# Revisions to Operational Requirements for the Use of Enhanced Flight Vision Systems (EFVS) and to Pilot Compartment View Requirements for Vision Systems > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2016-28714 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** December 13, 2016 - **Citation:** 81 FR 90126 ## Text 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. 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 §§ 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 (202) 267-8790; email Terry.King@faa.gov . 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 (§ 1.1) B. Consolidate EFVS Requirements in Part 91 in a New Section (§ 91.176) C. Equipment, Operating, and Visibility and Visual Reference Requirements for EFVS Operations to Touchdown and Rollout (§ 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 §§ 91.155 and 91.157 During Rotorcraft Operations D. Revisions to Requirements for EFVS Operations to 100 Feet Above the TDZE (§ 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 (§ 61.66) 1. Training Requirements for Persons Conducting EFVS Operations (§ 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 § 61.66(a), (b) and (c) 2. Recent Flight Experience and EFVS Refresher Training for Persons Conducting EFVS Operations (§ 61.66(d) and (e)) 3. EFVS Recent Flight Experience 4. Persons Authorized to Conduct EFVS Refresher Training 5. Revisions to § 61.57 6. Military Pilots and Former Military Pilots in the U.S. Armed Forces (§ 61.66(f)) 7. Use of Full Flight Simulators (§ 61.66(g)) 8. Exceptions (§ 61.66(h)) a. Manipulating the Controls (§ 61.66(h)(1)(i), (ii), and (iii) b. Exception to Ground and Flight Training (§ 61.66(h)(2)) c. Exception to Recent Flight Experience Requirements (§ 61.66(h)(3)) d. Grandfather Clause (§ 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 (§§ 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 (§§ 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 (§ 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 (§§ 23.773, 25.773, 27.773, and 29.773) 1. Vision Systems and Display Methods Addressed by §§ 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 (§§ 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 § 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 § 1.1. The FAA is creating new § 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 § 91.176(b) the regulations for EFVS operations to 100 feet above the TDZE, which were previously located in § 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 § 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 § 91.176(a) and (b). The FAA is also amending the operating rules for Category II and Category III operations in § 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 § 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 § 61.66(d) and (e). Additionally, § 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 § 91.176. 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 §§ 61.31 and 61.57 and consolidated them in new § 61.66. The FAA is revising §§ 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 § 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 § 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 §§ 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 §§ 23.773, 25.773, 27.773, and 29.773 include the general requirements that were previously contained in special conditions. Revising § 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 §§ 91.175, 91.905 and 135.225. The FAA is updating regulatory cross references and terms in § 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 § 91.905 to include § 91.176 as a regulation subject to waiver. Additionally, the FAA is revising § 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 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). II. Background A. Statement of the Problem The FAA created regulations in 2004, § 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 § 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 § 1.1. • Establish airworthiness standards for vision systems with a transparent display surface located in the pilot's outside field of view in §§ 23.773, 25.773, 27.773, and 29.773. • Require training and an endorsement for EFVS operations in § 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 § 61.57(i). • Re-designate § 91.175(l) and (m) as § 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 § 91.189 that provide and require the use of a DA/DH. • Add § 91.176 to the list of rules subject to waiver in § 91.905. • Amend §§ 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 § 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 § 121.651 also would have permitted EFVS-equipped part 121 operators to conduct EFVS operations in accordance with § 91.176 and their operations specifications issued for EFVS operations. • Permit flight release under §§ 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 §§ 125.325 and 125.381. Proposed § 125.381 also would have permitted EFVS-equipped part 125 operators to conduct EFVS operations in accordance with § 91.176 and their operations specifications. • Permit flights in EFVS-equipped aircraft to be initiated under § 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 § 135.225 when the reported visibility was below the authorized visibility minimums for the approach. Proposed § 135.225 also would have permitted EFVS-equipped part 135 operators to conduct EFVS operations in accordance with § 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 §§ 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 (§ 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 § 1.1 of the descriptive material from § 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 § 1.1 more consistent with proposed §§ 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 § 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 § 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 § 91.903 permits the FAA to grant a waiver from any rule listed in § 91.905 and a definition is not a rule. Therefore, § 1.1 defines the EFVS to which § 91.176 applies and § 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 § 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 § 1.1. Accordingly, the FAA is revising paragraphs (a) and (b) of § 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 § 1.1. B. Consolidate EFVS Requirements in Part 91 in a New Section (§ 91.176) The FAA created a new section, § 91.176, for the EFVS regulations to ensure organizational and regulatory clarity. As the FAA originally proposed in the NPRM, § 91.176(a) contains the requirements for EFVS operations to touchdown and rollout, and § 91.176(b) contains the requirements, which were previously located in § 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 § 91.176(b) to § 91.176(a), and move the regulations for EFVS operations to touchdown and rollout from § 91.176(a) to § 91.176(b). Boeing believed this format would facilitate reading and understanding the changes, because the existing EFVS rules, which were previously located in § 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 § 91.176(a) because it believes that operators will eventually conduct the majority of EFVS operations to touchdown and rollout. Placing these regulations in § 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 § 91.175(l) and (m), in § 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 § 91.176(a), the FAA is able to cross reference the equipment requirements of § 91.176(a)(1)(i)(A)-(a)(1)(i)(F) in § 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 (§ 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 §§ 1.1 and 91.176(a)(1)(i)(A). b. Head Up Presentation Requirement for EFVS Operations As originally proposed, § 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 § 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 § 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 § 91.175(m). 