[Federal Register Volume 88, Number 199 (Tuesday, October 17, 2023)]
[Rules and Regulations]
[Pages 71468-71478]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-22710]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 43 and 91

[Docket No. FAA-2023-1836; Amdt. Nos. 43-53 and 91-371]
RIN 2120-AL70


Inclusion of Additional Automatic Dependent Surveillance-
Broadcast (ADS-B) Out Technical Standard Orders; Incorporation by 
Reference

AGENCY: Federal Aviation Administration (FAA), U.S. Department of 
Transportation (DOT).

ACTION: Direct final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This rulemaking amends the Automatic Dependent Surveillance-
Broadcast (ADS-B) Out requirements to allow aircraft meeting the 
performance requirements in Technical Standard Order (TSO)-C166c 
(Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) 
and Traffic Information Service-Broadcast (TIS-B) Equipment Operating 
on the Radio Frequency of 1090 Megahertz (MHz)), or TSO-C154d, 
(Universal Access Transceiver (UAT) ADS-B Equipment Operating on the 
Radio Frequency of 978 Megahertz (MHz)) to meet the regulations. 
Aircraft equipped with

[[Page 71469]]

ADS-B Out that meets the performance requirements of either TSO-C166c 
or TSO-C154d will provide additional information to pilots and air 
traffic control, including weather information, spectrum monitoring, 
and airspeed. They will also enable new wake turbulence applications, 
enhance weather forecasting, and enable or enhance ADS-B In 
applications such as Flight Interval Management.

DATES: This direct final rule is effective December 18, 2023.
    Send comments on or before November 16, 2023. If the FAA receives 
an adverse comment, the FAA will advise the public by publishing a 
document in the Federal Register before the effective date of this 
direct final rule. That document may withdraw the direct final rule in 
whole or in part.
    Incorporation by reference: The incorporation by reference of 
certain publications listed in this rule is approved by the Director of 
the Office of the Federal Register as of December 18, 2023. The 
incorporation by reference of certain other publications listed in this 
rule was approved by the Director of the Office of the Federal Register 
as of August 11, 2010.

ADDRESSES: Send comments identified by docket number FAA-2023-1836 
using any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     Mail: Send comments to Docket Operations, M-30; U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at (202) 493-2251.
    Docket: Background documents or comments received may be read at 
https://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or Docket Operations in Room W12-140 of the 
West Building Ground Floor at 1200 New Jersey Avenue SE, Washington, 
DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Juan Sebastian Yanguas, Airspace Rules 
& Regulations, AJV-P21, Federal Aviation Administration, 800 
Independence Avenue SW, Washington, DC 20591; telephone (202) 267-8783; 
email [email protected].

SUPPLEMENTARY INFORMATION:

List of Abbreviations and Acronyms Frequently Used in This Document

ADS-B--Automatic Dependent Surveillance-Broadcast
ATC--Air Traffic Control
ICAO--International Civil Aviation Organization
MHz--Megahertz
MOPS--Minimum Operating Performance Standards
NTSB--National Transportation Safety Board
TCAS--Traffic Collision Avoidance System
TIS-B--Traffic Information Service-Broadcast
TSO--Technical Standard Order
UAT--Universal Access Transceiver

I. Executive Summary

    As of January 1, 2020, Federal Aviation Administration (FAA) 
regulations, codified in title 14 Code of Federal Regulations (14 CFR), 
Sec. Sec.  91.225 and 91.227, require aircraft to equip with Automatic 
Dependent Surveillance-Broadcast (ADS-B) Out to operate in expressly 
identified airspace areas.\1\ ADS-B Out equipment must meet the 
performance requirements in Sec.  91.227 along with those in Technical 
Standard Orders (TSO)-C166b or TSO-C154c. This rulemaking revises 
Sec. Sec.  91.225 and 91.227 to allow aircraft with equipment that 
meets the performance requirements in the new TSOs, TSO-C166c and TSO-
C154d, to also operate in compliance with the regulations. 
Specifically, to allow use of these new TSOs, the FAA is incorporating 
by reference TSO-C166c, TSO-C154d, section 2 of RTCA DO-260C, RTCA DO-
260C Change 1, and section 2 of RTCA DO-282C into 14 CFR 91.225 and 
91.227. Brief summaries of each document being incorporated by 
reference can be found in section IV.B. of this preamble. These new 
performance requirements enable new wake turbulence applications, 
incorporate functionality for high-altitude and high-velocity vehicles, 
and enhance weather forecasting. The addition of TSO-C166c and TSO-
C154d to the list of permitted TSOs will not negatively affect current 
users because TSO-C166b and TSO-C154c will remain as acceptable 
performance requirements.
---------------------------------------------------------------------------

    \1\ Section 91.225(h), as redesignated in this rule, requires 
unmanned aircraft (UA) to equip with ADS-B Out and broadcast when 
they are operating under a flight plan and in two-way radio 
communication with air traffic control (ATC). The ADS-B Out 
equipment must meet the performance requirements in Sec.  91.227 
along with those in TSO-C166b or TSO-C154c. Section 91.225(h), as 
redesignated in this rule, is updated to include the two new TSOs.
---------------------------------------------------------------------------

    This rulemaking also makes minor changes to other regulatory 
sections of part 91. It revises Sec.  91.215 to remove the requirement 
that transponders reply to intermode interrogations, as International 
Civil Aviation Organization (ICAO) prohibited those replies in ICAO 
Annex 10 Volume IV Standards and Recommended Practices and new 
transponder certifications do not include the capability to reply to 
intermode interrogations. This rulemaking also removes the requirement 
in part 43, appendix F, to verify response to an intermode 
interrogation.

II. Direct Final Rule

    An agency typically uses direct final rulemaking when it 
anticipates that a proposed rule is unnecessary as the rule is 
considered noncontroversial.\2\ The FAA has determined that this rule 
is suitable for direct final rulemaking as the rule provides an 
additional means of compliance with ADS-B Out rule requirements 
developed in conjunction with new industry standards. This amendment 
will not impose any additional burden on operators whose aircraft are 
currently equipped with ADS-B Out equipment meeting the performance 
requirements of TSO-C166b or TSO-C154c. Additionally, this change will 
increase the ADS-B Out rule compliance options with additional 
collateral benefits such as new wake turbulence applications, increased 
functionality for high-altitude and high-velocity vehicles, and 
enhanced weather forecasting. Moreover, the FAA previously published 
the TSOs being incorporated by reference in this direct final rule for 
public comment and addressed the comments received.\3\ Any remaining 
changes adopted by this rulemaking are technical, clarifying, or 
conforming with current legal interpretations or international 
requirements. As such, the FAA has determined that this rule is 
suitable for direct final rulemaking as these changes are 
noncontroversial.
---------------------------------------------------------------------------

    \2\ 14 CFR 11.13.
    \3\ The published TSOs and the adjudication of all public 
comments received for TSO-C166c and TSO-C154d can be found alongside 
each TSO in the FAA Dynamic Regulatory System (refer to https://drs.faa.gov).
---------------------------------------------------------------------------

    The FAA is providing notice and seeking comment prior to 
effectuating changes to the regulation.\4\ If the FAA

[[Page 71470]]

receives an adverse comment during the comment period, the FAA will 
advise the public by publishing a document in the Federal Register 
before the effective date of the direct final rule. This document may 
withdraw the direct final rule in whole or in part. If the FAA 
withdraws a direct final rule because of an adverse comment, the FAA 
may incorporate the commenter's recommendation into another direct 
final rule or may publish a notice of proposed rulemaking (NPRM).\5\
---------------------------------------------------------------------------

    \4\ See Adoption of Recommendations, 60 FR 43109, 43110-43111 
(Aug. 18, 1995) (describing Administrative Conference of the United 
States, Recommendation 95-4, Procedures for Noncontroversial and 
Expedited Rulemaking).
    \5\ 14 CFR 11.31(c).
---------------------------------------------------------------------------

