[Federal Register Volume 81, Number 239 (Tuesday, December 13, 2016)]
[Rules and Regulations]
[Pages 90126-90177]
[FR Doc No: 2016-28714]

Vol. 81

Tuesday,

No. 239

December 13, 2016

Part IV

 Department of Transportation

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 Federal Aviation Administration

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 14 CFR Parts 1, 23, 25, et al.

 Revisions to Operational Requirements for the Use of Enhanced Flight
Vision Systems and to Pilot Compartment View Requirements for Vision
Systems; Final Rule

Federal Register / Vol. 81 , No. 239 / Tuesday, December 13, 2016 /
Rules and Regulations

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 1, 23, 25, 27, 29, 61, 91, 121, 125, and 135

[Docket No.: FAA-2013-0485; Amdt. Nos. 1-70, 23-63, 25-144, 27-48, 29-
56, 61-139, 91-345, 121-376, 125-66, and 135-135]
RIN 2120-AJ94

Revisions to Operational Requirements for the Use of Enhanced
Flight Vision Systems (EFVS) and to Pilot Compartment View Requirements
for Vision Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: Prior to this final rule, persons could only use an Enhanced
Flight Vision System (EFVS) in lieu of natural vision to descend below
the decision altitude, decision height, or minimum descent altitude
(DA/DH or MDA) down to 100 feet above the touchdown zone elevation
(TDZE) using certain straight-in landing instrument approach procedures
(IAPs). This final rule permits operators to use an EFVS in lieu of
natural vision to continue descending from 100 feet above the TDZE to
the runway and to land on certain straight-in IAPs under instrument
flight rules (IFR). This final rule also revises and relocates the
regulations that permit operators to use an EFVS in lieu of natural
vision to descend to 100 feet above the TDZE using certain straight-in
IAPs. Additionally, this final rule addresses provisions that permit
operators who conduct EFVS operations under parts 121, 125, or 135 to
use EFVS-equipped aircraft to dispatch, release, or takeoff under IFR,
and revises the regulations for those operators to initiate and
continue an approach, when the destination airport weather is below
authorized visibility minimums for the runway of intended landing. This
final rule establishes pilot training and recent flight experience
requirements for operators who use EFVS in lieu of natural vision to
descend below the DA/DH or MDA. EFVS-equipped aircraft conducting
operations to touchdown and rollout are required to meet additional
airworthiness requirements. This final rule also revises pilot
compartment view certification requirements for vision systems using a
transparent display surface located in the pilot's outside field of
view. The final rule takes advantage of advanced vision capabilities,
thereby achieving the Next Generation Air Transportation System
(NextGen) goals of increasing access, efficiency, and throughput at
many airports when low visibility is the limiting factor. Additionally,
it enables EFVS operations in reduced visibilities on a greater number
of approach procedure types while maintaining an equivalent level of
safety.

DATES: The final rule is effective March 13, 2017, except for the
amendments to Sec. Sec.  61.66 (amendatory instruction no. 15), 91.175
(amendatory instruction no. 18), 91.1039 (amendatory instruction no.
23), 121.651 (amendatory instruction no. 27), 125.325 (amendatory
instruction no. 33), 125.381 (amendatory instruction no. 35), and
135.225 (amendatory instruction no. 38), which are effective March 13,
2018.

ADDRESSES: For information on where to obtain copies of rulemaking
documents and other information related to this final rule, see ``How
to Obtain Additional Information'' in the SUPPLEMENTARY INFORMATION
section of this document.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning
this action, contact Terry King, Flight Technologies and Procedures
Division, AFS-400, Flight Standards Service, Federal Aviation
Administration, 800 Independence Avenue SW., Washington, DC 20591;
telephone<PHONE_NUMBER>; email<EMAIL_ADDRESS>
SUPPLEMENTARY 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 49
U.S.C. 40103, which vests the Administrator with broad authority to
prescribe regulations to ensure the safety of aircraft and the
efficient use of airspace, and 49 U.S.C. 44701(a)(5), which requires
the Administrator to promulgate regulations and minimum standards for
other practices, methods, and procedures necessary for safety in air
commerce and national security.

List of Abbreviations and Acronyms Frequently Used in This Document

AC--Advisory circular
ADS-B--Automatic Dependent Surveillance-Broadcast
AFM--Airplane flight manual
AFMS--Airplane flight manual supplement
AIM--Aeronautical Information Manual
ALPA--Airline Pilots Association
APV--Approach (procedure) with vertical guidance
ASR--Airport surveillance radar
ATC--Air Traffic Control
AWO--All weather operations
AWOH ARC--All Weather Operations Harmonization Aviation Rulemaking
Committee
CAA--Civil aviation authority
CVS--Combined Vision System
DA--Decision altitude
DH--Decision height
EASA--European Aviation Safety Agency
EFVS--Enhanced Flight Vision System
EVS--Enhanced Vision System
FAA--Federal Aviation Administration
FAF--Final approach fix
FFS--Full flight simulator
FPARC--Flight path angle reference cue
FPV--Flight path vector
FSB--Flight Standardization Board
GAMA--General Aviation Manufacturers Association
GPS--Global positioning system
HAI--Helicopter Association International
HGS--Head Up Guidance System
HMD--Head mounted display
HUD--Head up display
IAP--Instrument approach procedure
ICAO--International Civil Aviation Organization
ICAO HESC--International Civil Aviation Organization HUD, EVS, SVS,
and CVS Subgroup
IFR--Instrument flight rules
ILS--Instrument landing system
IMC--Instrument meteorological conditions
IR--Infrared
LED--Light emitting diode
LIDAR--Laser imaging detection and ranging
LOA--Letter of authorization
LODA--Letter of deviation authority
LPV--Localizer performance with vertical guidance
MASPS--Minimum aviation system performance standards
MDA--Minimum descent altitude
MSpec--Management specifications
NextGen--Next Generation Air Transportation System
NPRM--Notice of Proposed Rulemaking
NVG--Night vision goggle
OEM--Original equipment manufacturer
OpSpec--Operations specifications
PAR--Precision approach radar
PCG--Pilot/Controller Glossary
PIC--Pilot in Command
RNAV--Area navigation
RNP--Required navigation performance
RVR--Runway visual range
SNPRM--Supplemental Notice of Proposed Rulemaking
TERPS--Terminal instrument procedures
TDZE--Touchdown Zone Elevation
VFR--Visual flight rules
VNAV--Vertical navigation
WAAS--Wide area augmentation system

Table of Contents

I. Overview of Final Rule
II. Background
    A. Statement of the Problem
    B. Related Actions
    C. Summary of the NPRM

    D. General Overview of Comments
III. Discussion of Final Rule and Public Comments
    A. Revise the Definition for EFVS and Add a Definition for EFVS
Operation (Sec.  1.1)
    B. Consolidate EFVS Requirements in Part 91 in a New Section
(Sec.  91.176)
    C. Equipment, Operating, and Visibility and Visual Reference
Requirements for EFVS Operations to Touchdown and Rollout (Sec.
91.176(a))
    1. Equipment Requirements
    a. Real-Time Imaging Sensors
    b. Head Up Presentation Requirement for EFVS Operations
    c. EFVS Terminology
    d. EFVS Equipment Requirements for Foreign-Registered Aircraft
    e. Line of Vision and Conformal Display
    f. Flight Path Angle Reference Cue (FPARC)
    g. Requirement to Display Height Above Ground Level
    h. Requirement to Display Flare Prompt or Flare Guidance
    i. Pilot Monitoring Display
    j. Applicability of EFVS Provisions to Rotorcraft Operations
    k. Requirement to Obtain a Certificate of Waiver When Conducting
Certain EFVS Operations
    2. Operating Requirements
    a. Approaches Permitted for EFVS Operations
    b. Touchdown Zone
    c. Definition of ``EFVS Operation'' and Underlying Operational
Concepts
    d. Light Emitting Diodes (LEDs) and EFVS Operations
    e. LOA Requirement for Part 91 Operators To Conduct EFVS
Operations to Touchdown and Rollout
    f. International EFVS Operations
    g. EFVS Authorizations
    h. EFVS for Takeoff Operations
    i. Combined Vision Systems
    j. Use of the Term ``EFVS'' in Rule Language
    k. Approach Plates and EFVS Operations
    l. References to EFVS-Specific Callouts
    m. Miscellaneous Revisions to EFVS Operating Requirements
    n. Opposing Comments on the FAA's Proposal
    3. Visibility and Visual Reference Requirements
    a. Visual References Below 100 Feet Above the TDZE During EFVS
Operations to Touchdown and Rollout
    b. Enhanced Flight Visibility Requirement During EFVS Operations
to 100 Feet Above the TDZE
    c. Visual References for Rollout
    d. Controlling Runway Visual Range (RVR) Values
    e. Emitter Technologies as Alternative Visual Aids
    f. Use of EFVS To Satisfy the Visibility Requirements of
Sec. Sec.  91.155 and 91.157 During Rotorcraft Operations
    D. Revisions to Requirements for EFVS Operations to 100 Feet
Above the TDZE (Sec.  91.176(b))
    1. Methods for Conducting Approaches During EFVS Operations to
100 Feet Above the TDZE
    E. Training, Recent Flight Experience, and Refresher Training
Requirements for Persons Conducting EFVS Operations (Sec.  61.66)
    1. Training Requirements for Persons Conducting EFVS Operations
(Sec.  61.66(a), (b) and (c))
    a. Separate Training for EFVS Operations to 100 Feet Above the
TDZE and EFVS Operations to Touchdown and Rollout
    b. EFVS and Aircraft-Specific Training
    c. Adaptation Period Prior to Using an EFVS in Flight Operations
    d. Revisions To Clarify Training Requirements in Sec.  61.66(a),
(b) and (c)
    2. Recent Flight Experience and EFVS Refresher Training for
Persons Conducting EFVS Operations (Sec.  61.66(d) and (e))
    3. EFVS Recent Flight Experience
    4. Persons Authorized to Conduct EFVS Refresher Training
    5. Revisions to Sec.  61.57
    6. Military Pilots and Former Military Pilots in the U.S. Armed
Forces (Sec.  61.66(f))
    7. Use of Full Flight Simulators (Sec.  61.66(g))
    8. Exceptions (Sec.  61.66(h))
    a. Manipulating the Controls (Sec.  61.66(h)(1)(i), (ii), and
(iii)
    b. Exception to Ground and Flight Training (Sec.  61.66(h)(2))
    c. Exception to Recent Flight Experience Requirements (Sec.
61.66(h)(3))
    d. Grandfather Clause (Sec.  61.66(h)(4))
    F. Dispatching, Releasing, or Initiating a Flight Using EFVS-
Equipped Aircraft When the Reported or Forecast Visibility at the
Destination Airport is Below Authorized Minimums (Sec. Sec.
121.613, 125.361, 135.219) and Initiating or Continuing an Approach
Using EFVS-Equipped Aircraft When the Destination Airport Visibility
is Below Authorized Minimums (Sec. Sec.  121.651, 125.325, 125.381,
135.225)
    G. Revisions to Category II and III General Operating Rules to
Permit the Use of an EFVS (Sec.  91.189)
    H. Pilot Compartment View Rules and Airworthiness Standards for
Vision Systems With Transparent Displays Located in the Pilot's
Outside Field of View (Sec. Sec.  23.773, 25.773, 27.773, and
29.773)
    1. Vision Systems and Display Methods Addressed by Sec. Sec.
23.773, 25.773, 27.773, and 29.773
    2. Pilot's Outside View--Terminology and Compensation for
Interference
    3. Undistorted View Requirements
    4. Alignment of Vision System Cues and Head Mounted Display
(HMD) Considerations
    5. Requirement To Provide a Means of Immediate Deactivation and
Reactivation of Vision System Imagery
    6. Vision Systems and Requirements Applicable to Duties and
Maneuvers
    7. Issue Papers for HUD, EFVS, EVS, SVS and CVS Installations
    8. Head Up Display (HUD) Installation and Bird Strike
Requirements
    I. Related and Conforming Amendments (Sec. Sec.  91.175, 91.905,
and 135.225)
    J. Implementation
    K. Miscellaneous Issues
    1. Minimum Crew Requirements
    2. Failure Modes
    3. EFVS Equipment and Operational Considerations
    4. Applicability of Previously Collected Data or Data Submitted
on the Basis of Similarity
    5. Public Aircraft Operations
    6. Qualification Requirements for Persons Conducting EFVS
Operations in the United States
    7. Economic Comments
IV. Regulatory Notices and Analyses
    A. Regulatory Evaluation
    B. Regulatory Flexibility Determination
    C. International Trade Impact Assessment
    D. Unfunded Mandates Assessment
    E. Paperwork Reduction Act
    F. International Compatibility and Cooperation
    G. Environmental Analysis
    V. Executive Order Determinations
    A. Executive Order 13132. Federalism
    B. Executive Order 13211, Regulations That Significantly Affect
Energy Supply, Distribution, or Use
VI. How to Obtain Additional Information
    A. Rulemaking Documents
    B. Comments Submitted to the Docket
    C. Small Business Regulatory Enforcement Fairness Act

