AC 20-167B Appendix B B.2.2.2 Continue an approach when the weather is reported to be equal to or greater than authorized minimums for use with an EFVS. (§§ 121.651,
125.325, 125.381, and 135.225.)
B.2.3 If the applicant intends the system to be used for EFVS operations that require OpSpec/MSpec/LOA C048, it is recommended that the applicant also demonstrate and document the EFVS’s quantified visual advantage during the certification testing of the EFVS. Further guidance on how to quantify the visual advantage of the EFVS is found in appendix C.
B.3 Minimum Flight Test Conditions Observed.
Testing should demonstrate fault-free approaches for EFVS approach systems or approach and landings for EFVS landing systems in as many of the conditions listed below as practicable and as applicable to the system’s intended function. Additionally, a sufficient number of approaches will be needed in a representative sampling of weather and environmental conditions with flight visibilities lower than the published instrument approach visibility minimums to demonstrate that the EFVS can provide sufficient enhanced flight visibility to complete the EFVS operation. Past experience has shown that the applicants with a new EFVS should plan for no less than 50 fault-free approaches for EFVS approach systems or approach and landings for EFVS landing systems. Include go-around performance in testing. Typically, at least five satisfactory go-arounds are included in testing.
B.3.1 The applicant and the FAA will agree on the minimum number of successfully demonstrated test approaches.
B.3.2 Testing of the EFVS systems should be conducted in as many of the environmental conditions listed below as practical and applicable to the system’s intended function.
The environmental conditions should be chosen to exercise both the automatic and manual control of items such as brightness, contrast, gain, and any other parameter that affects the image displayed to the pilot. The actual environmental conditions used for the flight test program must be agreed to by the FAA. Address the conditions in the following subsection when developing the flight test program:
B.3.2.1 EFVS approach and EFVS landing systems should be tested under the following conditions:
• Night visual flight rules (VFR) conditions over various topography (urban, rural, snow covered, etc.);
• Day and night IFR conditions over various topography;
• Representative levels of rainfall;
• Representative levels of snowfall;
• Representative levels of fog;
• Haze;
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AC 20-167B Appendix B
• Representative sun angles;
• Representative airport lighting configurations to include airports with LED lighting where relevant to the systems intended function;
• Representative airport/runway surface conditions (dry, wet, standing water, snow cover);
• Representative thermal crossover conditions as applicable for the EVS sensor;
• Representative crosswind and off-set approach course conditions regarding lateral FOR;
• Representative runway surface types (dirt, asphalt, concrete, etc.);
• Representative adjacent surfaces types (dirt, asphalt, concrete, etc.);
and
• Representative instrument approaches for the intended EFVS operations.
B.3.2.2 Additional conditions for EFVS landing systems.
• Representative runway widths usable to aircraft on which the EFVS is being installed; and
• Representative runway slopes (within the aircraft limitations).
B.3.3 Data Collection.
The applicant should propose a method to collect and analyze system performance in order to demonstrate that the installed EFVS meets all relevant criteria. The data collection method found in RTCA DO-390/EUROCAE ED-291, Test Procedures for Quantitative Visual Advantage, is recommended for use on all EFVS flight tests in support of appendix B. Collecting data in a manner consistent with RTCA DO-390/ED- 291 could support future certification or operational approval applications and mitigate the need to fly additional test flights.
B.3.4 Faulted Approaches.
A faulted approach occurs anytime the pilot is unable to complete a safe and successful approach, landing, or rollout and turnoff. Examples of faulted approaches are included below. The list provides examples. Each unique system design could generate additional faulted approach cases.
B.3.4.1 Examples of a faulted approach:
• HUD or EFVS approach system failure has occurred;
• At 100 ft above TDZE, the indicated airspeed, heading, or attitude are not satisfactory for a normal flare and landing, due to a confusing or misaligned EFVS approach system image;
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AC 20-167B Appendix B
• At 100 ft above TDZE, the aircraft is not positioned so that the flightdeck is within and tracking so as to remain within the lateral confines of the extended runway;
• Due to a confusing or misaligned image, the touchdown will be too short or too long; and/or
• The EFVS approach system image degrades the flyability of the display such that a successful approach to DA/DH or MDA is not possible.