    For purposes of this direct final rule, an adverse comment is one 
that explains (1) why the rule is inappropriate, including challenges 
to the rule's underlying premise or approach; or (2) why the direct 
final rule will be ineffective or unacceptable without a change.\6\ In 
determining whether an adverse comment necessitates withdrawal of this 
direct final rule, the FAA will consider whether the comment raises an 
issue serious enough to warrant a substantive response had it been 
submitted in response to publication of an NPRM. A comment recommending 
additional provisions to the rule will not be considered adverse unless 
the comment explains how this direct final rule would be ineffective 
without the added provisions.\7\
---------------------------------------------------------------------------

    \6\ 14 CFR 11.31(a).
    \7\ 14 CFR 11.31(a)(1).
---------------------------------------------------------------------------

    Under the direct final rule process, the FAA does not consider a 
comment to be adverse if that comment recommends an amendment to a 
different regulation beyond the regulation(s) in the direct final rule 
at issue. The FAA also does not consider a frivolous or insubstantial 
comment to be adverse.\8\
---------------------------------------------------------------------------

    \8\ 14 CFR 11.31(a)(1) and (2).
---------------------------------------------------------------------------

    If the FAA receives no adverse comments, the FAA will publish a 
confirmation notification in the Federal Register, generally within 15 
days after the comment period closes. The confirmation notification 
announces the effective date of the rule.\9\
---------------------------------------------------------------------------

    \9\ 14 CFR 11.31(b).
---------------------------------------------------------------------------

III. Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in 
title 49 of the United States Code (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 regulatory action is within the scope of both sections 40103 
and 44701 because it prescribes aircraft performance requirements to 
meet advanced surveillance needs to accommodate increases in national 
airspace system operations. As more aircraft operate within United 
States (U.S.) airspace, the FAA needs improved surveillance performance 
to accommodate the increased traffic safely and efficiently.

IV. Discussion of the Direct Final Rule

    Effective January 1, 2020, 14 CFR 91.225 requires aircraft 
operators to comply with Sec. Sec.  91.225 and 91.227 when the aircraft 
is operated in designated classes of airspace (whereas unmanned 
aircraft must comply with Sec.  91.225(h), as redesignated by this 
rule, when in two-way radio communication with air traffic control 
(ATC) and operating under a flight plan). To comply, the ADS-B Out 
equipment must meet the performance requirements of Sec.  91.227 and 
either TSO-C166b or TSO-C154c.\10\ Moreover, TSO-C166b and TSO-C154c 
reference and require compliance with RTCA DO-260B or RTCA DO-282B, 
respectively, which are minimum operational performance standards 
(MOPS).
---------------------------------------------------------------------------

    \10\ The following documents were incorporated by reference into 
14 CFR 91.225 and 91.227 as of August 11, 2010 by the final rule, 
Automatic Dependent Surveillance-Broadcast (ADS-B) Out Performance 
Requirements To Support Air Traffic Control (ATC) Service, 75 FR 
30159 (May 28, 2011):
    Technical Standard Order (TSO)-C166b, Extended Squitter 
Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic 
Information Service-Broadcast (TIS-B) Equipment Operating on the 
Radio Frequency of 1090 Megahertz (MHz) (Dec. 2, 2009);
    TSO-C154c, Universal Access Transceiver (UAT) Automatic 
Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the 
Frequency of 978 MHz (Dec. 2, 2009);
    Section 2, Equipment Performance Requirements and Test 
Procedures, of RTCA DO-260B, Minimum Operational Performance 
Standards for 1090 MHz Extended Squitter Automatic Dependent 
Surveillance-Broadcast (ADS-B) and Traffic Information Services-
Broadcast (TIS-B), December 2, 2009 (referenced in TSO-C166b); and
    Section 2, Equipment Performance Requirements and Test 
Procedures, of RTCA DO-282B, Minimum Operational Performance 
Standards for Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B), December 2, 2009 (referenced in TSO-
C154c).
---------------------------------------------------------------------------

    Specifically, Sec.  91.225 states no person may operate an aircraft 
in Class A airspace unless the aircraft has equipment installed that 
meets the performance requirements in TSO-C166b and Sec.  91.227. 
Additionally, no person may operate an aircraft below 18,000 feet mean 
sea level and in certain airspace described in the regulation unless 
the aircraft meets either the performance requirements in Sec.  91.227 
and either TSO-C166b or TSO-C154c.
    A TSO is a minimum performance standard for specified materials, 
parts, and appliances used on civil aircraft. These standards provide 
industry with the minimum requirements they must meet to certify an 
ADS-B Out system. The FAA may recognize certain TSOs as a means of 
compliance with regulatory requirements, or the regulation may 
explicitly incorporate the TSO requirements. For Sec. Sec.  91.225 and 
91.227, the FAA has specifically incorporated the TSOs into the 
regulations. This process ensures a harmonized approach for equipment 
functionality across equipment manufacturers.
    Currently, aircraft with equipment that meet the performance 
requirements in TSO-C166b or TSO-C154c are in compliance with the 
regulations. This rulemaking revises Sec. Sec.  91.225 and 91.227 to 
include the use of equipment compliant with TSO-C166c (Extended 
Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic 
Information Service-Broadcast (TIS-B) Equipment Operating on the Radio 
Frequency of 1090 Megahertz (MHz)) or TSO-C154d (Universal Access 
Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) 
Equipment Operating on the Radio Frequency of 978 Megahertz (MHz)) as 
options to meet the ADS-B Out regulations. These new TSOs increase 
information available (e.g., weather information or spectrum 
monitoring); enable new wake turbulence applications; incorporate 
functionality for high-altitude and high-velocity vehicles; and enhance 
weather forecasting. They also enable and enhance ADS-B In applications 
such as Flight Interval Management. These additions will not negatively 
affect current users, as there is no mandate for users to change from 
existing ADS-B Out rule-compliant equipment to meet the performance 
requirements in TSO-C166c or TSO-C154d. Persons using equipment meeting 
the performance requirements in either TSO-C166b or TSO-C154c may 
continue to use that

[[Page 71471]]

equipment after the adoption of this rule.
    This rulemaking also revises Sec. Sec.  91.225 and 91.227 to 
clearly associate each Technical Standard Order with its associated 
RTCA document. While Section 2 of RTCA DO-260B and Section 2 of RTCA 
DO-282B were previously incorporated by reference into Sec. Sec.  
91.225 and 91.227, they were not clearly associated with the TSOs to 
which they related. With the addition of two new TSOs and three new 
RTCA documents, it is important each TSO be clearly associated with its 
referenced RTCA document(s).

