

The equipage percentages by user group and location were combined to reflect the 

likelihood of the benefits being realized depending on whether one or two aircraft are 

involved in the scenario and whether or not ADS-B equipped aircraft can view 

transponder-equipped aircraft through the availability of TIS-B functionality. Equipage 

and infrastructure issues are discussed in more detail in the following sections. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

13
2.3 Economic Values: Safety and Efficiency 

Safety benefits are measured in terms of avoided accidents while efficiency benefits are 

valued as flight hours saved. Avoided accidents are translated into economic values by 

applying the unit costs associated with fatalities, injuries both serious and minor, and 

aircraft damages both destroyed and substantially damaged. The safety related values are 

provided in the Economic Values for Evaluation of Federal Aviation Administration 

Investment and Regulatory Programs [2] published by the FAA’s Office of Policy and 

Plans (APO) and are shown in Table 2-1. The economic value associated with flight 

hours saved is based on the aircraft direct operating costs (ADOC) of fuel, crew, and 

maintenance. The Passenger Value of Time (PVT) per aircraft type is based on average 

number of seats and load factor. Table 2-2 presents ADOC and PVT values for each user 

group in the TAF while Table 2-3 provides the same values for the primary user groups 

used in the SBS study. The SBS user groups are somewhat different than the TAF user 

groups because of different equipage assumptions (UAT and 1090) and the related 

difference in benefits. It is expected that all the air carrier and commuter airline fleets 

will use the 1090 link and mostly take advantage of the air-to-air efficiency applications. 

The air taxi and general aviation fleets will most likely equip with the UAT link and 

mainly take advantage of the FIS-B and TIS-B applications. 

Table 2-1. Safety Benefits – Economic Values (BY07 $) 

Injury Type Value

Fatalities $3,000,000

Serious Inj $580,700

Minor Inj $42,900

AC-Type GA Air Taxi Air Carrier & 

Commuter 

Aircraft Destroyed $390,000 $390,000 $12,370,000 

Aircraft Substantial Damage $40,000 $40,000 $3,990,000 

Table 2-2. Efficiency Benefits – Economic Values for TAF user groups (BY07 $) 

Flight Phase Air Carrier Commuter & Air Taxi General Aviation 

Airborne $3902 $1038 $526 

Ground $1957 $521 $526 

Block $3608 $944 $526 

PVT (per aircraft) $2702 $596.5 $78.42 

Table 2-3. Efficiency Benefits – Economic Values for SBS user groups (BY07 $) 

Flight Phase Air Carrier & 

Commuter Air Taxi General Aviation 

Airborne $2814 $1038 $526 

Ground $1411 $521 $526 

Block $2596 $944 $526 

PVT (per aircraft) $1966 $120.6 $78.42 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

14
2.4 Equipage and Infrastructure assumptions 

Equipage rates are defined as the percentage of the active population that will equip and 

are estimated for each user group. These percentages are used to estimate the magnitude 

to which SBS benefits are to be realized. 

2.4.1 Voluntary and Mandatory Equipage 

The SBS program has different equipage assumptions for different benefits. The current 

SBS program plan calls for the FAA to mandate of ADS-B broadcast out (ADS-B out) 

equipage for all users who use Class A, B, or C airspace by 2020. There are no current 

plans for a CDTI (ADS-B In) mandate so equipage will be voluntary; however, CDTI 

equipage will be influenced by the ADS-B out mandate because the different capabilities 

may be packaged together. Figure 2-5 displays the projected ADS-B Out and ADS-B In 

equipage curves for air carrier and commuter operators. Appendix A contains all the 

relevant equipage tables assumed within the model. 

0%

20%

40%

60%

80%

100%

120%

2005 2010 2015 2020 2025 2030 2035

Year

Percent Equipped 

(Air Carrier & Commuter)

ADS-B Out

ADS-B In

Figure 2-5. ADS-B Out and In Equipage for Air Carrier & Commuter Operators 

Many of the applications depend on early ADS-B broadcast-out or even CDTI equipage. 

In these instances, the service or capability will only be available to the equipped 

population. For example, broadcast weather information and the associated benefits will 

only be available to pilots equipped with a UAT ADS-B transceiver and a multi-function 

display. As another example, in the Gulf of Mexico, ADS-B will provide enhanced 

surveillance services for ADS-B broadcast-out equipped aircraft. The introduction of 

radar-like separation will increase sector capacity. Initial separation by surveillance will 

be limited to selected optimal altitudes where only equipped flights may operate. These 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

15
two examples show that there will be specific advantages to equipping with ADS-B. It is 

hoped these advantages will encourage early equipage. 

Some of the early commercial airline benefits are limited to CDTI-equipped aircraft 

owned by United Parcel Service (UPS) and operated at two major hubs: Louisville 

International Airport (SDF) and Philadelphia International Airport (PHL). By 2004, 

UPS had equipped 107 of their aircraft for ADS-B CDTI operations. They have been 

instrumental in the development of many CDTI applications and will continue to provide 

a test bed for advanced air-to-air and air-to-ground applications. These applications (and 

the associated benefits) are assumed to expand to other airlines and locations in later 

years 

2.4.2 Mixed Equipage Considerations 

As the NAS transitions into an ADS-B environment, we must consider the effects of 

mixed equipage on the CDTI-enabled benefits. We defined the following four equipage 

scenarios: 

• Independent equipage 

• Dependent ADS-B equipage 

• Order Specific Dependent Mixed equipage 

• Non-Order Specific Dependent Mixed equipage. 

Independent equipage applies to situations where only one aircraft must be CDTIequipped in order to realize benefits. For benefit elements such as reducing the number 

of weather related accidents, the likelihood of any given aircraft achieving improvements 

is independent of whether another aircraft is equipped. Therefore, the equipage rates for 

CDTI can be applied directly or linearly to determine expected benefits. 

However, for benefit elements that involve two aircraft, such as reducing the number of 

midair collisions, the likelihood of realizing benefits is dependent on both aircraft. This 

benefit requires not only that an aircraft have the capability to see other aircraft (CDTI) 

but that the conflicting aircraft is equipped with the avionics necessary to be seen (either 

ADS-B out or a Transponder). The dependent CDTI equipage scenario is estimated by 

multiplying the independent CDTI equipage rate for a given user group by the rate for all 

other user groups including itself to create a matrix of values that define the probabilities 

for the possible pairings of aircraft. 

The dependent mixed equipage scenarios incorporate all ADS-B out aircraft and the 

availability of TIS-B functionality. TIS-B provides CDTI equipped aircraft with the 

ability to recognize transponder equipped aircraft operating without ADS-B. The order 

specific dependent mixed equipage scenario is used to model conditions where the order 

of CDTI equipped aircraft must be specified to achieve the benefits. For applications 

such as approach spacing, the following aircraft in the pair must be CDTI equipped since 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

16
this aircraft needs to see the preceding aircraft in order to achieve improvements. 

However, given TIS-B functionality, the preceding aircraft can be either ADS-B out 

equipped or transponder equipped since it is only required that the preceding aircraft be 

seen by the following aircraft for this application. The non-order specific equipage 

scenario is reserved for cases where the benefit is realized as long as one of the aircraft 

can see the other regardless of which aircraft that may be. As in the benefit addressing a 

reduction in mid-air collisions, it was determined that if either of the aircraft involved in 

the conflict is made aware of the impending situation, then there is a potential for 

avoiding the accident. 

Figure 2-6 displays the relationship between the dependent equipage scenarios when both 

aircraft involved are operating as air carrier. Figure 2-6 is based on the independent 

equipage assumptions for the national equipage estimate. 

Figure 2-6. Dependent Equipage Curves – Example Air Carrier 

0

20

40

60

80

100

120

200620082010201220142016201820202022202420262028203020322034

Year

Percentage

Non-order specific mixed

Order-specific mixed

CDTI Dependent

The order specific dependent mixed equipage scenario is estimated by multiplying the 

probability that the first aircraft is CDTI equipped by the probability that the second 

aircraft is either ADS-B out or transponder equipped. Since some aircraft will be both 

ADS-B out and transponder equipped, the probability that an aircraft is equipped with 

either CDTI or ADS-B out or a transponder is equivalent to the probability of being 

equipped with CDTI plus the probability of being equipped with ADS-B out or a 

transponder minus the probability of being equipped with both. 

The non-order specific dependent mixed equipage scenario includes conditions where 

either the first or second aircraft is CDTI equipped with the other aircraft being either 

ADS-B out or transponder equipped as well as cases where both aircraft are CDTI 

equipped. The order specific calculation described accounts for cases where the first 

aircraft is CDTI equipped and the second aircraft is either transponder or ADS-B out 

equipped which allows for the possibility of both aircraft being CDTI equipped. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

17
Therefore, the non-order specific scenario is estimated as two times the order specific 

dependent mixed equipage estimate minus the dependent CDTI equipage estimate. 

2.4.3 Infrastructure phasing 

Many of the ADS-B benefits also depend on an underlying infrastructure that provides 

broadcast information services or surveillance services. The international community 

decided to receive and transmit ADS-B information using two data links UAT 987 and 

1090 ES). In the end-state, all services will be provided using a dual UAT/1090 data 

link. The schedule for services to these two links differs by year and location. The 

analyses take these different service schedules into account when estimating benefits. 

The benefits presented within the document depend heavily on the planned service 

schedules. Some of the benefits are exclusive to one of the data links. We mention the 

link dependence within the benefit analysis descriptions to follow. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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2.5 Flight Safety Benefits 

The Flight Safety benefits (see Figure 2-1) are derived from the following outcomes: 

• Fewer aircraft-to-aircraft conflicts 

• Fewer encounters with hazardous weather 

• More efficient weather deviations 

• Fewer controlled flights into terrain (CFIT). 

The SBS program also includes related flight safety benefits in Alaska. While the benefit 

mechanisms are quite similar to those in the other parts of the NAS, a different analytical 

method was performed by the previous program office to estimate these benefits. The 

SBS program decided to incorporate the analysis from the previous program office into 

the benefits case, as opposed to performing a new analysis. The Alaska Capstone Phase 

III flight safety benefits are presented as a separate section called: 

 • Fewer aviation accidents in Alaska. 

2.5.1 Fewer-aircraft-to-aircraft conflicts 

The principle of "see-and-avoid" (whereby the pilot visually searches out the window for 

other aircraft, and alters flight path to avoid them if necessary) is well established in 

regulation, procedure, and practice. However, there are practical limitations associated 

with the see-and-avoid principle due to the difficulty for the pilot to visually acquire other 

traffic in a consistent and reliable manner and the limitations. 

Through a CDTI, the SBS program will improve the pilot's ability to visually acquire 

(Enhanced Visual Acquisition) other traffic so that the see-and-avoid principle can be 

more effectively applied. Based on information gained from the CDTI, the pilot can then 

better focus his/her visual search for the other ADS-B aircraft, as well as better monitor 

its movements once acquired. This will result in greater pilot situational awareness, 

greater scan effectiveness, and the ability to plan for avoidance earlier in an encounter 

scenario (Conflict Detection). 

The SBS program will provide the data necessary to enhance see-and-avoid by two 

methods. CDTI-equipped aircraft will always see other ADS-B equipped aircraft within 

the line of sight of the ADS-B receiver. Additionally, CDTI-equipped aircraft will also 

be able to see local transponder-equipped aircraft positions broadcast where TIS-B 

service is available. Currently available CDTI avionics also includes a traffic warning for 

conflict detection. 

 

TIS-B service will be available above 6000 feet NAS-wide and even lower in the vicinity 

of the service broadcast points. As ADS-B equipage levels increase, the proportion of 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

19
additional aircraft broadcast using the TIS-B service will decrease. It is expected that 

TIS-B service will discontinue after full equipage. 

It should be noted that a majority of aircraft used in passenger revenue operations are 

currently equipped with the Traffic Alert and Collision Avoidance System (TCAS). 

TCAS-II is required on all aircraft with more than 30 seats and includes both traffic 

advisory and conflict resolution capabilities. TCAS-II utilizes input data that is sparse 

and has accuracy limitations and, therefore, it is expected that the ADS-B will provide 

improvements. In addition, TCAS-I is required on small 10 to 30 seat commuter aircraft 

and provides conflict detection. 

The ADS-B benefits associated with the incremental improvements to TCAS-II and 

TCAS-I were not included in the estimate and, therefore, all aircraft with 10 or more 

seats were excluded from the analysis. However, of 136 mid-air collisions recorded in 

the NTSB database between 1989 and 1998, only 3 involved an aircraft with 10 or more 

seats. 

The mid-air collision reduction benefits were estimated by multiplying the forecasted 

future accident costs, the assumed effectiveness percentage, the dependent equipage 

rates, and the TIS-B service schedule. The benefits were assumed to begin in 2007 for 

both ADS-B only and ADS-B with TIS-B. Table 2-3 summarizes the benefits from fewer 

aircraft-to-aircraft conflicts in both base year and risk-adjusted (RA) present value 

dollars. 

Table 2-3. Fewer aircraft-to-aircraft conflict benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Fewer aircraft-to-aircraft conflicts $719.8 M $203.6 M 

The mid-air collision historical accident rate was calculated as the number of collisions 

between 1989 and 2004 divided by the sum of the total number of annual operations 

squared over the 16-year period. The denominator incorporates the square of operations 

rather than applying a linear relationship to reflect an exponential increase in the risk of 

collisions as a function of traffic growth. Based on the ASDE-X Investment Analysis [3] 

and other studies, accidents involving two aircraft are estimated to increase more rapidly 

than traffic whereas single aircraft accidents, such as weather encounters or CFIT, are 

expected to increase at the same rate as traffic growth. 

Also, for benefits that involve two aircraft, the likelihood of realizing the benefits is 

dependent on both aircraft being equipped as described in Section 2.4.2. The reduction 

in mid-air collisions requires not only that an aircraft have the capability to see other 

aircraft, but that the conflicting aircraft is equipped with the avionics to be seen. For 

ADS-B only, the dependent ADS-B equipage curves are applied to estimate benefits 

beginning in 2007. From 2007 to 2025, the difference between the non-order specific 

dependent mixed equipage curve and the dependent ADS-B curve is used to reflect that 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

20
TIS-B increases the proportion of aircraft that can be displayed to ADS-B equipped 

aircraft in areas where there is TIS-B coverage. 

The overall effectiveness in reducing future mid-air collisions was estimated using the 

results from a two-day workshop held July 13-14, 2005 to determine ADS-B 

effectiveness rates. Five to six subject matter experts rated the effectiveness of an ADSB display on a sample of accidents using a score of 0 to 5, with 5 being the highest value. 

The mean effectiveness for mid-air collision prevention was 4.25. To adjust for risk we 

used a triangular distribution of (3.67, 4.25, 4.50) based on the distribution of responses. 

We assigned evenly-spaced percentage values to the scores to find effectiveness 

percentages. The maximum safety effectiveness for a score of 5 was agreed to be 85 

percent with a distribution of (.75, .85, .95). Therefore, a 4.25 translates to an 

effectiveness percentage of 72.3 percent. 

2.5.2 Fewer encounters with hazardous weather 

The primary objective of Flight Information Service-Broadcast (FIS-B) is to provide 

pilots with improved access to weather information and aeronautical data. The data will 

be provided directly to the cockpit, in flight, to enhance pilot situational awareness. The 

focus in the FIS application is on improved access to standard text weather products (i.e., 

METARs, TAFs, SIGMETs, and PIREPs), as well as standard graphical products (i.e., 

NEXRAD weather radar depictions). FIS-B benefit will only be available to UAT data 

link equipped GA and Air Taxi aircraft (see Section 2.4.3). Larger 1090 data link aircraft 

generally have weather radar and assistance from airline dispatchers, and are not 

considered in the analysis. 

While the SBS program is focused on providing elementary weather products in the near 

future, it is envisioned that the program will evolve to provide pilots with enhanced 

weather and aeronautical data in the out years. As a result, pilots will have better 

information on such hazards as icing, turbulence and volcanic ash. 

The user community will recognize benefits from having better access to standard 

weather products as well as access to information previously unavailable. Based on this 

information, pilots will have the ability to make better in-flight decisions, including better 

strategies for avoidance of areas of hazardous weather and, thereby, reduce the frequency 

of weather-related accidents. 

The weather accident reduction benefits were estimated by multiplying the forecast future 

accident costs, effectiveness measures, modified independent equipage rates, and the FISB service schedule. Table 2-4 summarizes the benefits from fewer encounters with 

hazardous weather in base year and risk-adjusted present value dollars. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

21
Table 2-4: Fewer encounters with hazardous weather benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Fewer encounters with hazardous weather $792.3 M $232.5 M 

 

The historical baseline for weather accidents was based on NTSB accident records from 

1989 through 2004. The NTSB database was first queried to identify all accident reports 

for Part 91, Part 135, and Part 121 operations that cite weather conditions as contributing 

to the event. The search criterion was the inclusion of code 20000 – Weather Conditions 

in the sequence of events section of the accident report. Weather accidents in phases of 

flight from climb to landing were included. While FIS-B information may not be 

available during the landing and approach phases at smaller airports, a recent survey 

conducted by the FAA Capstone office found that weather information is mainly used in 

the cruise phase (or before) to plan route changes or approaches at airports. The weather 

information is rarely used real-time during an approach because other duties occupy the 

pilot’s attention. 

Accidents involving both adverse weather conditions and a Controlled Flight Into Terrain 

(CFIT) were accounted for in the CFIT analysis (Section 2.5.4). Accidents that involved 

mid-air collisions were removed from the data set to avoid overstating benefits. 

 

The historical accident rate was estimated for each user group by dividing the number of 

accidents by the number of operations over the baseline period. In addition, the numbers 

of fatalities, injuries, and aircraft damages were evaluated to estimate the average 

accident cost for each weather and user group. The accident rate combined with the 

projected traffic levels and the average accident cost provided the potential weather 

accident benefits by weather and user group. 

The overall effectiveness in reducing future weather-related accidents was estimated 

using the results from a two-day workshop held July 13-14, 2005 to determine ADS-B 

effectiveness rates. Five to six subject matter experts rated the effectiveness of an FIS-B 

display on a sample of accidents using a score of 0 to 5, with 5 being the highest value. 

The mean effectiveness for weather-related accident collision prevention was 1.58. To 

adjust for risk we used a triangular distribution of (1.31, 1.58, 1.75) based on the 

distribution of responses. We assigned evenly-spaced percentage values to the scores to 

find effectiveness percentages. The maximum safety effectiveness for a score of 5 was 

agreed to be 85 percent with a distribution of (.75, .85, .95). Therefore, a 1.58 translates 

to an effectiveness percentage of 26.4 percent. 

An estimated 23 percent of GA flights already receive cockpit weather information using 

a commercial FIS. We assumed that the SBS FIS-B benefit would not apply to these 

aircraft and modified the independent equipage rate accordingly. However, the 

commercially-equipped flights would receive a cost avoidance benefit because they 

would no longer need to pay for this service. This cost avoidance benefit can be found in 

section 3.3. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

22
A further reduction of 10 percent was applied to the weather-related accident benefits to 

account for the Aeronautical Information Management (AIM) program planned by the 

FAA in the near future. 

2.5.3 More efficient weather deviations 

In addition to safety considerations, the efficiency of flight operations can also be 

increased with improved access to weather information. The primary objective of Flight 

Information Service-Broadcast (FIS-B) is to provide the pilot with improved access to 

weather information and aeronautical data. The focus is on improved access to standard 

text weather products (i.e. METARs, TAFs, SIGMETs, and PIREPs.), as well as a 

standard graphical product (i.e., NEXRAD weather radar depictions). 

NEXRAD weather radar graphics will offer the opportunity to make earlier decisions for 

deviations around some convective weather hazards, and provide a better characterization 

of all convective weather hazards. There are some organized weather events that are so 

wide-spread that little can be done to avoid large flight deviations. The deviation benefit 

is limited to weather events that are more dispersed, or unorganized. We assume that this 

benefit will be available to UAT data link equipped GA and Air Taxi aircraft (see Section 

2.4.3). Larger 1090 data link aircraft generally have weather radar and assistance from 

airline dispatchers, and are not considered in the analysis. 