B.3.4.2 A faulted approach does not occur due to a lack or loss of enhanced flight visibility due to the atmospheric conditions, so long as a successful missed approach or rejected landing is executed.
B.3.4.3 A faulted approach also does not occur due to a ir traffic control intervention, interference from other aircraft, interference from ground vehicles or persons, interference from animals (e.g. birds), or any other reason not directly related to the EFVS.
B.4 Taxi Evaluation Steps.
B.4.1 Assess EFVS/HUD combination while taxiing and making identification of objects on runways, taxiways, and parking aprons.
B.4.2 Verify that the EFVS display, with the image displayed, does not significantly alter the color perception of the external scene to an extent which jeopardizes the pilot’s ability to distinguish the relevant features of the environment, precluding the performance of any task.
B.4.3 Verify that the HUD combiner, with the image displayed, does not significantly alter the color perception of the external scene to an extent which jeopardizes the pilot’s ability to distinguish the relevant features of the environment, precluding the performance of any task.
B.4.4 Assess any burn-in or blooming (if applicable) on the EFVS image from high intensity heat sources such as operating engines, stationary lights etc.
B.5 Take off Evaluation Steps.
B.5.1 Ensure correct pitch angle is achieved using HUD pitch symbology.
B.5.2 Verify that the symbology in EFVS mode is clear, visible, and does not cause overcontrol or oscillations in acquiring and maintaining the required ground track.
B.5.3 Confirm that the HUD with EFVS provides the pilot with a quick-glance (instant) sense of flight parameters.
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AC 20-167B Appendix B B.5.4 Assess the transition to different selected vertical modes.
B.5.5 Evaluate the EFVS image during the take-off roll and throughout the climb segment, against the attributes listed in the flight test evaluation matrix. See Table B-1 and Table B-2.
B.6 Climb and Descent and Lateral Modes Evaluation Steps.
B.6.1 Evaluate climb, descent, and lateral modes in day and night instrument meteorological conditions and visual meteorological conditions to assess HUD/EFVS compatibility.
B.6.2 During vertical and lateral guidance maneuvers, evaluate the EFVS image against the attributes listed in the flight test evaluation matrix. See Table B-1 and Table B-2.
B.7 Instrument Approaches.
B.7.1 During any instrument approach for which approval is sought, EFVS compatibility should be evaluated against the attributes listed in the flight test evaluation matrix. See Table B-1 and Table B-2.
B.7.2 Speed control should be demonstrated to be maintained within +10/-5 knots of the approach speed, whether manually controlled or with auto-throttle, as proposed by the applicant up to the point where the throttles are retarded for landing.
B.7.3 EFVS landing systems may fly final approach courses with offsets greater than 3 degrees. In this case, establish the maximum allowable final approach course offset by flight test. The flight test should address factors related to the offset, such as HUD/EFVS field of view, crosswinds, and the maximum drift angle for a conformal FPV. Section 91.176 permits EFVS to touchdown for approaches with offsets up to 15 degrees. The flight test evaluation should factor this offset into potential limitations and airworthiness approvals.
B.7.4 The EFVS must present all display requirements of § 91.176(a)(1) or § 91.176(b)(1) throughout the entire instrument approach. If any of the required EFVS display elements are not shown during an approach type that the aircraft is approved to conduct
(i.e., steep approaches), then a limitation should be annotated in the AFM.
B.8 Final Approach from the DA/DH or MDA, Flare Landing, and Rollout to a Safe Taxi Speed.
B.8.1 While using EFVS during final approach and through the flare (below 50 ft), touchdown roll or go-around, and turn-off, assess the performance of the EFVS image and displayed symbology against the attributes listed in the flight test evaluation matrix.
See Table B-1 and Table B-2.
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AC 20-167B Appendix B B.8.2 Confirm that landing rollout information, if provided in the display, is sufficiently visible to the pilot and does not cause over-control or oscillations in acquiring and maintaining the required ground track.
B.8.3 For EFVS approach systems, assess the transition to natural vision and compatibility of the guidance when following the HUD/EFVS approach system flight cues.