A. Addition of TSO-C166c and TSO-C154d Performance Standards

    TSO-C166c, which is a subject of this rulemaking, is largely based 
on RTCA's Minimum Operating Performance Standards (MOPS) for ADS-B Out 
systems. RTCA is an independent standards development organization 
comprised of representatives from industry, government, associations, 
and academia. Representatives from these entities collaborated on the 
development of an updated standards document for ADS-B Out systems 
titled RTCA DO-260C, Minimum Operational Performance Standards for 1090 
MHz Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-
B) and Traffic Information Services--Broadcast (TIS-B). The same 
committee subsequently published RTCA DO-260C Change 1 as a 
supplemental document to correct errors and add clarifications. RTCA 
made both RTCA DO-260C and RTCA DO-260C Change 1 available to the 
public through the RTCA website, and the responsible committee 
adjudicated all comments received.
    Specifically, the FAA requires compliance with Section 2 of RTCA 
DO-260C as modified by Change 1 as part of TSO-C166c. Section 2 
establishes equipment performance requirements for 1090 MHz ADS-B 
systems. Compliance with the TSO, including Section 2 of RTCA DO-260C 
as modified by Change 1, allows industry to show the FAA that their 
system is designed and manufactured as required by FAA regulations.
    RTCA DO-260C as modified by Change 1, updates the previous RTCA DO-
260B performance standard to provide additional capabilities enhancing 
areas such as safety, equipment performance, airspace efficiency, and 
data reporting. The substantive changes from the previous MOPS include:
     Changes to support ICAO requirements that Autonomous 
Distress Tracking automatically provide position information at least 
once per minute when in distress. Although current Sec.  91.227(c) 
already requires the position information, the RTCA revision provides a 
means to initiate broadcast announcing that the aircraft is in 
distress.
     Additional elements in ADS-B Out messages, including wind 
and temperature data, to support more precise spacing of aircraft by 
air traffic control (ATC). In addition, the avionics will be able to 
support capability for ground radars to extract Flight Interval 
Management data from the aircraft.
     The broadcast of aircraft-derived weather data for 
applications such as Flight Interval Management, wake vortex avoidance 
and surfing, hazardous weather detection and avoidance, and aviation 
weather forecasting.
     The broadcast of pilot-observed weather during flight, 
including temperature, wind, turbulence, and hazardous weather 
information.
     The broadcast of an unmanned aircraft system (UAS)/
Remotely Piloted Aircraft System (RPAS) lost link condition. In this 
condition, the UAS/RPAS may broadcast its contingency plan, identifying 
the course of action the UAS/RPAS is following.
     Increased the reporting range of altitude and velocity to 
support commercial space and hypersonic aircraft operations.
     Inclusion of new capabilities for Airborne Collision 
Avoidance System (ACAS)-X, Detect and Avoid (DAA), as well as future 
Collision Avoidance Systems (CAS). The new capabilities include 
expanded information-laying framework for future passive CAS and 
alternate coordination techniques.
     Improved Geometric Altitude reporting by increasing the 
reportable difference between geometric and barometric altitude when 
information for both is available. Additionally, minimized the 
reporting of no integrity by expanding the Navigation Integrity 
Category (NIC) reporting when solely geometric altitude is available.
     Provisions for Phase Overlay (PO) techniques enhancing 
future capacity and efficiency of the 1090 MHz frequency. PO allows for 
transmission of additional data within existing ADS-B Out messages 
without the need for additional messages.
     Enhanced requirements for selection of transmission of 
airborne or surface message formats for aircraft without an automatic 
means of determining on-the-ground status (e.g., a landing gear weight 
on wheels switch).
     The broadcast of Interrogation/Reply Monitor data, 
including measurements of transponder interrogation and reply rate 
activity.
     Improved emitter category classifications and descriptions 
to prevent misuse by future applications.
     Transmission of transponder antenna offset information 
improving tracking of aircraft and vehicles operating on the airport 
surface by the airport surface detection systems.
    TSO-C154d, which is also the subject of this rulemaking, is largely 
based on RTCA DO-282C, Minimum Operational Performance Standards (MOPS) 
for Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B). RTCA made RTCA DO-282C available to the 
public through the RTCA website, and the responsible committee 
adjudicated all comments received.
    Specifically, the FAA requires compliance with Section 2 of RTCA 
DO-282C as part of TSO-C154d. Section 2 establishes equipment 
performance requirements for UAT ADS-B systems. Compliance with the 
TSO, including Section 2 of RTCA DO-282C, allows industry to show the 
FAA that their system is designed and manufactured as required by FAA 
regulations.
    RTCA DO-282C updates the previous RTCA DO-282B performance standard 
to provide additional capabilities enhancing areas such as safety, 
equipment performance, airspace efficiency, and data reporting. The 
substantive changes to the previous performance standard include:
     Changes to support ICAO requirements that Autonomous 
Distress Tracking automatically provide position information at least 
once per minute when in distress. Although current Sec.  91.227(c) 
already requires the position information, the RTCA revision provides a 
means to initiate broadcast announcing that the aircraft is in 
distress.
     Additional elements in ADS-B Out messages, including wind 
and temperature data, to support more precise spacing of aircraft by 
ATC. In addition, the avionics will be able to support capability for 
ground radars to extract Flight Interval Management data from the 
aircraft.
     The broadcast of aircraft-derived weather data for 
applications such as Flight Interval Management, wake vortex avoidance 
and surfing, hazardous weather detection and avoidance, and aviation 
weather forecasting.
     The broadcast of pilot-observed weather during flight, 
including temperature, wind, turbulence, and hazardous weather 
information.

[[Page 71472]]

     The broadcast of a UAS/RPAS lost link condition. In this 
condition, the UAS/RPAS may broadcast its contingency plan, identifying 
the course of action the UAS/RPAS is following.
     Increased the reporting range of altitude and velocity to 
support commercial space and hypersonic aircraft operations.
     Enhanced requirements for selection of transmission of 
airborne or surface message formats for aircraft without an automatic 
means of determining on-the-ground status (e.g., a landing gear weight 
on wheels switch).
     Improved emitter category classifications and descriptions 
to prevent misuse by future applications.
    This rule will allow aircraft with equipment compliant with the 
performance requirements of TSO-C166c and RTCA DO-260C as modified by 
Change 1, and TSO-C154d and RTCA DO-282C to operate in the airspace 
areas identified in Sec.  91.225. Importantly, this rulemaking does not 
impact any operators currently in compliance with Sec. Sec.  91.225 and 
91.227.
    Including TSO-C166c and TSO-C154d in Sec. Sec.  91.225 and 91.227 
allows the use of updated technology to meet ADS-B Out requirements and 
enables improvements in the ADS-B environment, such as the ability to 
transmit additional data; and to include ADS-B Out for high-altitude 
and high-velocity vehicles.

B. Incorporation by Reference

    Incorporation by reference (IBR) is a mechanism that allows Federal 
agencies to comply with the requirements of the Administrative 
Procedure Act to publish rules in the Federal Register and the CFR by 
referring to material published elsewhere.\11\ Material that is 
incorporated by reference has the same legal status as if it were 
published in full in the Federal Register and the CFR. The standards 
referenced in this rule include technical information and 
specifications for equipment and capabilities required to meet FAA ADS-
B Out requirements.
---------------------------------------------------------------------------

    \11\ 5 U.S.C. 552(a).
---------------------------------------------------------------------------

    The standards referenced in Sec. Sec.  91.225 and 91.227 of this 
rule are incorporated by reference with the approval of the Director of 
the Office of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 
51. In accordance with 5 U.S.C. 552(a) and 1 CFR part 51,\12\ all 
approved materials are available for inspection at the FAA's Office of 
Rulemaking, 800 Independence Avenue SW, Washington, DC 20590 (telephone 
(202) 267-9677). This material is also available from the sources 
indicated in paragraphs (i)(1) and (2) of Sec.  91.225, as redesignated 
by this rule, and paragraphs (g)(1) and (2) of Sec.  91.227 and as 
follows:
---------------------------------------------------------------------------

    \12\ 5 U.S.C. 552(a) requires that matter incorporated by 
reference be ``reasonably available'' as a condition of its 
eligibility. Further, 1 CFR 51.5(b)(2) requires that agencies 
seeking to incorporate material by reference discuss in the preamble 
of the final rule the ways that the material it is incorporating by 
reference is reasonably available to interested parties and how 
interested parties can obtain the material.
---------------------------------------------------------------------------