The more efficient routes in adverse weather benefits were estimated by multiplying the 

frequency of unorganized weather, the average flight time reduction per flight, projected 

traffic counts, modified independent equipage rates, estimated FIS-B service schedule, 

and airborne aircraft direct operating costs and passenger value of time. Estimates were 

developed separately for each user group. Table 2-5 summarizes the benefits by segment 

and location in both base year and present value dollars. 

Table 2-5. More efficient routes in adverse weather benefits 

Outcome Benefits (BY 07) Benefits (RA PV)

More efficient routes in adverse weather $18.4 M $4.9 M 

The average flight time reduction per flight was based on an analysis of airborne flight 

times for good and bad weather days performed by ATO-P Operations Research. They 

compared the flight time difference for commercial flights and GA flights separately. 

They assumed commercial flights had weather radar or other access to weather 

information through airline operations centers, while GA flights had little to no access to 

these products or services. The study estimated an average reduction of 7 seconds in 

flight time for flights with weather products. A triangular distribution based on the error 

in the average was used to adjust for risk (5 sec, 7 sec, 9 sec.) 

 The Corridor Integrated Weather System (CIWS) investment analysis [4] estimated that 

unorganized adverse weather affects 4.7 percent of all flights. To adjust for risk we 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

23
multiplied a triangular distribution of (.5, 1, 2) to the adverse weather occurrence 

percentage. The high number reflects uncertainty in the duration of adverse weather and 

somewhat higher results from a previous NASA study [5]. 

An estimated 23 percent of GA flights already receive cockpit weather information using 

a commercial FIS. We assumed that the ADS-B FIS-B benefit would not apply to these 

aircraft and modified the independent equipage rate accordingly. However, the 

commercially-equipped flights would receive a cost avoidance benefit because they 

would no longer need to pay for this service. This cost avoidance benefit is described in 

section 3.3. 

A further reduction of 10 percent was applied to the weather-related efficiency benefits to 

account for the Aeronautical Information Management (AIM) program planned by the 

FAA in the near future. 

2.5.4 Fewer controlled flights into terrain (CFIT) 

Controlled-Flight-Into-Terrain (CFIT) accidents are defined as those in which the pilot 

inadvertently allows the aircraft to strike terrain, a water surface or an obstacle, even 

though the aircraft is under his/her full control. In almost all cases, these accidents are 

attributable, to some extent, to the pilot's lack of awareness of aircraft altitude relative to 

proximate terrain and obstacles. CFIT accidents usually occur during flight conditions in 

which the pilot cannot visually ascertain terrain/obstacle clearance (e.g., visual 

obscuration from fog, clouds, or precipitation; nighttime with unlighted terrain features; 

and poor contrast in the landscape due to snow, glassy water surfaces, etc.). 

Since the mid-1970s, most U.S.-registered transport-category aircraft have been required 

to have Ground Proximity Warning Systems (GPWS). More recently, a mandate to 

include the Terrain Awareness and Warning System (TAWS) on a wider range of aircraft 

was issued. These systems are intended to warn pilots that the aircraft may be coming 

dangerously close to terrain while in the cruise configuration or that it may not be in the 

proper configuration for a normal landing. 

The TAWS mandate states that any aircraft with 6 or more passenger seats must be 

equipped with TAWS. Over 90% of aircraft in CONUS have fewer than 6 passenger 

seats. 

A basic objective of the SBS program is to provide pilots who are operating aircraft not 

included under the TAWS mandate with a safe and cost-effective means to be aware of 

the aircraft’s altitude with respect to the surrounding terrain. The focus is on the display 

of the navigation situation and terrain information. The equipment also provides 

additionally an alerting function that monitors terrain clearance and issues an appropriate 

warning to the pilot if inadequate terrain clearance is anticipated. The latter is an 

enhancement over TAWS that provides incremental benefits for aircraft already equipped 

TAWS. However, we did not consider the incremental TAWS benefit in the analysis. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

24
The CFIT accident reduction benefits were estimated by multiplying the forecast future 

accident costs, the assumed effectiveness percentages, modified independent equipage 

rates, and the FIS-B/TIS-B service schedule. While FIS-B/TIS-B service is not needed 

for the CFIT benefit, it was assumed that GA terrain map equipage associated with an 

ADS-B multifunction display would most likely occur only where the FIS-B/TIS-B 

service existed. Estimates were developed separately for each user group. Table 2-6 

summarizes the benefits in base year and risk-adjusted present value dollars. 

Table 2-6. Fewer controlled flights into terrain benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Fewer controlled flights into terrain $1,015.6 M $284.3 M 

The historical baseline for CFIT accidents was based on NTSB accident records from 

1989 to 2004. The NTSB does not explicitly categorize events as CFIT. However, in 

conversations with the NTSB, it was indicated that they do have a “mechanical means of 

selecting accidents that involve collisions with terrain or objects and which don't involve 

loss of control or power and which don't occur during some phases of flight (such as 

takeoff, landing or maneuvering).” The NTSB methodology identifies accidents that 

include occurrence code 220 In Flight Collision with Object or code 230 In Flight 

Collision With Terrain/Water. Events involving a loss of control or power are excluded 

as are events occurring during specified flight phases. The NTSB methodology was 

utilized to identify the set of applicable accidents for Part 91, Part 135 and Part 121 

operations. Furthermore, accidents involving both adverse weather conditions in-flight 

that were also categorized as a Controlled Flight Into Terrain (CFIT) event were only 

counted as CFIT accidents. 

The final list of CFIT accidents was segmented to reflect whether or not the aircraft 

involved would now be mandated to equip with TAWS. The TAWS mandate includes 

all turbine-powered airplanes with six or more passenger seats operating under Part 91 

and Part 135 and all turbine-powered airplanes operating under Part 121. 

The effectiveness in reducing future CFIT collisions was estimated using the results from 

a two-day workshop held July 13-14, 2005 to determine ADS-B effectiveness rates. Five 

to six subject matter experts rated the effectiveness of an ADS-B display on a sample of 

accidents using a score of 0 to 5, with 5 being the high highest value. After examining 

the data, we found that CFIT accidents could be separated in two distinct sets based on 

the occurrence of adverse weather. The mean effectiveness for CFIT accident prevention 

when adverse weather was a factor was 3.15. To adjust for risk we used a triangular 

distribution of (2.91, 3.15, 3.31) based on the distribution of responses. For CFIT 

accident prevention without adverse weather we used a triangular distribution of (0.98, 

1.04, 1.09). We assigned evenly-spaced percentage values to the scores to find 

effectiveness percentages. The maximum safety effectiveness for a score of 5 was agreed 

to be 85 percent with a distribution of (.75, .85, .95). Therefore, the mean values 3.15 

and 1.04 translate to effectiveness percentages of 53.2 percent and 17.6 percent, 

respectively. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

25
An estimated 50 percent of GA flights already receive some terrain awareness through 

GPS equipage. We assumed that the ADS-B CFIT benefit would not apply to these 

aircraft and modified the independent equipage rate accordingly. 

 

2.5.5 Fewer aviation accidents in Alaska 

The first large-scale implementation of ADS-B and FIS-B became operational in 

southwest Alaska starting in 2000. Alaska was a good test bed for these technologies 

because of limited radar surveillance, a somewhat small population of aircraft that needed 

to be equipped, and an accident rate that was relatively high compared to the CONUS. 

This early implementation (called the Alaska Capstone Program) provided a valuable 

proving ground for ADS-B and FIS-B data that the SBS used in supporting the NASwide business case. In 2007, the FAA decided it was time to reincorporate the continuing 

effort of the Alaska Capstone program into the NAS-wide SBS program. SBS plans to 

use the same service provider cost model for Alaska as in the other parts of the NAS. 

The Alaska Capstone Program consisted of three phases: 

• Phase I-provide avionics and surveillance and broadcast services to Part 135 

users in the Y-K Delta region of Alaska 

• Phase II-provide avionics and surveillance and broadcast services to Part 135 

users in Southeast region of Alaska 

• Phase III-expand surveillance and broadcast services to the remainder of the 

state and expand services to all aircraft types (Part 91, Part 121, Part 135) in 

each of the regions 

Capstone also included a number of airport infrastructure upgrades (such as automated 

weather stations, communications, and route and approach procedure development) that 

either supported providing better information to pilots and/or expanded use of IFR 

services available in addition to surveillance. 

By the time of incorporation into the SBS program, Alaska Capstone Phases I and II had 

been completed. The August 2007 business case included a rebaseline of the Capstone 

program to include costs and benefits for all phases. 

The historical accident rate was estimated for each region and user group combination by 

dividing the number of accidents by the number of operations over a fourteen-year period 

(1990-2004). The accidents were gathered from the NTSB and operations from the TAF. 

In addition, the numbers of fatalities, injuries, and aircraft damages were evaluated to 

estimate the average accident cost for each region and user group. The accident rate 

combined with the projected traffic levels and the average accident cost provided the 

potential accident benefits pool by region and user group. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

26
The method for determining effectiveness was somewhat different for the Capstone 

Program than for the other parts of the NAS. Instead of isolating CFIT, Weather-related, 

and Mid-Air accidents, the program considered all Alaskan aviation accidents. Each of 

the 2045 historical Alaskan accidents was assigned a combination of 23 risks. Table 2-7 

presents descriptions of the risks and Table 2-8 presents the frequency of these risks 

across the accidents. Table 2-9 presents a number of identified mitigations provided by 

the program. The mitigations also indicate when they depend on Ground-Based 

Transceiver (GBT) coverage. 

Table 2-7. Capstone risk descriptions 

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Intentional Disregard Failed to heed warnings about known hazards, grossly over weighted aircraft, etc.

Pilot loss of situational awareness leading to a decision to inadvertently fly into IMC, box 

En Route Tactical Decision Making canyon, etc.

Terminal Tactical Decision Making Pilot loss of situational awareness leading to a poorly executed approach, etc.

Pressure Time Schedule - Monetary Pressure - Company Reputation

Access WX Failed to access weather or NOTAM information before or during flight

Preflight Aircraft Inspection - Fuel Contamination - Planning of Route and Weight Balance

Other airport Personnel - Directing aircraft during taxi - improperly installed cargo (leaking 

Ground Procedures fuel drum) - Airport Markings, Plowing, Construction

Flight Standards - Decision Making - Planning - Pilot violated FARs or didn't complete 

Flt Procedures checklists while in-flight (Fuel Starvation/didn't switch tanks)

Low Airspeed - Stick and Rudder - Loss of control - Short term control execution and 

Skills memorized EM procedures (Autorotation, Forced Landing)

Crew Crew Ratings - Training - Experience - Physical Condition - Toxicology

Crew - Skill, 

Vigilance, 

and 

Decision 

Making

Fuel Exhaustion Fuel Quantity - Did not have enough fuel on board aircraft

Maintenance Miss-installed Parts - Neglected inspections or repairs

Aircraft Type - Equipage - Mechanical - Condition of Aircraft - Catastrophic failure of parts 

Aircraft Mechanical - No apparent cause

Related 

Failures

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

Traffic Traffic congestion 

Terrain Vertical Extent of Surrounding Terrain - Route of Flight - Charted Obstacles

Obstacle or Terrain near Runway Departure or Arrival ends or Terrain Unsuitable for 

Approach Departure Hazard Forced Landing

Surface Condition Surface Condition - Off Airport Locations - Runway Length

External 

Conditions

Obstacles, 

Terrain, 

Traffic

Dissemination of WX or NOTAM Information - Someone aware of info, failed to 

Dissemination Information disseminate - No PIREP written - Construction No NOTAM

Available WX and NOTAM Information Local Weather Trend Information - Information 

Available Information did not exist - No Nearby WX station - No NOTAM

Pressure Altitude Pressure Altitude during Takeoff/Landing - Due to high temperature or high elevation

Ceiling/Cloud Base/Tops - Precipitation - Visibility - Obscuration - Flat/Diffused Light -

Visibility Contrast Terrain/Sky - Time of Day 

Icing Temperature - Dew Point - Icing Conditions

Wind Turbulence - Cross/Gusty/Tail Wind

Weather and 

Information

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

27
Table 2-8. Capstone risk frequencies 

Part 135 Part 91

Risk Takeoff En Route Landing Takeoff En Route Landing

Wind 49 10 59 142 31 177

Icing 4 1

Visibility 15 69 34 11 64 48

Pressure Altitude 0 0 0

Available Airport Info 0 2 0

Dissemination 00 4 1 0 2

Surface Condition 59 48 139 216

App Dep Hazard 25 23 115 83

Terrain 1 57 10 3 71 16

Traffic 58 3 7 13 2

Mechanical 17 40 45 51 53 83

Maintenance 7 18 17 22 16 28

Fuel Exhaustion 0 1 5 2 20 20

Crew Experience 3 10 10 34 17 93

Skills 55 13 72 186 44 419

Flight Deck Procedures 15 8 32 48 26 55

En Route Tactical Decision Making 63 67

Terminal Tactical Decision Making 38 49 117 137

Intentional Disregard 32 716 5 10

Ground Procedures 21 2 3 17 0 6

Preflight 80 17 13 195 27 32

Access 02 0 1 3 2

Pressure 47 6 3 4 4

0

4

Table 2-9. Capstone risk mitigation descriptions 

Terrain Terrain and Obstacles Presented Relative to Ownship and Terrain/Obstacle Alerting

GPS Navigation and Moving Map, More Efficient Direct Routing, Preloading Standard Routes, 

Grid Based Search Patterns for Rescue and Wildlife Counts Moving Map

Transition to 121 Facilitate Transition to Part 121 Operations

More Weather Stations Reporting Data More Weather 

Stations

Safety Culture Improved Overall Safety Culture

System Wide

Improvement

Operators Purchasing More Capable IFR Aircraft (GBT Dependent) More Capable 

Aircraft

Enhanced Air Traffic Services: Increased Flight Following, IFR Operations, Monitoring, 

Availability of RNP RNAV Routes (GBT Dependent) ATC Monitoring

IFR Procedures Increased Availability of IFR Procedures (GBT Dependent)

Induced 

Changes to 

Operations

Data Collection to Support Safety Analyses and Data to Improve Accident Analysis Investigations

(GBT Dependent) Data Analysis

Enhanced Company Operational Control, Increased In-Flight Monitoring, Directing Search and 

Rescue (GBT Dependent)

Company 

Monitoring

Information

Provided to 

Support 

Personnel

Fuel Totalizer Reduces Fuel Exhaustion, Glide Distance Display Reduces Severity of Forced 

Landings

Additional 

Features

Reduced Navigation Workload Allows Pilots to Allocate Resources to Other Tasks, Increases 

Pilot Confidence, and Reduces Anxiety (Duress Leads to Mistakes)

Workload 

Reduction

Pilot-to-Pilot Condition Reports and Inferring Conditions by Observing Aircraft Behaviors, 

Monitoring and Notifying Other Pilots of Potential Safety Concerns

Pilot-to-Pilot 

PIREP

Textual Weather (including published NOTAMs and PIREPS) and Graphic Weather 

 Indication of Current Experienced Wind Conditions

(GBT 

Dependent) and Weather

Traffic Traffic Presented Relative to Ownship and Traffic Alerting

Direct Pilot 

Benefits

Terrain Terrain and Obstacles Presented Relative to Ownship and Terrain/Obstacle Alerting

GPS Navigation and Moving Map, More Efficient Direct Routing, Preloading Standard Routes, 

Grid Based Search Patterns for Rescue and Wildlife Counts Moving Map

Transition to 121 Facilitate Transition to Part 121 Operations

More Weather Stations Reporting Data More Weather 

Stations

Safety Culture Improved Overall Safety Culture

System Wide

Improvement

Operators Purchasing More Capable IFR Aircraft (GBT Dependent) More Capable 

Aircraft

Enhanced Air Traffic Services: Increased Flight Following, IFR Operations, Monitoring, 

Availability of RNP RNAV Routes (GBT Dependent) ATC Monitoring

IFR Procedures Increased Availability of IFR Procedures (GBT Dependent)

Induced 

Changes to 

Operations

Data Collection to Support Safety Analyses and Data to Improve Accident Analysis Investigations

(GBT Dependent) Data Analysis

Enhanced Company Operational Control, Increased In-Flight Monitoring, Directing Search and 

Rescue (GBT Dependent)

Company 

Monitoring

Information

Provided to 

Support 

Personnel

Fuel Totalizer Reduces Fuel Exhaustion, Glide Distance Display Reduces Severity of Forced 

Landings

Additional 

Features

Reduced Navigation Workload Allows Pilots to Allocate Resources to Other Tasks, Increases 

Pilot Confidence, and Reduces Anxiety (Duress Leads to Mistakes)

Workload 

Reduction

Pilot-to-Pilot Condition Reports and Inferring Conditions by Observing Aircraft Behaviors, 

Monitoring and Notifying Other Pilots of Potential Safety Concerns

Pilot-to-Pilot 

PIREP

Textual Weather (including published NOTAMs and PIREPS) and Graphic Weather 

 Indication of Current Experienced Wind Conditions

(GBT 

Dependent) and Weather

Traffic Traffic Presented Relative to Ownship and Traffic Alerting

Direct Pilot 

Benefits

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

28
A focus group (held in the spring of 2006) consisting of 20 Alaskan pilots estimated the 

overall Capstone mitigation for each risk by Phase of Flight, GBT coverage, and user 

type (Part 91 or Part 135). Table 2-10 displays the mitigations by phase of flight and user 

type inside GBT coverage. Table 2-11 gives an example of the mitigations inside and 

outside of coverage area for Part 91 operators during the en route phase of flight. The 

mitigations inside and outside of GBT coverage allowed us to differentiate between 

GBT-related benefits and avionics-related benefits. 

Table 2-10. Capstone risk mitigations by phase of flight and user type in GBT 

coverage 

Part 135 Part 91

Risk Takeoff En Route Landing Takeoff En Route Landing

Wind 9.5% 15.9% 30.0% 9.3% 19.7% 32.0%

Icing 29.1% 27.7%

Visibility 29.5% 59.4% 51.8% 27.7% 56.8% 50.5%

Pressure Altitude 4.6% 12.5% 4.1% 12.3%

Available Airport Info 19.1% 32.3% 19.5% 31.4%

Dissemination 11.4% 35.5% 30.0% 10.9% 36.4% 26.8%

Surface Condition 0.5% 8.2% 0.5% 9.1%

App Dep Hazard 10.9% 18.2% 10.9% 18.2%

Terrain 84.0% 84.0% 84.0% 81.7% 81.7% 81.7%

Traffic 58.6% 75.7% 70.5% 55.9% 71.8% 66.4%

Mechanical 1.4% 1.4% 1.4% 1.8% 1.8% 1.8%

Maintenance 2.3% 2.3% 2.3% 2.3% 2.3% 2.3%

Fuel Exhaustion 5.7% 5.7% 5.7% 10.0% 10.0% 10.0%

Crew Experience 4.5% 39.1% 18.6% 4.1% 35.0% 15.5%

Skills 3.2% 13.2% 1.8% 1.8% 11.4% 1.4%

Flight Deck Procedures 17.3% 17.3% 17.3% 17.3% 17.3% 17.3%

En Route Tactical Decision Making 68.6% 65.5%

Terminal Tactical Decision Making 40.5% 54.5% 38.6% 51.8%

Intentional Disregard 5.5% 5.5% 5.5% 5.0% 5.0% 5.0%

Ground Procedures 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

Preflight 3.6% 3.6% 3.6% 5.5% 5.5% 5.5%

Access 19.5% 19.5% 19.5% 20.0% 20.0% 20.0%

Pressure 9.1% 9.1% 9.1% 9.1% 9.1% 9.1%

Table 2-11. Capstone risk mitigations inside and outside GBT coverage for 

Part 91 en route flights 

Part 91 En Route Mitigations

Risk

in GBT area outside GBT area GBT-Related Non-GBT Related

Wind 20% 10% FIS-B PIREPS/Terrain Map

Icing 28% 8% FIS-B PIREPS/Terrain Map

Visibility 57% 45% FIS-B PIREPS/Terrain Map

Dissemination 36% 13% FIS-B/TIS-B Flight Monitoring PIREPS/Terrain Map/Safety Culture

Terrain 82% 82% N/A Moving Map/Terrain Map

Traffic 72% 70% TIS-B/Surveillance ADS-B to ADS-B

Mechanical 2% 2% N/A Safety Culture

Maintenance 2% 2% N/A Safety Culture

Fuel Exhaustion 10% 10% N/A Fuel Exhaustion Warning/Moving Map

Crew Experience 35% 28% FIS-B/Flight Monitoring/Surveillance Reduced Workload/Safety Culture

Skills 11% 11% N/A Reduced Workload/Safety Culture

Flt. Deck Procedures 17% 17% N/A Safety Culture

En Route Tactical Decision M 65% 50% FIS-B/Flight Monitoring/Surveillance PIREPS/ADS-B to ADS-B

Intentional Disregard 5% 1% Flight Monitoring/Surveillance Safety Culture

Preflight 5% 2% FIS-B Safety Culture

Access 20% 11% FIS-B PIREPS/Safety Culture

Pressure 9% 8% Flight Monitoring/Surveillance Safety Culture

Coverage Mitigation Mechanisms

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

29
 

Lastly, the risks and mitigations were combined for each accident to estimate a total 

accident risk reduction. 