I. Overview of Final Rule

    This final rule modifies the requirements for EFVS operations. The
FAA is revising the definition of an EFVS in Sec.  1.1 to describe the
components of an EFVS and to specify that an EFVS is an ``installed
aircraft system'' rather than an ``installed airborne system'' because
some EFVS operations may be conducted on the surface as well as
airborne. The FAA is also adding a new term, ``EFVS operation,'' to
Sec.  1.1.
    The FAA is creating new Sec.  91.176, which contains the operating
rules for EFVS operations to touchdown and rollout and for EFVS
operations to 100 feet above the TDZE. The FAA is relocating to Sec.
91.176(b) the regulations for EFVS operations to 100 feet above the
TDZE, which were previously located in Sec.  91.175(l) and (m), and is
revising and restructuring these regulations. Prior to this final rule,
persons could only use EFVS in lieu of natural vision to descend below
DA/DH or MDA down to 100 feet above the TDZE using certain straight-in
landing IAPs. Section 91.176(a) now expands the existing operational
capability by permitting persons to use an EFVS in lieu of natural
vision to continue descending below 100 feet above the TDZE to landing
and rollout. Paragraphs (a) and (b) of Sec.  91.176 are organized into
three main areas--equipment requirements, operating requirements, and
visibility and visual reference requirements. The equipment,

operating, and visibility requirements in paragraph (a) for conducting
an EFVS operation to touchdown and rollout are different from the
requirements in paragraph (b) for conducting an EFVS operation to 100
feet above the TDZE. In addition, persons are permitted to use two new
visual references for descent below 100 feet above the TDZE for EFVS
operations conducted under both Sec.  91.176(a) and (b). The FAA is
also amending the operating rules for Category II and Category III
operations in Sec.  91.189 to permit the use of EFVS in lieu of natural
vision during the performance of those operations.
    This final rule also establishes training and recent flight
experience requirements for persons conducting EFVS operations.\1\ The
ground and flight training requirements in Sec.  61.66(a), (b) and (c)
apply to pilots conducting EFVS operations to 100 feet above the TDZE
as well as to pilots conducting EFVS operations to touchdown and
rollout. A pilot must comply with the training provisions of part 61 in
addition to the training provisions of the part under which the
operation is conducted, which may require additional ground and flight
training appropriate to the particular assignment of the pilot
flightcrew member. Recent flight experience and refresher training
requirements for persons conducting EFVS operations are located in
Sec.  61.66(d) and (e). Additionally, Sec.  61.66(f) contains the
requirements applicable to military and former military pilots in the
U.S. Armed Forces who wish to conduct EFVS operations under Sec.
91.176.
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    \1\ As further discussed in section III.E of this preamble, the
FAA has reorganized the training, recent flight experience, and
proficiency requirements that were proposed in Sec. Sec.  61.31 and
61.57 and consolidated them in new Sec.  61.66.
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    The FAA is revising Sec. Sec.  121.651, 125.325, 125.381, and
135.225 to permit operators of EFVS-equipped aircraft to initiate or
continue an approach when the destination airport visibility is below
authorized minimums. The FAA is also revising Sec.  91.1039(e) to
permit part 91 subpart K operators to conduct takeoff operations using
EFVS when the visibility is less than 600 feet in accordance with the
certificate holders' Management Specifications (MSpec) for EFVS
operations, and to clarify that an EFVS operation is permitted when the
landing weather minimums are less than those prescribed by the
authority having jurisdiction over the airport.
    Section 91.176(a)(2)(viii) through (xi) requires operators
conducting EFVS operations to touchdown and rollout under part 91, 121,
125 (including part 125 Letter of Deviation Authority (LODA) holders),
129, or 135 to obtain FAA authorization to conduct those operations.
Section 91.176(b)(2)(vii) through (ix) requires operators conducting
EFVS operations to 100 feet above the TDZE under part 91 subpart K,
121, 125 (including part 125 LODA holders), or 135 to obtain FAA
authorization to conduct those operations. Under Sec.  91.176(b)(2),
part 91 operators, other than those operating under part 91 subpart K,
are not required to obtain FAA authorization to conduct EFVS operations
to 100 feet above the TDZE.
    The FAA now revises the pilot compartment view rules contained in
Sec. Sec.  23.773, 25.773, 27.773, and 29.773 to establish
airworthiness standards for vision systems with a transparent display
surface located in the pilot's outside field of view, such as a head up
display, head mounted display, or other equivalent display. This final
rule eliminates the current need to issue special conditions for vision
system video on a head up display. The FAA notes that its Notice of
Proposed Rulemaking (NPRM), ``Revision of Airworthiness Standards for
Normal, Utility, Acrobatic, and Commuter Category Airplanes,'' 81 FR
13452 (Mar. 14, 2016), contains proposals that significantly
restructure part 23. Because the part 23 NPRM is pending, references to
part 23 in this final rule refer to existing part 23, and revisions to
the pilot compartment view rules contained in Sec. Sec.  23.773,
25.773, 27.773, and 29.773 include the general requirements that were
previously contained in special conditions. Revising Sec.  23.773
establishes a requirement that could later be used as a means of
compliance if the proposed part 23 rule becomes final.
    This final rule also makes related and conforming amendments to
Sec. Sec.  91.175, 91.905 and 135.225. The FAA is updating regulatory
cross references and terms in Sec.  91.175 to coincide with this final
rule and with another FAA final rule, which was published after the
NPRM.\2\ The FAA is amending Sec.  91.905 to include Sec.  91.176 as a
regulation subject to waiver. Additionally, the FAA is revising Sec.
135.225 to correct a drafting error that arose from another final rule,
``Enhanced Flight Vision Systems,'' 69 FR 1620 (Jan. 9, 2004), and
later identified in an FAA legal interpretation dated September 20,
2013.\3\
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    \2\ Qualification, Service, and Use of Crewmembers and Aircraft
Dispatchers, 78 FR 67800 (Nov. 12, 2013).
    \3\ Legal Interpretation, Letter to Mr. Phillip Kelsey from Mark
W. Bury, Acting Assistant Chief Counsel for Regulations (September
20, 2013).
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II. Background

A. Statement of the Problem

    The FAA created regulations in 2004, Sec.  91.175(l) and (m), which
permitted persons to use an EFVS in lieu of natural vision to descend
an aircraft below DA/DH or MDA down to 100 feet above the TDZE. These
regulations, however, did not provide operators with the ability to
fully utilize the benefits of EFVS technology. The FAA believes it can
better leverage EFVS capabilities by issuing performance-based
requirements for current and future enhanced flight vision systems,
which should increase access, efficiency, and throughput at many
airports when low visibility is a factor.
    Under the 2004 EFVS regulations, the pilot of an aircraft operating
under part 121, 125, or 135 could not begin an approach or continue an
approach past the final approach fix (FAF), or, where a FAF was not
used, begin the final approach segment of an instrument approach
procedure, when the weather at the destination airport was reported to
be below authorized minimums. These restrictions prevented persons
conducting operations under parts 121, 125, or 135 from using EFVS for
maximum operational benefit.
    Under Sec.  91.175(l), persons could use the enhanced flight
visibility provided by an EFVS for operational benefit only in that
portion of the visual segment of an approach that extended from DA/DH
or MDA down to 100 feet above the TDZE. While that provided significant
benefits, the requirement to transition to natural vision at 100 feet
above the TDZE prevented operators from realizing the benefits of
permitting EFVS operations to touchdown and rollout.
    Furthermore, the 2004 EFVS regulations did not specify any
training, recent flight experience, or proficiency requirements in part
61 for persons conducting EFVS operations. Since the 2004 final rule
was enacted, the number of EFVS operations has significantly increased.
The FAA believes this final rule will further increase the number of
operators conducting EFVS operations to lower altitudes in low
visibility conditions. Therefore, training, recent flight experience,
and refresher training requirements in part 61 are needed to ensure an
appropriate level of safety is maintained.
    Additionally, the 2004 EFVS regulations did not permit persons to
use EFVS for operational benefit during Category II and Category III
operations. The FAA believes an EFVS can provide operational and safety
benefits during Category II and Category III operations,

especially as more advanced imaging sensor capabilities are developed,
which function more effectively in lower visibility conditions.
    Finally, prior to this final rule, there were no airworthiness
standards that specifically addressed vision systems, such as EFVS.
Accordingly, the FAA used special conditions to certificate aircraft
with vision systems, which imposed significant delays on the
certification process.

B. Related Actions

    The FAA revised Advisory Circular (AC) 90-106, Enhanced Flight
Vision Systems, and AC 20-167, Airworthiness Approval of Enhanced
Vision System, Synthetic Vision System, Combined Vision System, and
Enhanced Flight Vision System Equipment to incorporate the provisions
of this final rule. AC 90-106A contains guidance for the operational
approval of EFVS, and AC 20-167A specifies a means of compliance that
may be used to obtain airworthiness approval for EFVS.

C. Summary of the NPRM

    On June 11, 2013, the FAA published an NPRM titled ``Revisions to
Operational Requirements for the Use of Enhanced Flight Vision Systems
(EFVS) and to Pilot Compartment View Requirements for Vision Systems,''
78 FR 34935. The comment period was initially scheduled to close on
September 9, 2013. Dassault Aviation submitted a request to extend the
NPRM comment period to October 15, 2013, stating that it needed
additional time to evaluate and prepare comments for the NPRM, draft AC
90-106A, and draft AC 20-167A, all of which are directly related. On
September 6, 2013, the FAA published a notice in the Federal Register
extending the NPRM comment period to October 15, 2013, to coincide with
the close of comment period for draft AC 90-106A and draft AC 20-167A.
``Revisions to Operational Requirements for the Use of Enhanced Flight
Vision Systems (EFVS) and to Pilot Compartment View Requirements for
Vision Systems; Extension of Comment Period,'' 78 FR 54790.
    The regulatory evaluation associated with the NPRM was not posted
to the docket prior to the close of the comment period. Therefore, to
ensure that the public had the opportunity to provide comments
specifically on the regulatory evaluation posted in the docket, the FAA
published a notice in the Federal Register on August 20, 2015,
reopening the comment period for 30 days to allow for comments on the
regulatory evaluation only. ``Revisions to Operational Requirements for
the Use of Enhanced Flight Vision Systems (EFVS) and to Pilot
Compartment View Requirements for Vision Systems; Reopening of Comment
Period,'' 80 FR 50587.
    In the NPRM, the FAA proposed to--
     More fully define the components of an EFVS and provide a
definition of the term ``EFVS operation'' in Sec.  1.1.
     Establish airworthiness standards for vision systems with
a transparent display surface located in the pilot's outside field of
view in Sec. Sec.  23.773, 25.773, 27.773, and 29.773.
     Require training and an endorsement for EFVS operations in
Sec.  61.31(l).
     Require recent flight experience or a proficiency check
for a person conducting an EFVS operation or acting as pilot in command
(PIC) during an EFVS operation in Sec.  61.57(i).
     Re-designate Sec.  91.175(l) and (m) as Sec.  91.176(b).
The FAA proposed to place all EFVS regulations contained in part 91,
except those pertaining to Category II and Category III operations, in
a single new section for organizational and regulatory clarity.
     Permit EFVS to be used in lieu of natural vision to
continue descending below 100 feet above the touchdown zone provided
certain equipment, operating, visibility, and visual reference
requirements were met.
     Permit an EFVS to be used to identify the visual
references required to continue an approach below the authorized DA/DH
on Category II and Category III approaches conducted under Sec.  91.189
that provide and require the use of a DA/DH.
     Add Sec.  91.176 to the list of rules subject to waiver in
Sec.  91.905.
     Amend Sec. Sec.  121.613 and 121.615 to permit an EFVS-
equipped aircraft to be dispatched or released when the visibility was
forecast or reported to be below authorized minimums for a destination
airport.
     Permit a pilot conducting an EFVS operation in accordance
with Sec.  121.651 to continue an approach past the FAF, or begin the
final approach segment of an instrument approach procedure, when the
weather was reported to be below authorized visibility minimums.
Proposed Sec.  121.651 also would have permitted EFVS-equipped part 121
operators to conduct EFVS operations in accordance with Sec.  91.176
and their operations specifications issued for EFVS operations.
     Permit flight release under Sec. Sec.  125.361 and 125.363
for EFVS-equipped aircraft when weather reports or forecasts indicated
that arrival weather conditions at the destination airport would be
below authorized minimums.
     Permit the pilot of an EFVS-equipped aircraft to execute
an instrument approach procedure when the weather is reported below
authorized visibility minimums under Sec. Sec.  125.325 and 125.381.
Proposed Sec.  125.381 also would have permitted EFVS-equipped part 125
operators to conduct EFVS operations in accordance with Sec.  91.176
and their operations specifications.
     Permit flights in EFVS-equipped aircraft to be initiated
under Sec.  135.219 when weather reports or forecasts indicated that
arrival weather conditions at the destination airport would be below
authorized minimums.
     Permit the pilot of an EFVS-equipped aircraft to initiate
an instrument approach procedure under Sec.  135.225 when the reported
visibility was below the authorized visibility minimums for the
approach. Proposed Sec.  135.225 also would have permitted EFVS-
equipped part 135 operators to conduct EFVS operations in accordance
with Sec.  91.176 and their operations specifications issued for EFVS
operations.
     Make additional related and conforming amendments.
    In the NPRM, the FAA proposed performance-based requirements not
limited to a specific sensor technology. The FAA intended to
accommodate future developments in real-time sensor technologies and
maximize the benefits of advanced flight deck systems. The final rule
is consistent with the agency's Next Generation Air Transportation
System (NextGen) goals of increasing access and throughput during low
visibility operations.
    The operating requirements of the proposal only addressed enhanced
flight vision systems that utilize a real-time image of the external
scene topography. The proposed operating requirements did not address
synthetic vision, which uses a computer-generated image of the external
scene topography from the perspective of the flight deck, derived from
aircraft attitude, a high precision navigation solution, and a database
of terrain, obstacles and relevant cultural features. The airworthiness
standards proposed in Sec. Sec.  23.773, 25.773, 27.773, and 29.773,
however, addressed synthetic vision systems (SVS) with a transparent
display surface located in the pilot's outside field of view because
the airworthiness standards apply to more than enhanced flight vision
systems; they apply to all transparent display surfaces located in the
pilot's outside field of view.

