U .S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Enhanced Flight Vision System Operations Date: 5/2/22 AC No: 90-106B Initiated by: AFS-400 Change:
On December 13, 2016, the Federal Aviation Administration (FAA) published the final rule 81 FR 90126, Revisions to Operational Requirements for the Use of Enhanced Flight Vision Systems (EFVS) and to Pilot Compartment View Requirements for Vision Systems. This advisory circular (AC) provides an overview of the EFVS operation to 100 feet above the touchdown zone elevation (TDZE) and the EFVS operation to touchdown and rollout, as well as the EFVS training, checking, and recent flight experience necessary to conduct the operations. In addition, it includes a means for obtaining an EFVS authorization, developing an EFVS training curriculum, and using EFVS operational credit. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.
Robert C. Carty Deputy Executive Director, Flight Standards Service
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CONTENTS Paragraph Page
1 Introduction1
1.1 Purpose of This Advisory Circular (AC)1
1.2 Audience1
1.3 Where You Can Find This AC1
1.4 What This AC Cancels1
1.5 Terms and Definitions2
1.6 Regulatory Background2
2 Basic Concepts of the EFVS Operation2
2.1 What Is an EFVS Operation?2
2.2 What Is an Enhanced Flight Vision System (EFVS)?2
2.3 What Is Enhanced Flight Visibility?3
2.4 What Is Visual Advantage?3
3 EFVS Operations to Touchdown and Rollout—§ 91.176(a)4
3.1 General Description4
3.2 Approaches for EFVS Operations to Touchdown and Rollout4
3.3 The Use of the PM Display4
3.4 Limitations and Conditions That Apply to EFVS Operations to Touchdown
and Rollout5
3.5 Go-Around5
4 EFVS Operations to 100 Feet Above the TDZE—§ 91.176(b)5
4.1 General Description5
4.2 Approaches for EFVS Operations to 100 Feet Above the TDZE6
4.3 Identifying Visual References at 100 Feet6
4.4 Go-Around6
5 Aircraft Qualifications for EFVS Operations7
5.1 Aircraft Qualifications for U.S.-Registered Aircraft7
5.2 Aircraft Qualifications for Foreign-Registered Aircraft7
5.3 Aircraft Qualifications for Experimental Aircraft7
5.4 Aircraft Qualifications for Public Aircraft Operations7
6 Pilot Training for EFVS Operations8
6.1 EFVS System Familiarity8
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6.2 Training for FAA-Certificated Pilots, Pilots Operating Under Part 91K, 121, 125,
or 135, or Operating a U.S.-Registered Aircraft8
6.3 Training for Pilots Operating Under Part 129 or Operating Foreign-Registered
Aircraft8
6.4 Training for Pilots Conducting Public Aircraft Operations8
6.5 Training for Pilots Operating Aircraft Issued an Experimental Certificate9
7 Pilot Recent Flight Experience for EFVS Operations9
7.1 EFVS Recent Flight Experience for Operating Under Part 919
7.2 Recent Flight Experience for Part 91K, 121, 125, or 135 Operators10
7.3 Recent Flight Experience for Public Aircraft Operators10
8 EFVS Operational Credit10
8.1 What Is EFVS Operational Credit?10
8.2 What Is the Purpose of EFVS Operational Credit?11
8.3 Standard EFVS Credit11
8.4 Minimum Visibility with Use of EFVS11
8.5 Considerations for Using EFVS Minimum Visibility12
9 Developing an EFVS Training Curriculum12
9.1 Overview12
9.2 Pilot Training Cu rriculum12
9.3 Training Curriculum for Dispatchers and Other Persons Exercising Operational
Control for EFVS Operations14
9.4 Maintenance Personnel Training14
10 Operational Authorizations for Part 9114
10.1 Overview14
10.2 The Application14
10.3 EFVS Operational Demonstration for Part 91 Applications14
11 Operational Authorizations for Parts 91K, 121, 125, and 13515
11.1 Overview15
11.2 The Application15
11.3 EFVS Operational Demonstration for Parts 91K, 121, 125, and 135 Applications16
12 Operational Authorizations for Part 12917
12.1 Overview17
12.2 The Application17
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13 AC Feedback Form17
Appendix A. E lements of an EFVS Pilot Training CurriculumA-1
Appendix B. E FVS Maintenance Program and Personnel TrainingB-1
Appendix C. Ele ments of a Training Curriculum for Dispatchers and Other Persons
Authorized to Exercise Operational Control for EFVS OperationsC-1
Appendix D. R elated Regulations and GuidanceD-1
Li st of Figures
Figure 1. View During an Approach3
Figure 2. Visual Advantage4
Figure 3. EFVS Operation to Touchdown and Rollout5
Figure 4. EFVS Operation to 100 Feet Above the Touchdown Z o ne Elevation6
Figure 5. Recent Flight Experience Flowchart (§ 61.66(d) and (e))10
Lis t of Tables
Table 1. Sample Minimum Visibility Table12
1 1 INTRODUCTION.
