Federal Register: May 28, 2010 (Volume 75, Number 103)
DOCID: fr28my10-16 FR Doc 2010-12645
DEPARTMENT OF TRANSPORTATION
U.S. Citizenship and Immigration Services
CFR Citation: 14 CFR Part 91
Docket ID: [Docket No. FAA-2007-29305; Amdt. No. 91-314]
RIN ID: RIN 2120-AI92
NOTICE: Part III
DOCID: fr28my10-16
DOCUMENT ACTION: Final rule.
SUBJECT CATEGORY:
Automatic Dependent Surveillance--Broadcast (ADS-B) Out Performance Requirements To Support Air Traffic Control (ATC) Service
DATES: This final rule is effective on August 11, 2010. The compliance date for this final rule is January 1, 2020. Affected parties, however, do not have to comply with the information collection requirement in Sec. 91.225 until the FAA publishes in the Federal Register the control number assigned by the Office of Management and Budget (OMB) for this information collection requirement. Publication of the control number notifies the public that OMB has approved this information collection requirement under the Paperwork Reduction Act of 1995. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of August 11, 2010.
DOCUMENT SUMMARY:
This final rule amends FAA regulations by adding equipage requirements and performance standards for Automatic Dependent SurveillanceBroadcast (ADSB) Out avionics on aircraft operating in Classes A, B, and C airspace, as well as certain other specified classes of airspace within the U.S. National Airspace System (NAS). ADSB Out broadcasts information about an aircraft through an onboard transmitter to a ground receiver. Use of ADSB Out will move air traffic control from a radarbased system to a satellitederived aircraft location system. This action facilitates the use of ADSB for aircraft surveillance by FAA and Department of Defense (DOD) air traffic controllers to safely and efficiently accommodate aircraft operations and the expected increase in demand for air transportation. This rule also provides aircraft operators with a platform for additional flight applications and services.
SUMMARY:
Transportation Department, Federal Aviation Administration
SUPPLEMENTAL INFORMATION
Authority for This Rulemaking
The FAA's authority to issue rules on aviation safety is found in Title 49 of the United States Code (49 U.S.C.). Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the agency's authority.
This rulemaking is promulgated under the authority described in Subtitle VII, Part A, Subpart I, Section 40103, Sovereignty and use of airspace, and Subpart III, Section 44701, General requirements. Under section 40103, the FAA is charged with prescribing regulations on the flight of aircraft (including regulations on safe altitudes) for navigating, protecting, and identifying aircraft, and the efficient use of the navigable airspace. Under section 44701, the FAA is charged with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce.
This regulation is within the scope of sections 40103 and 44701
because it prescribes aircraft performance requirements to meet
advanced surveillance needs to accommodate increases in NAS operations.
As more aircraft operate within the U.S. airspace, improved
surveillance performance is necessary to continue to balance the growth
in air transportation with the agency's mandate for a safe and efficient air transportation system.
Guide to Terms and Acronyms Frequently Used in This Document ACINAAirports Council InternationalNorth America
ACSSAviation Communication and Surveillance Systems
ADIZAir Defense Identification Zone
ADSBAutomatic Dependent SurveillanceBroadcast
ADSCAutomatic Dependent SurveillanceContract
ADSRAutomatic Dependent SurveillanceRebroadcast
AGLAbove Ground Level
AIAAerospace Industries Association of America
ALPAAir Line Pilots Association, International
AOPAAircraft Owners and Pilots Association
ARCAviation Rulemaking Committee
ASAAircraft Surveillance Applications
ASASAircraft Surveillance Applications System
ASDEXAirport Surface Detection Equipment, Model X
ASSAAirport Surface Situational Awareness
ATCAir Traffic Control
CAACargo Airline Association
CDTICockpit Display of Traffic Information
CNSCommunication, Navigation, and Surveillance
EAAExperimental Aircraft Association
ELTEmergency Locator Transmitter
ESExtended Squitter
EUROCAEEuropean Organisation for Civil Aviation Equipment
EUROCONTROLEuropean Organisation for the Safety of Air Navigation FAROAFinal Approach Runway Occupancy Awareness
FedExFederal Express
FISBFlight Information ServiceBroadcast
FLFlight Level
GAGeneral Aviation
GAMAGeneral Aviation Manufacturers Association
GNSSGlobal Navigation Satellite System
GPSGlobal Positioning System
HAIHelicopter Association International
IATAInternational Air Transport Association
ICAOInternational Civil Aviation Organization
MHzMegahertz
MOPSMinimum Operational Performance Standards
MSLMean Sea Level
NAC
NAC
NASNational Airspace System
NBAANational Business Aviation Association
NextGenNext Generation Air Transportation System
NICNavigation Integrity Category
NMNautical Mile
NPRMNotice of Proposed Rulemaking
NTSBNational Transportation Safety Board
OPDOptimized Profile Descent
OMBOffice of Management and Budget
RAARegional Airline Association
RAIMReceiver Autonomous Integrity Monitoring
RFARegulatory Flexibility Act
RNPRequired Navigation Performance
SANDIASandia National Laboratories
SARPsStandards and Recommended Practices
SCAPSecurity Certification and Accreditation Procedures
SDASystem Design Assurance
SILSource Integrity Level
SSRSecondary Surveillance Radar
TCASTraffic Alert and Collision and Avoidance System
TISBTraffic Information ServiceBroadcast
TMATraffic Management Advisor
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TSOTechnical Standard Order
UATUniversal Access Transceiver
UPSUnited Parcel Service
URETUser Request Evaluation Tool
VFRVisual Flight Rules
WAASWide Area Augmentation System
Table of Contents
I. Background
A. Notice of Proposed Rulemaking
B. ADSB Aviation Rulemaking Committee
C. Summary of the Final Rule
1. Airspace
2. Datalink Requirements
3. System Performance Requirements
4. Antenna Diversity and Transmit Power Requirements
5. Latency of the ADSB Out Message Elements
6. Conforming Amendments and Editorial Changes