    Finally, the NPRM did not address the use of EFVS for takeoff
because the FAA can authorize these operations through existing
processes. Section 91.175(f) already provides a means for persons
conducting operations under parts 121, 125, 129, or 135 to obtain
authorization for lower than standard takeoff minimums, which could
include the use of EFVS. Additionally, the regulations do not prescribe
civil airport takeoff minimums for part 91 operators (other than part
91subpart K operators) as discussed in section III.C.2.h of this
preamble.

D. General Overview of Comments

    The FAA received comments from 34 commenters. The commenters
consisted of 16 original equipment manufacturers (OEMs), five industry
associations, several operators, an aircraft management service, an
aerospace consulting company, a standards organization, and several
individuals. All but one commenter generally supported the proposed
changes. Three commenters supported the proposal with no changes, and
the remaining 30 commenters generally supported the proposal with 171
comments containing questions, concerns, and suggested changes.
    A number of commenters stated that they support the FAA's intent to
better leverage EFVS capabilities by providing a performance-based
regulation for existing and evolving EFVS technology. One commenter
stated that future improvements in EFVS sensor technologies may enable
additional performance-based operations under the FAA's proposal, and
others commented that they believe EFVS technology has tremendous
potential for increasing safety and enhancing airspace utilization
within the NAS while creating economic benefits to the public. Several
industry associations said they strongly support the FAA creating and
supporting a flexible regulatory structure that encourages innovation
and improves operational efficiencies. Several OEMs specifically
supported the FAA's proposal to eliminate the need to issue special
conditions by revising the pilot compartment view certification
requirements in the airworthiness standards of parts 23, 25, 27, and
29.
    Specific changes recommended by the commenters as well as the
concerns expressed by one individual who opposed the FAA's proposal are
discussed in detail in ``Section III. Discussion of Final Rule and
Public Comments.''

III. Discussion of Final Rule and Public Comments

A. Revise the Definition for EFVS and Add a Definition for EFVS
Operation (Sec.  1.1)

    Section 1.1 defines enhanced flight vision system (EFVS) to mean
``an installed aircraft system which uses an electronic means to
provide a display of the forward external scene topography (the natural
or manmade features of a place or region especially in a way to show
their relative positions and elevation) through the use of imaging
sensors, such as forward-looking infrared, millimeter wave radiometry,
millimeter wave radar, or low-light level image intensification. An
EFVS includes the display element, sensors, computers and power
supplies, indications, and controls.'' This definition differs from
what was proposed in the NPRM, because the FAA is not including the
equipment requirements in the definition, which proposed ``The EFVS
sensor imagery and required aircraft flight information and flight
symbology are displayed on a head up display, or an equivalent display,
so that they are clearly visible to the pilot flying in his or her
normal position with the line of vision looking forward along the
flight path.'' The proposed definition would have inappropriately
embedded requirements.
    The definition of EFVS also differs from what was proposed in the
NPRM because the FAA is not using the word ``applicable'' to describe
the natural or manmade features that an EFVS may display. Upon further
reflection, the FAA has decided that the word ``applicable'' could
generate confusion because an EFVS cannot differentiate between
applicable and non-applicable items. An EFVS simply senses and displays
items. The FAA is, however, adopting the proposed relocation to Sec.
1.1 of the descriptive material from Sec.  91.175(m)(3).
    Garmin International suggested that the FAA revise the definition
of EFVS by replacing ``EFVS sensor imagery'' with ``EFVS image'' or
``EFVS sensor imagery and aircraft flight symbology.'' In other words,
Garmin was concerned that the term ``sensor imagery,'' as used in the
definition, might be misinterpreted to mean only the image from the
imaging sensor without encompassing the remaining EFVS elements. Garmin
also believed its suggested revision would make the proposed definition
in Sec.  1.1 more consistent with proposed Sec. Sec.
91.176(a)(1)(i)(B), 91.176(a)(1)(i)(E), and 91.176(a)(1)(ii).
    The FAA is not adopting the proposed equipment requirements in the
definition of EFVS, because Sec.  91.176(a)(1)(i)(B) already contains
these requirements.\4\ This decision is not intended to be a
substantive change as the FAA is relying on the equipment requirements
in Sec.  91.176(a)(1)(i)(B) to replace the requirements it had proposed
in the definition of EFVS. Definitions only describe what something is,
not what it must do. Accordingly, definitions should not contain
substantive regulatory provisions, such as regulatory requirements. If
the FAA were to adopt requirements in the definition of EFVS, the FAA
would not be able to grant an exemption from those requirements in the
future because the FAA's regulations describe an exemption as a request
for relief from the requirements of a regulation.\5\ Nor would the FAA
be able to grant a waiver from those requirements, if they were in the
definition, because Sec.  91.903 permits the FAA to grant a waiver from
any rule listed in Sec.  91.905 and a definition is not a rule.
Therefore, Sec.  1.1 defines the EFVS to which Sec.  91.176 applies and
Sec.  91.176 contains the regulatory requirements.
---------------------------------------------------------------------------

    \4\ Section 91.176(a)(1)(i)(B) requires an EFVS to present EFVS
sensor imagery, aircraft flight information, and flight symbology on
a head up display, or an equivalent display, so that they are
clearly visible to the pilot flying in his or her normal position
with the line of vision looking forward along the flight path.
    \5\ 14 CFR 11.15
---------------------------------------------------------------------------

    This change obviates addressing Garmin's concern because the
definition no longer contains the terminology Garmin sought to revise.
However, as a result of Garmin's comment, the FAA discovered that Sec.
91.176(a) and (b), as proposed, did not contain specific references to
``aircraft flight information,'' as had been proposed in the definition
of EFVS in Sec.  1.1. Accordingly, the FAA is revising paragraphs (a)
and (b) of Sec.  91.176 to include ``aircraft flight information''
where appropriate.
    Section 1.1 defines an ``EFVS operation'' as an operation in which
visibility conditions require an EFVS to be used in lieu of natural
vision to perform an approach or landing, determine enhanced flight
visibility, identify required visual references, or conduct the
rollout. This definition differs slightly from the NPRM, where the FAA
proposed to define ``EFVS operation'' as an operation in which an EFVS
is required to be used to perform such tasks. This change clarifies
that not all operations in which a pilot uses an EFVS constitute an
EFVS operation under the definition. Rather, an EFVS

operation is an operation that a pilot would not be permitted to
perform without the use of an EFVS. For example, a person may not
descend below the DA/DH using natural vision if the flight visibility
using natural vision is less than what is required by the instrument
approach procedure being flown. That person may, however, use an EFVS
in lieu of natural vision to descend below the DA/DH if the enhanced
flight visibility is not less than what is required by the instrument
approach procedure.
    Boeing commented that the FAA stated in the preamble that while an
EFVS can provide situation awareness in any phase of flight, such use
would not constitute an EFVS operation unless an EFVS was required in
lieu of natural vision to perform any visual task associated with
approach, landing, and rollout. Boeing recommended that the FAA
consider not just approach, landing, and rollout as part of an EFVS
operation but approach, landing, and/or rollout to clarify that EFVS
might be used for one segment of the terminal operation, but not other
segments.
    The FAA agrees but Boeing's concern is addressed in the definition
of ``EFVS operation'' in Sec.  1.1.

B. Consolidate EFVS Requirements in Part 91 in a New Section (Sec.
91.176)

    The FAA created a new section, Sec.  91.176, for the EFVS
regulations to ensure organizational and regulatory clarity. As the FAA
originally proposed in the NPRM, Sec.  91.176(a) contains the
requirements for EFVS operations to touchdown and rollout, and Sec.
91.176(b) contains the requirements, which were previously located in
Sec.  91.175(l) and (m), for EFVS operations to 100 feet above the
TDZE. Boeing recommended that the FAA move the regulations for EFVS
operations to 100 feet above the TDZE from Sec.  91.176(b) to Sec.
91.176(a), and move the regulations for EFVS operations to touchdown
and rollout from Sec.  91.176(a) to Sec.  91.176(b). Boeing believed
this format would facilitate reading and understanding the changes,
because the existing EFVS rules, which were previously located in Sec.
91.175(l) and (m), would be placed first.
    The FAA disagrees with Boeing and is retaining the format as
originally proposed. The FAA placed the new rules for EFVS operations
to touchdown and rollout in Sec.  91.176(a) because it believes that
operators will eventually conduct the majority of EFVS operations to
touchdown and rollout. Placing these regulations in Sec.  91.176(a)
facilitates quick reference. The FAA placed the rules for EFVS
operations to 100 feet above the TDZE, which were previously located in
Sec.  91.175(l) and (m), in Sec.  91.176(b) because it expects
operators will use these rules less frequently in the future.
Furthermore, the regulations for EFVS operations to touchdown and
rollout are more extensive than the regulations for EFVS operations to
100 feet above the TDZE. By placing the more extensive rules in Sec.
91.176(a), the FAA is able to cross reference the equipment
requirements of Sec.  91.176(a)(1)(i)(A)-(a)(1)(i)(F) in Sec.
91.176(b)(1)(ii), thereby eliminating significant redundancy.

C. Equipment, Operating, and Visibility and Visual Reference
Requirements for EFVS Operations to Touchdown and Rollout (Sec.
91.176(a))

1. Equipment Requirements
a. Real-Time Imaging Sensors
    Section 91.176(a)(1)(i)(A) requires, as originally proposed in the
NPRM, that an EFVS have an electronic means to provide a display of the
forward external scene topography, which consists of the applicable
natural or manmade features of a place or region, especially in a way
to show their relative positions and elevation, through the use of
imaging sensors, such as forward-looking infrared, millimeter wave
radiometry, millimeter wave radar, or low-light level image
intensification. Airbus and Thales commented on the list of imaging
sensors. Airbus suggested that the FAA use an ellipsis at the end of
the list to emphasize that it is not exhaustive, and Thales proposed
that the FAA add laser imaging detection and ranging (LIDAR) to the
list.
    The FAA finds that the use of the term ``such as'' after the
reference to imaging sensors indicates the list of examples is non-
exhaustive. However, based on the concerns raised by the commenters,
the FAA has revised the definition to clarify that imaging sensors
includes but is not limited to the list of examples in Sec. Sec.  1.1
and 91.176(a)(1)(i)(A).
b. Head Up Presentation Requirement for EFVS Operations
    As originally proposed, Sec.  91.176(a)(1)(i)(B) requires that an
EFVS present the sensor imagery, aircraft flight information, and
flight symbology on a head up display, or an equivalent display, so
that the imagery, information and symbology are clearly visible to the
pilot flying in his or her normal position with the line of vision
looking forward along the flight path.\6\ This requirement applies to
both EFVS operations to touchdown and rollout and EFVS operations to
100 feet above the TDZE.\7\
---------------------------------------------------------------------------

    \6\ Section 91.175(m) previously contained this requirement.
    \7\ Section 91.176(b)(1)(ii) requires the EFVS to meet the
requirements of Sec.  91.176(a)(1)(i) with the exception of the
flare prompt, flare guidance, and height above ground level
requirements.
---------------------------------------------------------------------------

    Several commenters expressed concerns about the requirement to
present sensor imagery, aircraft flight information, and flight
symbology on a head up display (HUD). Honeywell commented that the FAA
is unnecessarily restricting the goals of increased access, efficiency,
and throughput in low visibility conditions by this requirement.
Honeywell agreed that there is value in requiring EFVS information to
be displayed on a HUD for EFVS operations to touchdown and rollout but
believes EFVS operations to 100 feet above the TDZE should allow for
head down presentations.\8\ FedEx Express, Gulfstream Aerospace
Corporation (Gulfstream), Honeywell, and General Aviation Manufacturers
Association (GAMA) commented that the FAA should not limit an
equivalent display to a head up presentation. Instead, it should
consider all vision systems containing the required sensor imagery and
flight symbology that meet an acceptable level of performance and
safety for the intended operation. One commenter suggested that an
acceptable location for an EFVS display, or an equivalent display, was
in the normal line-of-sight established at 15 degrees below the
horizontal plane, +/-15 degrees for the vertical field-of-view, or +40
degrees up and -20 degrees down as a maximum deviation.
---------------------------------------------------------------------------

    \8\ Honeywell asserted that Sec.  91.176(a) and (b) describe two
different operations that do not necessarily require the same
equipment. Honeywell explained that operators may currently perform
Category II ILS approaches down to 100 feet above the TDZE using
head down primary displays. Honeywell's comments are out of scope as
the FAA did not propose to change the existing head-up display, or
equivalent display, requirements. Furthermore, the FAA notes that
EFVS operations to 100 feet above the TDZE and Category II ILS
approaches down to 100 feet above the TDZE are two distinct
operations.
---------------------------------------------------------------------------