The model was validated by a careful comparison of risk model results and Part 135 

accident trends in Southwest Alaska (Phase I) compared to the rest of the state. 

The average accident risk reductions were compiled for each region and user type and 

applied to the potential future accident pool. The difference between mitigations inside 

and outside of GBT coverage was used to develop a factor to allocate potential benefits 

as GBT-related or avionics-related. The potential avionics-related benefits were 

multiplied by the avionics equipage curve only, while the potential GBT-related benefits 

depended on the GBT implementation schedule, the total GBT coverage percentage per 

region, and the avionics equipage. 

The total GBT coverage percentage was determined using a radar coverage model of the 

state that took elevation into account. The percentage consists of the number of 

operations in each region that will be in GBT coverage divided by the total number of 

operations in the region. For the current implementation scheme the coverage averaged 

across the regions and user types is between 80 and 90 percent. 

Three additional factors were also considered when calculating the final aviation safety 

benefit. The first involves CFIT accidents. An estimated 38 percent of Part 91 and Part 

135 flights already receive some terrain awareness through GPS equipage. Much like 

subsection 2.5.4, we assumed that the avionics-related Capstone benefits would not apply 

to these aircraft and modified the equipage curve accordingly. This calculation also 

involved isolating the CFIT accidents from the total pool of accidents. CFIT accidents 

were separated in the same way as described in subsection 2.5.4. 

The second factor involves out-of-state aircraft. The Alaska equipage rate is separate 

from the assumed equipage rate in the rest of the NAS. An MOA with a coalition of 

Alaska aviation companies and associations has agreed to fund early avionics equipage 

for all Alaska users; however, this enhanced equipage would not apply to out-of-state 

aircraft. Historically, out-of-state aircraft accounted for 3.8 percent of the accidents, so 

this same percentage was subtracted from the final benefit. 

The last factor considered was sharing of benefits with another FAA program, Alaska 

Weather Cameras. The historical accidents that may have been affected by weather 

cameras were determined. The weather camera related accidents were a subset of the 

Capstone accidents. The focus group exercise held in 2006 also examined the mitigation 

from weather cameras, and the combined mitigations of Capstone and weather cameras. 

The total mitigation for weather camera accidents was then shared between Capstone and 

the weather camera program. The Capstone aviation safety benefit model consequently 

decreased the total benefit to account for sharing with weather cameras. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

30
As mentioned before, the current business case incorporates all three phases of the 

Capstone program. Table 2-12 presents the fewer aviation accidents in Alaska benefits in 

base year 2007 and risk adjusted present value dollars. 

Table 2-12. Fewer aviation accidents in Alaska benefits 

Outcome Benefits (BY 07) Benefits (RA PV)

Fewer aviation accidents in Alaska $760.2 M $300.1 M 

 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

31
2.6 Surface Benefits 

The Surface benefits (see Figure 2-2) are derived from the following outcomes: 

• Increased safety on surface by ATC 

• More efficient ATC management of surface movement 

• Increased safety on the surface by pilots 

Figure 2-2 lists additional outcomes that were not quantified in this study; however, in 

future investment decisions benefits from these additional outcomes may be examined. 

2.6.1 Increased safety on the surface by ATC 

To support the infrastructure requirements of ADS-B, the SBS program is upgrading 

ASDE-3 to ASDE-X at the 9 CONUS airports where this was not previously funded by 

Terminal Services. These airports are: 

 

Andrews Air Force Base (ADW) 

Ted Stevens Anchorage International Airport (ANC) 

Cleveland-Hopkins International Airport (CLE) 

 Cincinnati/Northern Kentucky International Airport (CVG) 

 Kansas City International Airport (MCI) 

 Louis Armstrong New Orleans International Airport (MSY) 

 Portland International Airport (PDX) 

 Pittsburgh International Airport (PIT) 

 San Francisco International Airport (SFO). 

Reducing the risk of runway collisions is a top priority of both the NTSB and the FAA. 

As traffic density increases at our nation’s airports, the potential for accidents on or near 

the runway surface also increases. 

The ASDE-X Investment Analysis Report [3] documents the methodology developed to 

estimate the total costs associated with future runway collisions. Additional details can 

be found in the Air Traffic Control Quarterly journal article Fatal US Runway Collisions 

Over the Next Two Decades [6]. A key distinction in the analysis is that estimates about 

the likelihood of future accidents at towered US airports are based solely on recent data 

from such airports. However, estimates of the consequences of future US runway 

accidents are based on worldwide data. Therefore, in making US forecasts, an overseas 

event like the Tenerife collision, which killed almost 600 people, should be used for some 

but not all purposes. 

The ASDE-X Investment Analysis team identified 5 runway collisions at US towered 

airports between 1989 and 1998. This historical number of events was combined with 

the square of operations for each towered airport as well as an airport visibility risk 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

32
multiplier to develop a forecast of future collisions. The expected accident cost per 

airport was based on the average number of people per operation at that location as well 

as assumptions as to the percentage of fatalities, injuries and aircraft damages. A fatality 

rate of 32.5% was assumed based on a survey of worldwide runway collisions. 

The ASDE-X Investment Analysis assumes approximately 73 percent effectiveness for 

surface surveillance with conflict alerting capability in avoiding future runway collisions. 

The SBS business case relies on the same assumptions and models used for ASDE-X to 

determine benefits. For more details on the model and assumptions see [3]. 

Table 2-13 presents the increased safety on the surface by ATC benefits in base year 

2007 and risk-adjusted present value dollars. 

Table 2-13. Increased safety on the surface by ATC benefits 

Outcome Benefits (BY 07) Benefits (RA PV)

Increased safety on the surface by ATC $11.6 M $3.2 M 

2.6.2 More efficient ATC management of surface movement 

Upgrading the 9 remaining ASDE-3 airports to ASDE-X also increases some surface 

efficiency benefits. The ASDE-X rebaseline report [3] describes efficiency benefits 

grouped into the following four general categories: 

1) Improved Identification of Aircraft Within a Queue 

2) Improved Ability to Perform Conformance Monitoring 

3) Improved Surface Surveillance During Heavy Precipitation 

4) Improved ATC Confidence in Surface Surveillance Data 

Descriptions of these categories follow. For more information on the individual 

scenarios within each category see [3]. 

Improved Identification of Aircraft within a Queue

In today’s environment, controllers rely on paper flight strips to determine the order of 

aircraft within a queue. At times, these logs can become out of order either through the 

rearrangement of the paper records or, more frequently, through the dynamics of traffic 

movements. When air traffic controllers issue instructions to aircraft that are erroneously 

thought to be at the front of the queue, confusion arises and additional time is needed to 

communicate with aircraft to sort out the correct order of the traffic. This communication 

time can be generally brief but, nonetheless, disrupts the flow of traffic on the airport 

surface. 

Through the incorporation of multilateration, ASDE-X provides data tags for all 

transponder equipped targets. As a result, controllers will now be able to view the 

ASDE-X display to determine the correct order of aircraft within a queue. Although 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

33
flight strips will continue to be maintained, controllers can now glance at the ASDE-X 

display to ensure accuracy or to rapidly resolve confusion when it arises. 

The individual benefit scenarios for this improvement category are based on the various 

locations where queues can form on the airport surface and the associated air traffic 

clearance instructions as follows: 

• Taxi Into Position and Hold 

• Taxi Across a Runway 

• Hand-Offs to the Taxi Movement Area 

• Departure Clearances During Severe Weather Avoidance Procedures (SWAPs). 

Improved Ability to Perform Conformance Monitoring

To ensure both safety and efficiency, controllers are responsible for monitoring whether 

aircraft follow their prescribed taxi routes. Additionally, once aircraft become airborne, 

controllers must validate that the proper beacon identification code is associated with the 

radar target for each aircraft. When aircraft deviate from their taxi routes or provide 

incorrect or missing identification information, controllers may slow down traffic as they 

address the situation. 

ASDE-X data tags enhance situational awareness and, therefore, the ability of controllers 

to perform conformance monitoring. By becoming aware of issues sooner, controllers 

are better equipped to respond in an efficient manner. 

The individual benefit scenarios for improving conformance monitoring are: 

• Taxi Routes 

• Beacon Codes. 

Improved Surface Surveillance During Heavy Precipitation

Heavy precipitation can cause the ASDE-3 to be unusable during these periods. The 

radar reflectivity generated by the storm results in a “white-out” or “wash-out” of the 

targets. Therefore, controllers are unable to distinguish the aircraft on the ASDE-3 

display and cannot use the system to effectively monitor traffic. 

During poor visibility conditions, either nighttime or weather related, controllers rely on 

the ASDE-3 information to monitor aircraft movements and to determine when to issue 

the appropriate clearances. These clearances include issuing taxi into position and hold 

instructions, take-off clearances, and clearance to taxi across an active runway. 

Without the ASDE-3, controllers must wait for pilot reports indicating their location and 

when they are clear of the runway, which has a major impact on the efficiency of 

operations. Controllers are unable to issue taxi into position and hold clearances to 

departures operating on runways servicing both arrivals and departures. Therefore, 

increased miles-in-trail is required between arrivals in order to have the necessary time 

for departures to access the runway. The increased aircraft spacing will reduce the 

capacity by up to 50 percent for runways supporting both arrivals and departures. 

Additionally, controllers must wait an additional 25 to 30 seconds prior to issuing a 

departure clearance when controlling traffic on intersecting runways. Finally, it is 

estimated that approximately an additional 10 seconds may be needed prior to clearing an 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

34
aircraft to taxi across an active runway. All of these delays combine to significantly slow 

down air traffic at a given airport. 

Improved ATC Confidence in Surface Surveillance Data

The ability of ASDE-X to process inputs from multiple sensors, such as both radar and 

multilateration ground stations, improves the overall quality of the surface surveillance 

information. ASDE-X performance will include better track continuity, fewer false 

targets, and an increased probability of detection as compared to the ASDE-3. These 

improvements in conjunction with target data tags will increase common situational 

awareness leading to improvements in surface traffic management. 

The SBS business case relies on the same assumptions and models used in the ASDE-X 

business case. For more details on the model and assumptions see [3]. 

Table 2-14 presents the more efficient ATC management of surface movement benefits in 

base year 2007 and risk-adjusted present value dollars. 

Table 2-14. More efficient ATC management of surface movement benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient ATC management of 

surface movement 

$92.1 M $26.9 M 

2.6.3 Increased safety on the surface by pilots 

Besides upgrading ASDE-3 to ASDE-X, the SBS program has a tool by which they hope 

to improve system safety: CDTI. The use of CDTI on the surface is reflected in two 

applications: Airport Surface Situational Awareness and Final Approach Runway 

Occupancy Awareness (FAROA). 

Using a CDTI on the surface is much like using it in the air (see Section 2.5.1). The 

CDTI will allow pilots to see other equipped aircraft on the surface and in the immediate 

terminal area (on approach). This extra information should aid the pilot in the see-andavoid procedure. 

The surface accident reduction benefits were based on the forecasted future accident costs 

by towered airport, which were estimated by applying the methodology developed as part 

of the ASDE-X Investment Analysis [3]. In addition, dependent equipage rates were 

applied to reflect the involvement of two aircraft in the accidents as discussed in Section 

2.4.2. Benefit estimates were developed separately for each of the top 200 airports. 

Effectiveness of ADS-B capabilities differed at ASDE and non-ASDE airports. 

Early benefits accrue only for CDTI-equipped UPS aircraft at SDF and PHL. Benefits 

from all CDTI-equipped flights at the top 200 airports accrue starting in 2014. Table 2-

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

35
15 summarizes the surface accident reduction benefits in base year 2007 and riskadjusted present value dollars. 

Table 2-15. Increased safety on the surface by pilots benefits 

Segment Benefits (BY 07) Benefits (RA PV)

Increased safety on the surface by pilots $299.5 M $70.5 M 

In a previous subsection (2.6.1), we described the safety benefits of ASDE-X. SBS hopes 

to provide additional safety benefits at both ASDE-X and non-ASDE-X sites. Therefore, 

the additional functionality provided by ADS-B capabilities must be viewed in terms of 

its incremental improvement at ASDE-X sites. Additionally, the Runway Safety 

Program Office is actively pursuing initiatives in the areas of training and education, 

procedures, and airport improvements, which will also reduce the risk of future runway 

collisions. It was assumed that the cumulative effect of these activities would be a 95 

percent reduction in runway collision accidents at the ASDE-X airports 

Given that a 73 percent reduction has previously been assigned to systems providing 

surface surveillance and conflict alert capability, the incremental benefits are to be 

allocated amongst the various remaining programs. To determine the proper allocation of 

runway collision benefits a two-day workshop was held April 12-13, 2006. Three to four 

subject matter experts rated the effectiveness of ADS-B applications on a sample of 

severe runway incursions and runway accidents using a score of 0 to 5, with 5 being the 

highest value. The group considered the effectiveness of ADS-B applications on runway 

collisions at airports without ASDE-X, and the incremental effectiveness on runway 

collisions at airports with ASDE-X. Concurrently, the group examined the runway 

collision prevention effectiveness of another program (Runway Status Lights) at airports 

with ASDE-X. Additionally, the experts rated the effectiveness of ADS-B on preventing 

off-runway accidents that occur during taxi or in the ramp area. 

The mean effectiveness for ADS-B runway accident prevention at non-ASDE airports 

was 3.2. To adjust for risk we used a triangular distribution of (2.5, 3.2, 3.9) based on the 

distribution of responses. Evenly-spaced percentage values were applied to the scores 

resulting in a mean effectiveness of 55 percent at non-ASDE airports. The mean 

effectiveness for ADS-B runway accident prevention at ASDE-X airports was 

approximately 5 percent. For ADS-B off-runway accident prevention we used a 

triangular distribution (1.9, 2.3, 2.6), which translates into a mean effectiveness of 32.5 

percent. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

36
2.7 Terminal and En Route Benefits 

The Terminal and En Route benefits (see Figure 2-3) are derived from the following 

outcomes: 

• Continuation of visual approaches in marginal conditions 

• More efficient spacing during visual approaches 

• Increased ability to allow Continuous Descent Approaches 

• More efficient en route metering to the arrival fix 

• More efficient en route conflict resolution 

Figure 2-3 lists additional outcomes that were not quantified in this study; however, in 

future investment decisions benefits from these additional outcomes may be examined. 

2.7.1 Continuing visual approaches in marginal conditions 

A visual approach clearance is an air traffic control authorization for an aircraft on an 

instrument flight rule flight plan to proceed visually to the airport. Prior to issuing a 

visual approach clearance, the controller must ascertain that the pilot has the airport 

and/or pertinent traffic in sight, and will issue advisories to help the pilot find the airport 

or traffic. When the pilot confirms that the required entity (airport/runway or traffic) is in 

sight, the controller can issue the visual approach clearance. 

Through the use of a CDTI in an application called CDTI Assisted Visual Separation 

(CAVS), the pilot should be able to correlate the target aircraft and trajectory information 

to the actual traffic as seen out-the-window, so that the controller may clear the aircraft 

for a visual approach. The number of aircraft for which call signs can be provided is 

expanded through TIS-B. 

Most airports have established weather minima below which visual approaches cannot be 

conducted - primarily due to the difficulty for the pilot to visually acquire the runway or 

traffic in such weather. With CDTI and ADS-B, pilots will be able to more reliably 

acquire relevant traffic in less-than-optimum meteorological conditions. As a result, this 

would increase the range of weather conditions in which visual approaches can be used. 

The SBS program refers to the times when CDTI could increase visual approaches in 

marginal visual meteorological conditions (MVMC) as “windows of opportunity.” 

The yearly benefits pool was estimated by an equilibrium queuing model developed by 

ATO-F Operations Research. The purpose of the model was to monetize the benefit of 

increasing the arrival capacity during MVMC to the same rate as during VMC. The 

model considered projected traffic counts, future capacities, frequency of MVMC 

conditions, and aircraft direct operating costs and passenger value of time. The 

continuation of visual approaches in marginal conditions benefits were estimated by 

multiplying the yearly delay savings from the queuing model, order-dependent mixed 

equipage rates, and a CAVS effectiveness estimate. Estimates were developed separately 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

37
for the 100 busiest airports. The benefits were assumed to begin NAS-wide in 2014 (and 

2009 for UPS airports) and only apply to air carrier and commuter aircraft. 

Early benefits accrue only for CDTI-equipped UPS aircraft at SDF and PHL. Benefits 

from all commercial air carrier and commuter CDTI-equipped flights at the top 100 

airports accrue starting in 2014. Table 2-16 summarizes the benefits in base year 2007 

and risk-adjusted present value dollars. 

Table 2-16. Continuation of Visual Approaches in marginal conditions benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Continuation of Visual Approaches in 

marginal conditions 

$803.7 M $196.4 M 

The equilibrium queuing model developed by ATO-F Operations Research allows the 

user to enter projected arrival and departure capacities for different meteorological 

conditions (i.e. VMC, MVMC, IMC) at each of the top 100 airports. The model was 

updated to accept inputs from the recent Future Airport Capacity Task (FACT 2) report. 

A second input is the projected change in inter-arrival/departure variance for the new 

procedure or technology. A third input is the aircraft equipage percentage that can be 

entered if the projected capacities or variances depend on equipage. The output is a 

monetization of the difference in delay between the added capacity scenario and a 

baseline scenario. The baseline arrival and departure capacities consider future runway 

construction through 2020. The queuing delay measurement is applied to historical 

arrival and departure delays at each airport to estimate a result. 

 

The model uses average hourly arrival and departure demand derived from ETMS yearly 

statistics. The growth in hourly demand is based on the TAF. Because the model is an 

equilibrium model it cannot create an estimate if the demand is greater than or equal to 

the baseline capacity. To handle this issue, the hourly demand is constrained to 95 

percent of the capacity. The truncation of demand is performed for each weather 

condition because there are different capacities for each weather condition. The 

historical frequency of meteorological condition per hour comes from a 30-year average 

of National Weather Service data at each airport. We believe the truncation of demand 

in the model produces a very conservative estimate for the benefits pool. A dynamic 

queuing model approach may be attempted for later segment investment decisions. 

The ATO-F Operations Research queuing model was modified somewhat to account for 

equipage. The original model uses the equipage to change the inter-arrival/departure 

variances and to scale the final answer. We did not change the affect on variance, but 

removed the influence on the final scaling because the equipage in the queuing model did 

not consider order-dependence. An order-dependent mixed equipage curve was used 

outside the queuing model to scale the result for equipage. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

38
The result from the queuing model is a monetization of delay savings after increasing 

capacity at an airport. For the queuing model, we assumed that the capacity for MVMC 

would be the same as for VMC for properly equipped dependent commercial aircraft. 