D. Differences Between the Proposed Rule and The Final Rule
E. Separation Standards Working Group
II. Discussion of the Final Rule
A. Airspace
1. 2,500 Feet Above Ground Level Exclusion in Class E Airspace
2. Airspace for Which ADSB is Required
3. Requests for Deviations From ADSB Out Requirements
B. DualLink Strategy
1. Altitude To Require the 1090 MHz ES Datalink
2. Automatic Dependent SurveillanceRebroadcast (ADSR)
3. 1090 MHz Frequency Congestion
C. Performance RequirementsSystem
1. Performance Requirements Tailored to Operator, Airspace, or Procedure
2. Navigation Accuracy Category for Position (NAC
3. Navigation Accuracy Category for Velocity (NAC
4. Navigation Integrity Category (NIC)
5. Surveillance Integrity Level
6. Source Integrity Level (SIL) and System Design Assurance (SDA)
7. Secondary Position Sources
D. Performance RequirementsAntenna Diversity
E. Performance RequirementsTransmit Power
F. Performance RequirementsTotal and Uncompensated Latency
G. Performance RequirementsTime To Indicate Accuracy and Integrity Changes
H. Performance RequirementsAvailability
1. Preflight Determination of Availability
2. System Availability
I. Performance RequirementsContinuity
J. Performance RequirementsTraffic Information Service Broadcast Integrity (TISB)
K. Broadcast Message Elements
1. NAC
2. Receiving ATC Services
3. Length and Width of the Aircraft
4. Indication of the Aircraft's Barometric Pressure Altitude
5. Indication of the Aircraft's Velocity
6. Indication if Traffic Alert and Collision Avoidance System II or Airborne Collision Avoidance System is Installed and Operating in a Mode That May Generate Resolution Advisory Alerts
7. For Aircraft With an Operable Traffic Alert and Collision Avoidance System II or Airborne Collision Avoidance System, Indication If a Resolution Advisory Is in Progress
8. Indication of the Mode 3/A Transponder Code Specified by ATC (Requires Flightcrew Entry)
9. Indication of the Aircraft's Call Sign That Is Submitted on the Flight Plan, or the Aircraft's Registration Number (Aircraft Call Sign Requires Flight Crew Entry)
10. Indication if the Flight Crew Has Identified an Emergency, Radio Communication Failure, or Unlawful Interference (Requires Flightcrew Entry)
11. Indication of the Aircraft's ``IDENT'' to ATC (Requires Flightcrew Entry)
12. Indication of the Emitter Category
13. Indication Whether an ADSB in Capability Is Installed
14. Indication of the Aircraft's Geometric Altitude
L. Ability To Turn Off ADSB Out Transmissions
M. Existing Equipment Requirements
1. Transponder Requirement
2. Emergency Locator Transmitter Requirement
N. Program Implementation
1. Timeline
2. Financial and Operational Incentives
3. Decommissioning Traffic Information ServiceBroadcast (TISB)
O. Safety
P. Efficiency
1. Improved Position Reporting
2. Optimized Profile Descents (OPDs)
3. Reduced Aircraft Separation
4. Expanded Surveillance Coverage
Q. ADSB In
R. ADSB In Applications
1. Surface Situational Awareness With Indications and Alerting
2. InTrail Procedures
3. Interval Management
4. Airport Surface Situational Awareness and Final Approach Runway Occupancy Awareness
S. International Harmonization
T. Backup ATC Surveillance
U. Privacy
V. Security
W. Alternatives to ADSB
X. ADSB Equipment Scheduled Maintenance
Y. Specific Design Parameters
Z. Economic Issues
1. ADSB Out Equipage Cost
2. FAA Cost Savings With ADSB Out Compared To Radar
3. Business Case for ADSB Out and In
4. Improved En Route Conflict Probe Benefit Performance
5. Capacity Enhancements, Airspace Efficiency, and Fuel Savings Benefits
6. Deriving Benefits From Capstone Implementation in Alaska
7. Regional Airline Benefits
8. General Aviation: High Equipage Costs With Little Benefit
AA. Revisions to Other Regulations
III. Regulatory Notices and Analyses
A. Paperwork Reduction Act
B. International Compatibility
C. Regulatory Impact Analysis, Regulatory Flexibility
Determination, International Trade Impact Analysis, and Unfunded Mandates Assessment
VI. Executive Order 13132, Federalism
VII. Regulations Affecting Intrastate Aviation in Alaska
VIII. Environmental Analysis
IX. Regulations That Significantly Affect Energy Supply,
Distribution, or Use
X. Availability of Rulemaking Documents
I. Background
While there is currently a drop in air travel due to a general economic downturn, delay and congestion continue to build in the nation's busiest airports and the surrounding airspace. The FAA must not only address current congestion, but also be poised to handle future demand that will surely return as the nation's economy improves. The FAA has been developing the Next Generation Air Transportation System (NextGen) for the purpose of changing the way the National Airspace System (NAS) operates. NextGen will allow the NAS to expand to meet future demand and support the economic viability of the system. In addition, NextGen will improve safety and support environmental initiatives such as reducing congestion, noise, emissions and fuel consumption through increased energy efficiency. for more information on NextGen, go to http://www.faa.gov/about/initiatives/nextgen/.
As part of NextGen development, the FAA has determined that it is essential to move from groundbased surveillance and navigation to more dynamic and accurate airbornebased systems and procedures if the agency is to enhance capacity, reduce delay, and improve environmental performance. Automatic Dependent SurveillanceBroadcast (ADSB) equipment is an advanced surveillance technology that combines an aircraft's positioning source, aircraft avionics, and a ground infrastructure to create an accurate surveillance interface between aircraft and ATC. It is a key component of NextGen that will move air traffic control (ATC) from a radarbased system to a satellitederived aircraft location system. ADSB is a performancebased surveillance technology that is more precise than radar. ADSB is expected to provide air traffic controllers and pilots with more accurate information to help keep aircraft safely separated in the sky and on runways. The technology combines a positioning capability, aircraft avionics, and ground infrastructure to enable more accurate transmission of information from aircraft to ATC.