1.1 Purpose of This Advisory Circular (AC). This AC provides an explanation of enhanced flight vision system (EFVS) operations conducted under Title 14 of the Code of Federal Regulations (14 CFR), guidance for obtaining Operations Specification (OpSpec), Management Specification (MSpec), or Letter of Authorization (LOA) C048, Enhanced Flight Vision System (EFVS) Operations, and information that may facilitate the development of a training curriculum for EFVS operations.
1.1.1 All regulatory references used in this AC are found in 14 CFR unless otherwise indicated.
References to part 91 are not inclusive of subpart K (part 91K).
1.1.2 This AC provides information for the use of an EFVS during an EFVS operation and does not provide information for the use of an EFVS for situation awareness during other aircraft operations such as taxi, takeoff, or approach operations that do not require its use.
1.1.3 This AC provides information applicable to the airplane category and does not include information pertaining to authorizations for EFVS operations in the rotorcraft category.
Airworthiness criteria, operational procedures, and specific authorizations have not been developed to support rotorcraft EFVS operations.
1.1.4 Requirements for conducting EFVS operations outside the United States may differ from those found in 14 CFR. Specific policies and procedures related to EFVS operations may be published in a State’s Aeronautical Information Publication. International Civil Aviation Organization (ICAO) Annex 6, Operation of Aircraft, and Doc 9365, Manual of All-Weather Operations, can be found on the ICAO Publications website at https://www.icao.int/publications/Pages/default.aspx.
1.1.5 The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies. Conformity with the guidance is voluntary only, and nonconformity will not affect rights and obligations under existing statutes and regulations.
1.2 Audience. This AC applies to the following:
1. Persons intending to conduct EFVS operations;
2. Persons responsible for operational control over airplanes conducting EFVS operations; or
3. Persons developing a training curriculum for EFVS operations.
1.3 Where You Can Find This AC. You can find this AC on the FAA’s website at https://www.faa.gov/regulations_policies/advisory_circulars and the Dynamic Regulatory System (DRS) at https://drs.faa.gov.
1.4 What This AC Cancels. AC 90-106A CHG 1, Enhanced Flight Vision Systems, dated July 10, 2018, is canceled.
1.5 Terms and Definitions.
1.5.1 Flight Standards Safety Assurance Office. An FAA Flight Standards District Office (FSDO), certificate management office (CMO), International Field Office (IFO), or certificate management unit (CMU) assigned by the FAA to have oversight responsibility for a particular operator.
1.5.2 P ilot Flying (PF) . The pilot who is manipulating the controls of the aircraft at any given time, in flight or on the ground.
1.5.3 P ilot Monitoring (PM). A required flight crewmember, other than the PF , who monitors the aircraft state and system status, calls out any perceived or potential deviations from the intended flightpath, and intervenes if necessary.