    Commenters were also concerned that the head up presentation
requirement might have limiting effects on future technology. Honeywell
contended that the FAA's HUD requirement for EFVS does not allow for
new technologies and new ways of presenting information that could be
developed in the future. It also believed that alternative means for
displaying the sensor imagery and flight information have already been
shown to satisfy the necessary performance criteria. Additionally,
several commenters stated that the FAA is unnecessarily limiting future
aircraft or

systems that may be capable of meeting performance-based criteria
appropriate for EFVS operations, such as vision systems that use head
down displays, high-speed aircraft that have reduced or limited front
window designs, or unmanned aerial systems (UASs). GAMA recommended
that the FAA create a performance-based framework rather than making
EFVS dependent only on HUD technology. It believes this would not only
permit different technology solutions but would allow manufacturers to
design an EFVS that enables operations to different performance minima.
    The FAA is not adopting these recommendations because they are
outside the scope of this rulemaking. The FAA did not propose to change
the existing head-up display, or equivalent display, requirements under
Sec.  91.175(m).\9\ Rather, the FAA proposed to expand EFVS operations
to touchdown and rollout using the existing operational construct in
Sec.  91.175(l) and (m). More specifically, the FAA proposed to apply
all the equipment requirements of the EFVS regulations found in Sec.
91.175(m), including the head-up presentation requirement, to EFVS
operations conducted to touchdown and rollout. As a result, others have
not had an opportunity to comment on the use of HDDs to conduct EFVS
operations. While the FAA is not issuing an SNPRM at this time to
propose the use of HDDs under Sec.  91.176, the FAA notes that it may
grant waivers to OEMs from the applicable sections of Sec.  91.176 to
enable OEMs to use HDDs during EFVS operations for the purpose of
research and development. After the FAA has had sufficient time to
gather information and analyze the safety of HDDs used to conduct EFVS
operations in the national airspace system, the FAA may contemplate
future rulemaking.
---------------------------------------------------------------------------

    \9\ The FAA notes that commenters raised these issues in 2004.
The FAA disagreed that it should permit the presentation of EFVS
information on head down displays, and noted that EFVS information
must be presented on a head up display, or an equivalent display, so
that the imagery, aircraft flight information, and flight symbology
are clearly visible to the pilot flying in his or her normal
position with the line of vision looking forward along the flight
path. Please see the previous disposition of comments in ``Enhanced
Flight Vision Systems,'' 69 FR 1620 (Jan. 9, 2004).
---------------------------------------------------------------------------

c. EFVS Terminology
    A couple of commenters sought clarification and alignment of the
EFVS terminology used in Sec.  91.176.
    Under Sec.  91.176(a)(1)(i), a U.S.-registered aircraft must have
an operable EFVS that meets the applicable airworthiness
requirements.\10\ The terminology in this requirement differs slightly
from the NPRM, which would have required an operable EFVS that had an
FAA type design approval certified for EFVS operations. Dassault
Aviation requested that the FAA clarify the terms ``approved EFVS,''
``certified EFVS,'' and ``EFVS-equipped operator.'' The FAA finds it
unnecessary to clarify the terms ``approved EFVS'' and ``EFVS-equipped
operator'' because it did not specifically use these terms in the
proposed regulations. Nor is the FAA using these terms in this final
rule. The FAA also finds it unnecessary to clarify the term ``certified
EFVS'' because it has deleted the word ``certified'' from proposed
Sec.  91.176(a)(1)(i), (a)(3)(i), and (b)(3)(i). Instead, the FAA is
using the phrase ``meets the applicable airworthiness requirements.''
\11\
---------------------------------------------------------------------------

    \10\ See AC No. 20-167A, Airworthiness Approval of Enhanced
Vision System, Synthetic Vision System, Combined Vision System, and
Enhanced Flight Vision System Equipment (providing guidance for
obtaining airworthiness approval for enhanced and synthetic vision
systems in aircraft).
    \11\ The disposition of Thales' comment in the next section of
the preamble explains why the FAA is using the phrase ``meets the
applicable airworthiness requirements.''
---------------------------------------------------------------------------

d. EFVS Equipment Requirements for Foreign-Registered Aircraft
    Under Sec.  91.176(a)(1)(i) and (b)(1)(i), an aircraft must be
equipped with an operable EFVS that meets the applicable airworthiness
requirements. The requirements in paragraphs (a)(1)(i) and (b)(1)(i)
differ from the NPRM based on a comment from Thales and the ICAO
standards that were adopted after the NPRM was published. Additionally,
the NPRM proposed Sec.  91.176(b)(1)(i) as Sec.  91.176(b)(1)(iii).\12\
---------------------------------------------------------------------------

    \12\ The FAA restructured the requirements in proposed Sec.
91.176(b)(1)(i)-(iii) to be more consistent with Sec.
91.176(a)(1)(i) for organizational clarity.
---------------------------------------------------------------------------

    Thales commented that an EFVS-equipped foreign-registered aircraft
that does not have an FAA type design approval, but has been certified
by its own Civil Aviation Authority (CAA) to operate with an EFVS,
should not have to demonstrate compliance to the FAA regulations.
Thales stated that this requirement is not always feasible as a foreign
CAA may not be able to correctly interpret the FAA regulations. In
addition, it stated that this requirement is not consistent with
International Civil Aviation Organization (ICAO) standards without
citing the specific standards at issue.\13\ Thales asserted that a
foreign operator operating in the United States should only have to
demonstrate that it has been authorized to operate the EFVS in
accordance with the rules of its own CAA and that the FAA should
recognize them as being compliant with FAA rules without requesting a
specific compliance demonstration.
---------------------------------------------------------------------------

    \13\ The FAA believes that Thales is referring to ICAO Annex 6,
Part I, 6.23.2 and ICAO Annex 6, Part II, <IP_ADDRESS>, which are
discussed in the following paragraph. The FAA notes that ICAO
adopted these standards after the NPRM was published on June 11,
2013.
---------------------------------------------------------------------------

    The FAA agrees that it should not require an EFVS-equipped foreign-
registered aircraft to have an EFVS that meets the FAA's certification
requirements if that EFVS has been certified by the foreign-registered
aircraft's own CAA in accordance with ICAO Annex 6. ICAO Annex 6
defines an enhanced vision system (EVS) as a ``system to display
electronic real-time images of the external scene achieved through the
use of image sensors.'' ICAO's definition of EVS encompasses the FAA's
definition of EFVS. Accordingly, the ICAO Annex 6 standards on EVS
apply to EFVS.
    Annex 6, Part I, Standard 6.23.2 requires the State of the
Operator, in approving the operational use of EVS, to ensure that the
equipment meets the appropriate airworthiness certification
requirements. Annex 6, Part II, Standard <IP_ADDRESS> requires the State of
Registry, in approving the operational use of EVS, to ensure that the
equipment meets the appropriate airworthiness certification
requirements.\14\ Based on the FAA's interpretation of these standards,
if an EFVS-equipped foreign-registered aircraft has an EFVS that has
been approved by the State of the Operator or the State of Registry to
meet the CAA's airworthiness certification requirements, the FAA cannot
subsequently require that foreign-registered aircraft's EFVS to meet
U.S. certification requirements.\15\
---------------------------------------------------------------------------

    \14\ ICAO adopted Annex 6, Part I, Standard 6.23.2 and Annex 6,
Part II, Standard <IP_ADDRESS> after the FAA issued the NPRM on June 11,
2013,
    \15\ The FAA could have required this prior to the adoption of
Annex 6, Part I, Standard 6.23.2 and Annex 6, Part II, Standard
<IP_ADDRESS>, which explains why Sec.  91.175(l)(7) previously required
a foreign-registered aircraft to have an EFVS that complies with all
of the EFVS requirements of 14 CFR and why the FAA proposed to
retain the requirement in the NPRM.
---------------------------------------------------------------------------

    Accordingly, paragraphs (a)(1)(i) and (b)(1)(i) now require an
aircraft to be equipped with an operable EFVS that meets the applicable
airworthiness requirements. By using the phrase ``meets the applicable
airworthiness requirements,'' the requirement applies to both U.S.-
registered aircraft and foreign-registered aircraft. The U.S.-
registered aircraft must be equipped with an EFVS that has demonstrated

compliance with the applicable airworthiness requirements by issuance
of a design approval through the type certification process (i.e., type
certificate, amended type certificate, or supplemental type
certificate).\16\ The foreign-registered aircraft must be equipped with
an EFVS that has been approved by either the State of the Operator or
the State of Registry to meet the appropriate airworthiness
certification requirements in accordance with ICAO Annex 6.
---------------------------------------------------------------------------

    \16\ Section 91.175(l)(7) previously required an EFVS to have an
FAA type design approval.
---------------------------------------------------------------------------

    While a foreign-registered aircraft with an EFVS certified to a
foreign airworthiness standard may operate within the United States
without obtaining an FAA type design approval and without meeting the
FAA's certification requirements, that EFVS-equipped foreign-registered
aircraft must meet all of the requirements in Sec.  91.176, including
the equipment requirements, in order to be used in EFVS operations in
the United States. This requirement is consistent with ICAO standards.
Article 11 of the Convention on International Civil Aviation requires
aircraft subject to its provisions and operating within the territory
of a contracting State to comply with the applicable laws and
regulations enacted by that State. ICAO Annex 6, Part I, Chapter 3
states that an operator shall meet and maintain the requirements of the
States in which the operations are conducted and that an operator shall
ensure that all pilots are familiar with the laws, regulations and
procedures pertinent to the performance of their duties prescribed for
the areas to be traversed.\17\ Similarly, ICAO Annex 6, Part II,
Chapter 2.1 requires the PIC to comply with the laws, regulations, and
procedures of those States in which operations are conducted and to be
familiar with the laws, regulations, and procedures pertinent to the
performance of his or her duties prescribed for the areas to be
traversed.\18\ ICAO Annex 2, Standard 2.1.1 states that the rules of
the air apply to aircraft of a contracting State to the extent they do
not conflict with the rules published by the State having jurisdiction
over the territory flown. The FAA also notes that certain foreign
authorities have imposed requirements on operators of U.S.-registered
aircraft in their airspace that are in addition to those established by
the FAA to permit the conduct of EFVS operations.
---------------------------------------------------------------------------

    \17\ ICAO Annex 6, Part I, Standards 3.1.1 and 3.1.2.
    \18\ ICAO Annex 6, Part II, Standards <IP_ADDRESS> and <IP_ADDRESS>.
---------------------------------------------------------------------------

e. Line of Vision and Conformal Display
    Section 91.176(a)(1)(i)(B) states, as originally proposed, that an
EFVS must present EFVS sensor imagery, aircraft flight information, and
flight symbology on a head up display, or an equivalent display, so
that the imagery, information and symbology are clearly visible to the
pilot flying in his or her normal position with the pilot's line of
vision looking forward along the flight path.
    Boeing commented that a sensor will likely be hard-mounted to the
airframe such that it is pointing straight along the longitudinal axis.
It also noted that a HUD is aligned with the longitudinal axis of the
aircraft, and when someone flies a ``crabbed'' approach the flight path
does not coincide with the longitudinal axis. Therefore, Boeing
recommended that the FAA revise the rule from ``looking forward along
the flight path'' to ``looking forward along the aircraft longitudinal
axis with adequate downward field of view to accommodate sight along
the normal flight path vector.'' Boeing noted that it is currently
allowed to ``ghost'' symbology on the HUD that appears outside the HUD
field of view, and that this capability should be preserved.
    The FAA is not adopting Boeing's recommendation because it could
unnecessarily restrict new technology that becomes available in the
future. The EFVS requirements are performance-based, with means of
compliance contained and updated as necessary in advisory circular
documents. While the FAA recognizes that the aircraft's flight path may
not necessarily coincide with the aircraft's longitudinal axis, the
phrase ``clearly visible to the pilot flying in his or her normal
position with the line of vision looking forward along the flight
path'' is intended to ensure that the EFVS provides a head up
presentation and will accommodate Boeing's recommendation.
    As proposed in the NPRM, Sec.  91.176(a)(1)(i)(C) requires an EFVS
to present the displayed EFVS sensor imagery, attitude symbology,
flight path vector (FPV), and flight path angle reference cue (FPARC),
and other cues, which are referenced to the EFVS sensor imagery and
external scene topography, so that they are aligned with, and scaled
to, the external view. The term ``referenced to'' is used to reflect
the FAA's expectation that the vision system imagery and certain
symbology use the same coordinate reference system as the pilot's
perspective outside view of the world. This is because the pilot uses
the vision system imagery and symbology in coordination with, and
sometimes in very low visibility as a substitute for, the outside view
of the world, including the terrain, features of the runway
environment, and topology in general.
    Rockwell Collins asked whether it could conduct EFVS operations
under the rule if the ``Flight Path Symbol'' became limited, and
therefore nonconformal, to the EFVS image due to severe crosswinds or
blowing snow conditions.
    The ability to perform an EFVS operation with a nonconformal FPV
depends on a variety of factors, such as the particular EFVS and the
type and severity of the limiting conditions. Because the EFVS is the
primary means by which the pilot will maneuver the airplane to land,
conditions that cause the FPV to become field-of-view limited, and
therefore nonconformal, could make the display unacceptable for
landing. An applicant should demonstrate EFVS operations on a variety
of instrument approach procedures and in various wind conditions with
pilot-in-the-loop simulation and a flight test, if possible, to
establish the operational effects that limiting conditions might have
on landing with an EFVS. The FAA may impose limitations in the Airplane
Flight Manual (AFM) or Airplane Flight Manual Supplement (AFMS) for
conditions where the required level of performance is not
satisfactorily demonstrated.
f. Flight Path Angle Reference Cue (FPARC)
    Pursuant to Sec.  91.176(a)(1)(i)(D), the EFVS must display the
FPARC with a pitch scale, and the FPARC must be selectable by the pilot
to the desired descent angle for the approach and be suitable for
monitoring the vertical flight path of the aircraft. The FAA made
changes to this paragraph from what it originally proposed based on
concerns raised by Boeing.
    Boeing asserted that the proposed requirement implied that the
pitch scale was selectable, not the FPARC. Boeing commented that the
FAA should revise Sec.  91.176(a)(1)(i)(D) to clarify that the FPARC
must be selectable by the pilot to the desired descent angle for the
approach being flown. Boeing also recommended that the provision
indicate that the appropriate descent angle associated with the
approach be selectable either by the pilot or automatically by the
flight management computer.
    The FAA agrees and is revising Sec.  91.176(a)(1)(i)(D)
accordingly. However, the FAA does not consider it necessary to specify
whether the