ATO-F considered the assumption of attaining the full VMC capacity to be too 

aggressive a change because it did not account for pilots that might not accept a visual 

approach during MVMC even after CDTI information. To account for this concern an 

additional CAVS effectiveness factor was developed using a triangular distribution of 

(0.7, 0.8, 0.9). 

Approaches at some large airports are also affected by en route metering automation. In 

section 2.7.4, we estimate the benefit of increasing the accuracy of metering automation 

at 18 large airports. Since en route metering would occur prior to the CAVS procedure 

during a flight, we considered the CAVS benefit incremental to the en route metering 

benefit for the 18 airports in the estimate. However, the airlines can take advantage of 

the CAVS benefit relatively early (as soon as equipped and after procedure approval 

assumed 2014) compared to the metering benefit which may take some automation 

adjustments (assumed 2020). 

2.7.2 More efficient spacing during visual approaches 

The previous section described the benefit of extending the use of visual approaches 

(VAs) to lower weather conditions. In this section, we focus on improving flight 

efficiency during visual approaches. 

One of the primary goals of the SBS program is to increase the precision and consistency 

of inter-arrival spacing of aircraft on visual and instrument approaches. The goal is not to 

define the optimum spacing, nor to explore the boundaries of minimum spacing. Rather, 

the objective is simply to exploit the potential of ADS-B and CDTI to allow the pilot to 

more precisely manage spacing on the aircraft ahead during approach. 

Managing the spacing between sequential aircraft on arrival paths in the terminal area can 

be challenging for both pilots and controllers, and the consequences for operating on 

either side of "optimum" spacing are significant. If the following aircraft is too close to 

the one ahead, a go-around may be necessary. On the other hand, runway capacity is 

wasted when the gap between sequential aircraft is excessively large. Consistently 

achieving inter-arrival spacing that is closer to the optimum is an important step in 

reducing terminal area congestion. 

Consistently working toward the optimum inter-arrival spacing is problematic for both 

pilots and controllers. For the pilot on a visual approach clearance behind another 

aircraft, visually estimating the distance and closure rate on the preceding aircraft is 

difficult and imprecise, especially in demanding visual fields such as looking into the 

sun, or at night. 

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39
A pilot can use the CDTI to achieve and maintain the desired in-trail spacing behind 

another specific aircraft during a visual approach. It is assumed that the proper context 

for a visual approach has been established. See Section 2.7.1 with regard to expanding 

the number of conditions during which a VA is possible. With reference to speed and 

other data on the CDTI, the pilot should be better able to make real-time speed 

adjustments in response to lead aircraft actions and projections. In the estimate below, 

we only consider improving spacing during visual approach. An expansion of this 

concept will include instrument meteorological conditions (IMC) in the context of an 

instrument approach procedure, where the "out-the-window" visual component is gone. 

Using the CDTI for all approaches should reduce the uncertainties associated with current 

methods, thereby reducing the excess spacing buffers that must be maintained in current 

operations. As a result, terminal area inefficiencies would be reduced through more 

efficient approaches. 

The more efficient spacing during approaches benefit was estimated by multiplying the 

average flight time savings per flight, aircraft direct operating costs and passenger value 

of time, projected traffic counts, the percentage of time visual approaches exist in the 

current system, a ratio of demand to capacity where benefit is applicable, and CDTI 

order-dependent mixed equipage rates. Estimates were developed separately for the 100 

busiest airports. The benefits were assumed to begin NAS-wide in 2014 and only apply 

to air carrier and commuter aircraft. 

Because UPS has been using CDTI for more efficient approaches in visual conditions 

since 2004, much of the early benefit was captured in the baseline for the SBS program 

and is not included in the estimate. Benefits from all CDTI-equipped flights at the top 

100 airports accrue starting in 2014 Table 2-17 summarizes the benefits in both base 

year 2007 and risk-adjusted present value dollars. 

Table 2-17. More efficient spacing during visual approaches benefit 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient spacing during visual 

approaches 

$1,247.8 M $300.4 M 

There are many NASA and Eurocontrol studies that examine increases in efficiency due 

to self-spacing using cockpit tools [8-13]. A recent large scale human-in-the-loop 

simulation claimed that inter-arrival spacing error decreased by half when comparing 

pilot cockpit tools to controller automation tools [8]. These results imply a large capacity 

increase for airports where the majority of flights are self-spaced with the aid of cockpitbased tools such as CDTI. To be consevative, we only use observational data from an 

operational test of ADS-B and CDTI at Louisville International Airport (SDF) as a basis 

for the benefit estimate. 

United Parcel Service (UPS) equipped 107 of their aircraft with an ADS-B enabled 

Cockpit Display of Traffic Information (CDTI) by the spring of 2004. UPS pilots used 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

40
the CDTI for increased situational awareness in the terminal area. Two separate analyses 

(outlined below) examined the benefits for CDTI-equipped aircraft in the terminal area. 

It should be noted that the operational measurements at SDF may not represent the full 

potential of CDTI for spacing during visual approaches. The benefit requires that both 

the leading and following aircraft are equipped with ADS-B. During the post-analysis 

period (2004) only 66 percent of the aircraft were equipped resulting in a 44 percent 

likelihood that a following aircraft had a view of the leading aircraft on a CDTI. 

2.7.2.1 Flight Distance Analysis 

The first analysis examined flight distance from a 40 nautical mile (nmi) ring to the 

runway for UPS arrivals, comparing one year of post-implementation data to two 

separate baseline periods, each a year long. [14] Baseline data came from an FAA 

archive of Surface Movement Advisor (SMA) track points and post-implementation data 

came from a data gathering exercise performed by the FAA ATO Technology 

Development Office. The analysis showed significant decreases in flight distances (from 

3.3 to 6 nmi less) during preferred airport configuration operations at SDF after 

implementation of ADS-B/CDTI. These changes were more dramatic when times with 

the highest percentage of equipped aircraft were examined. The results showed 

significant early benefits of using ADS-B/CDTI during terminal operations. 

The average decrease in terminal area flight distance for UPS aircraft was 3.3 nmi; 

however, non-UPS aircraft achieved a decrease of 1.7 nmi during the same time period. 

The overall decrease of 1.7 nmi may be due to the fact that mixed equipage is positively 

affecting non-equipped aircraft, or simply that other factors led to this decrease. 

Subtracting the overall decrease result from the UPS result leaves a decrease of 1.6 nmi 

during the preferred flow. Changing the distance into a time using the typical terminal 

area approach speed (250 knots), we found an estimated decrease in flight time of 23 

seconds (plus or minus 4.0 seconds) per arrival during the preferred airport configuration 

(North Flow). 

2.7.2.2 Flight Time Analysis 

The second analysis was performed to confirm the results seen in the initial distance 

analysis after some concerns were expressed about the data source. The analysis 

examined flight time from a 40 nautical mile (nmi) ring to the runway for UPS arrivals at 

SDF for the time period with the highest levels of equipage. This analysis compared one 

year of post-implementation data (calendar year 2004) to one year of baseline data 

(calendar year 2003). Crossing times at the 40 nmi ring were gathered from Enhanced 

Traffic Management System (ETMS) archived track data and landing times from the 

ASPM individual flight Out-Off-On-In (OOOI) data. The analysis showed a significant 

decrease in flight time of 22 seconds (plus or minus 4.5 seconds) per aircraft during 

preferred airport configuration at SDF after implementation of ADS-B/CDTI. This result 

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41
was almost identical to the result found using the distance measurement based on the 

previous data sources. We used the flight time results in the benefit estimate. 

2.7.2.3 Applying analysis results to form a benefit 

The average flight time savings seen at SDF were applied to all VA condition arrivals at 

the top 100 airports. The results at SDF only occurred during the preferred airport 

configuration. To apply this fact at other airports, we assumed that the preferred flow at 

an airport occurrs at least half of the time. (At SDF, UPS arrivals land in the preferred 

flow over 60 percent of the time.) The result is an average delay savings of 11 seconds 

(plus or minus 4.5 seconds) for each equipped arrival during visual approaches. 

One might also expect that this benefit will only occur at larger airports that currently 

have some inefficiencies in the terminal area due to traffic congestion. To account for 

this fact, we only quantify benefits for the 100 busiest airports (many of which are larger 

and more congested than SDF). We also applied a ratio that represents the percent of 

flights at each airport that arrive during times when the ratio of arrival demand to arrival 

capacity is greater than 50 percent. The ratio was found using the ATO-F equilibrium 

queuing model described in previous subsections (2.7.1). This factor ensures that there 

will be sufficient traffic to warrant examining the CDTI during arrival. The ratio 

 

While more efficient spacing assisted by a CDTI can increase airport throughput, the 

individual pilot will notice little benefit. For this reason, we assume that only air carrier 

and commuter airlines traffic will have sufficient economic incentive to increase airport 

capacity. Allowing significant changes in spacing will also require full integration of 

ADS-B onto air traffic control automation and certification of procedures. Because of 

these factors, we assume that NAS-wide benefits do not start accruing until 2014. 

Note that the current benefit estimate only assumes more efficient spacing during visual 

approach conditions. Further CDTI applications should be able to extend VAs to lower 

weather conditions, allowing the ability to provide more efficient spacing during those 

conditions. 

2.7.3 Increased ability to allow Continuous Descent Approaches 

The previous two sections focused on the SBS program benefits in the immediate 

terminal area. The following three applications examine the benefits of more accurate 

spacing in the en route environment. 

In the Merging and Spacing (M&S) application [17], precise speed instructions are sent 

from the ground (either from an airline operations center or an FAA facility) to en route 

aircraft to properly sequence aircraft approaching the terminal area. These exact speed 

instructions should allow aircraft to arrive at extended terminal area merge points at times 

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42
that are much more precise than currently feasible. After entering the terminal area, 

spacing instructions are processed by cockpit-based CDTI to optimize spacing. 

There are many possible benefits of M&S. One potential mechanism involves the shared 

responsibility of speed and spacing instructions allowing increased productivity for the 

controller and increasing sector capacity. Large scale NASA [8-10] and Eurocontrol [11-

13] studies support an increased capacity benefit because of cockpit-based spacing paired 

with controller merging tools. 

Another potential benefit focuses particular attention on controller merging tools. As part 

of the Merging and Spacing application, the SBS program is developing a tool that can be 

used to optimize aircraft spacing to enable a fuel-saving procedure called continuous 

descent approach (CDA) during increased levels of demand than currently feasible. The 

prototype tool will be used by UPS in their Airline Operations Center, where UPS will be 

allowed to adjust aircraft speeds into SDF at night when they constitute most of the 

demand. This tool will be incorporated into FAA automation to allow FAA controllers to 

space aircraft from multiple carriers into an airport using future surveillance data (ADS-B 

out). A follow-on tool could use an expanded set of data from ADS-B out (aloft winds, 

pressure, aircraft specific characteristics) to allow CDAs at somewhat higher demands. 

CDAs are Area Navigation (RNAV) / Required Navigation Performance (RNP) terminal 

arrival procedures specifically designed to keep an aircraft at idle or near idle power 

during the entire arrival until the Final Approach Fix (FAF). These procedures result in 

savings in time and fuel and reduce noise and emissions. The CDA eliminates step-down 

altitudes and the associated power increases. It is critical for the success of CDAs that 

there is little or no vectoring during the procedure to maintain the arrival stream. To 

accomplish this requires the aircraft to be spaced and sequenced prior to descent. 

The fuel savings from CDAs are well-documented and have been tested at SDF. 

Theoretical savings of 400-500 pounds of fuel per approach are claimed; however, 

current experiments [18] using the procedure have shown fuel savings between 181 and 

364 pounds per approach. A triangular distribution of (181, 273, 364) pounds was used 

in the estimate. A FY2006 Bureau of Transportation Statistics estimate of 29.9 cents per 

pound for scheduled and non-scheduled aircraft was used for fuel cost. 

The most important factor preventing many airlines from attempting more fuel-saving 

CDAs is interference from other aircraft in the terminal area. For multiple CDAs to 

occur over a relatively short time period, the aircraft must be sequenced and spaced 

accurately to avoid vectoring. Below a certain demand, CDAs can (and are) performed 

using current onboard equipment and procedures (RNP). As demand increases it 

becomes progressively more difficult for controllers to allow CDAs because of 

interference with other traffic in the pattern. As demand approaches capacity, the 

tradeoff between total airport throughput and individual flight profile efficiency (CDAs) 

would most likely prohibit CDAs for very high traffic situations. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

43
Figure 2-7 displays different regimes of CDA as a function of the ratio between demand 

and capacity. At low values of the ratio, CDAs are currently feasible. A spacing tool 

would expand the use of CDAs to higher values of the ratio. A follow-on spacing tool 

needing expanded information (available from ADS-B aircraft) could further expand the 

regime of CDAs. As the demand to capacity ratio approaches one, CDAs are prohibited 

because airport throughput would be of greater concern than individual flight efficiency. 

Expanded 

data needed 

CDAs 

prohibited 

Spacing tool needed to perform 

CDAs

0 1

CDAs currently feasible 

with RNP only 

Demand/Capacity 

Figure 2-7. CDA regimes as a function of the ratio between demand and capacity 

The regimes of CDA in relation to demand and capacity are not well-defined in the 

literature and require further study. To estimate a benefit, we calculated a regime of 

applicability using the following assumptions: 

• CDAs can currently be accommodated at a runway if there is no more than one 

arrival every 5 minutes (12/hour). At SAN (one runway) the maximum arrival 

capacity is 30 aircraft/hour. The ratio of demand/capacity is then 0.4. We used 

this ratio as the boundary between the regime of currently feasible CDAs and 

CDAs with spacing tool necessary. 

• Many airports start to exhibit significant delays when demand reaches 70 percent 

of capacity. The SBS spacing tool would enable CDAs from demand/capacity 0.4 

to 0.7; expanded ADS-B information into the spacing tool might allow CDAs 

from demand/capacity 0.7 to 0.9. 

• Because of the tradeoff between airport throughput and flight efficiency, CDAs 

would be prohibited when demand/capacity greater than or equal to 0.9. 

Using the ATO-F equilibrium queuing model described in previous subsections (2.7.1 

and 2.7.3) we found the percent of flights that arrive at each of the top 100 airports during 

periods when demand is between 40 and 70 percent of VMC capacity. As with the other 

advanced aircraft applications, we assume that only air carrier and commuter airlines will 

have sufficient economic incentive to apply CDAs on a day-to-day basis. 

A new spacing tool will also require full integration of ADS-B onto air traffic control 

automation and certification of procedures. Because of these factors, we assume that 

NAS-wide benefits do not start accruing until 2014. A number of factors allow UPS to 

take advantage of this benefit early (2009): early equipage, the time of night they plan to 

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44
use the application, and a specially allowed FAA permission to issue speed instructions 

from the Airline Operations Center (AOC) instead of from an FAA facility. 

The increased ability to allow Continuous Descent Approach benefits were estimated by 

multiplying the average fuel savings per CDA arrival to the percent of flights that arrive 

at each of the top 100 airports during periods when demand is between 40 and 70 percent 

of VMC capacity. The benefit was only taken during VMC (good weather) because 

reduced weather conditions in the extended terminal area may hinder CDAs. Estimates 

were developed separately for the 100 busiest airports. The benefits were assumed to 

begin NAS-wide in 2014 (and 2009 for UPS airports) and only apply to air carrier and 

commuter aircraft. Additionally, we further degraded the benefit by attributing much of 

the savings for CDAs during the spacing tool regime to other necessary elements like 

RNAV/RNP. To take account of the additional necessary elements, the SBS program 

only claimed one half of the final spacing tool regime CDA benefit. Table 2-18 

summarizes the benefits in base year 2007 and risk-adjusted present value dollars. 

Table 2-18. More efficient merging and spacing en route benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient merging and spacing en 

route benefits 

$2,876.7 $796.0 M 

2.7.4 More efficient en route metering to the arrival fix 

The improved accuracy and update rate of ADS-B position and speed information (over 

current information supplied by radar) will impact the capabilities of controller 

automation. One aspect of current automation is a metering capability called the Traffic 

Management Advisor (TMA). TMA is a decision support tool for en route controllers 

that optimizes arrival flows into busy airports. The controller display provides exact 

times for each aircraft to reach the arrival fix so that runway throughput is optimized. 

Because predictions of runway throughput and metering times are based on surveillance 

inputs, the increased accuracy and update rate of ADS-B (over radar) should allow better 

predictions, leading to an incremental increase in runway throughput. 

TMA was developed by NASA as part of the Center TRACON Automation System 

(CTAS). Many NASA studies have examined the uncertainty in factors such as initial 

position, aircraft speed, aircraft weight, and winds, and how these factors introduce errors 

into the CTAS calculations of meter fix arrival times. The study, “CTAS Error 

Sensitivity, Fuel Efficiency, and Throughput Benefits” (NASA 1996), compared the 

meter fix uncertainty of the current system, TMA (with the addition of weather 

information from the Integrated Terminal Weather System - ITWS) and a planned 

upgrade to TMA called the En route Descent Advisor (EDA). Table 2-19 presents a 

summary of the meter fix uncertainty information from the NASA paper. A further study 

comparing EDA and TMA, “EDA July 2004 Simulation Overview,” (NASA 2004) 

presented similar results. 

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Table 2-19. Meter Fix Uncertainty from NASA study 

ADS-B surveillance information should further reduce the uncertainty in initial position 

and speed allowing more accurate meter fix delivery. The “En route Descent Advisor 

Performance Analysis Final Report” (NASA, 2004) examined the CTAS input factors 

(e.g. position, speed, wind , weight, etc.) closely to determine the contribution of each to 

the meter fix uncertainty. They found that speed and initial position uncertainty account 

for approximately 40 percent of the remaining error. Table 2-20 repeats the information 

given in Table 2-19, but also applies the additional 40 percent reduction that would occur 

with no initial position and speed variance. Table 2-20 implies that if all position and 

speed error could be eliminated the remaining variance would be 13 seconds. If only half 

the variance could be eliminated the remaining would be 17 seconds. It is assumed in 

this estimate that the accuracy and update rate of ADS-B in the en route airspace will be 

at least twice as accurate as current en route radar requirements. The ADS-B signal will 

also downlink speed information directly into the automation, as opposed to the current 

method of estimating speed from multiple radar hits over time. 

Table 2-20. Meter Fix Uncertainty with increased accuracy 

Table 2-20 also lists the meter fix uncertainty as a percentage of the uncertainty in current 

operations. TMA reduces the meter fix uncertainty by 66 percent (44 percent of the 

original); the addition of EDA should bring the total uncertainty reduction to 83 percent 

(17 percent of original). If the speed and position accuracy from surveillance information 

were twice as certain as current information, the final reduction would amount to an 86 

percent decrease in meter fix uncertainty (14 percent of original). 

To translate the analysis described above into an economic benefit for the SBS program, 

we first examined the benefit of different arrival variance changes on airport delay using 

an equilibrium queuing model. The inputs for the model include current Future Airport 

Capacity Task (FACT 2) airport capacities, current demand profiles at each airport, and 

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46
future projected operations (TAF). The model allows changes in the arrival variance that 

should reflect the changes in uncertainty described in Tables 2-19 and 2-20. The benefits 

of TMA, TMA plus EDA, and TMA plus EDA plus ADS-B increased accuracy were 

tabulated. The ratio of the incremental ADS-B increased accuracy benefits to the TMA 

benefits equaled approximately 0.05. This leads us to believe that the increased accuracy 

of ADS-B information should at least result in a 5 percent increase in benefits beyond 

current TMA projections. In reality this estimate is conservative, because it already 

assumes that the introduction of ADS-B information will be incremental to EDA, a 

program that is still in the planning stages but will most likely come to fruition before full 

ADS-B equipage. 