ADSB consists of two different services: ADSB Out and ADSB In. ADSB Out, which is the subject of this
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rulemaking, periodically broadcasts information about each aircraft,
such as identification, current position, altitude, and velocity,
through an onboard transmitter. ADSB Out provides air traffic
controllers with realtime position information that is, in most cases,
more accurate than the information available with current radarbased
systems. With more accurate information, ATC will be able to position and separate aircraft with improved precision and timing.
ADSB In refers to an appropriately equipped aircraft's ability to
receive and display another aircraft's ADSB Out information as well as
the ADSB In services provided by ground systems, including Automatic
Dependent SurveillanceRebroadcast (ADSR),\1\ Traffic Information
ServiceBroadcast (TISB),\2\ and, if so equipped, Flight Information
ServiceBroadcast (FISB).\3\ When displayed in the cockpit, this
information greatly improves the pilot's situational awareness in
aircraft not equipped with a traffic alert and collision avoidance
system (TCAS)/airborne collision avoidance system (ACAS). Benefits from
universal equipage for ADSB In currently are not substantiated, and
standards for ADSB In airtoair applications are still in their
infancy. Thus it is premature to require operators to equip with ADSB
In at this time. This rule, however, imposes certain requirements that will support some ADSB In applications.
\1\ ADSR collects traffic information from each broadcast link
and rebroadcasts it to ADSB Inequipped operators on the other
broadcast link. This is further explained in section B.2., Automatic Dependent SurveillanceRebroadcast.
\2\ TISB uses primary and secondary surveillance radars and
multilateration systems to provide proximate traffic situational
awareness, including position reports from aircraft not equipped
with ADSB. TISB data may not provide as much information as could
be received directly from an aircraft's ADSB Out broadcast, because
of the required data processing. The TISB signal is an advisory service that is not designed for aircraft surveillance or
separation, and cannot be used for either purpose.
\3\ With FISB, aircraft equipped with 978 megahertz (MHz)
Universal Access Transceiver (UAT) ADSB In avionics can receive weather information, notices to airmen, temporary flight
restrictions, and other relevant flight information, at no additional cost.
As noted in the preamble of the Notice of Proposed Rulemaking (NPRM) associated with this rule, published in the Federal Register on October 5, 2007 (72 FR 56947), Congress enacted the ``Century of Aviation Reauthorization Act'' in 2003. That Act mandated that the Secretary of Transportation establish a Joint Planning and Development Office (JPDO) to manage NextGenrelated work, including coordinating the development and use of new technologies for aircraft in the air traffic control system. Since 2006, Congress has appropriated over $500 million to the FAA for implementing ADSB and developing airtoair capabilities. The FAA remains committed to implementing NextGen and adopts this final rule, with some modifications, as discussed in further detail below.
A. Notice of Proposed Rulemaking
The FAA published the NPRM for ADSB Out in the Federal Register on October 5, 2007 (72 FR 56947). The comment period for the NPRM was scheduled to close on January 3, 2008. In response to several commenters, the FAA subsequently extended the comment period to March 3, 2008 (72 FR 64966, Nov. 19, 2007). The FAA received approximately 190 comments to the docket on the NPRM. Commenters included air carriers, manufacturers, associations, Government agencies, and individuals.
B. ADSB Aviation Rulemaking Committee
As part of the rulemaking effort, the FAA chartered an aviation
rulemaking committee (ARC) on July 15, 2007, to provide a forum for the
U.S. aviation community to make recommendations on presenting and
structuring an ADSB Out mandate, and to consider additional actions
that may be necessary to implement its recommendations. The ADSB ARC
submitted its first report, ``Optimizing the Benefits of Automatic Dependent SurveillanceBroadcast,'' \4\ on October 3, 2007.
\4\ A copy of this report is available from the Web site http://
www.regulations.gov. To find the report, enter FAA2007293050009.1 in the search field.
The FAA also tasked the ARC to make specific recommendations
concerning the proposed rule based on the comments submitted to the
docket. The ARC submitted its second report, ``Recommendations on
Federal Aviation Administration Notice No. 715, Automatic Dependent
SurveillanceBroadcast (ADSB) Out Performance Requirements to Support
Air Traffic Control (ATC) Service; Notice of Proposed Rulemaking,'' \5\ to the FAA on September 26, 2008.
\5\ A copy of this report is available from the Web site http://
www.regulations.gov. To find the report, enter FAA2007293050221.1 in the search field
To give the public an opportunity to comment on the recommendations
received from the ARC, the FAA published a notice in the Federal
Register on October 2, 2008 (73 FR 57270), reopening the comment period
of the ADSB Out NPRM docket for an additional 30 days. The purpose of
reopening the comment period was to receive public comments on the ARC
recommendations only. This comment period closed November 3, 2008, with the FAA receiving approximately 50 comments to the ARC's
recommendations. Commenters included air carriers, manufacturers, associations, and individuals.
C. Summary of the Final Rule
This final rule will add equipage requirements and performance
standards for ADSB Out avionics. ADSB Out broadcasts information
about an aircraft through an onboard transmitter to a ground receiver.
Use of ADSB Out will move air traffic control from a radarbased
system to a satellitederived aircraft location system. As discussed
more fully in the sections of this preamble describing equipage
requirements and performance standards, operators will have two options
for equipage under this rulethe 1090 megahertz (MHz) extended
squitter \6\ (ES) broadcast link or the Universal Access Transceiver
(UAT) broadcast link. \7\ Generally, this equipment will be required
for aircraft operating in Classes A, B, and C airspace, certain Class E
airspace, and other specified airspace. See section C.1. ``Airspace'' below for additional details.
\6\ An extended squitter is a long message that Mode S
Transponders transmit automatically, without needing to be
interrogated by radar, to announce the ownship aircraft's presence
to nearby ADSB equipped aircraft or ground based Air Traffic Control.
\7\ The 1090 MHz ES broadcast link uses the 1090 MHz frequency. The UAT broadcast link uses the 978 MHz frequency.
The NPRM proposed performance requirements for ADSB Out to be used for ATC surveillance. In addition, several aspects of the proposal would be necessary for future ADSB In applications. The comments to the NPRM and the ARC recommendations raised significant concerns about the operational needs and costs of the proposed performance requirements, as well as the proposed antenna diversity requirement.