1.5.4 C urriculum . Subjects comprising a course that may be a part of a larger training program.
1.6 Regulatory Background. Prior to 2004, the only way a pilot could operate below the decision altitude (DA)/decision height (DH) or minimum descent altitude (MDA) of an instrument approach (i.e., the visual segment) was to use natural vision to meet the requirements of part 91, § 91.175. Section 91.176 allows specifically qualified pilots to use an installed aircraft system called an EFVS to operate in the visual segment of an instrument approach when the pilot’s natural vision is not sufficient. In addition, other regulations have been amended to make operational credits available to certain EFVS-equipped operators.
2 BASIC CONCEPTS OF THE EFVS OPERATION.
2.1 What Is an EFVS Operation? The official definition of an EFVS operation can be found in part 1, § 1.1, which can be summarized as an operation in which a pilot uses an EFVS during an instrument approach to assess enhanced flight visibility and to identify visual references because the flight visibility using natural vision is not sufficient to do so. There are two types of EFVS operations:
1. EFVS operations to touchdown and rollout (EFVS-TD), regulated under § 91.176(a);
and
2. EFVS operations to 100 feet above the touchdown zone elevation (TDZE) (EFVS-100), regulated under § 91.176(b).
2.2 What Is an Enhanced Flight Vision System (EFVS)? An EFVS is defined in § 1.1 as “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, including but not limited to 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.”
2.2.1 An EFVS approved to be used to conduct an EFVS operation provides an enhanced real-time image on a Head-Up Display (HUD) or equivalent display along with the applicable aircraft information and flight symbology. These equipment requirements are specified in § 91.176(a)(1) and (b)(1).
2.2.2 A pilot conducting an EFVS operation uses an EFVS to provide the enhanced visibility to perform the approach or landing, determine the enhanced flight visibility, identify the visual references for the runway of intended landing before they are visible naturally out the windscreen, or conduct the rollout. Infrared, a common type of EFVS imaging technology, differentiates objects by their thermal signature (see Figure 1 below).
Figure 1. View During an Approach Images courtesy of the National Aeronautics and Space Administration Langley Research Center.
2.3 What Is Enhanced Flight Visibility? Enhanced flight visibility is defined in § 1.1 as “the average forward horizontal distance, from the cockpit of an aircraft in flight, at which prominent topographical objects may be clearly distinguished and identified by day or night by a pilot using an enhanced flight vision system.” During an EFVS operation, a pilot may use the enhanced flight visibility provided by an EFVS to meet the visibility minimums published for the approach.
2.4 What Is Visual Advantage? Visual advantage is the difference between the distance a pilot can see using an EFVS compared to the distance the pilot can see without the use of the EFVS. (See Figure 2, Visual Advantage.) The visual advantage of an EFVS sensor is typically quantified during the EFVS certification process to support operational concepts for determining performance-based operational credit for EFVS users under parts 121, 125, 129, and 135. An EFVS that demonstrates a greater visual advantage may be eligible for an EFVS operational credit that allows use in lower reported visibilities.
4 Figure 2. Visual Advantage 3 E FVS OPERATIONS TO TOUCHDOWN AND ROLLOUT—§ 91.176(a).
3.1 General Description. During an EFVS-TD operation (see Figure 3, EFVS Operation to Touchdown and Rollout), the pilot uses enhanced vision imagery provided by an EFVS to descend from a DA/DH to touchdown and rollout when the flight visibility is not sufficient to conduct the approach with natural vision under § 91.175(c). The pilot conducts the entire visual segment of the instrument approach, including the landing and rollout, using the EFVS to comply with the enhanced flight visibility and visual reference requirements of § 91.176(a)(3).
3.2 Approaches for EFVS Operations to Touchdown and Rollout. A pilot may conduct an EFVS-TD operation on:
1. Any straight-in Category I instrument approach procedure (IAP) with a DA or DH.
2. A straight-in nonprecision approach with an MDA if the operator is authorized in OpSpec/MSpec/LOA C073, Vertical Navigation (VNAV) Instrument Approach Procedures (IAP) Using Minimum Descent Altitude (MDA) as a Decision Altitude (DA)/Decision Height (DH), to use a DA in lieu of MDA for that approach.
Note: Operators authorized to conduct EFVS-TD operations may use the EFVS in lieu of natural vision to verify that the airplane will touchdown in the touchdown zone during an authorized Category II or III IAP.