The TMA Program Office completed a future benefits analysis in February of 2007 that 

was submitted and approved within the FAA. The report presented yearly benefit results 

for 18 TMA airports through 2020. We leveraged these TMA results to estimate the 

additional benefit due to ADS-B. We first scaled the TMA results to reflect the current 

approved ADOC and PVT values. The ratio described in the previous paragraph was then 

applied to the TMA results in 2020 to estimate the additional benefits due to increased 

surveillance information. To add risk, we applied the ratio as a triangular distribution 

(0.03, 0.05, 0.07). The SBS benefits were assumed to begin by 2020 and continue 

through the SBS lifecycle. The 2020 benefit was extrapolated through 2035 using a 

linear scaling based on the growth in yearly operations at each relevant airport from the 

TAF. Table 2-21 summarizes the benefits in both base year 2007 and risk-adjusted 

present value dollars. 

Table 2-21. More efficient en route metering to the arrival fix benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient en route metering to the 

arrival fix 

$1,746.6 M $417.0 M 

2.7.5 More efficient en route conflict resolution 

As mentioned the previous section, the improved accuracy and update rate of ADS-B 

position and speed information (over current information supplied by radar) will impact 

the capabilities of controller automation. Another aspect of current and future 

automation is a conflict detection capability. More accurate surveillance information 

(position and speed) through ADS-B should allow the controller to predict potential 

conflicts better either manually because of a faster update rate and more accurate 

information on the display, or through conflict detection automation. Because of the 

difficulty in judging controller actions using future display capabilities, we focus on the 

effects of increased accuracy on current conflict detection automation. 

A current automated conflict detection capability resides within the User Request 

Evaluation Tool (URET). The URET automation forecasts flight paths up to 20 minutes 

into the future. One of the URET applications then determines potential separation issues 

in en route airspace. If a potential separation violation is predicted, the system provides 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

47
the strategic D-side controller with a conflict warning. The D-side controller monitors 

the potential conflict and informs the tactical R-side controller if necessary. The current 

tool is advisory in nature and is not currently on the tactical controller display. Future 

FAA plans call for incorporating the conflict detection algorithms onto the tactical 

display and modifying it to provide appropriate information to the tactical controller. The 

algorithms in the conflict detection program depend on uncertainties in the current 

surveillance information. The uncertainties result in additional buffers applied when 

calculating potential conflicts. An increase in position and speed accuracy from ADS-B 

will reduce the necessary buffer size leading to a reduction in the number of predicted 

conflicts and the maneuver size necessary to avoid a potential conflict. More specific 

details concerning the current and future surveillance capabilities and URET algorithms 

can be found in “ADS-B Benefits enabled from Improved En Route Conflict Probe 

Performance,” a 2007 report from the SBS Program Office. 

Each en route controller operation (acceptance or handoff of an aircraft in a sector) is 

recorded within the en route centers. The number of operations is directly proportional to 

the amount of traffic. Based on a physical argument, one would expect an increase in the 

probability of potential conflicts proportional to the square of the traffic. The simulated 

number of URET severe conflict warnings in 2006 was compared to the square of the 

number of IFR handles in 2006 to produce a ratio of severe conflict warnings to squared 

IFR handles for the current (radar) and the future (ADS-B) surveillance environments. 

The simulation used the URET potential conflict algorithm for the current system and a 

modified version for the future. More specific details concerning the simulations can be 

found in the report mentioned previously. The ratios were used to estimate the future 

conflict warnings with and without ADS-B in each year using FAA projections of IFR 

handles in future years. 

The future warning information was used to estimate the reduction in the number of 

potential conflict warnings and the remaining number of conflicts after ADS-B 

incorporation into the conflict probe. The ADS-B benefit estimates the impact of a 

decrease in potential conflict warnings (less needed maneuvers) and the impact of being 

able to make somewhat smaller maneuvers for the remaining conflicts. 

The benefit from prevented conflict warnings was calculated as a product of the number 

of prevented warnings, the percent of warnings that are acted upon, and the average cost 

of a prevented vector maneuver. 

The benefit of reduced maneuver size for remaining maneuvers was calculated as a 

product of the number of remaining conflict warnings, the percent of warnings that are 

acted upon, the percent of maneuvers that are vector maneuvers, the average baseline cost 

of a remaining vector maneuver, and the reduction in maneuver cost because of reduced 

maneuver distance. 

Subject matter experts determined that approximately 45 percent of severe URET alerts 

are acted upon in today’s system. A triangular risk distribution of (0.3, 0.45, 0.6) was 

applied for this variable within the estimate. The experts also considered of the impact of 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

48
incorporating conflict detection on the tactical controller display in the future. They 

estimated the impact to be an increase in controller action by approximately 40 percent. 

In the estimate we used a triangular risk distribution of (1.33, 1.4, 1.50) for this variable. 

The two variables described above result in an average of 63 percent of future alerts that 

are acted upon by the controller. 

When maneuvering to prevent a conflict the controller can choose to change altitude, 

speed, or lateral position depending on which is most appropriate. Potential savings from 

increasing maneuver efficiency primarily accrue during lateral maneuvers (i.e. vector 

maneuvers). The program office study mentioned earlier used flight data to estimate that 

nearly all the prevented maneuvers would be vector maneuvers and 65 percent of 

remaining maneuvers would be vector maneuvers. 

An analysis performed for the Controller Pilot Datalink Program (CPDLC) examined the 

vector (lateral) maneuver distance for a large set of potential conflicts. The average 

conflict maneuver was found to be 3.51 nm. One would expect the maneuvers prevented 

by increased accuracy to be smaller than the average. The average distance of the 

maneuvers below the 15th percentile (1.04 nm) was used for the mean distance of possible 

prevented maneuvers, while the average of the maneuvers greater than the 15th percentile 

(4.01 nm) was assumed to be the remaining baseline maneuver size. The change in 

buffer size due to increased accuracy is approximately 1/8th, so it was assumed that 

maneuvers for the remaining conflicts could be reduced by 1/8th (0.13 nm). 

The average cost associated with the prevented conflict maneuver (1.04 nm) or the 

reduction in cost for remaining conflict maneuver (0.13 nm) was estimated using an 

average flight speed (356 nm/hour), the percentage of user type among IFR flights and 

the average ADOC and PVT per user type. 

The lifecycle benefit also depends on the percent of IFR aircraft that are ADS-B out 

equipped and the date of conflict probe ADS-B information integration. ADS-B 

information will be integrated into NAS automation by 2014 and the conflict probe is 

planned to be available to the R-side controller by 2016. The conflict probe increased 

accuracy benefit was assumed to begin in 2017, two years before maximum equipage and 

continue through the lifecycle. Table 2-22 summarizes the benefits in both base year 

2007 and risk-adjusted present value dollars. 

Table 2-22. More efficient en route conflict resolution benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient en route conflict resolution $3,258.1 M $801.8.0 M 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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2.8 Non-radar Benefits 

The Non-radar benefits are derived from the outcomes outlined in Figure 2-4. Because of 

the variance in implementation at the different non-radar locations, we isolated the 

outcomes and benefits by location. Below is a list of the outcomes by location from 

which the benefits are derived. 

Gulf of Mexico High Altitude: 

• More efficient separation en route (non-radar) 

• Optimal routing 

Gulf of Mexico Low Altitude: 

• Increased ability to fly Part 135 operations 

• Fewer encounters with hazardous weather 

Juneau: 

• More efficient separation on approach (non-radar) 

• Improved search and rescue services 

Alaska Capstone: 

• Increased access to lower altitude routes 

• Improved search and rescue services 

• Increased commercial access to remote villages 

• Increased Medevac access to remote villages 

Gulf of Mexico High Altitude

2.8.1 More efficient separation en route (non-radar) 

The SBS program will provide ATC with surveillance for non-radar regions in the Gulf 

of Mexico. Surveillance should allow radar-like separation (~ 5 miles in trail), as 

opposed to current non-radar procedural separation (~ 50 miles in trail). The introduction 

of radar-like separation will increase sector capacity. Initial separation by surveillance 

will be limited to selected altitudes, but widens to most altitudes above 24,000 feet after 

heightened ADS-B out equipage. 

Current non-radar separation in the Gulf of Mexico constrains the number of flights that 

can operate in each of the Air Route Traffic Control Center (ARTCC) Gulf sectors 

(ZHU79 and ZHU72). ZHU controllers claim that many flights experience ground or air 

delay, because of this constrained airspace. Currently, delay only occurs during highly 

seasonal peak traffic days. We developed a dynamic queuing model to determine future 

delays from projected demand. The benefit derives from an increase in sector capacity 

after surveillance. 

The more efficient separation en route (non-radar) benefits were estimated by multiplying 

the annual delay savings from the queuing model, ADS-B out independent equipage 

curves, aircraft direct operating costs and passenger value of time, and the Gulf of 

Mexico high-altitude surveillance service schedule. To account for risk in the model, 

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50
estimates were developed separately for three scenarios (low benefit, high benefit, and 

most likely benefit) based on differences in demand profile. We assumed the benefits to 

begin in 2011 and ramp up to steady-state in 2020 after full equipage. Table 2-23 

presents the more efficient en route separation (non-radar) benefits in both base year 

2007 and risk-adjusted present value dollars. 

Table 2-23. More efficient en route separation (non-radar) benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient en route separation (nonradar) $2,064.7 $459.3 

The first step in the queuing analysis was estimating the increase in capacity that will 

arise from radar-like separation. The monitor alert parameter (MAP) value is generally 

considered the maximum instantaneous load a controller can manage over an extended 

period. Sector ZHU 79 has a MAP value of 18 and sector ZHU72 has a MAP value of 

12. The average time an aircraft spends in the region (both sectors) is 32 minutes. 

Combining these gives an hourly capacity of 56 aircraft per hour. Representatives from 

ZHU estimated that the combined MAP value would rise to 40 after surveillance. 

Subsequently, the hourly capacity would be 75 aircraft per hour. The instantaneous 

capacity with true radar-like separation would be much higher than 40; however, the new 

capacity assumption takes Mexican border constraints and maintaining the current 

number of sectors into account. Table 2-24 presents instantaneous and hourly capacities 

assumed in the analysis. 

Table 2-24. Capacity estimates for Gulf of Mexico before and after Surveillance 

Configuration Instantaneous Capacity (MAP) Hourly Capacity 

Baseline 30 or (18 + 12) 56 

Baseline with Surveillance 40 75 

Traffic levels in the Gulf are highly variable day-to-day. The peak traffic days can be 

three times busier than off-peak days. Currently there are few days that exhibit peak 

demand; however, as Gulf traffic continues to grow, we expect an increase in the number 

of peak demand days. Using the 2004 demand1 as a base, we used FAA APO 

projections for US to/from Latin America traffic to increase yearly demand through 2017. 

After 2017 we assumed yearly growth of 4.0 percent (the minimum growth in the APO 

numbers from 2006 through 2017 was 4.2 percent). We consider this estimate 

conservative because the average annual growth in the Gulf of Mexico from 1990 to 2004 

was 8 percent and the growth from 2003 to 2004 was 14 percent. 

Usually, for a queuing model analysis, the average daily demand or demand over a 

representative week is examined. Because of the large demand variability in the Gulf, it 

 

1

 2004 Gulf demand from Air Traffic Data Activity System (ATADS) Houston Oceanic operation counts, 

available on the FAA Office of Policy and Plans (APO) website: http://www.apo.data.faa.gov/. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

51
was decided that using average data would not capture delay properly. Alternatively, we 

decided to examine delay in daily demand bins. To do this, we applied the projected 

growth rate to each day in 2004 separately. Table 2-25 presents the projected number of 

days per year that fall in the daily demand bins for selected years when the daily demand 

is unconstrained. 

Table 2-25. Unconstrained Gulf of Mexico flight demand in daily bins 

Year

2007 2010 2015 2020 2025 2030 2035

Less Than 200 45 11 1 0 0 0 0

200 to 249 130 63 10 1 0 0 0

250 to 299 118 136 45 9 1 0 0

300 to 349 44 88 99 33 3 1 0

350 to 399 18 36 97 63 18 1 0

400 to 449 8 18 56 85 39 9 0

450 to 499 2 9 27 75 64 17 0

500 to 549 0 4 16 40 69 35 3

550 to 599 0 0 7 25 62 49 23

600 to 649 0 0 5 18 42 63 25

650 to 699 0 0 2 5 16 60 31

700 to 749 0 0 0 7 24 41 52

750 to 799 0 0 0 3 13 24 49

800 to 849 0 0 0 1 3 14 52

850 to 899 0 0 0 0 5 19 31

900 to 949 0 0 0 0 3 13 27

950 to 999 0 0 0 0 3 5 17

1000 to 1049 0 0 0 0 0 5 7

1050 to 1099 0 0 0 0 0 4 18

1100 to 1149 0 0 0 0 0 1 11

1150 to 1199 0 0 0 0 0 4 5

1200 to 1249 0 0 0 0 0 0 2

1250 to 1299 0 0 0 0 0 0 4

1300 to 1349 0 0 0 0 0 0 4

1349+ 0 0 0 0 0 0 4

Daily Demand 

Bins

To run the queuing model with hourly capacities, we need an hourly demand profile. 

ZHU ARTCC provided the hourly demand profile based on the four peak days in 2004 

where over 400 aircraft flew. We applied the demand growth to the hourly demand 

profile to forecast future hourly demand for days with the traffic levels presented in Table 

2-25. The percentage of traffic in each hour is kept constant. Figure 2-8 shows the result 

of this unconstrained hourly profile. The thickest line in Figure 2-8 shows the current 

demand seen on peak days in the Gulf, and the horizontal lines represent the current and 

future hourly capacities. Notice that many of the demand bin profiles include demands 

far above both the current and proposed capacities. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

52
0

20

40

60

80

100

120

140

160

180

200

6 8 10 12 14 16 18 20 22

Local Hour

Hourly Flight

s

Figure 2-8. Hourly demand profile for different demand bins 

Because the unconstrained demand is so much larger than the capacity, the results from a 

queuing model will become quite large unless some modifications are made to the 

demand. After consulting with FAA APO and FAA ATO-P Operations Research, we 

decided to modify the demand using three methods. The methods represent a low, most 

likely, and high estimate of the benefits. 

1. Most Likely - Constrain daily demand when average queuing delay is 20 min or 

less for baseline capacity case. Repeat process for surveillance capacity case. 

Estimate delay savings and take note of newly accommodated flights. 

2. High - Constrain daily demand when average queuing delay using is 20 min or 

less for baseline capacity case. Estimate delay savings by applying the 

surveillance capacity to the baseline constrained demand. 

3. Extreme low - Spread yearly demand evenly over all days and develop a new 

hourly profile that spreads demand over hours. Figure 2-9 displays the average 

hourly demand profile for the low case. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

53
0

20

40

60

80

100

120

140

160

180

200

6 8 10 12 14 16 18 20 22

Local Hour

Hourly Flights (Avg. Day)

Figure 2-9. Hourly demand profile for low estimate 

2.8.1.1 Queuing delay results for high and most likely methods 

Using the unconstrained hourly demand profiles, we ran a queuing model to estimate 

delay for the baseline and surveillance cases for the high and most likely methods. The 

queuing model included an exponential distribution for the inter-arrival time of flights 

into the region and a distribution of service times based on data from an ATO-P 

Operations Research flight model of the region. Table 2-26 presents the average minutes 

of delay per aircraft for each daily demand bin using the unconstrained hourly demand 

profiles from Figure 2-8. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

54
Table 2-26. Average queuing delay results per aircraft for different demand bins 

Daily Demand Bins Baseline 

(minutes)

Most Likely 

Surveillance 

(minutes)

High 

Surveillance 

(minutes)

Less Than 200 0 0 0

200 to 249 0 0 0

250 to 299 0 0 0

300 to 349 0 0 0

350 to 399 0 0 0

400 to 449 0 0 0

450 to 499 0.43 0 0

500 to 549 1.37 0 0

550 to 599 3.92 0.07 0.07

600 to 649 8.87 0.27 0.27

650 to 699 20.00 0.76 0.76

700 to 749 capped 1.91 capped

750 to 799 3.93

800 to 849 7.65

850 to 899 14.56

900 to 949 20.00

950 to 999 capped

1000 to 1049

1050 to 1099

1100 to 1149

1150 to 1199

1200 to 1249

1250 to 1299

1300 to 1349

1350+

Average Daily Delay per 

Aircraft

For estimate methods 1 and 2 the daily demand is capped when the average minutes of 

delay is greater than 20 minutes. For the baseline case and the high surveillance case, the 

capping occurs for any day when the demand is greater than or equal to 650 aircraft; for 

the most likely surveillance case the capping occurs when demand is greater than or equal 

to 950 aircraft. Table 2-27 presents the new flight demand in daily demand bins 

constrained by the average 20 minute delay cap seen in the queuing delay results (Table 

2-26.) 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

55
Table 2-27. Gulf of Mexico flight demand in daily bins constrained by delay cap 

Baseline and High Surveillance Case Most Likely Surveillance Case

Daily Demand 

Bins

2007 2010 2015 2020 2025 2030 2035

Daily Demand 

Bins

2007 2010 2015 2020 2025 2030 2035

Less Than 200 45 11 1 Less Than 200 45 11 1

200 to 249 130 63 10 1 200 to 249 130 63 10 1

250 to 299 118 136 45 9 1 250 to 299 118 136 45 9 1

300 to 349 44 88 99 33 3 1 300 to 349 44 88 99 33 3 1

350 to 399 18 36 97 63 18 1 350 to 399 18 36 97 63 18 1

400 to 449 8 18 56 85 39 9 400 to 449 8 18 56 85 39 9

450 to 499 2 9 27 75 64 17 450 to 499 2 9 27 75 64 17

500 to 549 4 16 40 69 35 3 500 to 549 4 16 40 69 35 3

550 to 599 7 25 62 49 23 550 to 599 7 25 62 49 23

600 to 649 5 18 42 63 25 600 to 649 5 18 42 63 25

650 to 699 2 16 67 190 314 650 to 699 2 5 16 60 31

700 to 749 700 to 749 7 24 41 52

750 to 799 750 to 799 3 13 24 49

800 to 849 800 to 849 1 3 14 52

850 to 899 850 to 899 5 19 31

900 to 949 900 to 949 6 32 99

950 to 999 950 to 999

1000 to 1049 1000 to 1049

1050 to 1099 1050 to 1099

1100 to 1149 1100 to 1149

1150 to 1199 1150 to 1199

1200 to 1249 1200 to 1249

1250 to 1299 1250 to 1299

1300 to 1349 1300 to 1349

1350+ 1350+

The daily queuing delay results of Table 2-26 and the flight demand results of Table 2-27 

are combined to create yearly delay estimates. Table 2-28 presents an example of an 

annual delay estimate for one year (2025). Table 2-28 displays the delay calculation for 

both baseline and most likely surveillance cases, presents the difference, and notes the 

number of additional flights accommodated by the surveillance capacity. 

Table 2-28. Example of annual delay calculation for 2025 (most likely case) 

Daily Demand 

bins

2025 # Days 

per bin

Delay 

per 

Aircraft 

Delay per 

bin (hrs)

2025 # 

Days per 

bin

Delay 

per 

Aircraft 

Delay per 

bin (hrs.)

Addition

al 

Accomm

Less Than 200 175

200 to 249 225

250 to 299 275 1 1

300 to 349 325 3 3

350 to 399 375 18 18

400 to 449 425 39 0.08 22 39

450 to 499 475 64 0.43 218 64

500 to 549 525 69 1.37 827 69

550 to 599 575 62 3.92 2329 62 0.07 42

600 to 649 625 42 8.87 3881 42 0.27 118

650 to 699 675 67 20.00 15075 16 0.76 137

700 to 749 725 capped 24 1.91 516* 1200

750 to 799 775 13 3.93 575* 1300

800 to 849 825 3 7.65 258* 450

850 to 899 875 5 14.56 819* 1000

900 to 949 925 6 20.00 1350* 1500

950 to 999 975 capped

1000 to 1049 1025

Total 22352 3814 5450

Delay Savings 2025 (hrs) 18538

*Surveillance Delay per bin only counted against flights in the baseline (max 675)

Baseline Most Likely Surveillance

Daily demand 

bin midpoint

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

56
2.8.1.2 Queuing delay results for extreme low method 

For the extreme low method we developed the constrained hourly demand profiles 

(Figure 2-10) that ignore the variation in daily demand seen in the Gulf and consider only 

the daily demand averaged over the entire year. Using these profiles, we ran a queuing 

model to estimate delay for the baseline and surveillance cases for the extreme low 

method. The queuing model included an exponential distribution for the inter-arrival 

time of flights into the region and a distribution of service times based on data from an 

ATO-P. Table 2-29 presents the average queuing delay per aircraft for each day in the 

year. Note that no delay accrues using this method until 2026. 