    1. Copies of the following Technical Standard Orders (TSOs) may be 
obtained from the U.S. Department of Transportation, Subsequent 
Distribution Office, DOT Warehouse M30, Ardmore East Business Center, 
3341 Q 75th Avenue, Landover, MD 20785; telephone (301) 322-5377. 
Copies are also available on the FAA's website at www.faa.gov/aircraft/air_cert/design_approvals/tso/. Select the link ``Search Technical 
Standard Orders.''
a. TSO-C166c, Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service--Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz) 
(March 10, 2023);
    i. This TSO contains the minimum performance standards that 1090 
MHz ADS-B and TIS-B equipment must meet for approval and identification 
with the applicable TSO marking.
b. TSO-C154d, Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B) Equipment Operating on the Radio 
Frequency of 978 Megahertz (MHz) (March 10, 2023).
    i. This TSO contains the minimum performance standards that UAT 
ADS-B equipment and/or UAT diplexers must meet for approval and 
identification with the applicable TSO marking.
    2. Copies of the following documents may be obtained from RTCA, 
Inc., 1150 18th St. NW, Suite 910, Washington, DC 20036, telephone 
(202) 833-9339. Copies are also available on the RTCA Inc. Website at 
https://www.rtca.org/products.
    a. RTCA DO-260C, Minimum Operational Performance Standards for 1090 
MHz Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-
B) and Traffic Information Services-Broadcast (TIS-B), Section 2, 
Equipment Performance Requirements and Test Procedures, December 17, 
2020; and Minimum Operational Performance Standards for 1090 MHz 
Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) 
and Traffic Information Services-Broadcast (TIS-B) Change 1, January 
25, 2022 (referenced in TSO-C166c);
    i. Section 2 of RTCA DO-260C contains the equipment performance 
requirements and test procedures for 1090 MHz ADS-B and TIS-B 
equipment.
    ii. DO-260C Change 1 contains updates, corrections, and additional 
material to support the implementation of RTCA DO-260C.
    b. RTCA DO-282C, Minimum Operational Performance Standards (MOPS) 
for Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS B), Section 2, Equipment Performance 
Requirements and Test Procedures, June 23, 2022 (referenced in TSO-
C154d).
    i. Section 2 of RTCA DO-282C contains the equipment performance 
requirements and test procedures for UAT ADS-B equipment.
    The following standards appear in the amendatory text of this 
document and were previously approved for the locations in which they 
appear: TSO-C166b, TSO-C154c, RTCA DO-260B, Section 2, and RTCA DO-
282B, Section 2.

C. Advisory Circulars Updated as Part of This Rulemaking

    As part of this rulemaking, the FAA is updating FAA Advisory 
Circular (AC) 90-114B, Automatic Dependent Surveillance--Broadcast 
Operations, to modify references to the TSOs listed for ADS-B Out 
equipment that complies with title 14 of the Code of Federal 
Regulations part 91, Sec. Sec.  91.225 and 91.227.

D. Miscellaneous Amendments

    This rule also includes a number of minor miscellaneous changes to 
Sec. Sec.  91.215, 91.225, and 91.227 to incorporate updated ICAO 
requirements, clarify ambiguities identified in past requests for legal 
interpretations, clarify vague requirements, correct previous 
typographical errors, change a physical location address, and ensure 
valid website links.
    The FAA amends Sec. Sec.  91.215 and 91.227 by replacing the term 
``Mode 3/A'' with ``Mode A'' in both Sec.  91.215(b) and Sec.  
91.227(d)(7). Mode A is a civilian mode intended to elicit transponder 
replies for identity and surveillance. Mode 3 is a military mode also 
used to elicit transponder replies for identity and surveillance. Mode 
3 contains all the functionality of Mode A along with additional 
military-specific capability. For this reason, the military community

[[Page 71473]]

often uses the term ``Mode 3/A,'' a term the civil community does not 
widely use. This editorial change will properly emphasize that the 
regulation requires the Mode A functionality and not the military-
specific functionality of Mode 3. In addition, using the term Mode A is 
consistent with the language used by ICAO and RTCA documents.
    This rule also removes the requirement in Sec.  91.215(b) to reply 
to intermode interrogations, and removes the requirement in part 43, 
appendix F, to verify response to an intermode interrogation. 
Currently, Sec.  91.215(b) requires aircraft equipped with a Mode S 
capability to reply ``to Mode 3/A interrogations with the code 
specified by ATC and intermode and Mode S interrogations in accordance 
with the applicable provisions specified in TSO C-112.'' Additionally, 
part 43, appendix F, paragraph (h), requires verification that an ATC 
transponder respond to an Air Traffic Control Radar Beacon System 
(ATCRBS)/Mode S all-call interrogation. ICAO Annex 10 Volume IV 
establishes two types of intermode interrogations: Mode A/C/S all-call 
and Mode A/C-only all-call. Mode A/C/S all-call interrogations were 
designed to produce a Mode S reply in Mode S capable transponders and a 
Mode A or C reply in non-Mode S capable transponders. Mode A/C-only 
all-call interrogations were designed to not produce a reply by Mode S 
capable transponders and to produce a Mode A or C reply in non-Mode S 
transponders. Therefore, the only type of intermode interrogation that 
a Mode S transponder was intended to reply to per Sec.  91.215(b) was a 
Mode A/C/S all-call interrogation. However, ICAO now prohibits replies 
to Mode A/C/S all-call interrogations in new equipment 
certifications.\13\ Mode A/C/S all-call interrogations were never 
implemented in U.S. ground radar systems, but the inclusion of this 
capability within existing transponders led to an increase in what is 
known as False Replies Un-synchronized In Time (FRUIT). Radio Frequency 
(RF) propagation effects often result in a Mode A/C-only all-call 
interrogation appearing to be a Mode A/C/S all-call interrogation at 
the receiver of a transponder. When a Mode S transponder decodes a Mode 
A/C/S all-call interrogation, an undesired reply is transmitted by the 
transponder, resulting in the increase of FRUIT. Removal of the 
requirement to reply to intermode interrogations ensures compliance 
with ICAO requirements and reduces the number of unsolicited replies, 
thus reducing 1090 MHz spectrum congestion. RTCA DO-181F, referenced by 
TSO-C112f, also prohibits Mode S transponders from responding to Mode 
A/C/S all-call interrogations. Equipment certified to TSO-C112 versions 
prior to TSO-C112f will retain the capability to reply to Mode A/C/S 
all-call interrogations and will continue to be compliant with Sec.  
91.215(b).
---------------------------------------------------------------------------

    \13\ See ICAO Annex 10 Vol IV sec. 3.1.2.4.1.3.2.1.
---------------------------------------------------------------------------

    Accordingly, this rule removes the requirement in 14 CFR part 43, 
appendix F, paragraph (h), to verify response to an intermode 
interrogation, specifically the ATCRBS/Mode S all-call formats (1.6 
microsecond P4 pulse), which is another name for the Mode A/C/S all-
call interrogation. This conforming amendment aligns the inspection and 
test requirements in part 43 with the ICAO prohibition to reply to Mode 
A/C/S all-call interrogations.
    This rule also amends part 43, appendix F, paragraph (j), which 
requires verification that the Mode S transponder generates a correct 
squitter approximately once per second, by clarifying the squitter is 
an acquisition squitter.
    Additionally, the FAA amends Sec.  91.225(e) by adding the term 
``engine-driven'' before ``electrical system.'' This amendment will 
clarify that the relief described in Sec.  91.225 applies to aircraft 
whose electrical system was not originally or subsequently certificated 
to be powered by the aircraft's engine. This rephrasing is consistent 
with the phrase used in Sec.  91.215(b)(3) to describe the same 
category of aircraft. The difference in language has led to confusion 
among regulated entities, as evidenced by the FAA's legal 
interpretation sent to David Schober on January 5, 2017.\14\ Mr. 
Schober requested clarification on the applicability of Sec.  91.225(e) 
to aircraft that had not been originally certificated with an 
electrical system but which have subsequently had batteries or electric 
starters installed. The FAA determined that the intent of the language 
was to cover the same types of aircraft as in the transponder 
regulation. This amendment will make it clear that both regulatory 
provisions refer to the same category of aircraft.
---------------------------------------------------------------------------

    \14\ Available at https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations.
---------------------------------------------------------------------------