9 Rather, the FAA proposed to expand EFVS operations to touchdown and rollout using the existing operational construct in § 91.175(l) and (m). More specifically, the FAA proposed to apply all the equipment requirements of the EFVS regulations found in § 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 § 91.176, the FAA notes that it may grant waivers to OEMs from the applicable sections of § 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 § 91.176. Under § 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 § 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 § 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 § 91.176(b)(1)(i) as § 91.176(b)(1)(iii). 12 12 The FAA restructured the requirements in proposed § 91.176(b)(1)(i)-(iii) to be more consistent with § 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, 2.4.15.2, 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 2.4.15.2 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 2.4.15.2 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 2.4.15.2, which explains why § 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 § 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 2.1.1.1 and 2.1.1.2. 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, § 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 § 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 § 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 § 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, § 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, § 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 § 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, § 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 § 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, § 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 §§ 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 §§ 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 §§ 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 § 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 § 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 § 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 § 91.176(a)(3) and (b)(3) were derived from the visual reference requirements under § 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 § 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 § 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 § 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 § 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 § 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 § 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 § 91.176(d) to the introductions in § 91.176(a) and (b). The FAA finds that eliminating the waiver requirement, which resulted from the promulgation of § 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 § 91.176(d) exception. 2. Operating Requirements a. Approaches Permitted for EFVS Operations Under § 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 § 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, § 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 § 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, § 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 § 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 § 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, § 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 § 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, § 91.176(a) now permits EFVS operations to touchdown and rollout on approaches with minimums that include a DA/DH. Additionally, as mentioned previously, § 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 § 91.176(a) to clarify that persons must follow the requirements specified in paragraph (a). The commenter recommended similar revisions to § 91.176(b). The FAA agrees with the commenter and adopted the editorial changes in § 91.176(a), which more clearly articulate the regulatory requirements. The FAA did not, however, adopt the editorial changes in § 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 § 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, § 91.176(b) continues to permit EFVS operations down to 100 feet above the TDZE on non-precision approaches, just as § 91.175(l) has allowed these operations since 2004. Finally, Gulfstream commented that § 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 § 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 § 91.176(a) as a result of comments. In making these changes, § 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 § 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 § 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 § 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, § 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 § 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 § 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 § 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 §§ 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 § 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 § 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 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. 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 § 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 § 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 § 21.191 for the purpose of research and development or showing compliance with regulations. 27 The FAA also added language to § 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. 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 § 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 § 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 § 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 § 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 § 91.176(a)(2)(viii) now excepts EFVS operations conducted under part 91 in aircraft issued an experimental certificate under § 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. 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 § 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 § 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). f. EFVS Operations Outside the U.S. 29 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 § 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 § 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 § 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 § 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 § 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 § 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 § 91.176(b) contains the regulations for EFVS operations to 100 feet above the TDZE. Under § 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 § 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 § 91.175(l) and (m) will have to reapply for authorization to conduct EFVS operations under new § 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 § 91.175(f), which prescribes civil airport takeoff minimums for persons conducting operations under part 121, 125, 129, or 135. Under § 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 § 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 § 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 § 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. The FAA disagrees that § 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 § 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 § 91.176(a), EFVS operations to touchdown and rollout may be conducted at any airport below the authorized DA/DH. Under § 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 § 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 required for pilots to perform EFVS operations. It pointed out that most airlines only permit [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2016-28714. Public record. Not legal advice.