Table 2-29. Average queuing delay results per aircraft using constrained demand 

Average Delay Per Aircraft

Year

Average Ops 

per Day

Baseline 

(minutes)

Surveillance 

(minutes)

2007 260 0 0

2008 273 0 0

2009 286 0 0

2010 299 0 0

2011 313 0 0

2012 328 0 0

2013 343 0 0

2014 358 0 0

2015 374 0 0

2016 390 0 0

2017 406 0 0

2018 423 0 0

2019 440 0 0

2020 457 0 0

2021 475 0 0

2022 494 0 0

2023 514 0 0

2024 535 0 0

2025 556 0 0

2026 578 0.19 0

2027 602 0.34 0

2028 626 0.58 0

2029 651 0.99 0

2030 677 1.63 0

2031 704 2.8 0.01

2032 732 6.63 0.04

2033 761 11.93 0.08

2034 792 19.41 0.15

2035 823 20 0.31

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

57
2.8.1.3 Combined results 

Table 2-30 presents the annual delay savings in hours from all three methods. The range 

in lifecycle benefits is between 300k hours and 600k hours with a most likely value of 

430k hours. APO and ATO-P Operations Research suggested that most delay would be 

taken on the ground, so ground ADOC and PVT were used to value the delay. An 

additional factor of 1.31 was multiplied to the PVT delay to account for downstream PVT 

delay on US airlines arriving into US airports. The 31 percent increase represents an 

assumed 80 percent downstream delay factor multiplied by the percentage of flights that 

are operated by US airlines (79 percent) and the percentage of those flights with US 

destinations (50 percent). 

Table 2-30. Annual delay results for all three methods 

Year High Most 

Likely

Extreme 

Low

2007 0 0 0

2008 0 0 0

2009 0 0 0

2010 0 0 0

2011 15 15 0

2012 60 60 0

2013 144 144 0

2014 327 327 0

2015 727 727 0

2016 1275 1275 0

2017 2156 2137 0

2018 3266 3225 0

2019 5021 4866 0

2020 6781 6506 0

2021 9442 8912 0

2022 11380 10410 0

2023 15160 13770 0

2024 17680 15400 0

2025 21620 18540 0

2026 25730 21630 668

2027 30880 25300 1245

2028 36100 28970 2209

2029 42480 33200 3921

2030 49060 36710 6713

2031 54600 39470 11950

2032 59860 41540 29350

2033 64850 42240 54860

2034 67700 40390 92790

2035 71090 38400 98580

Total 597404 434164 302286

Annual Delay Savings (Hrs.)

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

58
Because the daily demand cap in the baseline period is lower than the demand cap used in 

the surveillance period for the most likely case, there are additional flights 

accommodated in the most likely surveillance case. Table 2-31 displays the yearly 

number of additional flights accommodated by the additional capacity. 

Unfortunately, the FAA does not have an agreed upon method to value these additional 

flights; consequently, the value of the newly accommodated flights was set to zero in the 

estimate. 

Table 2-31. Additional flights accommodated by surveillance capacity (most 

likely case) 

Year

Additional 

Flights 

Accomodated

2007 0

2008 0

2009 0

2010 0

2011 0

2012 0

2013 0

2014 0

2015 0

2016 0

2017 100

2018 200

2019 550

2020 800

2021 1300

2022 1900

2023 2650

2024 3900

2025 5450

2026 6950

2027 9150

2028 11400

2029 14500

2030 18350

2031 22800

2032 27450

2033 33350

2034 39350

2035 46250

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

59
2.8.2 Optimal routing 

The SBS program will provide ATC surveillance above 24,000 feet for non-radar regions 

in the Gulf of Mexico and the Caribbean. Surveillance should allow radar-like 

separation, as opposed to current non-radar procedural separation. The introduction of 

radar-like separation will permit creation of additional routes and/or the granting of more 

direct requests. These changes will allow decreases in flight distance due to more 

efficient routes. Table 2-32 presents an estimate of the Optimal routing benefits based on 

examination of current routes in and around the Gulf. 

Table 2-32. Optimal routing benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Optimal routing $256.5 M $86.5 M 

Currently, flights crossing the non-radar region of the Gulf of Mexico are constrained to 

10 routes with set entry and exit fixes as seen in Figure 2-10. Flights are also constrained 

by the large SUAs located in the Gulf (orange areas in Figure 2-10). Because of spacing 

restrictions along the main routes, controllers sometimes treat routes as one-way 

corridors. The addition of surveillance across the gulf would allow a variety of new 

entry/exit locations on the U.S. side of the region. In the near term, however, these 

flights would be constrained to the same entry/exit fixes on the Mexican airspace border 

of the region. The ability to allow new entry/exit points on the U.S. side should allow 

controllers to grant more directs from U.S. locations to the fixes on the Mexican airspace 

border. Also, greater capacity along current routes should allow more flights to take 

optimum routes between city pairs. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

60
SUA

SUA

Current Routes

Non-radar 

Region

Figure 2-10. Airspace and routes in the Gulf of Mexico 

We first examined routes between the top twenty city pairs from the US to Mexico and 

South America whose direct paths crossed the non-radar region for April 2003. We 

chose to examine savings in terms of excess distance between current routes and more 

direct routes, where possible. The types of savings fell into two general categories. The 

first category involved flights that already pass through the non-radar region, but were 

not allowed to fly directly to the fix on the Mexican border that was closest to their 

destination. The flights were not allowed a more direct path because, either the more 

direct route was being used as a one-way corridor in the opposite direction, or no direct 

path on the current route structure existed between the entry and exit points. The other 

category involved flights that avoided the non-radar region. An attempt was made to 

determine if these circuitous routes around the region were weather-related. If a route 

between city pairs was filed more than 20 percent of the time, we assumed that it was not 

weather-related, but involved either capacity or equipage considerations. We removed 

routes filed less than 20 percent of the time from the analysis. Savings for this second 

category focused on allowing these flights to take the more optimal non-radar region 

route. 

Table 2-33 displays the excess distance data for the top twenty city pairs. The savings 

are broken into columns for flights that took routes through the non-radar regions and 

those who avoided the non-radar region. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

61
Table 2-33. Optimal route savings between selected city pairs 

City 1 City2 Count Savings for flights 

that took non-radar 

routes (nmi) 

Savings for flights 

that avoided nonradar route (nmi) 

Total savings 

(nmi) 

MIA MMMX 574 5344 8686 14,030 

IAH MMUN 338 1922 1922 

DFW MMUN 292 354 354 

ATL MMMX 271 690 690 

MSP MMUN 215 0 

ATL MMUN 219 2968 2968 

ORD MMUN 212 306 2716 3022 

JFK MMMX 217 544 574 

CLT MMUN 198 245 15,143 15,388 

EWR MMUN 185 1867 4197 6064 

IAH MZBZ 183 0 

DTW MMUN 168 520 2798 3318 

EWR MMMX 158 389 389 

DEN MMUN 137 9464 9464 

IAH MROC 126 0 

STL MMUN 130 0 

IAH MGGT 116 0 

IAH MSLP 111 0 

PHL MMUN 108 275 6173 6448 

JFK MMUN 105 1071 2140 3211 

TOTAL 4063 16,495 51,347 67,842 

Using only these twenty city pairs and the fact that April represents 9% of the yearly 

traffic load, we estimate savings of approximately 750,000 nmi a year from more optimal 

routes. 

The optimal routing benefit directly links to the capacity benefit. Optimal routing for 

flights that currently avoid the non-radar region while operating between the top twenty 

city pairs represents the potential for an 11 percent increase in total traffic. With 

surveillance, sufficient capacity to accommodate these flights without increasing delays 

occurs until the daily demand reaches 550 operations. Benefits for flights that currently 

avoid the non-radar region decrease once future demand exceeds capacity with 

surveillance. 

The benefits were assumed to begin in 2011 and increase with equipage. To adjust for 

risk, we applied a distribution to the distance savings using standard deviations from the 

data. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

62
Gulf of Mexico Low Altitude

2.8.3 Increased ability to fly Part 135 operations 

There are approximately 4000 oil platforms in the Gulf of Mexico. A fleet of 

approximately 650 helicopters provide air transportation to more than three million 

passengers, an average of 11,000 people on 4000+ flights per day to approximately 3000 

offshore structures. The busiest times are during mid-week platform crew changes, 

which require 7000 to 9000 flights per day. During good weather, most flights use 

Visual Flight Rules (VFR) to meet the demand; however, during IMC the demand cannot 

be met because of constraints on the ability to initiate Instrument Flight Rules (IFR) 

flights in the region. IFR flights also involve inefficient routes and restrictions due to 

lack of infrastructure. 

There are three main constraints on IFR flights: 

1. Weather observations are required to fly Part 135 IFR operations. Due to the lack of 

automated weather information, operators must rely on manual observations to conduct 

flights during poor visibility conditions. When certified weather observers are not 

available, flights are unable to be executed. 

2. Because of the lack of surveillance and limited communications during IMC, IFR 

operators must verbally acknowledge that they are clear of their departure or arrival point 

prior to another aircraft being granted access to the geographical area. With 

communications limited to 4,000 ft above the surface or water, positional reports below 

this altitude will not be available until the aircraft lands and calls in to report landing or 

departs and calls in once it has climbed to 4,000 ft. 

3. The current IFR route structure is composed of a Grid System (See Figure 2-11) 

defined by 300 offshore waypoints and IFR instrument approach procedures such as 

Offshore Standard Approach Procedures (OSAPs), Helicopter En Route Descent Areas 

(HEDAs), and Airborne Radar Approaches (ARAs). Due to the lack of surveillance and 

limited communication, aircraft operating under IFR are required to fly from grid point to 

grid point limiting the route efficiency. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

63
Figure 2-11. IFR En Route Grid System in low-altitude Gulf of Mexico 

The SBS program will upgrade communications stations and automated weather 

reporting stations as support for providing ATC surveillance in the Gulf of Mexico lowaltitude region. Improved weather, communications, and surveillance will increase the 

ability to provide Part 135 operations during IMC, increase IFR capacity, and allow 

optimal routing within the region. We modeled these effects together and present the 

results below. 

The yearly benefits pool was estimated by a dynamic queuing model. The purpose of the 

model was to quantify the delay savings of increasing the arrival capacity and decreasing 

service time during IMC when demand is large on a crew change day. The model 

considered current IFR demand, baseline and future capacities, duration of IMC weather 

on IMC days, and current and future IMC flight times. The increased ability to fly Part 

135 operations benefits were estimated by multiplying the daily IMC delay savings from 

the queuing model, the frequency of IMC weather in the region, the percentage of days 

that are shift change days, independent equipage curves for IFR helicopters in the Gulf, 

aircraft direct operating costs and industry labor costs, and the infrastructure schedule. 

Table 2-34 presents an estimate of the increased ability to fly Part 135 operations benefits 

in both base year 2007 and present value dollars. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

64
Table 2-34. Increased ability to fly Part 135 operations benefits 

Segment Benefits (BY 07) Benefits (RA PV) 

Increased ability to fly 

Part 135 operations $238.3 M $84.2 M 

As mentioned in the opening paragraph, demand on crew change days is quite large 

(~7000-9000 flights.) The current number of IFR capable helicopters in the Gulf is 117. 

Even if the IMC capacity were unconstrained, these few IFR helicopters could not meet 

the demand. Consequently, we limit the demand to the maximum number of flights per 

hour that can be serviced by the IFR capable fleet. We assume each IFR helicopter can 

make 8 flights a day and that there are 12 operating hours in a day, giving an hourly 

demand of 78 flights. 

The monitor alert parameter (MAP) value is generally considered the maximum 

instantaneous load (or capacity) a controller can manage over an extended period. The 

baseline and future estimated MAP values were obtained from ZHU. We separated the 

capacity from upgraded communications and weather and the capacity from added 

surveillance because the infrastructure schedule for these services is different. The 

communications and weather upgrades begin operation in 2010 while surveillance begins 

in 2011. Also, the mean flight time (or service time in the queuing model) is less after 

surveillance service begins because flights will not be constrained to the grid structure. 

Average service times are expected to decrease by approximately 10 minutes from this 

benefit. Combining the MAP and service time values allows an estimate of the hourly 

capacity. Table 2-35 displays the MAP value, the service time, and the hourly capacity 

for each of the scenarios (baseline, upgraded communications and weather, and 

surveillance.) The addition of surveillance would allow a much greater capacity than 

listed in Table 2-35; however, an increase in the MAP value beyond 18 would involve 

airspace resectorization and additional controllers, neither of which were considered in 

the cost estimate. 

Table 2-35. Capacity and service time by scenario 

Scenario Baseline + Upgraded 

Communications and 

Weather 

+ Surveillance 

MAP value 7 15 18 

Service Time 30 min 30 min 20 min 

Hourly Capacity 13 30 54 

The frequency of days with IMC between 6 am and 6 pm (operating hours) was assumed 

to be the same as that for George Bush Intercontinental Airport (IAH). National Climatic 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

65
Data Center data showed a distribution from 54 to 72 days of IMC weather with the 

median being 63 days. The duration of IMC weather was examined using hourly weather 

data from calendar year 2002. Over 85 percent of the time weather started at 6 am. We 

used the distribution of IMC hourly duration in the queuing analysis. 

The results of the queuing model indicated that the increased capacity from upgraded 

communications and weather would decrease baseline delay on IMC crew change days 

by 28 percent. The addition of surveillance would decrease baseline delays by 65 

percent. 

The Helicopter Safety Advisory Conference (HSAC) and industry contacts provided the 

percent of days that are shift change days (3 out of 7), the distribution of passengers per 

IFR capable helicopter (triangular distribution 4,8,12 passengers), and the average 

overtime industry labor cost for delay per passenger ($52.50 an hour). The aircraft direct 

operating costs were assumed to be the same as for the NAS-wide Part 135 fleet. ADS-B 

out equipage of the IFR fleet was assumed to begin in 2011 and finish by 2014. 

2.8.4 Fewer encounters with hazardous weather 

Due to the lack of automated weather information in the Gulf of Mexico, helicopter 

operators do not always have the most current weather information. Additionally, 

meteorologists do not have the quality of weather observations required to produce 

accurate forecasts of hazardous weather conditions such as convective weather, 

turbulence, and icing. Because of these issues, helicopter operators are more likely to 

encounter hazardous weather, increasing the likelihood of weather-related accidents. 

Automated weather provided by the SBS program should allow pilots to make moreinformed decisions regarding hazardous weather in the Gulf of Mexico. 

Between 1991 and 2003 there were 6 weather-related accidents that involved 13 

fatalities. These accidents exclude those that involved heavy winds and a helicopter on 

or directly above a helipad. 

We constructed a weather accident rate and subsequent future baseline weather-related 

accident costs. We assumed that the mean effectiveness of automated weather in 

preventing weather accidents to be approximately 1 out of 6 accidents (16 percent). To 

account for risk we used a triangular distribution for effectiveness (.12, .16, .20). The 

fewer encounters with hazardous weather benefits were estimated by multiplying the 

future accident costs, the automated weather accident prevention effectiveness, and the 

service schedule for additional weather stations in the low-altitude Gulf of Mexico. 

Table 2-36 displays the benefits in base year and present value dollars. 

Table 2-36. Fewer encounters with hazardous weather benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Fewer encounters with hazardous weather $13.1 M $5.0 M 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

66
Juneau

The description of the improved search and rescue services benefit for Juneau has been 

combined with the search and rescue description for the Alaska Capstone project in a 

subsequent subsection. 

2.8.5 More efficient separation on approach 

IFR operations at Juneau International Airport (JNU) average 30-50 per day during the 

summer when the Air Traffic Control Tower (ATCT) is open. An additional 6 or more 

occur after the ATCT is closed. The IFR throughput rate is about 2 to 3 per hour when 

mixed with departures. In the summer of 2004, there were 6-12 incidents per day of IFR 

ground or airborne delays due to ATC system limitations. 

The limited throughput of JNU is directly related to a lack of surveillance. Anchorage 

ARTCC radar coverage in Southeast Alaska is limited to 12,000 feet Mean Sea Level 

(MSL) and above. Juneau International Airport is at sea level. Arriving IFR aircraft may 

be out of radar coverage 6-18 minutes before being visually sighted by Juneau ATCT. 

Departing aircraft may fly 20-30 miles before entering radar coverage. Because of this 

lack of surveillance, controllers must use procedural separation. 

Visual Approaches (VAs) greatly increase the capacity of an airport. Section 2.7.1 

addresses the benefits of continuing visual approaches during marginal conditions at 

CONUS airports. At JNU, effective VAs cannot be performed because IFR arrivals are 

not permitted to cancel IFR services until below 3,700 feet MSL (generally within 9 

miles of the airport) due to lack of surveillance flight following. 

The SBS program will provide surveillance services in Southeast Alaska starting in 2010. 

The surveillance will consist of a combination of ADS-B out and wide-area 

multilateration inputs. Surveillance will allow Anchorage Center the ability to ensure 

separation between all IFR aircraft. Surveillance will also allow the Juneau ATCT the 

ability to allow flight following for VAs. Both of these capabilities should allow more 

efficient spacing on approach for arrivals into JNU. 

The more efficient spacing on approach (non-radar) benefits were estimated by 

multiplying the annual hours of IFR flight arrival delay, the percent of delay caused by 

terminal volume, projected operations counts, passenger value of time, and the 

surveillance schedule for Anchorage Center and JNU tower. Table 2-37 displays the 

benefits in base year and present value dollars. 

Table 2-37. More efficient spacing on approach (non-radar) benefits by segment 

Outcome Benefits (BY 07) Benefits (RA PV) 

More efficient spacing on approach 

(non-radar) $3.0 M $1.1 M 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Examination of the FAA Operational Network (OPSNET) database from 2000 through 

2005 showed that 8.6 percent of arrival delays at JNU were caused by terminal volume. 

A study of ASPM gate arrival delay for IFR flights into JNU over the same period 

exhibits a mean delay of 712 hours a year (the standard deviation of 52 hours was used to 

create a distribution of annual hours of delay in the estimate). Combining the means 

produces an estimated 61 hours of delay per year in the baseline case. Virtually all 

arrival delays into JNU are taken at the departure airport, so only passenger value of time 

was used to monetize the delay. The TAF was used to increase the benefits pool linearly 

based on future traffic. We assumed that surveillance would virtually eliminate the 

terminal volume delays for flights into JNU. 

Alaska Capstone Phase III

2.8.6 Increased access to lower altitude routes 

The increased access to lower routes benefit assumes that ATC ADS-B surveillance will 

allow creation of a lower IFR route structure in mountainous areas of Alaska. In the 

current system, many aircraft have to cancel flights during IMC because reaching the 

required altitude in the current IFR structure increases the possibility of icing and 

requires supplemental oxygen for passengers. Capstone avionics will provide positive 

guidance in obstacle-rich terrain while protecting from icing. Lowering the Minimum En 

route Altitude (MEA) for an airway should eliminate most of the current cancellations. 

As an initial step, Capstone proposed a representative RNAV IFR Navigation 

Infrastructure by lowering the MEA for parts of Victor routes listed in Table 2-38. The 

current benefit relies on this representative set of lowered routes, it is expected that a 

different set of routes will produce benefit results in the same order of magnitude. 