The FAA specifically proposed higher ADSB Out and antenna diversity requirements than what is needed for ATC surveillance to enable certain ADSB In applications. As discussed in further detail in this document, the FAA has reconsidered these elements in view of the comments and has changed the implementation plan for ADSB.
The FAA has concluded that this rule will require only the
performance requirements necessary for ADSB Out. While certain
requirements adopted in this rule will support some ADSB In applications, the agency is not adopting
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the higher performance standards that would enable all of the initial
ADSB In applications. The agency is mindful, and operators are
advised, that in accepting the commenters' and the ARC's positions
regarding antenna diversity and position source accuracy, compliance
with this rule alone may not enable operators to take full advantage of
certain ADSB In applications. Operators may voluntarily choose
equipment that meets the higher performance standards in order to enable the use of these applications.
The following table provides an overview of the costs and benefits of this final rule.
Summary of Costs and Benefits
3% Discount Rate:
Low Costs................................................. $2.74
High Benefits............................................. 5.03
Net BenefitsHigh Benefit/Low Cost...................... 2.29 =========== High Costs................................................ 5.47 Low Benefits.............................................. 3.98
Net BenefitsLow Benefits/High Costs.................... (1.49)
=========== 7% Discount Rate:
Low Costs................................................. 2.15
High Benefits............................................. 2.74
Net BenefitsHigh Benefit/Low Cost...................... 0.59 =========== High Costs................................................ 4.11 Low Benefits.............................................. 2.09
Net BenefitsLow Benefits/High Costs.................... (2.02) 1. Airspace
This final rule prescribes ADSB Out performance requirements for all aircraft operating in Class A, B, and C airspace within the NAS; above the ceiling and within the lateral boundaries of a Class B or Class C airspace area up to 10,000 feet mean sea level (MSL); and Class E airspace areas at or above 10,000 feet MSL over the 48 contiguous United States and the District of Columbia, excluding the airspace at and below 2,500 feet above the surface.
The rule also requires that aircraft meet these performance
requirements in the airspace within 30 nautical miles (NM) of certain
identified airports \8\ that are among the nation's busiest (based on
annual passenger enplanements, annual airport operations count, and
operational complexity) from the surface up to 10,000 feet MSL. In
addition, the rule requires that aircraft meet ADSB Out performance
requirements to operate in Class E airspace over the Gulf of Mexico at
and above 3,000 feet MSL within 12 NM of the coastline of the United States.
\8\ These airports are listed in appendix D to part 91. 2. Datalink Requirements
ADSB requires a broadcast link for aircraft surveillance and to
support ADSB In applications. Operators have two options for equipage
under this rule the 1090 MHz ES broadcast link or the UAT broadcast
link. The 1090 MHz ES broadcast link is the internationally agreed upon
link for ADSB and is intended to support ADSB In applications used by
air carriers and other highperformance aircraft. The 1090 MHz ES
broadcast link does not support FISB (weather and related flight
information) because the bandwidth limitations of this link cannot
transmit the large message structures required by FISB. The UAT
broadcast link supports ADSB In applications \9\ and FISB, which are important for the general aviation (GA) community.
\9\ These applications include enhanced visual acquisition,
conflict detection, enhanced visual approach, Airport Surface
Situational Awareness (ASSA), and Final Approach Runway Occupancy Awareness (FAROA).
This final rule requires aircraft flying at and above 18,000 feet MSL (flight level (FL) 180) (Class A airspace) to have ADSB Out performance capabilities using the 1090 MHz ES broadcast link. This rule also specifies that aircraft flying in the designated airspace below 18,000 feet MSL may use either the 1090 MHz ES or UAT broadcast link.
3. System Performance Requirements
When activated, ADSB Out continuously transmits aircraft
information through the 1090 MHz ES or UAT broadcast link. The accuracy
and integrity of the position information transmitted by ADSB avionics
are represented by the navigation accuracy category for position
(NAC
In the proposed rule, the FAA referenced the accuracy and integrity
requirements to the appropriate NAC
\10\ Extended Squitter Automatic Dependent Surveillance
Broadcast (ADSB) and Traffic Information ServiceBroadcast (TISB)
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz).
\11\ Universal Access Transceiver (UAT) Automatic Dependent
SurveillanceBroadcast (ADSB) Equipment Operating on the Frequency of 978 MHz.
\12\ RTCA, Inc. is a notforprofit corporation formed to
advance the art and science of aviation and aviation electronic
systems for the benefit of the public. The organization functions as a Federal Advisory Committee and develops consensusbased
recommendations on contemporary aviation issues. The organization's
recommendations are often used as the basis for government and
private sector decisions as well as the foundation for many FAA
TSOs. For more information, see http://www.rtca.org.
\13\ Minimum Operational Performance Standards for 1090 MHz
Extended Squitter Automatic Dependent SurveillanceBroadcast (ADS B) and Traffic Information ServicesBroadcast (TISB).
\14\ Minimum Operational Performance Standards for Universal Access Transceiver (UAT) Automatic Dependent Surveillance
Broadcast.
After the NPRM was published, the ADSB ARC issued numerous
recommendations in response to public comments on the TSOs referenced
in the proposal. Based on the ARC recommendations and broad industry
input, RTCA revised DO260A to become DO260B \15\ and revised DO282A
to become DO282B.\16\ The new RTCA revisions include: (1) An allowance
for transmitting a NIC of 7 on the surface, (2) procedures for
correctly setting the NAC
\15\ Minimum Operational Performance Standards for 1090 MHz
Extended Squitter Automatic Dependent SurveillanceBroadcast (ADSB) and Traffic Information ServicesBroadcast (TISB).
\16\ Minimum Operational Performance Standards for Universal
Access Transceiver Automatic Dependent SurveillanceBroadcast.
\17\ A number of these items address issues with the current TSOs.
The FAA updated the TSOs in accordance with these new RTCA standards. In addition, the FAA has
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decided that it is necessary to require the new standards contained in
TSOC166b \18\ (1090 MHz ES) and TSOC154c \19\ (UAT) as the minimum
performance standards in this final rule.\20\ The updated standards
incorporate multiple changes that address public comments and the ARC's
recommendations on the proposal. On September 11, 2009, the FAA
announced in the Federal Register the availability of draft TSOC166b
and TSOC154c for comment (74 FR 46831). The FAA issued final versions
of the above TSOs on December 2, 2009. The FAA also added additional
language in Sec. Sec. 91.225 and 91.227 stating that equipment with an
approved deviation under Sec. 21.618 also meet the requirements of the rule.