    The FAA is revising the definitions for ``Navigation Accuracy 
Category for Position (NACP)'', ``Navigation Accuracy Category for 
Velocity (NACV)'', ``Navigation Integrity Category (NIC)'', ``Source 
Integrity Level (SIL)'', and ``System Design Assurance (SDA)'' in Sec.  
91.227(a) to remove the references to TSO-C166b and TSO-C154c. The FAA 
has determined that including references to these standards in the 
definitions themselves is unnecessary and could lead to confusion as 
more Technical Standard Orders are added to this regulation. The FAA 
notes that references to the Technical Standard Orders appear in the 
actual regulatory requirements of Sec.  91.227.
    Further, the FAA also amends the way it describes the System Design 
Assurance (SDA) reporting requirements in Sec.  91.227(c)(1)(iv) and 
the Source Integrity Level (SIL) reporting requirement in Sec.  
91.227(c)(1)(v) without changing the underlying substantive requirement 
itself. Under the FAA's current regulation, the FAA codified numerical 
values used by RTCA to represent probability values. That is, per DO-
260B, an SDA value of 2 represents ``the probability of a position 
transmission chain fault causing false or misleading position 
information to be transmitted'' to be <=1 x 10-5 per flight 
hour. This action revises Sec.  91.227(c)(1)(iv) to require an SDA of 
<=1 x 10-5 per flight hour instead of the equivalent RTCA 
DO-260B value of 2. A SIL of 3 represents ``the probability of the 
reported horizontal position exceeding the radius of containment 
(RC) defined by the NIC, without alerting, assuming no 
avionics faults'' to be <=1 x 10-7 per flight hour or per 
sample. Therefore, Sec.  91.227(c)(1)(v) will require a SIL value of 
<=1 x 10-7 per flight hour or per sample instead of the 
equivalent RTCA DO-260B value of 3. This change does not alter the 
underlying performance requirements. Instead, it codifies the actual 
probability requirement rather than the equivalent conversion used by 
RTCA DO-260B. This editorial change makes the regulation's performance 
requirements clear within the regulation without having to consult RTCA 
DO-260B. It also ensures that this performance standard remains 
constant in case RTCA revises SDA and SIL.
    Additionally, this rule amends Sec.  91.227(d)(13) to conform to 
the FAA's intent that the element indicate that the aircraft has the 
capability to receive ADS-B In services, not necessarily that this 
capability be installed. The revised regulatory text will replace the 
current word ``installed'' with the word ``available.'' After the 
amendment's effective date, Sec.  91.227(d)(13) will require ``[a]n 
indication of whether ADS-B In capability is available.'' The FAA 
became aware of the confusion after John D. Collins' September 20, 2012 
letter requesting an interpretation

[[Page 71474]]

of Sec.  91.227(d)(13).\15\ Mr. Collins explained that some aircraft 
operators use portable ADS-B In receivers without installing the 
equipment. By using the word ``installed'' in the regulatory language, 
some aircraft operators and installers believed that an aircraft could 
not indicate ADS-B In capability if the appropriate equipment was not 
physically installed on the aircraft.
---------------------------------------------------------------------------

    \15\ Available at www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations.
---------------------------------------------------------------------------

    Per the preamble to the Automatic Dependent Surveillance-Broadcast 
(ADS-B) Out Performance Requirements to Support Air Traffic Control 
(ATC) Service published on May 28, 2010,\16\ the ADS-B In capability is 
meant to provide ADS-B ground stations with an indication of what, if 
any, FAA ADS-B services should be provided to the aircraft. In a legal 
interpretation sent to John D. Collins on August 23, 2013, the FAA 
explained that the intent was for this message element to indicate that 
the aircraft has the capability to receive ADS-B In services, not 
necessarily that this capability is installed. Therefore, this change 
clarifies that aircraft are to indicate that ADS-B reception capability 
is available, even if the system receiving the data is not installed on 
the aircraft. The FAA ground stations will provide ADS-B In services to 
all eligible aircraft indicating an ADS-B In capability.
---------------------------------------------------------------------------

    \16\ 75 FR 30159.
---------------------------------------------------------------------------

    The FAA also clarifies Sec.  91.227(d)(5) by revising ``TCAS II or 
ACAS'' to ``collision avoidance system.'' While the FAA often uses the 
term TCAS in various rules and regulations, other nations and ICAO 
generally use the term ACAS. For this reason, Sec.  91.227 used the 
term ``TCAS II or ACAS'' in an attempt to reduce confusion. Since the 
initial publication of Sec.  91.227, the FAA published a new TSO (TSO-
C219) for an additional collision avoidance system: ACAS Xa/Xo. TSO-
C219 was published by the FAA on February 28, 2020.\17\ Additionally, 
various other collision avoidance systems are currently in development. 
Due to the long-standing confusion with the terminology, RTCA, ICAO, 
and international regulators all use the generic term ``collision 
avoidance system (CAS).'' This editorial change provides enhanced 
clarity but does not alter the existing broadcast requirements.
---------------------------------------------------------------------------

    \17\ Available at https://drs.faa.gov/browse.
---------------------------------------------------------------------------

    Further, the FAA clarifies Sec.  91.227(d)(8) by changing the 
required broadcast information from ``an indication of the aircraft's 
call sign that is submitted on the flight plan, or the aircraft's 
registration number'' to ``an indication of the aircraft identification 
that is submitted on the flight plan or used for communicating with 
ATC.'' The change will clarify, not alter, the substantive meaning of 
the paragraph. On July 27, 2017, the FAA sent an internal request for 
legal interpretation of Sec.  91.225(d)(8). Some manufacturers and 
operators interpreted the existing language to mean that the aircraft 
registration number could be programmed into the aircraft 
identification field of the ADS-B avionics and yet a different aircraft 
call sign could be filled in the flight plan. The FAA legal 
interpretation sent to Jere Hayslett on August 3, 2017, stated that in 
the preamble to the final rule, to satisfy Sec.  91.227(d)(8) a pilot 
would have to provide the same call sign on their flight plan as they 
transmit out using ADS-B to avoid ATC confusion. This amendment makes 
clear that the aircraft identification included on the flight plan must 
match the aircraft identification transmitted via ADS-B Out. 
Furthermore, the change also clarifies that for those aircraft that do 
not file a flight plan, the aircraft identification transmitted via 
ADS-B Out must match the aircraft identification used for communicating 
with ATC and ensures ATC can correlate flight plan information with 
information displayed on the radar display.
    In addition, the FAA is undertaking the following purely clerical 
changes:
     Corrects typographical errors in Sec. Sec.  91.225(i)(1), 
as redesignated by this rule, and 91.227(c) and (g)(1) and (2). These 
include removing of extra spaces, correcting capitalizations, and 
correcting placement of dash marks.
     Updates website addresses in Sec. Sec.  91.225(i) 
introductory text and (i)(1) and (2), as redesignated by this rule, and 
91.227(g) introductory text and (g)(1) and (2).
     Updates the RTCA physical address in Sec. Sec.  
91.225(i)(2), as redesignated by this rule, and 91.227(g)(2).

V. Regulatory Notices and Analyses

    Federal agencies consider impacts of regulatory actions under a 
variety of executive orders and other requirements. First, Executive 
Order 12866 and Executive Order 13563, as amended by Executive Order 
14094 (``Modernizing Regulatory Review''), direct that each Federal 
agency shall propose or adopt a regulation only upon a reasoned 
determination that the benefits of the intended regulation justify the 
costs. Second, the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) 
requires agencies to analyze the economic impact of regulatory changes 
on small entities. Third, the Trade Agreements Act (Pub. L. 96-39) 
prohibits agencies from setting standards that create unnecessary 
obstacles to the foreign commerce of the United States. Fourth, the 
Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires agencies 
to prepare a written assessment of the costs, benefits, and other 
effects of proposed or final rules that include a Federal mandate that 
may result in the expenditure by State, local, and tribal governments, 
in the aggregate, or by the private sector, of $100 million or more 
(adjusted annually for inflation) in any one year. The current 
threshold after adjustment for inflation is $177 million using the most 
current (2022) Implicit Price Deflator for the Gross Domestic Product. 
This portion of the preamble summarizes the FAA's analysis of the 
economic impacts of this rule.
    In conducting these analyses, the FAA has determined that this rule 
has benefits that justify its costs; is not significant as defined in 
section 3(f)(1) of Executive Order 12866; will not have a significant 
economic impact on a substantial number of small entities; will not 
create unnecessary obstacles to the foreign commerce of the United 
States; and, will not impose an unfunded mandate on State, local, or 
tribal governments, or on the private sector.