descent angle selected is accomplished manually or automatically. The
rule does not prohibit the automatic setting of the flight path angle;
however, the pilot must have the ability to either manually select the
flight path angle or to manually override the automatic setting.
g. Requirement To Display Height Above Ground Level
    Section 91.176(a)(1)(i)(B) specifies an equipment requirement for
EFVS operations to touchdown and rollout, which requires an EFVS to
display height above ground level, such as that provided by a radio
altimeter or other device capable of providing equivalent performance.
Dassault Aviation asked whether the FAA could provide an example of
such a device.
    The FAA is not providing an example of an equivalent device,
because it intends this rule to be a performance based requirement that
is not limited to one device and that could accommodate future advances
in technology. The FAA notes, however, that such a device must be
capable of equivalently performing the function of a radio altimeter,
which is to provide an accurate and reliable indication of aircraft
height above the ground.
h. Requirement To Display Flare Prompt or Flare Guidance
    For EFVS operations to touchdown and rollout in aircraft other than
rotorcraft, Sec.  91.176(a)(1)(i)(B) requires the EFVS to display flare
prompt or flare guidance. This requirement reflects a slight change
from what was proposed in the NPRM, where the FAA would have required
the display of flare prompt or flare guidance for all aircraft, for
achieving acceptable touchdown performance.
    Helicopter Association International (HAI) commented that
rotorcraft certificated under parts 27 and 29 should be excluded from
the requirement to display flare prompt or flare guidance, because
parts 27 and 29 do not require flare prompt or flare guidance based on
lower operating speed and maneuverability. The FAA agrees for the
reasons the commenter provided. Accordingly, Sec.  91.176(a)(1)(i)(B)
now excepts rotorcraft from the requirement.
    Boeing and Airbus also raised concerns about the definition of
acceptable touchdown performance. Boeing stated that the FAA should
define acceptable touchdown performance in guidance material, because
it was unsure whether the term meant landing in the touchdown zone,
compliance with landing performance specified in AC 120-28D,
equivalency to the AIII mode of a head up guidance system, or
compliance with some other performance standard. Boeing also suggested
that the FAA address quantitative standards in guidance material to
ensure an applicant or designer can demonstrate compliance with the
regulatory requirement. Airbus provided a similar comment, suggesting
that the FAA provide pass/fail criteria for acceptable touchdown
performance during an EFVS operation using flare prompt or flare
guidance.
    The FAA is not adopting a requirement ``as appropriate, for
acceptable touchdown performance'' under Sec.  91.176(a)(1)(i)(B)
because the term ``acceptable touchdown performance'' is both vague, as
identified by the commenters, and extraneous. ``Acceptable touchdown
performance'' is not a regulatory term to date. Nor is it defined in
the regulations. Furthermore, Sec.  91.176(a)(1)(i)(F) already requires
an EFVS to display characteristics, dynamics, and cues that are
suitable for manual control of the aircraft to touchdown in the
touchdown zone of the runway of intended landing. Because paragraph
(a)(1)(i)(F) requires the flare cue, i.e. flare prompt or flare
guidance, to be suitable for manual control of the aircraft to
touchdown in the touchdown zone of the runway of intended landing, it
is therefore unnecessary to require an EFVS to display flare prompt or
flare guidance for achieving ``acceptable touchdown performance'' in
paragraph (a)(1)(i)(B). Each applicant for a type design approval must
demonstrate touchdown performance for their particular EFVS
implementation using either flare prompt or flare guidance. AC 20-167,
paragraph 6-2(f)(4) specifically discusses landing performance
demonstrations for EFVS operations conducted to touchdown and rollout
and provides a means of demonstrating compliance for applicants or
designers.
    Boeing further commented that the FAA should provide touchdown
requirements that are strictly performance-based and asserted that the
FAA should not require flare guidance or flare cue for a particular
EFVS implementation if the pilot can achieve acceptable sink rate and
position without them. The FAA disagrees. The FAA finds it necessary to
provide the pilot with additional information to conduct a flare
maneuver during conditions of low visibility typically encountered
during EFVS operations to touchdown and rollout. The FAA based the
requirement in Sec.  91.176(a)(1)(i)(B) on RTCA DO-315A and
incorporated it in the interest of safety to ensure continued safe
approaches and landings in low visibility conditions.\19\ The FAA notes
that by requiring flare prompt or flare guidance for EFVS operations to
touchdown and rollout, it provides manufacturers flexibility to use
either means to achieve acceptable touchdown performance.
---------------------------------------------------------------------------

    \19\ RTCA is a private, not-for-profit association. It was
founded in 1935 as the Radio Technical Commission for Aeronautics 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 consensus-based
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
documents. For more information, see http://www.rtca.org.
---------------------------------------------------------------------------

    Airbus and Thales raised concerns about the requirement to display
flare prompt or flare guidance when using autoland during EFVS
operations. Airbus commented that EFVS operations using autoland should
be possible, but the requirement to display flare prompt or flare
guidance is not relevant when using it. Thales stated that the FAA
should mandate flare prompt or flare guidance for manual operations
using the EFVS to achieve acceptable touchdown performance, but it
should not require an EFVS to display flare prompt or flare guidance
during an approach using EFVS that is performed with a certified
autoland function.
    The FAA disagrees with the commenters. All autoland systems to date
have been approved based on performance demonstrations at runways with
Category III approach infrastructure. If conducting an autoland
approach with any other kind of runway infrastructure (i.e., less than
Category III), the visual conditions must be sufficient for the pilot
to monitor the operation and, if necessary, take immediate manual
control. EFVS provides enhanced flight visibility to compensate for
what the pilot cannot see unaided. In the case of an EFVS landing, the
EFVS must be equipped with an approved flare prompt or flare guidance
as part of the required visual information to be eligible for EFVS
operational approval to land. For this reason, even if the crew is
approved to use autoland during an EFVS operation, the EFVS must be
equipped with and must display all of the required features.
i. Pilot Monitoring Display
    When a minimum flightcrew of more than one pilot is required, Sec.
91.176(a)(1)(ii) requires the aircraft to be equipped with a display
that provides the pilot monitoring \20\ with

EFVS sensor imagery Also, as proposed, the pilot monitoring display may
provide symbology but any symbology displayed may not adversely obscure
the sensor imagery of the runway environment. However, the FAA is not
adopting the requirement for the pilot monitoring display to be located
within the maximum primary field of view \21\ of the pilot monitoring.
This departure from what the FAA originally proposed arose as a result
of the FAA's own continued review of the proposal. The FAA is also not
adopting the requirement for the EFVS sensor imagery and aircraft
flight symbology to be displayed to the pilot monitoring on a HUD or an
equivalent display for certain future EFVS operations at the
Administrator's discretion. This departure from what the FAA originally
proposed arose out of comments.
---------------------------------------------------------------------------

    \20\ The term ``pilot monitoring'' refers to the individual who
is sitting at the pilot controls and monitoring the operation of the
aircraft. Historically, the FAA has referred to this individual as
the pilot not flying. In 2003, the FAA amended AC 120-71A, Standard
Operating Procedures for Flight Deck Crewmembers, and replaced the
term ``pilot not flying'' with ``pilot monitoring'' to convey that
the pilot not flying should be actively engaged in the safe
operation of the aircraft and, as such, should be trained and
evaluated in performing active pilot monitoring skills. See
Qualification, Service, and Use of Crewmembers and Aircraft
Dispatchers, 78 FR 67800, 67812 (Nov. 12, 2013) (discussing pilot
monitoring duties and training).
    \21\ Maximum primary field of view is based on the maximum
vertical and horizontal visual fields from the design eye reference
point. The values for the maximum vertical visual field (relative to
normal line-of-sight forward of the airplane) are +40 degrees up and
-20 degrees down. The values for the maximum horizontal visual field
are +35 degrees left and +35 degrees right. AC 25-11B and AC 20-
167A.
---------------------------------------------------------------------------

    Upon further reflection, the FAA is not adopting the requirement
for the PM display to be located in the ``maximum primary field of
view'' because the term ``maximum primary field of view'' is not used
or defined in the regulations to-date and the proposed location
requirement is unnecessary. When a PM display is installed on an
aircraft, it must meet the arrangement and visibility requirements in
Sec. Sec.  23.1321, 25.1321, 27.1321, and 29.1321, which will achieve
the same objective as the proposed requirement by requiring the PM
display to be located so that any pilot seated at the controls can
monitor the airplane's flight path and the instruments with minimum
head and eye movement. The FAA will also require aircraft that pre-date
Sec. Sec.  23.1321, 25.1321, 27.1321, and 29.1321 to meet the
arrangement and visibility requirements in those sections for the
installation of PM displays. Because the airworthiness requirements of
Sec. Sec.  23.1321, 25.1321, 27.1321, and 29.1321 will already ensure
the proper placement of a PM display, the FAA finds it unnecessary to
adopt a location requirement in the operating rule.
    Several commenters shared concerns about the provision in proposed
Sec.  91.176(a)(1)(ii) that would have allowed the Administrator to
require a head up display, or equivalent display, for the pilot
monitoring based upon the EFVS operation to be conducted. Boeing noted
that designers and operators needed to know the conditions under which
the FAA might require a head up display for the pilot monitoring.
Similarly, Airbus asked the FAA for clarification, and Thales suggested
that the FAA develop criteria to define when a pilot monitoring had to
have a head up display. Additionally, Bombardier Aerospace was
concerned that, while the FAA intended the language to provide for
future technological advancements, the agency could immediately apply
the requirement to current installations where it would be impractical
to implement.
    The FAA agrees with the commenters that the proposal was unclear.
The FAA intended to address future EFVS operations and technological
advancements; however, based on the confusion surrounding the
provision, the FAA has decided not to adopt it. Instead, to facilitate
the performance of future EFVS operations, the FAA is adding new Sec.
91.176(a)(4) that states that the Administrator may prescribe
additional equipment, operational, and visibility and visual reference
requirements to account for specific equipment characteristics,
operational procedures, or approach characteristics. These requirements
will be specified in an operator's operations specifications,
management specifications, or letter of authorization authorizing the
use of EFVS. This provision will better facilitate the FAA's ability to
respond to future technological developments without causing confusion
around the pilot monitoring requirement.
    Boeing also commented that the pilot monitoring display
requirements should include a horizon line, flight path vector cue, and
FPARC in addition to the EFVS sensor imagery. Boeing contended that
without this aircraft flight symbology, the pilot monitoring would have
no cues with which to judge performance and noted that RTCA DO-315A
specifies the additional cues.
    During EFVS operations to touchdown and rollout, when a minimum
flightcrew of more than one pilot is required, the aircraft must be
equipped with a display that provides the pilot monitoring with EFVS
sensor imagery. The FAA finds it unnecessary to require additional
features on the pilot monitoring display, such as an artificial horizon
line, a flight path vector cue, and a FPARC, because the pilot
monitoring display requirements are intended only to enable that pilot
to see a real time sensor image of the required visual references.
Section 91.176(a)(1)(ii) is a minimum requirement, however.
Accordingly, it does not preclude OEMs and operators from including
additional features, such as those described by the commenters. The FAA
notes that any additional features that are displayed on the pilot
monitoring display may not interfere with the EFVS image of the
required visual references.
    Boeing further stated that it was unclear whether the pilot
monitoring display had to be a repeater of the display provided to the
flying pilot, or an independent system. Sierra Nevada Corporation
submitted a similar comment asking the FAA to clarify whether the EFVS
sensor imagery required to be provided to the pilot monitoring had to
be identical to that provided to the pilot flying on the HUD, or
whether the pilot monitoring display could utilize imagery that was
augmented by color, symbolic representation of features and obstacles,
a synthetic database of features and obstacles, an alternate
perspective view such as a top-down view, an alternate EFVS sensor
source, or blending.
    The FAA intends the regulatory requirement for the pilot monitoring
display to be performance based. Accordingly, the provision does not
specifically require a repeater display or an independent system. Nor
does it preclude the display of imagery that is augmented by features
such as those described by Sierra Nevada Corporation. Whether the pilot
monitoring display should be a repeater display or an independent
system will depend on the operation to be conducted. AC 20-167A
contains means of compliance for the pilot monitoring display. The FAA
also notes that, as display technology continues to improve, it will
evaluate additional display capabilities and features that become
available provided the display meets applicable airworthiness
requirements.
    Rockwell Collins also submitted comments on the pilot monitoring
display. It asserted that the FAA should take into account other
monitoring methods, such as those used by a pilot monitoring the safe
conduct of a Head up Guidance System (HGS)-flown Category III approach,
landing, and rollout. Such monitoring methods would not require a
second HUD, nor would they require the pilot monitoring display to
repeat the HUD symbology.