\18\ Extended Squitter Automatic Dependent Surveillance
Broadcast (ADSB) and Traffic Information ServiceBroadcast (TISB)
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz).
\19\ Universal Access Transceiver (UAT) Automatic Dependent
SurveillanceBroadcast (ADSB) Equipment Operating on the Frequency of 978 MHz.
\20\ Operators with equipment installed that meets a later
version of TSOC166b or TSOC154c, as applicable, are in compliance with this rule.
In addition, this final rule specifies the performance requirements
for accuracy and integrity (NAC
Table 1 summarizes the NAC
[GRAPHIC] [TIFF OMITTED] TR28MY10.000
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[GRAPHIC] [TIFF OMITTED] TR28MY10.001
In this final rule, the NAC
\21\ In the NPRM, SIL was defined as surveillance integrity
level and represented the maximum probability of exceeding the NIC
containment radius and a maximum probability of a failure causing
false or misleading data to be transmitted. In this final rule, SIL
is referred to as source integrity level and defines the probability
of exceeding the NIC containment radius; SDA represents the probability of transmitting false or misleading position
information.
\22\ Global navigation satellite system (GNSS) is a generic term
for a satellite navigation system, such as the Global Positioning
System (GPS), that provides autonomous worldwide geospatial
positioning and may include local or regional augmentations. 4. Antenna Diversity and Transmit Power Requirements
The aircraft antenna is a major contributor to ADSB system link performance and an important part of the overall ADSB Out system. In the NPRM, the FAA proposed an antenna diversity requirement that would support ADSB In applications, such as Airport Surface Situational Awareness (ASSA) and Final Approach Runway Occupancy Awareness (FAROA).
The FAA has reconsidered the need for antenna diversity in view of
the comments submitted. The agency has determined that a single bottom
mounted antenna is the minimum requirement for ATC surveillance.
Furthermore, the analysis of ASSA and FAROA does not conclude that
antenna diversity is required for these applications. As discussed
later, the FAA decision to require a NAC
If future analysis indicates that antenna diversity is required for
ASSA and FAROA, a higher NAC
Aircraft must transmit signals at a certain level of power to ensure ground stations and ADSB Inequipped aircraft and vehicles can receive the transmitted signals. As proposed, the final rule requires UAT systems to broadcast at a 16watt minimumtransmit power, and 1090 MHz ES systems to broadcast at a 125watt minimumtransmit power. 5. Latency of the ADSB Out Message Elements
When using an ADSB system, aircraft receive information from a
position source and process it with onboard avionics. The aircraft's
ADSB system then transmits position and other information to the
ground stations through antenna(s) using either the UAT or 1090 MHz ES
broadcast link. Generally, latency is the time lag between the time
that position measurements are taken to determine the aircraft's
position, and the time that the position information is transmitted by
the aircraft's ADSB transmitter. The latency requirements in this
final rule, although different from the proposal, represent a more
appropriate way to address latency. The proposal created ambiguities
that are addressed in these modifications and are supported by the commenters. Under this rule, total
[[Page 30166]]
latency cannot exceed 2.0 seconds. Within those 2.0 seconds,
uncompensated latency cannot exceed 0.6 seconds. Total and
uncompensated latency are explained in further detail in section II F.
``Performance RequirementsTotal And Uncompensated Latency.'' 6. Conforming Amendments and Editorial Changes
Section 91.225 requires ADSB Out for operations in Class A, B, and C airspace. In the NPRM, the FAA inadvertently left out the proposed conforming amendments to Sec. Sec. 91.130, 91.131, and 91.135, which address Class A, B, and C airspace. This rule amends these sections to include the ADSB Out performance requirements for the appropriate airspace.
In addition, the regulatory text for Sec. 91.225 has been reorganized from the proposed rule language. The restructuring of the text should make this section clearer and more readerfriendly.
Lastly, the proposed regulatory text has been moved from Appendix H to new Sec. 91.227.
All substantive changes to this rule are fully discussed in Section II, Discussion of the Final Rule.
D. Differences Between the Proposed Rule and the Final Rule
Table 3 summarizes the substantive changes between the proposed
rule and this final rule. Editorial changes and clarifications are explained elsewhere in this preamble.
Table 3. Substantive Differences Between the Proposed Rule and the Final Rule
Issue area The NPRM The final rule
Technical Standard Order.... Proposed performance Requires performance
standards as standards as
defined in TSO defined in TSO
C166a (1090 MHz ES) C166b (1090 MHz ES)
or TSOC154b (UAT). or TSOC154c (UAT).
Airspace.................... Proposed requiring Requires all
all aircraft above aircraft in Class A
FL 240 to transmit airspace (FL 180
on the 1090 MHz ES and above) to
broadcast link. transmit on the
1090 MHz ES
broadcast link.
Proposed ADSB Requires ADSB
performance performance
standards for standards for
operations in all operations in Class
Class E airspace at E airspace at and
and above 10,000 above 10,000 feet
feet MSL. MSL, excluding the
airspace at and
below 2,500 feet AGL.
NACP........................ Proposed a NACP >= Requires NACP < 0.05 9, which provides NM.
navigation accuracy (NACP >= 8) < 30 meters.
NIC......................... Proposed changes in Requires changes in
NIC be broadcast NIC be broadcast
within 10 seconds. within 12 seconds.
SIL......................... Proposed a SIL of 2 Requires an SDA of or 3. 2.
Requires a SIL of 3.
Antenna Diversity........... Proposed antenna Does not require
diversity in all antenna diversity. airspace specified
in the rule.
Total Latency............... Proposed latency in Requires
the position source uncompensated
< 0.5 seconds and latency <= 0.6
latency in the ADS seconds and maximum
B source < 1 second. total latency <=
2.0 seconds.