B.8.4 The EFVS landing system should be evaluated to ensure that the system provides:
• A smooth transition through flare to landing;
• Approach, flare, and landing at a normal sink rate for the aircraft;
• Have 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 and during rollout;
• Touchdown within the touchdown zone and that the lateral touchdown performance should be demonstrated to be no worse than that achieved in visual landings for the specific aircraft;
• Prompt and predictable correction of any lateral deviation away from the runway centerline to smoothly intercept the centerline;
• Touchdowns with a bank angle that is not hazardous to the airplane;
• Demonstrated performance of the installed EFVS landing system at the representative RVR/visibility, as described in this document, will determine any additional limitations (for example, crosswind and offset);
• A normal de-rotation rate;
• Satisfactory and smooth control of the airplane from touchdown to a safe taxi speed; and
• Satisfactory and smooth control of the path of the airplane along the runway centerline through rollout to a safe taxi speed.
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AC 20-167B Appendix B B.9 Rejected Landing.
Confirm that at any time during the EFVS operation, a rejected landing can be safely conducted in all configurations to be approved.
B.10 Pilot Monitoring (PM) Display Steps.
B.10.1 Display Location.
B.10.1.1 EFVS Approach Systems.
A PM display is not required by the FAA for operations within the United States. However, if one is installed, the applicant should assess the ergonomic aspects of the image on the copilot’s EFVS approach system monitor.
B.10.1.2 EFVS Landing System.
Section 91.176(a) requires a PM display. Under §§ 23.2500, 23.2610,
25.1321, 27.1321, 29.1321, verify that the display’s location meets the certification requirement and any symbology displayed does not adversely obscure the sensor imagery of the runway environment.
B.10.2 Verify satisfactory display of imagery in all lighting and environmental conditions and that dimming controls of the display are adequate.
B.10.3 If the display has dual purposes, verify that the means of switching the display to the EFVS approach system monitor and back is satisfactory and clearly evident.
B.10.4 Verify no unacceptable flicker and/or jitter in the display.
B.10.5 Verify that no objectionable glare or reflections are generated by the display or are visible in the display.
B.10.6 Verify that the co-pilot’s use of the EFVS approach system monitor does not require undue head/body movement away from their normal scan pattern or their normal seated position.
B.10.7 If the PM display is a HUD or equivalent display, verify that the PM display provides a conformal image with the visual scene over the range of aircraft attitudes and wind conditions for each mode of operation.
B.10.8 The PM display should be shown to be acceptable for the pilot monitoring to see and identify visual references and verify that all visual requirements for the approach and/or landing are satisfied.
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AC 20-167B Appendix B B.11 Failure Cases.
Failure cases to support the FHA should be assessed and tested as required, for example, uncommanded full image brightness, misaligned image, frozen image, etc.
during the approach testing specified in this appendix.
B.12 Ice Protection System Evaluation.
B.12.1 If the EFVS approach system sensor installation has ice protection capability, the EFVS image should be evaluated with the ice protection on and off in representative environmental conditions.
B.12.2 Icing of the sensor fairing/radome should be appropriately assessed in accordance with the approved flight envelope.
B.13 Flight Test Evaluation Matrix.
The flight test evaluation matrix is a table of recommended aspects of the EFVS installation that should be evaluated during the flight test program. The applicant should propose a flight test evaluation matrix that is suitable for the applicant’s specific EFVS installation. As a starting point, Table B-1 contains the recommended minimum flight test evaluation matrix for all EFVS installations. Table B-2 contains the recommended minimum supplemental test evaluations specific to EFVS landing systems.
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AC 20-167B Appendix B Table B-1. EFVS Flight Test Evaluation Matrix
A Confirm flightcrew workload is not adversely affected by the EFVS installation.
B Verify no adverse physiological effects from using the EFVS (for example, fatigue, eye strain).
C Verify EFVS symbology is visible within pilot field of view (FOV). (When viewed by both eyes from any off-center position within eye box, non-uniformities should not produce perceivable differences in binocular view.)
D Verify no unacceptable jitter or flicker of EFVS symbology/image.
E Verify that the EFVS image does not have noise, local disturbances or artifacts that distract from the use of the system.
F If HUD symbology has been modified to accommodate the EFVS image, assess HUD guidance and ensure that introduction of EFVS does not induce lag in control symbols inducing p ilot induced oscillation (PIO).