For example, a person could use expanded deviation scales based on
global positioning system (GPS) to verify alignment with the runway,
and ADS-B information to monitor other aircraft and vehicles on the
runway. Rockwell Collins also proposed that the requirement identify
the items that the pilot monitoring must monitor and assess, rather
than indicating the actual equipment the pilot monitoring must use to
perform the monitoring tasks, such as a display of EFVS imagery.
    The FAA is not adopting Rockwell Collins' recommendations. When a
minimum flightcrew of more than one pilot is required, the pilot
monitoring must have a display that provides him or her with EFVS
sensor imagery. This requirement is necessary because, when the pilot
flying relies on EFVS from DA/DH to touchdown and rollout, it cannot be
assumed that the pilot monitoring sees anything of the outside
environment using natural vision. Providing the pilot monitoring with
EFVS sensor imagery supports his or her view of the outside
environment, enables confirmation of the required visual references and
safe conduct of the approach and landing, and provides common
situational awareness between the pilot flying and the pilot
monitoring. The FAA notes, however, that the pilot monitoring display
is not the only source of flight path information available to the
pilot monitoring. The pilot monitoring may use GPS and ADS-B
information, as Rockwell Collins suggested, in addition to the EFVS
sensor imagery. The FAA further notes that the pilot monitoring should
monitor sources of information that he or she would normally monitor
during an approach and landing.
j. Applicability of EFVS Provisions to Rotorcraft Operations
    The GAMA, HAI, and Eurocopter and American Eurocopter commented
that the scope of the NPRM appeared to apply to both fixed-wing
airplanes and rotorcraft; however, the technical requirements appear to
apply only to fixed wing airplanes. GAMA and Eurocopter and American
Eurocopter recommended that the FAA modify Sec.  91.176(a)(1), as
proposed in the NPRM, to ensure the equipment requirements accommodated
the differences between airplanes and rotorcraft. They also recommended
that the FAA consider permitting the use of EFVS in rotorcraft IFR
operations, such as wide area augmentation system/localizer performance
with vertical guidance (WAAS/LPV) approaches, published instrument
approach procedures to heliports, offshore helicopter operations, and
point in space instrument approaches.
    The FAA notes that this rule does not preclude persons from
conducting EFVS operations under IFR in rotorcraft. Section 91.176(a)
limits EFVS operations to touchdown and rollout to approaches with a
DA/DH and prohibits the pilot from using circling minimums. Currently,
there are no instrument approach criteria or procedures that have been
developed for straight-in landing operations below DA/DH under IFR to
heliports or platforms. If such approach procedures were developed in
the future for heliports or platforms, along with appropriate visual
reference requirements for rotorcraft operations,\22\ persons could
conduct EFVS operations to a landing in rotorcraft on these approaches.
However, EFVS operations may not be conducted on approaches to a point-
in-space followed by a ``proceed VFR'' visual segment, or on approaches
designed to a specific landing site using a ``proceed visually'' visual
segment.
---------------------------------------------------------------------------

    \22\ The visual reference requirements under Sec.  91.176(a)(3)
and (b)(3) were derived from the visual reference requirements under
Sec.  91.175(c)(3), which were established for runways.
---------------------------------------------------------------------------

    HAI also commented that the FAA should expand its references to
landing and rollout to address the maneuverability of aircraft
certificated under parts 27 and 29 and that it should specify
``approach to hover'' and ``hover taxiing.'' The FAA disagrees with the
commenter. The FAA finds it unnecessary to expand the terminology in
the EFVS regulations to specifically encompass the maneuverability of
rotorcraft because it did not intend the terms landing and rollout to
restrict persons from conducting EFVS operations in rotorcraft. The FAA
also notes that this rule does not address taxi operations.
Accordingly, this rule does not apply to hover taxiing.
k. Requirement To Obtain a Certificate of Waiver When Conducting
Certain EFVS Operations
    Section 91.176(d) states that the requirement to have an EFVS that
meets the applicable airworthiness requirements specified in Sec.
91.176(a)(1)(i), (a)(2)(iii), (b)(1)(i), and (b)(2)(iii) does not apply
to operations conducted in an aircraft issued an experimental
certificate under Sec.  21.191 for the purpose of research and
development or showing compliance with regulations provided the
Administrator has determined that the operations can be conducted
safely in accordance with operating limitations issued for that
purpose. This paragraph was added as a result of comments.
    The 2004 EFVS regulations, specifically Sec.  91.175(l)(2),
required a person to have a certified EFVS in order to use the EFVS in
lieu of natural vision to descend below the authorized DA/DH or MDA.
Proposed Sec.  91.176 would have required the same. The FAA recognizes,
however, that an EFVS used to obtain an FAA type design approval may
not yet be certified. To date, a person obtaining an FAA type design
approval with an EFVS that has not yet been certified has been required
to obtain a certificate of waiver \23\ in order to use the EFVS in lieu
of natural vision to descend below the DA/DH or MDA during flights
prior to type design approval.
---------------------------------------------------------------------------

    \23\ Section 91.175(l) was a rule subject to waiver under Sec.
91.905.
---------------------------------------------------------------------------

    FedEx Express, Gulfstream, Elbit Systems of America, Sierra Nevada
Corporation, and GAMA commented that the FAA should eliminate the
requirement to obtain a certificate of waiver from the EFVS rules in
order to demonstrate compliance during EFVS certification flights.
Several of these commenters further stated that the FAA should remove
the term ``certified'' because the operating rules assume the equipment
is certified. Additionally, many commenters felt that the FAA should
not require waivers for certification flight tests that are conducted
with aircraft in the experimental category.
    The FAA acknowledges the commenters' concerns and is revising the
EFVS regulations by adding Sec.  91.176(d), which enables persons to
conduct EFVS certification flights without obtaining a waiver, provided
the Administrator has determined that the operations can be conducted
safely in accordance with operating limitations issued for that
purpose. The FAA will issue operating limitations when it approves an
applicant's program letter describing the flight operations to be
conducted and issues the experimental certificate for the purpose of
research and development or showing compliance with regulations. The
FAA is also adding the exception and a reference to Sec.  91.176(d) to
the introductions in Sec.  91.176(a) and (b). The FAA finds that
eliminating the waiver requirement, which resulted from the
promulgation of Sec.  91.175(l) and (m) in 2004, will streamline the
process both for the FAA and for applicants seeking to certify an EFVS.
This will be accomplished without a reduction in FAA oversight. The FAA
notes, however, that an operator is not relieved from complying with
the EFVS operating rules when it places an aircraft in the experimental
category; it

is only relieved from the requirement to have an EFVS with an FAA type
design approval for the purpose of research and development or showing
compliance with the regulations. AC 90-106A and AC 20-167A contain
guidance material pertaining to the Sec.  91.176(d) exception.
2. Operating Requirements
a. Approaches Permitted for EFVS Operations
    Under Sec.  91.176(a), a person conducting an EFVS operation in an
aircraft below the authorized DA/DH to touchdown and rollout must
conduct the operation on an approach with minimums \24\ that include a
DA/DH. In the NPRM, the FAA had proposed to permit an EFVS operation
below the authorized DA/DH to touchdown and rollout only using a
straight-in precision instrument approach procedure or an approach
procedure with approved vertical guidance. This change in the final
rule arises out of comments asking the FAA to clarify what instrument
approach procedures can be used for EFVS operations to touchdown and
rollout. This change in language does not constitute a change in
operational concept.
---------------------------------------------------------------------------

    \24\ See Instrument Flying Handbook, FAA-H-8083-15B (2012)
(stating that the term ``minimums'' refers to the landing section of
an instrument approach chart, which sets forth the lowest altitude
and visibility approved for the instrument approach procedure).
---------------------------------------------------------------------------

    Boeing and the Airline Pilots Association (ALPA) objected to
proposed Sec.  91.176(a) because it was unclear which approach
procedures they could use to conduct EFVS operations. For the reasons
discussed in greater detail below, Sec.  91.176(a) no longer states
that EFVS operations to touchdown and rollout may be conducted using
only straight-in precision instrument approach procedures or approach
procedures with approved vertical guidance.
    Boeing objected to limiting EFVS operations to ``straight-in''
approaches as defined in the Pilot/Controller Glossary (PCG). Relying
on the PCG, Boeing asserted that a straight-in approach applies to an
approach with no procedure turn, and a straight-in landing refers to a
landing made on a runway aligned within 30 degrees of the final
approach course following completion of an instrument approach. Boeing
contended that flying a procedure turn should not affect whether
someone could conduct EFVS operations. Boeing recommended that EFVS
operations to touchdown and rollout be permitted using a ``straight-in
landing'' from a precision approach or an approach with approved
vertical guidance. Boeing recommended similar revisions to Sec.
91.176(b).
    The FAA agrees with Boeing that operators could have concluded from
the proposal that a ``straight-in'' instrument approach procedure
refers to an approach with no procedure turn. This is because the term
``straight-in approach'' is used differently in the Aeronautical
Information Manual (AIM), the PCG, and the United States Standard for
Terminal Instrument Procedures (TERPS).\25\ The FAA did not intend to
limit EFVS operations to touchdown and rollout to instrument approaches
where the final approach was begun without first having executed a
procedure turn. Therefore, Sec.  91.176(a) now requires that a person
must conduct an EFVS operation to touchdown and rollout on an approach
with minimums that include a DA/DH. This revision ensures that a person
may conduct EFVS operations to touchdown and rollout using precision
approaches or approaches with approved vertical guidance regardless of
whether the pilot first executes a procedure turn. Furthermore,
paragraph (a)(2)(i) clarifies that EFVS operations to touchdown and
rollout are not permitted on circling approaches. Adding paragraph
(a)(2)(i) eliminates the confusion surrounding the terms straight-in
approach and straight-in landing, while achieving the same objective--
prohibiting EFVS operations using circling minimums. The FAA made
similar revisions to Sec.  91.176(b)(2)(i) as suggested by Boeing.
---------------------------------------------------------------------------

    \25\ The AIM provides the aviation community with basic flight
information and Air Traffic Control (ATC) procedures. The PCG
promotes a common understanding of terms used in the ATC system,
including terms which are intended for pilot/controller
communications. The TERPS consists of criteria for constructing
terminal instrument procedures. In the AIM, ``straight-in approach''
describes a procedure with straight-in landing minimums, without
regard to whether or not a procedure turn is required. In the PCG,
``straight-in approach'' means an instrument approach where the
final approach is begun without first having executed a procedure
turn, but not necessarily completed with a straight-in landing or
made to straight-in landing minimums. The PCG defines a ``straight-
in landing'' as ``a landing made on a runway aligned within 30
degrees of the final approach course following completion of an
instrument approach.'' The use of ``straight-in approach'' in TERPS
criteria generally refers to an approach that is aligned with a
runway--not necessarily within 30 degrees--and for which straight-in
landing minimums are authorized.
---------------------------------------------------------------------------

    Boeing also recommended that the FAA permit EFVS operations on
curved required navigation performance (RNP) approaches, which may have
a straight-in landing segment. Boeing stated that the use of curved RNP
approaches is increasing, that they are often used in mountainous
terrain where go-arounds could be more of an issue, and that EFVS could
improve safety and efficiency in such situations.
    The FAA agrees that Sec.  91.176(a) and (b) should not prohibit
persons from conducting EFVS operations on curved RNP approaches that
have a straight-in landing segment. RNP approaches are approved,
vertically guided instrument approach procedures that are designed to
align with a specific runway and terminate with a DA. While their line
of minima is charted somewhat differently than other approaches with
straight-in ``S'' line of minima, the curved RNP line of minima
specifies a DA. Accordingly, Sec.  91.176(a) and (b) permit RNP
approaches. However, because EFVS performance may affect the specific
approaches that an operator may conduct, the FAA may define applicable
limitations in an operator's Operations Specifications (OpSpec),
Management Specifications (MSpec), or Letter of Authorization (LOA)
accordingly.
    ALPA stated that the proposal would permit an EFVS operation to
touchdown and rollout on a ``straight-in precision instrument approach
procedure or an approach with approved vertical guidance,'' which would
seem to encompass an approach procedure with vertical guidance (APV).
However, APV describes a class of approach procedures defined in ICAO
Annex 6 as an approach procedure ``which utilizes lateral and vertical
guidance but does not meet the requirements established for precision
approach and landing operations.'' Based on this definition, a person
could conclude that an APV approach is a non-precision approach
procedure. The proposal indicated that EFVS operations to touchdown and
rollout would not be permitted on non-precision approaches. ALPA noted
that this could cause confusion and recommended that the FAA clarify
what it meant by ``approved vertical guidance.''
    The FAA agrees with ALPA that the phrase ``straight-in precision
approach procedure or an approach with approved vertical guidance'' is
confusing because persons could conclude that APV approaches are non-
precision approaches, which are not permitted under Sec.  91.176(a).
The FAA did not intend to prohibit persons from conducting EFVS
operations to touchdown and rollout on APV approaches, which will have
a charted DA/DH. Therefore, for this reason and in addition to the
reasons Boeing raised, Sec.  91.176(a) now permits EFVS operations to
touchdown and rollout on approaches with minimums that include a DA/DH.
Additionally, as mentioned previously, Sec.  91.176(a)(2)(i)