A. Regulatory Evaluation

    ADS-B enhances safety and efficiency and directly benefits pilots, 
controllers, airports, airlines, and the public. This rule enables 
additional features of ADS-B Out as an option to meet all ADS-B 
requirements by revising Sec. Sec.  91.225 and 91.227. Since this 
direct final rule maintains the performance standards by providing 
aircraft operators the option, on a voluntary basis, to implement 
additional features into the ADS-B equipment, the direct final rule 
will not incur any costs to the operators and the public. Revising 
Sec.  91.215 adds no new cost to the public because it removes the 
requirement to support a capability that has no operational use. By 
increasing the information available, enabling new wake turbulence 
applications, incorporating functionality for high-altitude and high-
velocity vehicles, and enhancing weather forecasting, this direct final 
rule has unquantifiable benefits to aircraft operators.

B. Regulatory Flexibility Determination

    The Regulatory Flexibility Act (RFA), Public Law 96-354, (5 U.S.C. 
601-612),

[[Page 71475]]

as amended by the Small Business Regulatory Enforcement Fairness Act 
(Pub. L. 104-121) and the Small Business Jobs Act (Pub. L. 111-240), 
requires Federal agencies to consider the effects of the regulatory 
action on small business and other small entities and to minimize any 
significant economic impact. The term ``small entities'' comprises 
small businesses and not-for-profit organizations that are 
independently owned and operated and are not dominant in their fields, 
and governmental jurisdictions with populations of less than 50,000.
    Agencies must perform a review to determine whether a rulemaking 
would have a significant economic impact on a substantial number of 
small entities. If the agency determines that it will, the agency must 
prepare a regulatory flexibility analysis as described in the RFA. 
However, if an agency determines that a rule is not expected to have a 
significant economic impact on a substantial number of small entities, 
section 605(b) of the RFA provides that the head of the agency may so 
certify, and a regulatory flexibility analysis is not required.
    This direct final rule adds an option for aircraft operators to 
incorporate additional features into ADS-B equipment described in 
Sec. Sec.  91.225 and 91.227 and allows for the removal of an unused 
capability in Sec.  91.215. This direct final rule will not require 
additional reporting, recordkeeping, and other compliances for small 
businesses.
    Therefore, as provided in section 605(b), the head of the FAA 
certifies that this direct final rule does not result in a significant 
economic impact on a substantial number of small entities.

C. International Trade Impact Assessment

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the 
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal 
agencies from establishing standards or engaging in related activities 
that create unnecessary obstacles to the foreign commerce of the United 
States. Pursuant to these Acts, the establishment of standards is not 
considered an unnecessary obstacle to the foreign commerce of the 
United States, so long as the standard has a legitimate domestic 
objective, such as the protection of safety, and does not operate in a 
manner that excludes imports that meet this objective. The statute also 
requires consideration of international standards and, where 
appropriate, that they be the basis for U.S. standards. The FAA has 
assessed the potential effect of this rule and determined that it will 
impose no costs on either domestic or international entities and thus 
has a neutral trade impact.

D. Unfunded Mandates Assessment

    Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement 
assessing the effects of any Federal mandate in a proposed or final 
agency rule that may result in an expenditure of $100 million or more 
(in 1995 dollars) in any one year by State, local, and tribal 
governments, in the aggregate, or by the private sector; such a mandate 
is deemed to be a ``significant regulatory action.'' The FAA currently 
uses an inflation-adjusted value of $177.0 million in lieu of $100 
million.
    This rule does not contain such a mandate. Therefore, the 
requirements of title II of the Act do not apply.

E. Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires 
that the FAA consider the impact of paperwork and other information 
collection burdens imposed on the public. The FAA has determined that 
there is no new requirement for information collection associated with 
this direct final rule.

F. International Compatibility and Cooperation

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to conform to 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices (SARPs) to the maximum extent practicable. ICAO 
plans to update its current SARPs to reflect harmonized changes to both 
RTCA and EUROCAE minimum performance standards, as appropriate, for 
ADS-B Out operations. The FAA also will continue to work with the 
international community to ensure harmonization.

G. Environmental Analysis

    FAA Order 1050.1F identifies FAA actions that are categorically 
excluded from preparation of an environmental assessment or 
environmental impact statement under the National Environmental Policy 
Act in the absence of extraordinary circumstances. The FAA has 
determined this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 5-6.6f for regulations and involves 
no extraordinary circumstances.

VI. Executive Order Determinations

A. Executive Order 13132, Federalism

    The FAA has analyzed this direct final rule under the principles 
and criteria of Executive Order 13132, Federalism. The agency 
determined that this action will not have a substantial direct effect 
on the States, or the relationship between the Federal Government and 
the States, or on the distribution of power and responsibilities among 
the various levels of government, and, therefore, does not have 
federalism implications.

B. Executive Order 13211, Regulations That Significantly Affect Energy 
Supply, Distribution, or Use

    The FAA analyzed this direct final rule under Executive Order 
13211, Actions Concerning Regulations that Significantly Affect Energy 
Supply, Distribution, or Use. The agency has determined that this rule 
is not a ``significant energy action'' under the Executive order and 
the rule is not likely to have a significant adverse effect on the 
supply, distribution, or use of energy.

C. Executive Order 13609, International Cooperation

    Executive Order 13609, Promoting International Regulatory 
Cooperation, promotes international regulatory cooperation to meet 
shared challenges involving health, safety, labor, security, 
environmental, and other issues and to reduce, eliminate, or prevent 
unnecessary differences in regulatory requirements. The FAA analyzed 
this action under the policies and agency responsibilities of Executive 
Order 13609 and has determined that this action would have no effect on 
international regulatory cooperation.

VII. Additional Information

A. Comments Invited

    The FAA invites interested persons to participate in this 
rulemaking by submitting written comments, data, or views. The most 
helpful comments reference a specific portion of the rule, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit only one time.
    The FAA will file in the docket all comments it receives, as well 
as a report summarizing each substantive public contact with FAA 
personnel concerning this rulemaking. Before acting on this rulemaking, 
the FAA will consider all

[[Page 71476]]

comments it receives on or before the closing date for comments. The 
agency may change this rule in light of the comments it receives.
    Privacy: In accordance with 5 U.S.C. 553(c), DOT solicits comments 
from the public to better inform its rulemaking process. DOT posts 
these comments, without edit, including any personal information the 
commenter provides, to www.regulations.gov, as described in the system 
of records notice (DOT/ALL-14 FDMS), which can be reviewed at 
www.dot.gov/privacy.

B. Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), 
CBI is exempt from public disclosure. If your comments responsive to 
this direct final rule contain commercial or financial information that 
is customarily treated as private, that you actually treat as private, 
and that is relevant or responsive to this direct final rule, it is 
important that you clearly designate the submitted comments as CBI. 
Please mark each page of your submission containing CBI as ``PROPIN.'' 
The FAA will treat such marked submissions as confidential under the 
FOIA, and they will not be placed in the public docket of this direct 
final rule. Submissions containing CBI should be sent to the person in 
the FOR FURTHER INFORMATION CONTACT section of this document. Any 
commentary that the FAA receives which is not specifically designated 
as CBI will be placed in the public docket for this rulemaking.

C. Electronic Access and Filing

    A copy of this direct final rule, all comments received, any 
confirmation document, and all background material may be viewed online 
at https://www.regulations.gov using the docket number listed above. A 
copy of this direct final rule will be placed in the docket. Electronic 
retrieval help and guidelines are available on the website. It is 
available 24 hours each day, 365 days each year. An electronic copy of 
this document may also be downloaded from the Office of the Federal 
Register's website at https://www.federalregister.gov and the 
Government Publishing Office's website at https://www.govinfo.gov. A 
copy may also be found on the FAA's Regulations and Policies website at 
https://www.faa.gov/regulations_policies.
    Copies may also be obtained by sending a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW, Washington, DC 20591, or by calling (202) 267-9677. 
Interested persons must identify the docket or amendment number of this 
rulemaking.
    All documents the FAA considered in developing this rule, including 
economic analyses and technical reports, may be accessed in the 
electronic docket for this rulemaking.

D. Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 
1996 requires the FAA to comply with small entity requests for 
information or advice about compliance with statutes and regulations 
within its jurisdiction. A small entity with questions regarding this 
document may contact its local FAA official or the person listed under 
the FOR FURTHER INFORMATION CONTACT heading at the beginning of the 
preamble. To find out more about SBREFA on the internet, visit https://www.faa.gov/regulations_policies/rulemaking/sbre_act/.

List of Subjects

14 CFR Part 43

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

14 CFR Part 91

    Air traffic control, Aircraft, Airports, Aviation safety, 
Incorporation by reference, Transportation.

The Amendment

    In consideration of the foregoing, the Federal Aviation 
Administration amends chapter I of title 14, Code of Federal 
Regulations as follows:

PART 43--MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND 
ALTERATION

0
1. The authority citation for part 43 continues to read as follows:

    Authority: 42 U.S.C. 7572; 49 U.S.C. 106(f), 106(g), 40105, 
40113, 44701-44702, 44704, 44707, 44709, 44711, 44713, 44715, 45303.


0
2. Amend appendix F to part 43 by revising paragraphs (h) and (j) to 
read as follows:

Appendix F to Part 43--ATC Transponder Tests and Inspections

* * * * *
    (h) Mode S All-Call Interrogations: Interrogate the Mode S 
transponder with the Mode S-only all-call format UF = 11 and verify 
that the correct address and capability are reported in the replies 
(downlink format DF = 11).
* * * * *
    (j) Squitter: Verify that the Mode S transponder generates a 
correct acquisition squitter approximately once per second.
* * * * *

PART 91--GENERAL OPERATING AND FLIGHT RULES

0
3. The authority citation for part 91 continues to read as follows:

    Authority:  49 U.S.C. 106(f), 106(g), 40101, 40103, 40105, 
40113, 40120, 44101, 44111, 44701, 44704, 44709, 44711, 44712, 
44715, 44716, 44717, 44722, 46306, 46315, 46316, 46504, 46506-46507, 
47122, 47508, 47528-47531, 47534, Pub. L. 114-190, 130 Stat. 615 (49 
U.S.C. 44703 note); articles 12 and 29 of the Convention on 
International Civil Aviation (61 Stat. 1180), (126 Stat. 11).


0
4. Amend Sec.  91.215 by revising the introductory text of paragraph 
(b) to read as follows:


Sec.  91.215  ATC transponder and altitude reporting equipment and use.

* * * * *
    (b) All airspace. Unless otherwise authorized or directed by ATC, 
and except as provided in paragraph (e)(1) of this section, no person 
may operate an aircraft in the airspace described in paragraphs (b)(1) 
through (5) of this section, unless that aircraft is equipped with an 
operable coded radar beacon transponder having either Mode A 4096 code 
capability, replying to Mode A interrogations with the code specified 
by ATC, or a Mode S capability, replying to Mode A interrogations with 
the code specified by ATC and Mode S interrogations in accordance with 
the applicable provisions specified in TSO-C112, and that aircraft is 
equipped with automatic pressure altitude reporting equipment having a 
Mode C capability that automatically replies to Mode C interrogations 
by transmitting pressure altitude information in 100-foot increments. 
The requirements of this paragraph (b) apply to--
* * * * *

0
5. Amend Sec.  91.225 by:
0
a. Revising paragraphs (a)(1), (b), and (e) introductory text.
0
b. Redesignating paragraphs (h) and (i) as set out in the following 
redesignation table.

------------------------------------------------------------------------
               Old paragraph                        New paragraph
------------------------------------------------------------------------
paragraph (h).............................  paragraph (i).
paragraph (i).............................  paragraph (h).
------------------------------------------------------------------------

0
c. Revising newly redesignated paragraphs (h)(1)(i) and (i).
    The revisions read as follows:


Sec.  91.225  Automatic Dependent Surveillance-Broadcast (ADS-B) Out 
equipment and use.

    (a) * * *

[[Page 71477]]

    (1) Meets the performance requirements in-
    (i) TSO-C166b and Section 2 of RTCA DO-260B (as referenced in TSO-
C166b); or
    (ii) TSO-C166c and Section 2 of RTCA DO-260C as modified by DO-
260C--Change 1 (as referenced in TSO-C166c); and
* * * * *
    (b) After January 1, 2020, except as prohibited in paragraph (h)(2) 
of this section or unless otherwise authorized by ATC, no person may 
operate an aircraft below 18,000 feet MSL and in airspace described in 
paragraph (d) of this section unless the aircraft has equipment 
installed that--
    (1) Meets the performance requirements in--
    (i) TSO-C166b and Section 2 of RTCA DO-260B (as referenced in TSO-
C166b);
    (ii) TSO-C166c and Section 2 of RTCA DO-260C as modified by DO-
260C--Change 1 (as referenced in TSO-C166c);
    (iii) TSO-C154c and Section 2 of RTCA DO-282B (as referenced in 
TSO-C154c); or
    (iv) TSO-C154d and Section 2 of RTCA DO-282C (as referenced in TSO-
C154d);
    (2) Meets the requirements of Sec.  91.227.
* * * * *
    (e) The requirements of paragraph (b) of this section do not apply 
to any aircraft that was not originally certificated with an engine-
driven electrical system, or that has not subsequently been certified 
with such a system installed, including balloons and gliders. These 
aircraft may conduct operations without ADS-B Out in the airspace 
specified in paragraph (d)(4) of this section. These aircraft may also 
conduct operations in the airspace specified in paragraph (d)(2) of 
this section if those operations are conducted--
* * * * *
    (h) * * *
    (1) * * *
    (i) That aircraft has equipment installed that meets the 
performance requirements in TSO-C166b (including Section 2 of RTCA DO-
260B, as referenced in TSO-C166b), TSO-C166c (including Section 2 of 
RTCA DO-260C as modified by DO-260C--Change 1, as referenced in TSO-
C166c), TSO-C154c (including Section 2 of RTCA DO-282B, as referenced 
in TSO-C154c), or TSO-C154d (including Section 2 of RTCA DO-282C, as 
referenced in TSO-C154d); and
* * * * *
    (i) The standards required in this section are incorporated by 
reference with the approval of the Director of the Office of the 
Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. This 
incorporation by reference (IBR) material is available for inspection 
at the FAA and the National Archives and Records Administration (NARA). 
Contact the FAA at: Office of Rulemaking (ARM-1), 800 Independence 
Avenue SW, Washington, DC 20590 (telephone 202-267-9677). For 
information on the availability of this material at NARA, visit https://www.archives.gov/federal-register/cfr/ibr-locations.html or email 
[email protected]. This material is also available from the 
following sources in this paragraph (i).
    (1) U.S. Department of Transportation, Subsequent Distribution 
Office, DOT Warehouse M30, Ardmore East Business Center, 3341 Q 75th 
Avenue, Landover, MD 20785; telephone (301) 322-5377; website: 
www.faa.gov/aircraft/air_cert/design_approvals/tso/ (select the link 
``Search Technical Standard Orders'').
    (i) TSO-C166b, Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service-Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz), 
December 2, 2009.
    (ii) TSO-C166c, Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service-Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz), 
March 10, 2023.
    (iii) TSO-C154c, Universal Access Transceiver (UAT) Automatic 
Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the 
Frequency of 978 MHz, December 2, 2009.
    (iv) TSO-C154d, Universal Access Transceiver (UAT) Automatic 
Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the 
Radio Frequency of 978 Megahertz (MHz), March 10, 2023.
    (2) RTCA, Inc., 1150 18th St. NW, Suite 910, Washington, DC 20036; 
telephone (202) 833-9339; website: www.rtca.org/products.
    (i) RTCA DO-260B, Minimum Operational Performance Standards for 
1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast 
(ADS-B) and Traffic Information Services-Broadcast (TIS-B), Section 2, 
Equipment Performance Requirements and Test Procedures, December 2, 
2009.
    (ii) RTCA DO-260C, Minimum Operational Performance Standards for 
1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast 
(ADS-B) and Traffic Information Services-Broadcast (TIS-B), Section 2, 
Equipment Performance Requirements and Test Procedures, December 17, 
2020.
    (iii) RTCA DO-260C, Minimum Operational Performance Standards for 
1090 MHz Extended Squitter Automatic Dependent Surveillance--Broadcast 
(ADS-B) and Traffic Information Services--Broadcast (TIS-B), Change 1, 
January 25, 2022.
    (iv) RTCA DO-282B, Minimum Operational Performance Standards for 
Universal Access Transceiver (UAT) Automatic Dependent Surveillance-
Broadcast (ADS-B), Section 2, Equipment Performance Requirements and 
Test Procedures, December 2, 2009.
    (v) RTCA DO-282C, Minimum Operational Performance Standards (MOPS) 
for Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B), Section 2, Equipment Performance 
Requirements and Test Procedures, June 23, 2022.