Message Elements............ Proposed a broadcast Does not require a
message element for broadcast message
``receiving ATC element for
services''. ``receiving ATC
services.''
An ability to turn off ADSB Proposed that the Does not require the
Out. pilot be able to pilot be able to
turn off ADSB disable or turn off transmissions if ADSB
directed by ATC. transmissions. E. Separation Standards Working Group
The FAA established an internal Surveillance and Broadcast Systems Separation Standards Working group (SSWG) to develop methodologies and define metrics as appropriate that evaluate the endtoend performance of ADSB and wide area multilateration surveillance systems. These evaluations include investigating the integration of these technologies in conjunction with legacy surveillance technologies, that is, separation between target positions that are derived from ADSB, radar, and wide area multilateration on ATC displays.
This SSWG was tasked to perform: (1) Analyses of performance using system models and simulations, including the identification of key performance drivers and the development of test scenarios; (2) preliminary evaluations with prototype system components to enable verification and validation of the models and as early evidence of system performance; and (3) analyses of test results, operational testing and dedicated separation standards flight tests for each key site with fully functional endtoend systems. Also included is a test period for each system where performance data is collected on aircraft operating in the surveillance service volume.
The SSWG analyses and evaluations are the basis for most of the performance requirements specified in this rule.\23\
\23\ The SSWG findings are available from the Web site http://
www.regulations.gov. The docket number for this rulemaking is FAA 200729305.
II. Discussion of the Final Rule
Below is a more detailed discussion of the final rule relative to the comments received on the proposal:
A. Airspace
1. 2,500 Feet Above Ground Level Exclusion in Class E Airspace
The NPRM proposed that aircraft meet ADSB Out performance requirements to operate in Class E airspace at and above 10,000 feet MSL over the 48 contiguous states and the District of Columbia.
Several commenters, including the DOD and the Experimental Aircraft Association (EAA), stated that the proposed ceiling of 10,000 feet MSL for aircraft without ADSB would be a major hardship and safety issue for aircraft operators flying in mountainous terrain. Commenters and the ARC suggested that the final rule exclude Class E airspace at and below 2,500 feet above ground level (AGL), similar to the exclusion in Sec. 91.215, ATC Transponder and Altitude Reporting Equipment and Use.
The FAA recognizes the benefit of excluding this airspace in the
rule, particularly for visual flight rules (VFR) pilots flying in
mountainous areas. This modification addresses airspace that is not
affected by the agency's efforts to maximize NAS efficiency and
capacity. Excluding this airspace from the rule minimizes any
unnecessary financial and operational burdens being placed on aircraft operators who fly in mountainous areas that encroach on
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Class E airspace at and above 10,000 feet MSL, but choose not to equip
for the ADSB Out performance standards in this rule. Consequently, the
final rule does not require ADSB performance standards for operations
2,500 feet AGL and below in Class E airspace at and above 10,000 feet MSL.
2. Airspace for Which ADSB Is Required
The NPRM proposed requiring ADSB performance standards for operations in most classes of airspace where operators currently are required to carry a transponder.
Numerous commenters recommended that the FAA limit ADSB performance requirements to aircraft operating in Class A airspace only, or Class A and B airspace only. Several commenters questioned the proposed ADSB performance requirements in Class E airspace above 10,000 feet MSL. Many of these commenters made varying requests to the FAA concerning the proposed altitude for which ADSB Out would be required, including 12,000 feet MSL, 15,000 feet MSL, FL 180, and FL 250. The United States Parachute Association noted that skydiving operations are typically conducted above 10,000 feet MSL and sometimes conducted in Class A, B, and C airspace.
ADSB cannot be used for ATC surveillance if all aircraft are not appropriately equipped. Moreover, it is unreasonable to set up a regulatory framework and performance standards that are based on using two primary systems for surveillance; nor is it feasible to fund and maintain two such systems. The airspace requirements specified in this rule for ADSB Out meet ATC surveillance needs.
Class B and C airspace have the highest volume of air carrier and GA traffic. They also experience the most complex transitions of aircraft from the en route environment to the terminal area. With the intricate nature of the airspace, current regulations dictate more stringent operational requirements to operate within Class B and C airspace areas.
In addition, ATC must have surveillance data for all aircraft operating in these areas to ensure appropriate situational awareness and to maximize the use of the NAS. ADSB Out will enhance surveillance in controlled airspace areas where secondary surveillance radar (SSR) currently exists.
One commenter stated that the FAA should expand the airspace in
which ADSB is required and specifically recommended including Air
Defense Identification Zones (ADIZ) \24\ and Offshore Control Area Extensions.
\24\ An Air Defense Identification Zone (ADIZ) is an area of
airspace over land or water in which the ready identification,
location, and control of civil aircraft is required in the interest of national security.
This rule applies to aircraft operating within U.S. airspace, which extends 12 NM from the U.S. coast. (The airspace also includes the Washington, DC, Special Flight Rules Area (SFRA), referred to as an ``ADIZ'' prior to 2009.) Most of the airspace in the ADIZ falls outside the 12 NM boundaries.
3. Requests for Deviations From ADSB Out Requirements
This rule requires operators to broadcast ADSB Out information when operating in specified airspace. If an aircraft is not capable of meeting the performance requirements, the operator may request a deviation from the ATC facility responsible for that airspace. However, as noted in the NPRM, ATC authorizations may contain conditions necessary to provide the appropriate level of safety for all operators in the airspace. ATC may not be able to grant authorizations in all cases for a variety of reasons, including workload, runway configurations, air traffic flows, and weather conditions.
B. DualLink Strategy
The NPRM proposed a duallink strategy for ADSB Out broadcasts. Under the proposal, aircraft operating above FL 240 would be required to use the 1090 MHz ES broadcast link. Aircraft operating below FL 240 and in airspace where ADSB Out performance requirements were proposed could use either the 1090 MHz ES or UAT broadcast link.
Many commenters suggested that a singlelink system would reduce operational complexity. The commenters noted that the installation and maintenance costs of a duallink system exceed those of a singlelink system. Some of the commenters proposed a singlelink solution but disagreed over which link should be chosen. Commenters supporting a singlelink UAT system noted that 1090 MHz ES does not support FISB and is at risk for frequency congestion in a future air traffic management environment. Commenters supporting a singlelink 1090 MHz ES system explained that UAT is not internationally interoperable and opposed a system that requires international operators to equip with both links.