3.3 The Use of the PM Display. During an EFVS-TD operation, a display of the enhanced image is provided to the pilot monitoring the approach. This display enables the PM to assess the safe conduct of the approach, landing, and rollout, and intervene if necessary in visibilities where natural vision may not be sufficient.
5 Figure 3. EFVS Operation to Touchdown and Rollout
3.4 Limitations and Conditions That Apply to EFVS Operations to Touchdown and Rollout. In accordance with § 91.176(a)(4), the FAA has prescribed conditions and limitations for the use of EFVS in an operator’s OpSpec/MSpec/LOA. Authorizations limit visibilities for conducting EFVS operations based on the suitability of a specific system, the demonstrated sensor performance, or the conditions in which the EFVS operations are conducted. In addition, EFVS-TD operations are limited to airports that have weather reporting facilities, since it may not be possible to ensure the approach is conducted in visibilities for which the system is suitable.
3.5 Go-Around. In the event that the enhanced flight visibility or visual references cannot be maintained or a failure of any EFVS component (image or symbology) occurs in the visual segment prior to touchdown, a go-around should be initiated. This does not preclude a pilot’s authority to continue an approach if continuation is considered to be a safer course of action.
4 EFVS OPERATIONS TO 100 FEET ABOVE THE TDZE—§ 91.176(b).
4.1 General Description. During an EFVS-100 operation (see Figure 4 below), the pilot uses a combination of enhanced vision imagery provided by an EFVS and natural vision to descend from a DA/DH or MDA to landing when the flight visibility is not sufficient to conduct the approach with natural vision under § 91.175(c) and (d). The pilot begins the visual segment using the EFVS to comply with the enhanced flight visibility requirements in § 91.176(b)(3)(i) and the visual reference requirements in § 91.176(b)(3)(ii). The pilot continues the visual segment below 100 feet through landing
6 and rollout using the EFVS to comply with the enhanced flight visibility requirements in § 91.176(b)(3)(i) and concurrently using natural vision to comply with the visual reference requirements in § 91.176(b)(3)(iii).
Figure 4. EFVS Operation to 100 Feet Above the Touchdown Zone Elevation
4.2 Approaches for EFVS Operations to 100 Feet Above the TDZE. A pilot may conduct an EFVS-100 operation on any straight-in Category I precision or nonprecision IAP. This includes nonprecision approaches that may have final segments offset by as much as 30 degrees.
4.3 Identifying Visual References at 100 Feet. At 100 feet above the TDZE, pilots are also required by § 91.176(b)(3)(iii) to have sufficient natural visibility to see the threshold or the touchdown zone in order to continue. In order to remain in compliance with § 91.176(b)(3)(i), pilots should not turn off the EFVS image at any time during an EFVS operation.
4.4 Go-Around. In the event that the enhanced flight visibility or visual references cannot be maintained or a failure of any EFVS component (image or symbology) occurs in the visual segment prior to touchdown, a go-around should be initiated. This does not preclude a pilot’s authority to continue an approach if continuation is considered to be a safer course of action.
7 5 AIRCRAFT QUALIFICATIONS FOR EFVS OPERATIONS.
5.1 Aircraft Qualifications for U.S.-Registered Aircraft. As required in § 91.176(a)(1) and (b)(1), an EFVS installed on a U.S.-registered aircraft intended for use in EFVS operations must be approved in accordance with an FAA type design approval (e.g., type certificate, amended type certificate, or supplemental type certificate). The current version of AC 20-167, Airworthiness Approval of Enhanced Vision System, Synthetic Vision System, Combined Vision System, and Enhanced Flight Vision System Equipment, contains guidance for obtaining airworthiness approvals for EFVS.
5.1.1 EFVS-TD Capability. An EFVS that meets the applicable airworthiness criteria for use in EFVS-TD operations may be described in an Airplane Flight Manual or its supplement (AFM(S)) as:
1.
An EFVS Landing System;
2.