ATO-F designed a model to calculate the benefit. We describe the methodology below, 

for more information see [19]. 

In order to quantify this benefit ATO-F estimated: 

• The traffic count for flights that currently fly over all lowered fixes listed in Table 

2-38. 

• The percentages of flight cancellations due to icing conditions or the lack of 

necessary equipment to fly at higher altitudes. 

For traffic counts they used Digital Aeronautical Chart Supplement (DACS) data to build 

a network of existing victor and colored routes in Alaska. They identified airports in 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

68
Table 2-38. Proposed FIXES for Lowering MEAs 

Rt ID Fix Name FixID 

Current 

MEA 

MOC

A Fix Type 

Proposed 

GPS MEA 

A15 NICHOLS ICK 7000 5100 NDB 5000

B28 NICHOLS ICK 6900 6000 NDB 6000

G1 HORTH HORTH 8000 2500 REP-PT 5000

G1 MORDI MORDI 8000 5300 REP-PT 7000

G1 TESPE TESPE 8000 REP-PT 7000

G1 CHUNA CHUNA 8000 REP-PT 7000

G15 ANVIK ANV 9000 6000 NDB/DME 7000

G4 WOOD RIVER BTS 4500 3000 NDB 3000

G4 27551 27551 4500 AWY-INTXN 3000

G8 DUTCH HARBOR DUT 9000 5700 NDB/DME 6000

G8 MORDI MORDI 8000 5300 REP-PT 7000

G8 TESPE TESPE 8000 REP-PT 7000

G8 CHUNA CHUNA 8000 REP-PT 7000

G8 SALDO AK 6000 4900 NDB 5000

V308 FISHH FISHH 8000 6000 REP-PT 6000

V308 CERGU 

CERG

U 8000 REP-PT 6000

V319 MALAS MALAS 10000 5000 REP-PT 9000

V319 KATAT KATAT 7000 5000 REP-PT 5000

V319 PEPPI PEPPI 10000 8000 REP-PT 8000

V319 WILER WILER 10000 7000 REP-PT 7000

V319 YONEK YONEK 12000 5000 REP-PT 5000

V319 TORTE TORTE 12000 10300 REP-PT 10000

V319 VEILL VEILL 12000 6000 REP-PT 6000

V319 ARSEN ARSEN 4000 2000 REP-PT 2000

V322 MALLT MALLT 9000 3000 REP-PT 3000

V385 EMMONAK ENM 3500 2800 VOR/DME 3000

V385 PICNI PICNI 3500 REP-PT 3000

V385 28516 28516 3500 AWY-INTXN 3000

V385 KEGEY KEGEY 3500 REP-PT 3000

V385 WARVI WARVI 3500 REP-PT 3000

V385 RIRIO RIRIO 3500 GPS 3000

V431 SISTERS ISLAND SSR 8000 5800 VORTAC 5800

V473 LEVEL ISLAND LVD 7000 6000 VOR/DME 6000

V507 PHOTO PHOTO 13000 6000 REP-PT 6000

V507 CIVED CIVED 13000 REP-PT 6000

V510 ANVIK ANV 10000 6200 NDB/DME 7000

V510 ABEAR ABEAR 10000 6200 REP-PT 7000

V510 MIGAN MIGAN 10000 8500 REP-PT 9000

V617 HOMER HOM 12000 8600 VOR/DME 9000

V617 27516 27516 12000 AWY-INTXN 9000

V617 27515 27515 12000 AWY-INTXN 9000

 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

69
Alaska and connected them to all fixes and NAVAIDS within a 40 nm radius. They used 

a linear programming method to calculate the shortest path using the existing network for 

all city pairs and counted the number of flights that flew over all fixes in the region. 

They then used ETMS data to identify city pair demand in the area. Since ETMS 

captures IFR flights only, they used the TAF to adjust the demand by city pair to capture 

all demand reported in TAF. While the TAF provides overall demand for each airport, it 

does not provide demand by city pair. 

The benefit is driven by cancellation costs. The cancellation cost per flight was calculated 

by ATO-F in terms of PVT. The wasted passenger times due to cancellations are 

assumed to be 3 hours for part 121 flights and 24 hours for part 135 and 91 flights. The 

PVT cancellation cost is then calculated by multiplying time, load factor and PVT. The 

cancellation cost for an average GA flight was $1339 while the average cancellation cost 

for a Part 135 flight changed from $1236 to $1394 between 2006 and 2035 based on an 

increasing prediction in load factor over time. Table 2-39 presents the assumed Alaska 

cancellation costs in constant dollars. 

Table 2-39. Alaska cancellation costs 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

70
Year Part 91 

BY2007 $

Part 135 

BY2007 $

2006 1339 1236

2007 1339 1245

2008 1339 1253

2009 1339 1260

2010 1339 1268

2011 1339 1276

2012 1339 1284

2013 1339 1291

2014 1339 1298

2015 1339 1304

2016 1339 1310

2017 1339 1317

2018 1339 1323

2019 1339 1330

2020 1339 1336

2021 1339 1342

2022 1339 1348

2023 1339 1348

2024 1339 1354

2025 1339 1359

2026 1339 1364

2027 1339 1369

2028 1339 1374

2029 1339 1373

2030 1339 1377

2031 1339 1381

2032 1339 1386

2033 1339 1389

2034 1339 1389

2035 1339 1394

To estimate the percentage of cancellation they adjusted the linear programming model 

(see [19]) to cancel the flight when there no route available (due to disconnected fixes) or 

when the cost of flying a longer route was more than canceling the flight. 

They ran the model under 2 scenarios: 

1. Allowed all fixes to remain open assuming all 42 fixes listed in Table 2-38 have 

been lowered. 

2. Baseline scenario, with all 42 fixes listed in Table 2-38 closed due to icing and 

high MEAs. 

The difference in costs between the two scenarios was assumed to be the benefits for the 

lowered route structure for days where all affected flights are cancelled or forced to fly a 

longer route due to icy and cold weather conditions. In the absence of any historical data 

on the frequency of icing conditions for all fixes, ATO-F assumed that the number of 

days a year that all 42 fixes listed in Table 2-38 would be closed and impassable follows 

a triangular distribution with parameters (15, 23, 40). 

The total benefit is the product of user equipage, GBT implementation, the frequency of 

bad weather, cost savings from avoided cancellation and longer flight time. The 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

71
projected route development costs were incorporated into the benefit. Table 2-40 

presents the increased access to lower altitude routes benefit in base year 2007 and 

present value dollars. 

Table 2-40. Increased access to lower altitude routes benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Increased access to lower altitude routes $53.1 M $19.5 M 

 

2.8.7 Improved search and rescue services 

Not all US airspace is under radar surveillance coverage. Flights operating at lower 

altitudes or away from terminal areas will likely traverse non-radar airspace. Search and 

Rescue (SAR) activities can be better focused if radar data are available for a flight 

presumed missing. One of the objectives of the SBS program is to make the techniques 

and services associated with radar surveillance also available in non-radar airspace 

through the use of ADS-B. Therefore, the ATC system will be able to offer more 

services to pilots including enhanced search and rescue. The current focus of this effort 

is in Alaska. 

This service was put to test when a Capstone Program ADS-B equipped Part 135 aircraft 

went down in southwest Alaska in October 2002. The wreckage was located and the pilot 

was rescued because of the Capstone equipment on the aircraft. According to the report, 

the aircraft did not emit an electronic locator transmission (ELT). The searchers used the 

plane’s last Capstone transmission to locate the plane. 

There are two components of the SBS search and rescue benefit. The first is the ADS-B 

only benefits of SAR in Alaska. The second involves a transponder-based multilateration 

system that the SBS program is installing in the Juneau area as a test backup for ADS-B. 

The program is also supporting the automation integration of the ADS-B and 

multilateration data and displays in the Juneau ATCT. Consequently, the ADS-B SAR 

benefits in Juneau represent the incremental increase in benefits from near-term 

surveillance using transponder multilateration. As ADS-B equipage increases, the benefit 

from multilateration decreases. 

The improved search and rescue services outcome allows more timely SAR. The benefit 

is an increased likelihood of survival for those involved in aviation accidents. The 

estimated reduction in future fatalities is based on an analogy to the National Oceanic and 

Atmospheric Administration (NOAA) study [20] of the advantages of 406 MHz 

Emergency Locator Transmitters (ELTs). The benefits were assumed to apply primarily 

to the general aviation population and, therefore, the independent equipage curve for this 

user class was applied to reflect the magnitude of the benefit. Table 2-41 summarizes the 

benefits in base year and present value dollars. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

72
Early benefits only accrue in Juneau because of the early surveillance capability the SBS 

program will provide in that location (2010). The later benefits occur throughout Alaska 

after complete automation integration. Both SAR estimates include a risk distribution 

based on the likelihood of a new 406 MHz ELT mandate per year. We assumed that the 

ADS-B SAR benefit would go to zero after such a mandate. 

Table 2-41. Improved search and rescue services benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Improved search and rescue services $15.8 M $7.0 M 

In the 1970s, Congress mandated the installation of 121.5 and 243.0 MHz ELTs in the 

general aviation fleet to aid in locating missing aircraft. However, soon after the 

implementation, it was discovered that many distresses were not detected since detection 

was based on over flying aircraft and fixed radio receivers. As a result, space-based 

instruments are now the primary sensors for identifying distress signals. The Search and 

Rescue Satellite-Aided Tracking (SARSAT) System is part of an international satellite 

system for search and rescue. SARSAT provides for the location of old technology ELTs 

as well as the new 406 MHz ELTs. 

The 406 MHz ELTs have several advantages, including incorporating digital technology, 

providing uniquely identified alerts, reducing the search area to a negligible area, and 

having virtually no false alarms. As a result, converting the general aviation fleet to the 

406 MHz ELTs is expected to save lives and reduce needless search efforts in response to 

inadvertent activation of the existing ELTs. However, while most aircraft operators are 

mandated to carry an ELT, they have the option to choose between the 121.5 MHz ELT 

and the 406 MHz ELT. 

The 406 MHz ELTs currently cost about $2,500, which is about $2,000 more than the 

cost of a 121.5 MHz ELT. There are over 170,000 121.5 ELTs in existence while only 

several hundred of the 406 MHz ELTs have been purchased to date. It is unlikely that the 

general aviation population will equip with 406 MHz ELTs with the existing cost 

differential. However, if the general aviation population elects to equip with ADS-B, 

then many of the improvements associated with the 406 MHz ELTs can be achieved. As 

a result, the NOAA study of the benefits of 406 MHz ELTs was used as an analogy to 

determine the more timely search and rescue benefits attributable to ADS-B. 

The NOAA study included safety benefits associated with more efficient search and 

rescue activities for cases in which the 121.5 MHz ELT activated as well as in situations 

where it did not issue an alert. Since ADS-B is not providing enhancements to the 

alerting function of the ELTs, only the benefits associated with more quickly locating 

downed aircraft that had transmitted an alert via the ELT are included. It should be noted 

that ADS-B can provide air traffic control with the ability to recognize that a tracked 

aircraft is in trouble regardless of whether the ELT has activated, but this scenario has not 

been captured in the analysis. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

73
The NOAA study identified the number of NTSB accident reports from 1983 to 1988 in 

which the ELT operated and a search was required. Rescue Coordination Center (RCC) 

records were used to supplement the NTSB data since search data is an optional entry in 

the accident investigation records. Using both data sources, it was determined that 85 

accidents annually involved searches based on ELT alerts. Since the NOAA study, the 

accident rate has decreased due to other FAA safety initiatives. An examination of more 

recent accident data (from 1998 to 2003) shows that the accident rate was 65 percent of 

what it was from 1983 to 1988. Using the more recent accident data to scale, we 

estimate 55.25 applicable events occur annually. NTSB records also indicate that, on 

average, 2.5 people were onboard the aircraft during these events. 

Based on the time savings associated with locating an aircraft equipped with a 406 MHz 

ELT as compared to the 121.5 MHz ELT, the delta increase in the likelihood of survival 

was estimated to be 16 percent for the 406 MHz ELT. The time savings associated with 

the 406 MHz ELT are within the notification, planning/evaluation, and search stages of a 

search and rescue operation. The notification stage begins with the aircraft crash and 

ends when either the RCC is notified or when the aircraft is reported overdue. As 

mentioned, ADS-B is not enhancing the alerting function of the ELTs and was not 

estimated to achieve savings in this stage. The planning/evaluation stage begins when the 

RCC is notified and ends when a mission is open and rescue forces are dispatched to the 

search area. The time savings associated with this stage is associated with resolving 

whether or not the alert represents an actual crisis or a false alarm. The 406 MHz ELT 

drastically reduces the frequency of false alarms and, therefore, alleviates much of the 

time spent in resolving the ambiguity of the alert. Again, since ADS-B is not defined to 

provide emergency alerting capability, the savings associated with the 

planning/evaluation stage was not deemed to be entirely applicable. Instead, a fraction of 

the savings, 25 percent, was applied to represent that ADS-B tracks could be used by 

ATC to reduce this stage to a more limited extent. Finally, the search stage is defined as 

beginning when the resources arrive in the search area and ends when the crash site is 

located or the search is terminated. It was determined that, once an ELT alert is received 

and then validated, ADS-B would provide equivalent accuracy to the 406 MHz ELT and 

achieve the time savings assessed for this stage. Table 2-42 shows the time savings 

attributed to the 406 MHz ELT by stage as well as the portion assumed to be analogous 

for the ADS-B estimate. The numbers in parentheses in Table 2-42 represent the 

triangular distributions applied to adjust for risk in the model. 

Table 2-42. Search and Rescue Time Savings by Stage 

Search and Rescue Stage 406 MHz ELT 

Time Savings (hrs) % Applicable ADS-B Time Savings (hrs) 

Notification 1.8 0% 0 

Planning/Evaluation 3.2 25% (0,.25,.3) 0.8 

Transit 

Search 1.7 100% (0.5,1,1) 1.7 

Recovery 

Total 6.7 2.5 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

74
The ratio between the time savings assumed for ADS-B to the time savings estimated for 

the 406 MHz ELTs was applied to the 406 MHz ELT survivability improvement to 

determine the increase associated with ADS-B. The increase likelihood in survival was 

multiplied by the annual number of accidents and the number of people per accident to 

determine the potential number of lives saved each year. Finally, the infrastructure 

implementation curve and the independent equipage curve for the general aviation 

population in the CONUS and Hawaii were applied to determine the benefit. 

The Juneau SAR benefit represents the incremental benefit available because of increased 

surveillance of transponder-equipped aircraft using the multilateration system. The 

additional ADS-B SAR benefits for Juneau are claimed in Segment 2 of the program. 

Since the ADS-B SAR benefits depend on an analogy with the 406 MHz ELT, if a 406 

MHz mandate were to occur, the ADS-B benefits would go to zero. We assumed a 50 

percent likelihood per year that a new ELT mandate would occur for the years 2009 

through 2035. 

2.8.8 Increased access to remote villages 

Alaska has a high dependency on aviation for both residents and visitors. There is 

limited highway access in Alaska and there have no new interurban highways built in 

Alaska since the opening of the Parks Highway to Fairbanks in the early 1970’s. The 

2001 DOT Appropriations report, (House Report 106-940), directed the FAA 

Administrator to determine the extent of the problem of aviation access in remote 

locations in Alaska. 

To solve some of the access issues to remote villages in Alaska and to support the new 

IFR services available with ADS-B surveillance, the SBS program will upgrade airports 

with IFR approaches where cost-beneficial. The goal is to provide GPS or LPV 

approaches at new IFR airports and automated local weather reporting at existing airports 

to obtain the lowest possible weather planning minimums thereby increasing access in 

IMC. One benefit of increased aviation access to remote villages is fewer cancellations 

during IMC. Subject matter experts suggested that if weather prevented a Part 135 or 

Part 91 flight to a remote village, the operator would most likely postpone the trip until 

the next day. The ATO-F calculated cancellation costs (see Table 2-39) are the same as 

were used in the lower routes benefit (subsection 2.8.6). 

Hourly ceiling and visibility readings from across the state for 2004 were used to estimate 

weather at the selected sites. The potential lowering of weather minimums was examined 

at each airport and this allowed the determination of an increased IFR access percentage 

for each airport. Weather variability in the percent of IMC and MVMC hours/year was 

introduced based on NCDC data at Anchorage from 1976 to 2005 as compared to 2004. 

A triangular distribution of (.74, .94, 1.19) was multiplied to the result. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

75
To take advantage of this increased access, aircraft need to be IFR equipped. Because 

IFR equipage increased with Capstone equipage in Southwest Alaska [21], we assume 

that IFR equipage in the remainder of the state will do the same. We also use a factor of 

63 percent to set a maximum amount of IFR equipage. 

The benefit also depends on approach, AWS, and communication infrastructure 

implementation schedules as well as the Capstone avionics equipage curve. At airports 

cited in the FAA Wide Area Augmentation System (WAAS) business case, the benefit 

was shared using an algorithm designed by ATO-F with the WAAS program. Table 2-43 

lists the selected airports, the increased access percentage, the yearly arrivals recorded in 

the TAF, and the WAAS sharing scheme. Table 2-44 presents the increased access to 

remote village results in base year and present value dollars. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

76
Table 2-43. Remote airport increased access and operations counts 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

77
Table 2-44. Increased commercial access to remote villages benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Increased commercial access to remote villages $215.3 M $90.0 M 

2.8.9 Increased Medevac access to remote villages 

In addition to deriving an economic benefit from average flight cancellation costs, the 

FAA also examined the effect of increased medical care (through Medical Evacuation or 

Medevac) available because of increased access. 

The FAA Alaskan Region prepared a study with the cooperation of the (17th District) 

USCG and the Alaska Indian Health Service (IHS) that focused on the role of aviation in 

access to medical facilities. The study found that 201 Alaskan communities have no road 

access to the nearest inpatient medical facility; however, only 53 were equipped for IFR 

services 

As mentioned in the last subsection, a series of airport and procedure upgrades will allow 

increased IFR access to some remote villages during reduced weather. Increased access 

should lead to reduced time for medical evacuation that will avoid fatalities. The benefit 

assumes that with prompt medical care, remote village accidental death, acute illness 

fatality, and infant mortality rates will be similar to city (Anchorage) average rates. An 

alternate access function was developed to account for non-aviation means of 

transportation to medical care. 

Most health statistics were taken from the Alaska Division of Public Health, Bureau of 

Vital Statistics website. For Anchorage the accidental death rate is 34.5 per 100,000 

people and the infant mortality rate is 8.1 per 100,000. The infant mortality per person is 

calculated by multiplying the infant mortality per birth by the number of births per 

population over a time period. Also, the CDC/NCHS National Vital Statistics System 

2003 reports that the Alaska statewide death rate from acute illness (e.g. Heart Disease, 

Flu, etc.) was 168.2 per 100,000. The similar rates for the villages are higher than for 

Anchorage. The ratio between the average accidental death rate in the villages and the 

accidental death rate in Anchorage was used to scale the statewide death rate from acute 

illness resulting in an estimated rate of 67.1 acute illness deaths per 100,000 in 

Anchorage. The total mortality rate in Anchorage due to accidents, illness, and infant 

mortality was then assumed to be the addition of the rates or 109.7 per 100,000. 

Similar accidental death rates are not available for each of the remote villages, but are 

available for larger geographic areas called boroughs. We assumed that the village rates 

were the same as the borough in which they reside. This is conservative because the 

villages are by definition “remote” and are most likely farther away from medical service 

than the bigger towns in the same borough. The infant mortality rate for each borough 

was not available; however, we had an average Alaska statewide infant mortality rate 

(10.8 per 100,000) and an Anchorage infant mortality rate (8.1 per 100,000). We used the 

ratio between the average and the Anchorage rates to estimate a village rate of 14.4 per 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

78
100,000. Finally, the ratio between the accidental death rate in each borough and the 

accidental death rate in Anchorage was used to scale the statewide acute illness rate to 

estimate the acute illness rate per village. 