Boeing noted that most of the NAS system delays are associated with arrivals and departures. Therefore, Boeing recommended that the airborne surveillance functions should provide benefits at all altitudes and on the ground. Ultimately, Boeing commented that a single 1090 MHz ES broadcast link would advance future ADSB In applications at low altitudes.
In mandating ADSB, the FAA is mindful that some members of the international air transport community and the GA community have already purchased ADSB Out equipment, which use either the 1090 MHz ES or UAT broadcast link. The FAA finds that a duallink system is necessary for the United States to meet the operational needs of all NAS operators. Moreover, if the FAA were to require one segment of the aviation community to equip to meet the needs of another segment of the community, this would present additional costs for some operators to equip.
1. Altitude To Require the 1090 MHz ES Datalink
Under the proposal, aircraft operating above FL 240 would be required to use the 1090 MHz ES broadcast link. Operators using only the UAT broadcast link would be limited to operations below FL 240.
The Air Line Pilots Association, International (ALPA) recommended that the FAA require operators to use 1090 MHz ES above 18,000 feet MSL to be consistent with the Class A airspace lower boundary (rather than introduce a new subclassification of established airspace). In addition, several GA commenters requested limiting ADSB performance requirements to only Class A airspace. The EAA and some individuals stated that UAT would work just as well as 1090 MHz ES above FL 240 and that aircraft should be permitted to use exclusively UAT for operations above FL 240.
The final rule specifies FL 180 (the lower boundary of Class A airspace) as the ceiling for operating an aircraft equipped only with UAT. Using 1090 MHz ES at or above FL 180 provides a clear operational boundary for controllers and pilots, and does not create conditions of mixed equipage for existing or future applications. The FAA recognizes that this modification will affect certain operators that want to operate above FL 180 and equip only with UAT. However, the agency concludes that requiring 1090 MHz ES performance standards for operations in all of Class A airspace is not only reasonable for surveillance, but also establishes a baseline for ADSB In.
The requirement to broadcast 1090 MHz ES at and above FL 180 does not
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preclude UAT reception of FISB services up to FL 240 for aircraft with a duallink reception capability.
2. Automatic Dependent SurveillanceRebroadcast (ADSR)
Under a duallink strategy, the FAA will use ADSR to allow ADSB Inequipped aircraft using one type of broadcast link to receive messages about aircraft transmitting on the other broadcast link.
Various commenters, including the Air Transport Association of America, Inc. (ATA), Airservices Australia, the Australia Civil Aviation Safety Authority, the Aircraft Owners and Pilots Association (AOPA), Boeing, British Airways, and the International Air Transport Association (IATA), expressed concern about a duallink system. Some of these commenters asserted that the need for ADSR introduces additional systemwide latency into the ADSB system and poses a single point of failure for the degradation or loss of surveillance data. In their view, this could limit potential separation and efficiency improvements and affect the airtoair surveillance element of future ADSB In applications. In addition, some commenters expressed concern about the additional risk of faults or failures that could result from translating, merging, and rebroadcasting data from the 1090 and 978 MHz frequencies.
Some commenters, including Boeing, contended that ADSR may not
have sufficient growth capability to support future ADSB In airtoair
applications. Such applications include merging and spacing, self
separation, or using ADSB data to supplement or replace TCAS because
of potential of latency or loop delays. RockwellCollins stated that
ADSR should be able to support many ADSB In airtoair applications,
including closely spaced parallel approaches and enhanced visual
approach. It recommended developing ADSR to support more demanding aircraft surveillance applications (ASA).\25\
\25\ ASA comprises a number of flightdeckbased aircraft
surveillance and separation assurance capabilities that may directly
provide flight crews with surveillance information and alerts.
Several commenters, including AOPA, asserted that the duallink system presents a safety hazard because aircraft equipped with different links cannot ``see'' each other on ADSB In displays in areas without ADSR coverage. The commenters suggested providing ADSR at all public airports where a mix of both systems will be encountered.
The FAA is deploying ADSR in all areas where ADSB ATC surveillance exists.\26\ ADSR collects traffic information broadcast on the 978 MHz UAT broadcast link and rebroadcasts the information to 1090 MHz ES users. Similarly, ADSR collects traffic information provided on the 1090 MHz ES broadcast link and rebroadcasts the information to UAT users. ADSR permits aircraft equipped with either 1090 MHz ES or UAT to take advantage of ADSB In applications. \26\ The service coverage volume for ADSB In applications is explained in greater detail at http://www.adsb.gov.
The FAA disagrees with the comments suggesting that ADSR
introduces safety issues because of the added latencies attributed to
ADSR processing. ATC automation systems do not require or use ADSR to
provide surveillance. The added latency in the rebroadcast of the
original ADSB message are measurably small and do not degrade the
reported NAC
\27\ ADSB ARC Task II Report to the FAA Appendix N, ADSR
Latency and Reliability Expectations (September 26, 2008), available
on the Web site, http:///www.regulations.gov, FAA2007293050221.1.
The intended functions of ADSB, as identified in the NPRM, are not
compromised by the latency introduced with rebroadcasting the messages.
However, future ADSB In applications necessarily may be limited
becauseof the latency associated with ADSR.\28\ The FAA has a strong
interest in providing the option for operators to equip with UAT, so
they may benefit from FISB service. In making the decision to use a
duallink strategy, the FAA acknowledged and weighed the fact that
potential benefits of future applications may not be fully realized
based on this decision. In situations where an airport is not within
the planned ADSB coverage area, the airport will not have ADSR
coverage. Consequently, an aircraft with ADSB In will not have the
benefit of ADSR, and ADSB In will not provide awareness of aircraft that are broadcasting on a different broadcast link.
\28\ To date, the requirements for using ADSB for advanced
iterations of merging and spacing, and self separation have yet to be defined.