Eligible for operations under § 91.176(a); or
3. Eligible for EFVS operations to touchdown and rollout.
Note: An EFVS landing system is approved for use in EFVS-100 operations.
5.1.2 EFVS- 100 Capability. An EFVS that meets the applicable airworthiness criteria for use in EFVS-100 operations may be described in an AFM(S) as:
1.
An EFVS Approach System;
2.
Eligible for operations under § 91.176(b);
3. Eligible for EFVS operations to 100 feet above the TDZE; or
4. An AFM that has not been updated may still reference operations under § 91.175(l) or (m).
5.2 Aircraft Qualifications for Foreign-Registered Aircraft. An EFVS installed on a foreign-registered aircraft used to conduct EFVS operations in the United States should be approved by the State of the Operator or the State of Registry to meet the requirements of ICAO Annex 6 and should meet all of the requirements in § 91.176(a)(1)(i) or (b)(1)(i), as applicable.
5.3 Aircraft Qualifications for Experimental Aircraft. Section 91.176(d) provides an exception for aircraft manufacturers and EFVS developers that may have a need to use an EFVS without a type design approval to conduct an EFVS operation for research and development or for a flight test in conjunction with an aircraft certification project.
5.4 Aircraft Qualifications for Public Aircraft Operations. All aircraft used in public aircraft operations, other than the U.S. Military, must meet the EFVS civil certification and airworthiness requirements, per § 91.176(c). This includes the requirement for the EFVS to conform to an FAA type design approval.
8 6 PILOT TRAINING FOR EFVS OPERATIONS.
6.1 EFVS System Familiarity. As required by § 91.176(a)(2)(ii) and (b)(2)(ii), each pilot must have adequate knowledge of, and familiarity with, the aircraft, the EFVS, and the procedures to be used during an EFVS operation.
6.2 Training for FAA-Certificated Pilots, Pilots Operating Under Part 91K, 121, 125, or 135, or Operating a U.S.-Registered Aircraft. As required by part 61, § 61.66(a)(1)(ii) and (b)(1)(ii), a pil ot conducting an EFVS operation must have a logbook or training record endorsement showing satisfactory completion of an FAA-approved ground and flight training program for that EFVS operation and aircraft category.
Note 1: As allowed by § 61.66(f), a military pilot (or former military pilot) in the U .S. Armed Forces may use documentation showing completion of U.S. Armed Forces ground and flight training in EFVS operations to meet the EFVS pilot training requirements.
Note 2: A pilot who can show documentation of satisfactory completion of training on EFVS-100 operations prior to March 13, 2018, is not required to obtain a logbook or training record endorsement for EFVS-100 operations, per § 61.66(h)(4).
6.2.1 Ground Tr aining. Per § 61.66(a)(1), ground training is required for any pilot in command (PIC), any PF, and any PM during an EFVS operation.
6.2.2 Flight Tra ining. Per § 61.66(b)(1), flight training is required for any PIC or any PF during an EFVS operation.
6.2.3 Supplemental and Differences Training. P ilots may utilize training programs that integrate subjects and tasks required for both operations (i.e., EFVS-TD or EFVS-100) or a training curriculum designed to train on the differences between the two EFVS operations when appropriate.
6.2.4 Checking for P arts 91K, 121, 125, and 135. Per §§ 91.1065, 121.441, 125.287, and 135.293, program managers or certificate holders (CH) are required to incorporate EFVS tasks applicable to their operation into their pilot checking. In addition, the FAA recommends that recurrent training provide a sufficient refresher on EFVS subjects and tasks to successfully complete the check.
6.3 Training for Pilots Operating Under Part 129 or Operating Foreign- Registered Aircraft. As required by § 91.176(a)(2)(vii)(B) and (b)(2)(vi)(B), pilots operating under part 129 must be qualified in accordance with the training requirements of the civil aviation authority (CAA) of the State of the Operator.
6.4 Training for Pilots Conducting Public Aircraft Operations. As required by § 91.176(c)(2), pilots conducting public aircraft operations, other than the U.S. Military, must meet the training requirements of § 61.66.