specifies that persons conducting EFVS operations may not use circling
minimums. The FAA believes these revisions clarify that EFVS operations
to touchdown and rollout may be conducted on APV approaches.
    Sierra Nevada Corporation suggested editorial changes to proposed
Sec.  91.176(a) to clarify that persons must follow the requirements
specified in paragraph (a). The commenter recommended similar revisions
to Sec.  91.176(b). The FAA agrees with the commenter and adopted the
editorial changes in Sec.  91.176(a), which more clearly articulate the
regulatory requirements. The FAA did not, however, adopt the editorial
changes in Sec.  91.176(b) because they did not coincide with the
revised language in that paragraph.
    Dassault Aviation asked whether the FAA would take into account the
new approach classifications described in the revised draft ICAO All
Weather Operations (AWO) Manual in the EFVS regulations. Dassault
Aviation stated that the draft AWO Manual describes 2D and 3D
approaches rather than ``precision approaches'' and ``approaches with
vertical guidance.'' The FAA is not including the ICAO terms or
definitions in this final rule as they are outside the scope of the
NPRM. The necessary references and descriptions in U.S. guidance
material have not been updated at this time, but the FAA notes that the
agency continues to work with ICAO on this subject.
    Rockwell Collins commented that the FAA's statement in the proposal
about not permitting EFVS operations to touchdown and rollout on non-
precision approaches implies that non-precision approaches are no
longer an approved EFVS operation. The FAA disagrees. Section 91.176
contains two distinct types of EFVS operations. Section 91.176(a)
contains the new regulations, which enable EFVS operations to touchdown
and rollout. Section 91.176(b) contains the regulations originally
found in Sec.  91.175(l) and (m), which enable EFVS operations to 100
feet above the TDZE. Section 91.176(a) permits EFVS operations to
touchdown and rollout only on approaches that have a DA/DH. However,
Sec.  91.176(b) continues to permit EFVS operations down to 100 feet
above the TDZE on non-precision approaches, just as Sec.  91.175(l) has
allowed these operations since 2004.
    Finally, Gulfstream commented that Sec.  91.176(a) should allow
EFVS operations to touchdown and rollout on the same instrument
approach procedures for which EFVS to 100 feet operations are
permitted, which would include approaches without published vertical
guidance. The FAA does not agree. The intent of Sec.  91.176(a) is to
provide for a stabilized descent and to ensure the aircraft is oriented
toward the runway of intended landing while conducting an EFVS
operation to touchdown and rollout. A stabilized descent reduces the
need to maneuver at low altitudes, thereby minimizing risk. Therefore,
the pilot must conduct the EFVS operation to touchdown and rollout on
an approach to a DA or DH using vertical guidance that is part of the
approach design.
    The FAA notes, however, that operators who have been issued OpSpec/
MSpec/LOA C073, ``Vertical Navigation (VNAV) Instrument Approach
Procedures (IAP) Using Minimum Descent Altitude (MDA) as a Decision
Altitude (DA)/Decision Height (DH),'' may conduct EFVS operations to
touchdown and rollout on certain non-precision approaches that use an
MDA as a DA/DH in accordance with the OpSpec/MSpec/LOA.
    OpSpec/MSpec/LOA C073 authorizes operators to use an MDA as a DA/DH
using vertical navigation (VNAV) on certain instrument approach
procedures, which are listed in OpSpec/MSpec/LOA C052, ``Straight-In
Non-Precision, APV, and Category I Precision Approach and Landing
Minima--All Airports.'' It has always been the FAA's intent to allow
EFVS operations on certain non-precision approaches in accordance with
OpSpec/MSpec/LOA C073. However, as discussed above, we made changes to
proposed Sec.  91.176(a) as a result of comments. In making these
changes, Sec.  91.176(a) would have prohibited EFVS operations on
certain non-precision approaches conducted in accordance with OpSpec/
MSpec/LOA C073 because paragraph (a) would have restricted EFVS
operations to touchdown and rollout to approach procedures with
minimums that included a DA or DH. Accordingly, the FAA is adding
language to Sec.  91.176(a) that allows an operator who is otherwise
authorized by the Administrator, such as through OpSpec, MSpec, or LOA
C073, to use an MDA as a DA/DH with vertical navigation on an
instrument approach procedure, to conduct an EFVS operation to
touchdown and rollout in an aircraft below the authorized MDA in
accordance with that authorization. When an operator is conducting an
EFVS operation in accordance with OpSpec/MSpec//LOA C073, that operator
must still meet the requirements of paragraphs (a)(1) through (a)(4) of
Sec.  91.176.
    The FAA notes that it is revising the regulatory language to be
performance based and allow for new technologies and approaches that
ensure a stabilized visual segment. Accordingly, this final rule allows
EFVS operations to touchdown and rollout on all approach procedures
with an authorized DA or DH, and it omits direct reference to the types
of approach procedures permitted and eliminates the term ``approved
vertical guidance.'' The FAA recognizes that many factors may affect an
operator's ability to conduct an EFVS operation. As stated in Sec.
91.176(a)(4), the FAA may prescribe additional limitations through an
OpSpec, MSpec, or LOA to ensure the safe conduct of EFVS operations.
b. Touchdown Zone
    As proposed in the NPRM, for EFVS operations to touchdown and
rollout, Sec.  91.176(a)(2)(v) requires the aircraft to continuously be
in a position from which a descent to a landing on the intended runway
can be made at a normal rate of descent using normal maneuvers, and
Sec.  91.176(a)(2)(vi) requires the descent rate to allow touchdown to
occur within the touchdown zone of the runway of intended landing.
    Several commenters raised concerns about the term ``touchdown
zone'' in Sec.  91.176(a)(2)(vi). Boeing commented that the FAA needs
to define the term ``touchdown zone'' for purposes of EFVS operations
and pointed out that it is defined differently in different documents.
For example, the AIM defines the touchdown zone as the first 3,000 feet
of the runway beginning at the threshold, but RTCA DO-315A and its
revision, RTCA DO-315B, define the touchdown zone as the first 3,000
feet or first one-third of the runway, whichever is shorter. Boeing
asked the FAA for clarification because applicants and EFVS equipment
designers need to know what the performance expectations are for the
EFVS equipment. Dassault Aviation recommended that the FAA specify that
the touchdown zone is the first 3,000 feet or the first one-third of
the runway because the 3,000-foot metric may not be adequate for short
runways. An individual commenter expressed similar concerns and added
that ICAO defines touchdown zone as the portion of a runway, beyond the
threshold, where it is intended that a landing aircraft first contact
the runway. He also noted that other FAA documents contain guidance to
land in the first one-third of a runway. Given the operational
implications of EFVS operations, he recommended that the FAA revise the
EFVS rule and the AIM to emphasize that landing in the first third of
the

runway or the first 3,000 feet, whichever is less, should suffice for
almost all landing operations by fixed wing aircraft.
    The FAA agrees with the commenters that, for the purpose of EFVS
operations, pilots should touch down in the first 3,000 feet or the
first one-third of the runway, whichever is shorter. However, the FAA
will not amend the definition of ``touchdown zone'' in the AIM, nor
define ``touchdown zone'' in the EFVS rule because the term has a
broader application than EFVS operations. The AIM contains the ICAO
definition of touchdown zone but also defines it as the first 3,000
feet of the runway beginning at the threshold. This definition is used
to determine TDZE in the development of straight-in landing minimums
for instrument approaches. The subject of landing performance is
complex and is affected by many variables such as available landing
runway, surface conditions, aircraft performance, operating procedures,
and many other factors. Furthermore, the use of the term touchdown zone
in Sec.  91.176(a)(2)(vi) is similar to its use in other sections of
the regulations that address both EFVS and other operations, such as
Sec. Sec.  91.175(c)(1), 121.651(c)(1), 121.651(d)(1), and
91.175(l)(1), the latter of which is being moved to Sec.
91.176(b)(2)(v) in this final rule.
    Accordingly, although the FAA does not consider it appropriate to
amend the definition of ``touchdown zone'' in this rule, the FAA notes
that AC 20-167A specifies a relevant means of compliance to obtain
airworthiness approval for EFVS. AC 20-167A, paragraph 6-2(f)(4) states
that, during airworthiness performance demonstrations, persons should
demonstrate longitudinal touchdown performance within the first one-
third, or the first 3,000 feet of the runway, whichever is more
restrictive, and touchdown performance should be equivalent to or
better than that achieved in visual operations for the specific
aircraft.
c. Definition of ``EFVS Operation'' and Underlying Operational Concepts
    Section 1.1 defines ``EFVS operation'' as an operation in which
visibility conditions require an EFVS to be used in lieu of natural
vision to perform an approach or landing, determine enhanced flight
visibility, identify required visual references, or conduct the
rollout.
    Dassault Aviation asked the FAA to clarify why the definition of an
EFVS operation includes determining enhanced flight visibility,
identifying required visual references, and conducting the rollout,
whereas the EFVS I and EFVS II operations referred to in AC 90-106A
only appear to address approaches below DA/DH and approaches to
touchdown.
    The definition of an EFVS operation is consistent with the
operational descriptions in proposed AC 90-106A. While an EFVS can
provide situational awareness in any phase of flight, such use does not
constitute an EFVS operation unless visibility conditions require the
use of an EFVS in lieu of natural vision to perform an approach or
landing, determine enhanced flight visibility, identify required visual
references, or conduct the rollout. When flight visibility using
natural vision is less than what is required by the instrument approach
procedure being flown, a person may perform an EFVS operation. It would
be an EFVS operation in this scenario because the visibility conditions
require the person to use the EFVS in lieu of natural vision to descend
below DA/DH. More specifically, the person must use the EFVS to assess
that the enhanced flight visibility is not less than what is required
by the instrument approach procedure and to identify the required
visual references. The EFVS I and EFVS II operations referred to in
proposed AC 90-106A are consistent with the definition of an EFVS
operation, because they address operations where the visibility
conditions require the use of an EFVS for descent, namely, EFVS
operations. The FAA notes, however, that AC 90-106A no longer contains
the terms EFVS I and EFVS II. Instead, that AC uses terminology
consistent with Sec.  91.176.
d. Light Emitting Diodes (LEDs) and EFVS Operations
    The Aerospace Medical Association commented that many airports are
installing new position, taxi, and obstruction lights that use LED
lights. It stated that night vision goggles (NVGs) and current EFVS
systems are unable to sense LED lights. As a result, aircrew using EFVS
to descend through the weather may not acquire visual aids or
obstruction lights that use LEDs. Central Management Services (CMS)
submitted a similar comment noting that EFVS is designed to sense
incandescent lights, not LED lights, and that as airports install LED
lighting to save money, the new lighting will eliminate the benefits of
EFVS. The commenter also stated that the FAA should require airports to
install Infrared (IR) emitters in all new LED airport lighting systems
and retrofit existing LED installations. Additionally, the commenter
stated that airports will not spend the money to install IR emitters on
their own, and it is only a matter of time before LEDs appear in
approach lighting and runway lighting systems.
    The FAA acknowledges the commenters' concerns regarding LED
lighting; however, the FAA disagrees that the installation of LED
lights will eliminate the benefits of EFVS and it does not mandate the
installation of specific lighting technologies. On January 4, 2007,
Congress passed the Energy Independence and Security Act, which
mandates phasing out certain incandescent lights for energy
conservation purposes. As a result, LED lighting is becoming more
prevalent in the NAS. While currently approved IR-based EFVS cannot
sense LED lighting, LEDs do not completely eliminate the benefits of
EFVS. The EFVS regulations provide for required visual references other
than lighting, such as markings, the runway threshold, and the runway
touchdown zone landing surface. Therefore, as long as a pilot can see
the required visual references using an EFVS, he or she may conduct an
EFVS operation. The FAA also notes that the presence of LEDs does not
make an EFVS operation unsafe. If the required visual references are
not distinctly visible and identifiable by the pilot, then the pilot
must execute a missed approach just as he or she would if the approach
were being conducted with natural vision instead of EFVS. The FAA has
addressed operational considerations associated with LED lighting in AC
90-106A and Information for Operators (InFO) 11004, Enhanced Flight
Vision System (EFVS), Enhanced Vision Systems (EVS), and Night Vision
Goggles (NVG) Compatibility with Light-Emitting Diodes (LEDs) at
Airports and on Obstacles. Also, EFVS sensors based on other
technologies might be developed and approved in the future, and thus
would be unaffected by the installation of LED airport and runway
lighting.\26\
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    \26\ The FAA and industry are currently working together to
address EFVS and LED interoperability through the SAE G-20 Airport
Lighting Committee. This committee was tasked by the FAA to evaluate
and recommend potential solutions. To date, several prototype IR/LED
light fixtures have been developed and are currently being tested at
the FAA's William J. Hughes Technical Center. Additionally, in
October 2014, the FAA conducted an LED Symposium comprised of FAA,
other government agencies, SAE G-20, and industry participants. One
of the action items from the LED Symposium was to develop a
comprehensive operational test plan and conduct operational flights
and evaluations using EFVS, the LED approach lighting system at the
FAA's William J. Hughes Technical Center, and prototype infrared
emitters.