If an aircraft leaves the ADSB coverage area, there will be an indication to the pilot that the aircraft is no longer within range of ADSR service. In this case, the pilot needs to maintain separation in the same manner done today, which is relying on visual scanning and directions from ATC. The FAA will ensure that the duallink strategy does not impact safety as future applications are developed. 3. 1090 MHz Frequency Congestion
Boeing, Federal Express (FedEx), and IATA suggested that the FAA assess future 1090 MHz frequency congestion. The ARC supported the duallink strategy, but recommended that the FAA study the necessary mitigations of 1090 MHz frequency congestion. The ARC specifically recommended that these mitigations ensure 1090 MHz ES is interoperable with ACAS and SSR, while providing sufficient airtoair range to support NextGen ADSB In applications.
Congestion on the 1090 MHz frequency is a risk shared by TCAS/ACAS
and SSR systems using the Mode S transponder. The FAA conducted a study
to assess 1090 MHz frequency congestion in the future air traffic
environment.\29\ The FAA is analyzing alternatives and will enact the
necessary mitigations to reduce the 1090 MHz frequency congestion risk
for ADSB, TCAS, and SSR, while enabling ranges appropriate for many ADSB In applications through 2035.
\29\ A copy of this report is available from the Web site http:/
/www.regulations.gov. The docket number for this rulemaking is FAA 200729305.
C. Performance RequirementsSystem
While some commenters supported the proposed performance
requirements, numerous organizations and individuals commented that the
performance requirements generally were too stringent, unnecessary, and would entail an undue economic burden on operators.
1. Performance Requirements Tailored to Operator, Airspace, or Procedure
The NPRM proposed specific performance requirements for ADSB Out. Several commenters, including the Aerospace Industries Association of America (AIA), Boeing, the DOD, EAA, Honeywell, Lockheed Martin, and the ARC, asked the FAA to tailor the ADSB performance requirements based on specific application requirements or airspace.
Lockheed Martin and the DOD noted that some military aircraft may not meet the proposed equipage requirements and would need accommodations to operate in ADSB Outdesignated airspace. One commenter was concerned that the DOD was exempt from the proposed requirements.
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The FAA has determined that it is not operationally feasible to assign different performance requirements dependent on the nature of the operation. It would not be effective to require both pilots and controllers to verify specific performance parameters before any given operation or change of airspace. Therefore, the FAA is specifying minimum performance requirements for all ADSB Outequipped aircraft to operate in certain designated airspace.
No special allowance is made in this rule to relieve the military
from the same performance requirements as the civilian aviation
community. The FAA recognizes that the DOD and other Federal agencies
are NAS users, and need access to all areas of the NAS today and in the
future. This rule provides procedures for an aircraft that does not
meet the ADSB Out performance requirements, i.e., to obtain an ATC
authorized deviation to operate in the airspace for which ADSB is
required. The FAA will collaborate with the appropriate U.S. Government
departments or agencies (including but not limited to DOD, and the
Department of Homeland Security) to develop Memorandums of Agreement to
accommodate their National defense mission requirements while supporting the needs of all other NAS users.
2. Navigation Accuracy Category for Position (NAC
The NPRM proposed requiring a NAC
Airbus, ATA, Aviation Communication and Surveillance Systems
(ACSS), Boeing, RockwellCollins, United Airlines, and United Parcel
Service (UPS) questioned the necessity of a NAC
\30\ ADSB ARC Task II Report to the FAA 6 (September 26,
2008), available on the Web site, http://www.regulations.gov, FAA 2007293050221.1.
Boeing commented that there is no need for vertical accuracy
because neither ATC nor any of the initial ADSB In applications
require it. The ARC recommended that the FAA not apply the vertical
position accuracy requirement associated with a NAC
The FAA reviewed these comments and the necessary requirements for
the ADSB Out and ADSB In applications that are contemplated today. A
NAC
\31\ ASDEX is a traffic management system for the airport
surface that provides seamless coverage and aircraft identification
to air traffic controllers. The system uses a combination of surface
movement radar and transponder multilateration sensors to display aircraft position.
While the higher NAC
\32\ ADSB ARC Report to the FAA Appendix P, Programmatic
Decision Analysis (September 26, 2008), available at http:// www.regulations.gov, FAA2007293050221.1.
In addition, the FAA considered the comments regarding the vertical
accuracy component of NAC
3. Navigation Accuracy Category for Velocity (NAC
The NPRM proposed requiring a NAC
The European Organisation for the Safety of Air Navigation
(EUROCONTROL) commented that a NAC
Different air navigation service providers may need different
performance requirements depending on the airspace in which they
implement ADSB separation services. The FAA reviewed this requirement
and concludes that a NAC
4. Navigation Integrity Category (NIC)
The NPRM proposed requiring a NIC greater than or equal to 7, which provides navigation integrity of less than 0.2 NM. Boeing questioned the necessity of this requirement. The ARC recommended that the FAA adopt NIC requirements based on airspace, with minimum NIC values ranging from 0 to 7.
The FAA reviewed this requirement and determined that a NIC of less
than 0.2 NM is necessary for ATC separation services, particularly in
the approach environment. Similar to the NAC
5. Surveillance Integrity Level
The FAA's proposal for surveillance integrity level stated that the
surveillance integrity level is based on both the design assurance
level of the ADSB Out avionics and the position source. Several
commenters, including RockwellCollins, pointed out that the proposed
definition was inconsistent with the surveillance integrity level
definition provided in DO260A. Commenters stated that DO260A Change 2
defined surveillance integrity level as including only the position
source. The ARC recommended that the FAA use the definition of surveillance integrity level found in RTCA DO
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289,\34\ which also limited the design assurance to the position source.
\34\ Minimum Aviation System Performance Standards (MASPS) for Aircraft Surveillance Applications (ASA).
The FAA asserts that the design assurance of the
FOR FURTHER INFORMATION CONTACT
For technical questions concerning this final rule, contact Vincent Capezzuto, Surveillance and Broadcast Services, AJE6, Air Traffic Organization, Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591; telephone (202) 3858637; email vincent.capezzuto@faa.gov.
For legal questions concerning this final rule, contact Lorelei Peter, Office of the Chief Counsel, AGC220, Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591; telephone 2022673134; email lorelei.peter@faa.gov.