0
6. Amend Sec.  91.227 by:
0
a. In paragraph (a), revising definitions for ``Navigation Accuracy 
Category for Position (NACP)'', ``Navigation Accuracy 
Category for Velocity (NACV)'', ``Navigation Integrity 
Category (NIC)'', ``Source Integrity Level (SIL)'', and ``System Design 
Assurance (SDA)''; and
0
b. Revising paragraphs (b)(1), (b)(2)(i) and (ii), (c)(1)(iv) and (v), 
(d) introductory text, (d)(5) through (8), (11), and (13), and (g).
    The revisions read as follows:


Sec.  91.227  Automatic Dependent Surveillance-Broadcast (ADS-B) Out 
equipment performance requirements.

    (a) * * *
    Navigation Accuracy Category for Position (NACP) specifies the 
accuracy of a reported aircraft's position.
    Navigation Accuracy Category for Velocity (NACV) specifies the 
accuracy of a reported aircraft's velocity.
    Navigation Integrity Category (NIC) specifies an integrity 
containment radius around an aircraft's reported position.
* * * * *
    Source Integrity Level (SIL) indicates the probability of the 
reported horizontal position exceeding the containment radius defined 
by the NIC on a per sample or per hour basis.
    System Design Assurance (SDA) indicates the probability of an 
aircraft malfunction causing false or misleading information to be 
transmitted.
* * * * *
    (b) * * *
    (1) Aircraft operating in Class A airspace must have equipment 
installed

[[Page 71478]]

that meets the antenna and power output requirements of Class A1S, A1, 
A2, A3, B1S, or B1 equipment as defined in TSO-C166b and Section 2 of 
RTCA DO-260B (as referenced in TSO-C166b), or TSO-C166c and Section 2 
of RTCA DO-260C as modified by DO-260C--Change 1 (as referenced in TSO-
C166c).
    (2) * * *
    (i) Class A1S, A1, A2, A3, B1S, or B1 as defined in TSO-C166b and 
Section 2 of RTCA DO-260B (as referenced in TSO-C166b) or TSO-C166c and 
Section 2 of RTCA DO-260C as modified by DO-260C--Change 1 (as 
referenced in TSO-C166c); or
    (ii) Class A1S, A1H, A2, A3, B1S, or B1 equipment as defined in 
TSO-C154c and Section 2 of RTCA DO-282B (as referenced in TSO-C154c), 
or TSO-C154d and Section 2 of RTCA DO-282C (as referenced in TSO-
C154d).
    (c) * * *
    (1) * * *
    (iv) The aircraft's SDA must be less than or equal to 
10-5 per flight hour; and
    (v) The aircraft's SIL must be less than or equal to 
10-7 per flight hour or per sample.
* * * * *
    (d) Minimum Broadcast Message Element Set for ADS-B Out. Each 
aircraft must broadcast the following information, as defined in TSO-
C166b (including Section 2 of RTCA DO-260B, as referenced in TSO-
C166b), TSO-C166c (including Section 2 of RTCA DO-260C as modified by 
DO-260C--Change 1, as referenced in TSO-C166c), TSO-C154c (including 
Section 2 of RTCA DO-282B, as referenced in TSO-C154c), or TSO-C154d 
(including Section 2 of RTCA DO-282C, as referenced in TSO-C154d). The 
pilot must enter information for message elements listed in paragraphs 
(d)(7) through (10) of this section during the appropriate phase of 
flight.
* * * * *
    (5) An indication if a collision avoidance system is installed and 
operating in a mode that can generate resolution advisory alerts;
    (6) If an operable collision avoidance system is installed, an 
indication if a resolution advisory is in effect;
    (7) An indication of the Mode A transponder code specified by ATC;
    (8) An indication of the aircraft identification that is submitted 
on the flight plan or used for communicating with ATC, except when the 
pilot has not filed a flight plan, has not requested ATC services, and 
is using a TSO-C154c or TSO-C154d self-assigned temporary 24-bit 
address;
* * * * *
    (11) An indication of the aircraft assigned ICAO 24-bit address, 
except when the pilot has not filed a flight plan, has not requested 
ATC services, and is using a TSO-C154c or TSO-C154d self-assigned 
temporary 24-bit address;
* * * * *
    (13) An indication of whether an ADS-B In capability is available;
* * * * *
    (g) Incorporation by reference. The standards required in this 
section are incorporated by reference with the approval of the Director 
of the Office of the Federal Register under 5 U.S.C. 552(a) and 1 CFR 
part 51. This incorporation by reference (IBR) material is available 
for inspection at the FAA and the National Archives and Records 
Administration (NARA). Contact the FAA at: Office of Rulemaking (ARM-
1), 800 Independence Avenue SW, Washington, DC 20590 (telephone 202-
267-9677). For information on the availability of this material at 
NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or 
email [email protected]. This material is also available from the 
following sources indicated in this paragraph (g).
    (1) U.S. Department of Transportation, Subsequent Distribution 
Office, DOT Warehouse M30, Ardmore East Business Center, 3341 Q 75th 
Avenue, Landover, MD 20785; telephone (301) 322-5377; website: 
www.faa.gov/aircraft/air_cert/design_approvals/tso/ (select the link 
``Search Technical Standard Orders'').
    (i) TSO-C166b, Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service-Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz), 
December 2, 2009.
    (ii) TSO-C166c, Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service-Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz), 
March 10, 2023.
    (iii) TSO-C154c, Universal Access Transceiver (UAT) Automatic 
Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the 
Frequency of 978 MHz, December 2, 2009.
    (iv) TSO-C154d, Universal Access Transceiver (UAT) Automatic 
Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the 
Radio Frequency of 978 Megahertz (MHz), March 10, 2023.
    (2) RTCA, Inc., 1150 18th St. NW, Suite 910, Washington, DC 20036; 
telephone (202) 833-9339; website: www.rtca.org/products.
    (i) RTCA DO-260B, Minimum Operational Performance Standards for 
1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast 
(ADS-B) and Traffic Information Services-Broadcast (TIS-B), Section 2, 
Equipment Performance Requirements and Test Procedures, December 2, 
2009.
    (ii) RTCA DO-260C, Minimum Operational Performance Standards for 
1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast 
(ADS-B) and Traffic Information Services-Broadcast (TIS-B), Section 2, 
Equipment Performance Requirements and Test Procedures, December 17, 
2020.
    (iii) RTCA DO-260C, Minimum Operational Performance Standards for 
1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast 
(ADS-B) and Traffic Information Services-Broadcast (TIS-B), Change 1, 
January 25, 2022.
    (iv) RTCA DO-282B, Minimum Operational Performance Standards for 
Universal Access Transceiver (UAT) Automatic Dependent Surveillance-
Broadcast (ADS-B), Section 2, Equipment Performance Requirements and 
Test Procedures, December 2, 2009.
    (v) RTCA DO-282C, Minimum Operational Performance Standards (MOPS) 
for Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B), Section 2, Equipment Performance 
Requirements and Test Procedures, June 23, 2022.

    Issued under authority provided by 49 U.S.C. 106(f), 40103, and 
44701, in Washington, DC.
Polly E. Trottenberg,
Acting Administrator.
[FR Doc. 2023-22710 Filed 10-16-23; 8:45 am]
BILLING CODE 4910-13-P