A final factor used in determining the medical access benefit was alternate access. The 

factor accounts for the delay to get a seriously injured, ill person to the hospital by other 

means than air or to a nearby IFR airport. If no alternate access would be available 

within 12 hours, the value of the function was 1.0, meaning that the full benefit may be 

claimed by increased IFR access. If alternate access could be provided in less than 12 

hours the scaling followed a step function that is based on the chance for mortality: 

 

 Alternate Access Function = 1.0 for >12 hours 

 0.5 for 6 to 12 hours 

 0.25 for 3 to 6 hours 

 0.12 for < 3 hours. 

The function is based on the “Trimodal Distribution of Casualty Death” as documented in 

[22] and shown in Figure 2-12. The function accounts for mortality rates from delays in 

critical care within the first three hours, emergency surgery with 6 hours [23-25], and 

receiving antibiotics and the onset of infection within 12 hours. Times were estimated 

using maps of villages, accessible roads, hospital and nearby IFR airport locations. 

Figure 2-12. Trimodal distribution of casulty death[22] 

Table 2-45 displays the village airports examined, the population of each village (US 

Census Bureau), the accident rate and infant mortality assumed at each village, and the 

alternate access function for each village. 

Table 2-46 lists the increased Medevac access to remote villages benefit in base year and 

present value dollars. The difference between the remote location death rates and the 

Anchorage death rate is used to calculate potential fatalities to be avoided based on 

population. The potentially preventable deaths are multiplied by the increased access 

percentage (Table 2-43), the weather variability, the alternate access function, the IFR 

upgrade schedule, the Part 135 equipage percentage, and fatality costs to estimate an 

economic benefit. Much like section 2.8.8 this benefit was also shared with WAAS.

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

79
Table 2-45. Assumptions used in medical access benefit 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

80
Table 2-46. Increased Medevac access to remote villages benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Increased Medevac access to remote villages $411.8 M $175.4 M 

3 COST AVOIDANCE BENEFITS 

The cost avoidance benefits are derived from three sources: 

• Surveillance cost avoidance 

• Reduction in FAA subscription charges due to value added services 

• Reduction in costs to obtain weather info 

3.1 Surveillance Cost Avoidance 

A primary reason for interest in ADS-B is the opportunity to increase surveillance 

accuracy while significantly reducing FAA costs. An ADS-B surveillance infrastructure 

is less costly to maintain than the existing radar infrastructure. A NAS-wide ADS-B 

implementation would also avoid any further acquisition costs for future radar once the 

transition is complete. A surveillance backup report suggested that half of the current 

secondary surveillance radars along with primary radar will provide the initial backup to 

ADS-B surveillance and continue to provide a security function for the Department of 

Homeland Security (DHS). The cost savings assume decommissioning of half of the 

current inventory of secondary surveillance radar starting in 2018. The accuracy of ADSB data should also allow decommissioning of current Surface Movement Radar (SMR) at 

Airport Surface Detection Equipment (ASDE) sites. Table 3-1 presents the surveillance 

cost avoidance benefits in base year and present value dollars. 

Table 3-1. Surveillance cost avoidance benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Surveillance cost avoidance $1,263.2 M $371.1 M 

3.2 Reduction in FAA subscription charges due to value added services 

The selected surveillance vendor intends to sell value added surveillance products to 

selected users (airlines, companies, private users, etc.) The vendor will provide the FAA 

with a certain percentage of the profit from these products thereby reducing the effective 

subscription charge. Since the reduction in effective subscription charges is dependent 

on user participation and therefore somewhat uncertain, the SBS program decided not to 

use this as a reduction in the program cost baseline, but as a potential FAA cost 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

81
avoidance benefit. Table 3-2 lists the Reduction in FAA subscription charges benefit in 

base year and present value dollars. 

Table 3-2. Reduction in FAA subscription charges due to value added services 

benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Reduction in FAA subscription charges $232.0 M $80.6 M 

3.3 Reduction in costs to obtain weather info 

Broadcast of NAS-wide FIS-B weather broadcasts may influence some current 

subscribers of commercial weather services to switch to the free service. The commercial 

services may still retain some subscribers due to value added products beyond what will 

be available in the FIS-B. The benefit assumes half of current subscribers will move to 

the free service thereby reducing costs for those users. Table 3-3 lists the reduction in 

costs to obtain weather info benefits in base year and risk-adjusted present value dollars. 

 

Table 3-3. Reduction in costs to obtain weather info benefits 

Outcome Benefits (BY 07) Benefits (RA PV) 

Reduction in costs to obtain weather info $88.9 M $26.1 M 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

82
4 SUMMARY OF PROGRAM BENEFITS 

The following two tables present a summary of the total benefits (Table 4-1), and the 

benefits organized by location, application, and desired outcome (Table 4-2). 

Table 4-1. Summary benefits for the SBS program 

Segment Benefits 2007-2035 

(BY 07 M$) 

Benefits 2007-2035 

(Risk-Adjusted PV M$) 

SBS Program $18,498.1 M $5,043.2 M 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

83
Table 4-2. SBS program benefits by location, application, and desired outcome 

Location Application Outcome Benefit 

(BY7 $M) 

Benefit 

(PV $M) 

CONUS, 

Hawaii, and 

Caribbean 

Surveillance 

Radar Airspace ATC 

Surveillance 

Surveillance cost avoidance $1,263.2 $371.1 

More efficient en route conflict resolution $3,258.1 $801.8 

More efficient en route metering to the arrival 

fix 

$1,746.6 $417.0 

Increased safety on the surface by controllers $11.6 $3.2 

More efficient ATC management of surface 

movement 

$92.1 $26.9 

Reduction in FAA subscription charges due to 

value added services 

$232.0 $80.6 

CONUS, 

Hawaii, and 

Caribbean 

Broadcast 

Services 

Enhanced Visual Acquisition 

and Conflict Detection Fewer aircraft-to-aircraft conflicts 

$719.8 $203.6 

Weather and NAS Status 

Situational Awareness 

Fewer encounters with hazardous weather $792.3 $232.5 

More efficient routes in adverse weather $18.4 $4.9 

Reduction in user costs to obtain weather info $88.9 $26.1 

Fewer controlled flights into terrain $1,015.6 $284.3 

CONUS, 

Hawaii, and 

Caribbean 

Aircraft 

Applications 

Enhanced Visual Approach - 

Initial Application More efficient spacing on approach in VMC $1,247.8 $300.4 

Enhanced Visual Approach - 

CAVS 

Continuation of Visual Approaches in 

marginal conditions 

$803.7 $196.4 

Enhanced Visual Approach - 

Merging and Spacing Increased ability to allow continuous descent 

approaches 

$2,876.7 $796.0 

ADS-B ATC Automation 

Integration 

Airport Surface Situational 

Awareness 

Increased safety on the surface by pilots 

$299.5 $70.5 

Final Approach and Runway 

Occupancy Awareness 

Gulf of Mexico 

Surveillance 

Non-radar Airspace ATC 

Surveillance (includes weather 

and comm as needed) 

High Altitude - Increased Capacity $2,064.7 $459.3 

High Altitude - Optimal Routing $256.5 $86.5 

Low Altitude - Increased Capacity $238.3 $84.2 

Fewer encounters with hazardous weather – 

low altitude Gulf 

$13.1 $5.0 

Alaska 

Surveillance and 

Broadcast 

Services 

Weather and NAS Status 

Situational Awareness and 

Enhanced Visual Acquisition 

and Conflict Detection 

Fewer aviation accidents in Alaska 

$760.2 $300.1 

Non-Radar Airspace ATC 

Surveillance 

Access to lower altitude routes in Alaska $53.1 $19.5 

Increased IFR capacity (JNU) $3.0 $1.1 

Fewer aircraft-to-aircraft conflicts (JNU) $0.0 $0.0 

Improved search and rescue services in 

Alaska 

$15.8 $7.0 

Alaska Airport 

IFR Upgrade 

Services 

Weather Automation upgrade 

and IFR Approach 

Development 

Increased access to remote villages in Alaska $215.3 $90.0 

Increased Medevac access to remote villages 

in Alaska 

$411.8 $175.4 

Total $18,498.1 $5,043.2 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

84
5 REFERENCES 

1 FAA Safe Flight 21 Product Team, ”Safe Flight 21 Pre-Investment Analysis Cost 

Benefit Analysis Phase II Report”, May 1, 2001. Available URL: 

http://www.faa.gov/and/and500/DocMGR/anddoc.cfm

2 FAA Office of Policy and Plans, “Economic Values for Evaluation of Federal 

Aviation Administration Investment and Regulatory Programs,” 2005. 

3 FAA Terminal Services. “Exhibit 300 Attachment 2 Business Case Analysis 

Report for Airport Surface Detection Equipment, Model-X (ASDE-X),” August 

2005. 

4 FAA En Route Services. Corridor Integrated Weather System (CIWS) Benefits 

Assessment. March 2005. 

5 Scanlon, C.H., “Cockpit Graphical Weather Information Shown to Enhance 

Efficiency, Safety, and Situation Awareness,” Proceedings of the 39th Annual 

Corporate Aviation Safety Seminar (CASS), St. Louis, MO, April 1994. 

6 Barnett, A., G. Paull and J. Iaedeluca, “Fatal US Runway Collisions Over the 

Next Two Decades” Air Traffic Control Quarterly, 8, No. 4, 2000. 

7 McCann, R.S., B.L. Hooey, B. Parke, D.C. Foyle, A.D. Andre, and B. Kanki, “An 

Evaluation of the Taxiway Navigation and Situation Awareness (T-NASA) 

system in High-Fidelity Simulation,” SAE Transactions: Journal of Aerospace, 

107, 1612-1625, 1998. 

8 Callantine, T.J., P.U. Lee, J. Mercer, T. Prevot, and E. Palmer, “Air and Ground 

Simulation of terminal-Area FMS Arrivals with Airborne Spacing and Merging,” 

Proceedings of the 6th USA/Europe Air Traffic Management R&D Seminar, 

Baltimore, MD June, 2005. 

9 Lee, P.U., T. Prevot, J. Mercer, N. Smith, and E. Palmer, “Ground-side 

Perspective on Mixed Operations with Self-separating and Controller-managed 

Aircraft,” Proceedings of the 6th USA/Europe Air Traffic Management R&D 

Seminar, Baltimore, MD June, 2005. 

10 Barmore, B., T. Abbott, and K. Krishbamurthy, “Airborne-Managed Spacing in 

Multiple Arrival Streams,” Proceedings of 24th International Congress of the 

Aeronautcal Sciences, Yokohama, Japan, 2004. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

85
11 Boursier, L., B. Favennec, E. Hoffman, L. Rognin, F. Vergne, and K. Zeghal, 

“Combining Sequencing Tool and Spacing Instructions to Enhance the 

Management of Arrival Flows of Aircraft,” Proceedings of the 5th AIAA Aviation 

Technology, Integration, and Operations Conference, Arlington, VA, September, 

2005. AIAA-2005-7302. 

12 Eurocontrol Experimental Centre, “COSPACE 2003 Controller Model Based 

Study Assessment of Airborne Spacing Tasks in the Extended TMA,” EEC 

Report No. 392, May, 2004. 

13 Eurocontrol Experimental Centre, “COSPACE 2003 Controller Experiment 

Assessing the Impact of Spacing Instructions in E-TMA and TMA,” EEC Report 

No. 386, December, 2003. 

14 Howell, D., T. Spriesterbach, and J. Marksteiner, “Efficiency Benefits of using a 

Cockpit Display of Traffic Information at SDF,” Proceedings of the 5th AIAA 

Aviation Technology, Integration, and Operations Conference, Arlington, VA, 

September, 2005. AIAA-2005-7348 

15 Jones, S.R., “ADS-B Surveillance Quality Indicators: Their Relationship to 

System Operational Capability and Aircraft Separation Standards,” Air Traffic 

Control Quarterly Vol 11(3) pp 225-250, August 2003. 

16 Surveillance and Broadcast Services Systems Engineering Separation Standards 

Working Group, “Final Report on Operational Evaluation of 5 Nautical Mile 

ADS-B to Radar Separation Services in Alaska,” November 2006. 

17 FAA SafeFlight21 M&S Development Group, “Flight-Deck Based Merging and 

Spacing (M&S) Initial Phase Application Description,” December 2005. 

18 Clarke, J.P.B., N.T. Ho, L. Ren, J.A. Brown, K.R. Elmer, K. Tong, and J.K. Wat, 

“Continuous Descent Approach: Design and Flight Test for Louisville 

International Airport,” Journal of Aircraft, Vol. 41, No. 5, September-October 

2004. 

19 FAA, “Capstone Statewide Business Case Analysis Report (BCAR),” outlines 

analyses used in Capstone Phase III JRC 2A decision, September 2005. 

20 National Oceanic and Atmospheric Administration comparison of 406 MHz ELT 

and 121.5 MHz ELT. 

21 University of Alaska Anchorage, MITRE CAASD, and Embry-Riddle 

Aeronautical University, “The Impact of Capstone Phase 1 Program Final 

Report,” September 2005. 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

86
22 Trunkey, DD. “Trauma.” Scientific American 249, no.2 (1983):20-7 

23 Allied Joint Medical Support Doctrine, paragraph 0027 

24 Wheeler, Bronwyn, “Military Trauma Management.” ADF Health, Defence 

Health Services Division, Australian Government Department of Defence 

25 Taylor, JC., “Whither the Field Ambulance?”, Canadian Forces College, Oct 

2002. 

 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

87
6 ACRONYMS 

ADIZ Air Defense Identification Zone 

ADOC Airline Direct Operating Costs 

ADS-B Automatic Dependent Surveillance – Broadcast 

ADS-R Automatic Dependent Surveillance –Rebroadcast 

AIM Aeronautical Information Management 

AMASS Airport Movement Area Safety System 

AOC Airline Operations Center 

AOPA Aircraft Owners and Pilots Association 

APO FAA Office of Policy and Plans 

ARTCC Air Route Traffic Control Center 

ARTS Automated Radar Tracking System 

ASDE-X Airport Surface Detection Equipment Model X 

ASPM Aviation System Performance Metrics 

ASR Airport Surveillance Radar 

ATA Air Transport Association 

ATC Air Traffic Control 

ATCT Air Traffic Control Tower 

ATO Air Traffic Organization 

B-757 Boeing 757 

B-767 Boeing 767 

BY Base Year 

CAVS CDTI Assisted Visual Separation 

CBA Cost Benefit Analysis 

CDA Continuous Descent Approach 

CDTI Cockpit Display of Traffic Information 

CFIT Controlled Flight into Terrain 

CIWS Corridor Integrated Weather System 

CONUS Contiguous United States 

CTAS Center TRACON Automation System 

DHS Department of Homeland Security 

ELT Emergency Location Transmitter 

E-PIREP Electronic Pilot Report 

ES Extended Squitter 

ETMS Enhanced Traffic Management System 

EVA Enhanced Visual Approach 

FAA Federal Aviation Administration 

FAF Final Approach Fix 

FAROA Final Approach and Runway Awareness Occupancy 

FIS-B Flight Information Service-Broadcast 

FL Flight Level 

GA General Aviation 

GBT Ground-Based Transceiver 

GOMEX Gulf of Mexico 

GPS Global Positioning System 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

88
GPWS Ground Proximity Warning System 

IA Instrument Approaches 

IAH George Bush Intercontinental Airport 

IFR Instrument Flight Rules 

IMC Instrument Meteorological Conditions 

JHUAPL Johns Hopkins University Applied Physics Laboratory 

JRC Joint Resources Council 

M&S Merging and Spacing 

MAP Monitor Alert Parameter 

METAR Aviation Routine Weather Report - French 

MFD Multi-functional Display 

MLAT Multilateration 

MSL Mean Sea Level 

MVMC Marginal Visual Meteorological Conditions 

NAS National Airspace System 

NASDAC National Aviation Safety Data Analysis Center 

NASA National Aeronautics and Space Administration 

NATCA National Air Traffic Control Association 

NCDC National Climatic Data Center 

NCRCC National Capitol Region Command Center 

NEXRAD NEXt generation of RADar 

nmi Nautical mile(s) 

NOAA National Oceanic and Atmospheric Administration 

NORAD North American Aerospace Defense Command 

NTSB National Transportation Safety Board 

ONT Ontario International Airport 

OOOI Out Off On In 

OPSNET FAA Operational Network 

ORD Chicago O’Hare International Airport 

PD Pilot Deviation 

PHL Philadelphia International Airport 

PIREP Pilot Report 

PRM Precision Runway Monitor 

PV Present Value 

PVT Passenger Value of Time 

RAA Regional Airport Authority 

RNAV Area Navigation 

RNP Required Navigational Performance 

SARSAT Search and Rescue Satellite-Aided Tracking 

SBS Surveillance and Broadcast Services 

SDF Louisville International Airport – Standiford Field 

SF-21 Safe Flight 21 

SIGMET Significant Meteorological Advisory 

SMM Surface Moving Map 

SMR Surface Movement Radar 

SMS Surface Management System 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

89
SUA Special Use Airspace 

TAF Terminal Area Forecast 

TAWS Terrain Awareness Warning System 

TCAS Traffic Alert and Collision Avoidance System 

TFR Temporary Flight Restriction 

TIS-B Traffic Information Service-Broadcast 

TRACON Terminal Radar Approach Control Facility 

UAT Universal Access Transceiver 

UPS United Parcel Service 

VA Visual Approaches 

VERN VHF Extended Range Network 

VFR Visual Flight Rules 

VMC Visual Meteorological Conditions 

WAAS Wide Area Augmentation System 

ZHU Houston ARTCC 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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7 APPENDIX A: EQUIPAGE 

This appendix lists the equipage rates assumed for the cost and benefits model used in the 

February 2007 SBS JRC. In future analyses they may change as more information 

becomes available. 

Table 7-1. ADS-B broadcast out equipage in CONUS 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

91
Table 7-2. ADS-B In equipage in CONUS 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

92
Table 7-3. Additional CFIT eligible equipage in CONUS

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

93
Table 7-4. Gulf of Mexico equipage assumptions 

Low-Altitude Gulf High Altitude Gulf

Helicopter ADS-B out Broadcast equipage

2006 0% 2006 0%

2007 0% 2007 0%

2008 0% 2008 0%

2009 0% 2009 0%

2010 0% 2010 0%

2011 25% 2011 10%

2012 50% 2012 20%

2013 75% 2013 30%

2014 100% 2014 40%

2015 100% 2015 50%

2016 100% 2016 60%

2017 100% 2017 70%

2018 100% 2018 80%

2019 100% 2019 90%

2020 100% 2020 100%

2021 100% 2021 100%

2022 100% 2022 100%

2023 100% 2023 100%

2024 100% 2024 100%

2025 100% 2025 100%

2026 100% 2026 100%

2027 100% 2027 100%

2028 100% 2028 100%

2029 100% 2029 100%

2030 100% 2030 100%

2031 100% 2031 100%

2032 100% 2032 100%

2033 100% 2033 100%

2034 100% 2034 100%

2035 100% 2035 100%

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Table 7-5. UPS CDTI equipage 

UPS CDTI equipage

2006.00 0.00

2007.00 0.00

2008.00 0.33

2009.00 0.66

2010.00 1.00

2011.00 1.00

2012.00 1.00

2013.00 1.00

2014.00 1.00

2015.00 1.00

2016.00 1.00

2017.00 1.00

2018.00 1.00

2019.00 1.00

2020.00 1.00

2021.00 1.00

2022.00 1.00

2023.00 1.00

2024.00 1.00

2025.00 1.00

2026.00 1.00

2027.00 1.00

2028.00 1.00

2029.00 1.00

2030.00 1.00

2031.00 1.00

2032.00 1.00

2033.00 1.00

2034.00 1.00

2035.00 1.00

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

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Table 7-6. Alaska Capstone avionics equipage 

F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

96
F E D E R A L A V I A T I O N A D M I N I S T R A T I O N 

97

Table 7-7. Alaska Capstone additional CFIT eligible equipage