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    Furthermore, the FAA does not mandate installation of specific
lighting technologies. Airport operators decide what approved lighting
technologies they will install at their airport location, and
incandescent and LED airport lighting technologies both meet the
requirements of Sec.  139.311, ``Marking, signs, and lighting.''
Lighting technology manufacturers have significantly reduced the
availability of traditional incandescent lighting technology for
airport applications as a result of the Energy Independence and
Security Act.
e. LOA Requirement for Part 91 Operators To Conduct EFVS Operations to
Touchdown and Rollout
    Section 91.176(a)(2)(viii) requires a person conducting EFVS
operations under part 91 to conduct the operation in accordance with an
LOA unless the operation is conducted under subpart K of part 91, or
conducted in an aircraft that has been issued an experimental
certificate under Sec.  21.191 for the purpose of research and
development or showing compliance with regulations.\27\ This slightly
differs from what was proposed in the NPRM, in that the FAA did not
propose to provide an exception from the LOA requirement for EFVS
operations conducted under part 91 in aircraft issued an experimental
certificate under Sec.  21.191 for the purpose of research and
development or showing compliance with regulations.
---------------------------------------------------------------------------

    \27\ The FAA also added language to Sec.  91.176(a)(2)(viii) so
persons who are otherwise authorized to conduct EFVS operations
under other operating rules (i.e. subpart K of part 91 and parts
121, 125, 129, and 135) do not have to obtain an LOA to conduct part
91 operations such as ferry flights.
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    Three commenters expressed concerns about requiring an LOA for part
91 operators to conduct EFVS operations to touchdown and rollout. An
individual commented that requiring part 91 operators to obtain an LOA
is an unnecessary regulatory requirement; however, he supported the
FAA's proposal to require training and recent flight experience for
EFVS operations. Central Management Services and an individual
commented that pilots with a demonstrated history of EFVS training and
currency should not be required to obtain an LOA and should be
``grandfathered'' under the new EFVS regulation. Central Management
Services further stated that only pilots new to EFVS technology and
equipment should be required to obtain an LOA. Central Management
Services and an individual contended that there is precedence for
``grandfathering'' pilots with previous experience and pointed to those
paragraphs in Sec.  61.31 pertaining to pilots who had previous
experience operating pressurized aircraft above 25,000 feet and pilots
who had previous tailwheel experience. HAI, Central Management
Services, and an individual expressed concern about the length of time
it generally takes the FAA to issue an LOA.
    Because of the performance-based structure of the EFVS regulations
under Sec.  91.176(a), the FAA finds it necessary to require part 91
operators, other than those conducting operations under part 91 subpart
K or in an aircraft that has been issued an experimental certificate
under Sec.  21.191 for the purpose of research and development or
showing compliance with regulations, to obtain an LOA to conduct EFVS
operations to touchdown and rollout. The FAA has written Sec.
91.176(a) in a way that is performance-based rather than explicitly
specifying visibilities or other EFVS operating conditions and
limitations in rule language. The FAA has structured the regulations so
that it can manage the operating conditions and limitations for EFVS
operations to touchdown and rollout through an operator's OpSpec,
MSpec, or LOA. The FAA specifically structured the EFVS regulations
this way to provide flexibility and to enable the FAA to structure an
operator's authorization in a way that links equipage and system
performance to specific operational capabilities. This structure also
enables the FAA to respond more rapidly to new technology. Rather than
restricting the use of all EFVS to a rigid and limiting set of
visibility values and operating conditions and limitations, the FAA can
permit a range of EFVS operations as vision system technologies and
appropriate equipment certification guidance are developed. The FAA
believes this structure best accommodates future growth while
eliminating the need for additional rulemaking. Lastly, the FAA
acknowledges the commenters' concerns about the length of time it
generally takes to issue an LOA. The FAA notes that every effort is
made to process applications in a timely manner.
    The FAA notes that Sec.  91.176(a)(2)(viii) now excepts EFVS
operations conducted under part 91 in aircraft issued an experimental
certificate under Sec.  21.191 for the purpose of research and
development or showing compliance with regulations from the requirement
to obtain an LOA. These operations typically consist of a series of
flights conducted to collect data or show compliance with regulations
during EFVS certification activities using aircraft that have been
placed in the experimental category. The flights are authorized when
the FAA approves the program letter \28\ describing the flight
operations to be conducted and issues the experimental certificate with
operating limitations. The FAA authorization is time-limited and
carries an expiration date. Because these operations require FAA-
approval, are time-limited, and carry operating limitations specific to
the flights to be conducted, an LOA to conduct these operations is not
required.
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    \28\ For an aircraft to be eligible for an experimental
certificate the aircraft must be registered and the applicant must
satisfy one or more of the purposes stated in 14 CFR 21.191.
Pursuant to Sec.  21.193, applicants for experimental certificates
must submit certain information with an application for
airworthiness certification. This information is referred to as the
``program letter.'' The FAA uses the program letter to assist in
establishing eligibility for an experimental certificate. The
program letter must contain the required items listed in Sec.
21.193 and be detailed enough to permit the FAA to prescribe the
conditions and limitations necessary to ensure safe operation of the
aircraft. ``Airworthiness Certification of Products and Articles,''
Order 8130.2H (Feb. 4, 2015).
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f. EFVS Operations Outside the U.S.\29\
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    \29\ A person serving as a required flightcrew member of a
foreign registered aircraft conducting operations under part 91 is
not required to obtain an LOA in order to conduct EFVS operations to
100 feet above the TDZE because Sec.  91.176(b)(2) does not require
part 91 operators, other than those operating under part 91 subpart
K, to obtain FAA authorization to conduct EFVS operations to 100
feet above the TDZE.
---------------------------------------------------------------------------

    Pursuant to Sec.  91.176(a)(2)(x) and (b)(2)(viii), any person
serving as a required flightcrew member for a foreign air carrier
subject to part 129 must conduct both EFVS operations to touchdown and
rollout and EFVS operations to 100 feet above the TDZE in accordance
with OpSpecs authorizing the use of EFVS. The appropriate International
Field Office (IFO) is responsible for authorizing part 129 foreign air
carriers for EFVS operations. AC 90-106A contains additional
information for EFVS operations conducted by foreign air carriers in
the United States.
    Part 91 operators (other than part 91, subpart K operators, who are
required to obtain an MSpec under Sec.  91.176(b)(2)(vii)) are not
required to obtain an LOA in order to conduct EFVS operations to 100
feet above the TDZE under Sec.  91.176(b). Verizon conducts EFVS
operations to 100 feet above the TDZE under part 91 in the United
States and pointed out that the rules for EFVS operations to 100 feet
already in effect do not contain a provision for issuing an LOA to a
part 91 operator. Verizon commented that, because it does not have an
LOA, it has been unable to obtain approval from a foreign CAA to
conduct EFVS operations to 100 feet

above the TDZE in the foreign country. As a result, it has been unable
to use EFVS on its Gulfstream fleet for operational benefit outside of
the United States. Verizon requested that the FAA revise Sec.
91.176(b) to make provision for issuing an LOA to part 91 operators to
facilitate approval by foreign CAAs.
    The FAA is not revising Sec.  91.176(b) as the commenter suggested.
Part 91 operators have been authorized to conduct EFVS operations to
100 feet above the TDZE in the United States without an LOA for over 12
years. However, the FAA is aware that certain foreign CAAs require an
authorization from the State of the operator in order to obtain
approval to conduct EFVS operations in that country. The FAA is
developing a process to facilitate foreign CAA approval for part 91
operators. AC 90-106A contains additional information about
international EFVS operations.
g. EFVS Authorizations
    Section 91.176(a) contains the regulations for EFVS operations to
touchdown and rollout, and Sec.  91.176(b) contains the regulations for
EFVS operations to 100 feet above the TDZE. Under Sec.
91.176(a)(2)(viii)-(xii), operators must obtain an LOA, MSpec, or
OpSpec authorizing the use of EFVS in order to conduct EFVS operations
to touchdown and rollout. Similarly, under Sec.  91.176(b)(2)(vii)-(x),
operators, except for part 91 operators (other than part 91, subpart K
operators) must obtain an LOA, MSpec, or OpSpec authorizing the use of
EFVS in order to conduct EFVS operations to 100 feet above the TDZE.
Thales asked the FAA to clarify whether it will issue authorizations
for EFVS operations to touchdown and rollout separately from
authorizations for EFVS to 100 feet above the TDZE. Thales also asked
whether authorizations for EFVS operations to touchdown and rollout
will include EFVS operations to 100 feet above the TDZE. Lastly, Thales
asked if operators who are currently authorized to conduct operations
under Sec.  91.175(l) and (m) will have to reapply for authorization to
conduct EFVS operations under new Sec.  91.176.
    The FAA will issue separate authorizations for EFVS operations to
touchdown and rollout and EFVS operations to 100 feet above the TDZE.
Operators who are currently authorized to conduct EFVS operations to
100 feet above the TDZE, who wish to conduct additional operations now
permitted under this rule, may do so only if those operations are
authorized by their OpSpec, MSpec, or LOA for EFVS operations.
    Operators currently conducting EFVS operations to 100 feet above
the TDZE may continue to conduct those operations under their existing
authorization until the FAA revises the operator's authorization to
conform to the applicable provisions of the EFVS final rule. Lastly, AC
90-106A, Section 10, ``Operational Approval Process for EFVS
Operations,'' provides guidance on the operational approval process and
obtaining authorizations for EFVS operations.
h. EFVS for Takeoff Operations
    FedEx Express, Gulfstream, Dassault Aviation, Elbit Systems of
America, and Sierra Nevada Corporation commented that the FAA's notice
did not address takeoff credit for EFVS. They noted that the FAA
referenced existing processes through which takeoff credit for EFVS
could be approved and requested that the FAA clarify those processes.
In addition, Dassault Aviation requested that the FAA address when it
plans to develop operational requirements and associated guidance
material for takeoff using EFVS.
    The FAA did not propose to enable the use of EFVS during takeoff
operations because it may already authorize these operations through
existing processes under Sec.  91.175(f), which prescribes civil
airport takeoff minimums for persons conducting operations under part
121, 125, 129, or 135. Under Sec.  91.175(f), a person conducting
operations under part 121, 125, 129, or 135 may obtain an authorization
from the FAA, such as an OpSpec or LOA, authorizing lower than standard
takeoff minimums, which may include the use of EFVS. The regulations,
however, do not prescribe any takeoff minimums for part 91 operators
(other than part 91, subpart K operators which under Sec.  91.1039(e)
have a minimum takeoff visibility of 600 feet). Therefore, part 91
operators (other than part 91, subpart K operators) may conduct takeoff
operations using EFVS without obtaining an authorization from the FAA
to conduct such operations.
    It has come to the FAA's attention, however, that there is no
existing process under the regulations for part 91, subpart K operators
to obtain an authorization from the FAA to conduct takeoff operations
using EFVS when the visibility is less than 600 feet. The FAA is
therefore amending Sec.  91.1039(e) to permit part 91, subpart K
operators to conduct takeoff operations using EFVS when the visibility
is less than 600 feet, provided these operations are conducted in
accordance with the certificate holder's MSpec for EFVS operations.
    The FAA is aware of the need for operational guidance regarding the
use of EFVS during takeoff operations and is currently working to
develop it.
i. Combined Vision Systems
    A couple of commenters raised concerns about the use of synthetic
vision. The HAI commented that Sec.  91.176 and AC 90-106A should
address the use of synthetic vision, when combined with an EVS that
uses a real-time sensor image and appropriate flight information.
Rockwell Collins commented that there are future technologies that
could provide a real-time image of the external scene topography, which
may be based on a database or communicated position information. It
further commented that while these technologies may be considered
combined vision system (CVS) applications,\30\ the lines between
enhanced vision, synthetic vision, and combined vision may become even
less defined over time. Rockwell Collins suggested that only synthetic
vision systems which exclusively use a computer-generated image of the
external scene topography should not be addressed by the operational
requirements in this rule. Furthermore, Eurocopter and American
Eurocopter commented that the FAA should clarify whether a person could
use CVS as an EFVS provided the CVS satisfied part 91's requirements.
---------------------------------------------------------------------------

    \30\ A combined vision system involves a combination of SVS and
EVS or EFVS. See AC No. 20-167A, Airworthiness Approval of Enhanced
Vision System, Synthetic Vision System, Combined Vision System, and
Enhanced Flight Vision System Equipment.
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    The FAA disagrees that Sec.  91.176 should address the use of
synthetic vision. The amendments to part 91 address new operational
benefits and requirements for EFVS only. However, a CVS consisting of
an enhanced flight vision system and synthetic vision could be approved
for EFVS operations if it met all of the requirements of the EFVS
regulations.
j. Use of the Term ``EFVS'' in Rule Language
    Garmin International commented that the proposed rule language
unnecessarily references EFVS. It pointed out that in the future, part
91 might be updated to include additional technologies. Removing
references to EFVS, and using only references to Sec.  91.176, would
eliminate the necessity for future revisions of the regulations.
    The FAA disagrees with Garmin. The FAA is retaining the references
to EFVS in the rule language because the rule is intended to address
new operational

benefits and requirements for EFVS; it is not intended to address other
systems that do not meet requirements applicable to EFVS.
k. Approach Plates and EFVS Operations
    Under Sec.  91.176(a), EFVS operations to touchdown and rollout may
be conducted at any airport below the authorized DA/DH. Under Sec.
91.176(b), EFVS operations to 100 feet above the TDZE may be conducted
at any airport below the authorized DA/DH or MDA to 100 feet above the
TDZE. Additionally, EFVS operations using circling minimums are not
authorized pursuant to Sec.  91.176(a)(2)(i) and (b)(2)(i).
    The Aerospace Medical Association commented that an EFVS approach
plate should be developed that specifies the procedure, equipment
requirements, and visibility required to conduct EFVS operations. The
FAA disagrees because persons may conduct EFVS operations on any
instrument approach procedure that meets the criteria specified above.
Therefore, an approach plate specifically for EFVS operations is not
necessary.
    The Aerospace Medical Association also asked whether the FAA will
issue a special rating for pilots who conduct EFVS operations. The
commenter stated that minimum qualification and experience should be