G Verify the system is not adversely affected by aircraft maneuvering or changes in attitudes encountered during the referenced environmental conditions.
H Ensure that the required flight and navigation functions applicable for the phase of flight being evaluated are clearly displayed on the HUD with no unacceptable occlusions during testing.
I Verify that the total data presented by the EFVS imagery and HUD symbology does not over clutter the HUD combiner display area.
J Assess the degree of obscuration of the pilot’s outside view or field of view through the flightdeck window as a result of EFVS imagery and HUD symbology.
K Confirm the pilot’s ability to detect hazards, maneuver, avoid traffic, terrain or other obstacles, is not impaired or degraded by the display of EFVS imagery.
L Confirm that there is no discrepancy between the conformal HUD symbols, sensor image, and the outside view through the flightcrew’s windows.
M Verify that outside visibility as viewed through combiner sensor imagery is adequately aligned and conformal to the external scene and HUD symbology.
N Confirm that the EFVS imagery does not obscure the desired imagery of the scene, impair the pilot’s ability to detect and identify visual references, mask flight hazards, or distract the pilot.
O Assess the ease of operating the HUD with the sensor image displayed, during aircraft maneuvers and change in attitude encountered in normal operations.
P Determine whether there is any glare or reflection that could interfere with the EFVS image either in day or night lighting conditions.
Q Determine if any impairment is experienced in the ability to use the display due to visible external surfaces within the HUD.
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AC 20-167B Appendix B
R Determine whether the sensor image displayed on the HUD combiner objectionably impairs the pilot compartment view.
S Assess impact of water droplets running across the sensor window to ensure that it does not distract the pilot or degrade their task performance or safety.
T Verify that the enhanced flight visibility provided by the EFVS is greater than the instrument approach procedure minimums and required visual references are clearly identifiable with the EFVS at DA/DH or MDA.
U Confirm that the EFVS image is suitable and performs its intended function.
V Confirm that the sensor image on the pilot monitor display (if installed) is useable and performs its intended function.
W Evaluate the EFVS approach system image during the takeoff roll and throughout the climb segment against the attributes listed in the attached fight test evaluation matrix.
X During vertical and lateral guidance maneuvers, evaluate the EFVS image against the attributes listed in the pilot evaluation matrix.
Z Evaluate the EFVS using all available HUD modes and/or declutter options as appropriate for the phase of flight and condition.
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AC 20-167B Appendix B Table B-2. EFVS Landing System Supplemental Flight Test Evaluation Matrix
A Confirm that the EFVS provides the correct and appropriate visual cues for the pilot to perform the required stabilized approach from the DA/DH.
B Confirm that approach speed can be controlled within +10/-5kts, both with and without autothrottle if fitted, up to the point where the throttles are retarded for landing.
C Confirm that the EFVS provides the correct visual cues for the pilot to perform a smooth transition through flare to landing.
D Confirm that the EFVS provides the correct visual cues for the pilot to perform a flare and landing with a normal sink rate.
E Confirm that the EFVS provides the correct visual cues to always allow a consistent touchdown in the defined touchdown zone.
F Confirm that the EFVS provides the correct visual cues to allow a consistent touchdown with a bank angle that is not hazardous to the airplane.
G Confirm that the EFVS provides the correct visual cues to allow normal derotation rate.
H Confirm that EFVS provides the correct visual cues to allow satisfactory and smooth control of the airplane from touchdown to a safe taxi speed.
I Confirm that the EFVS provides the correct visual cues to allow prompt and predictable correction of any lateral deviation away from the runway centerline to smoothly intercept the centerline.
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AC 20-167B Appendix C APPENDIX C. DETERMINING QUANTIFIED VISUAL ADVANTAGE C.1 Introduction.
Demonstrating a quantified visual advantage is not required for the installed EFVS to be approved. However, any operator that uses the installed EFVS to dispatch the aircraft in accordance with § 121.613, § 125.361, or § 135.219, or to commence an instrument approach under § 121.561, § 125.325, § 125.381, or § 135.225 requires an operational approval from the FAA’s Flight Standards Service. For the operator to receive the required operational approval, the applicant must demonstrate and document a quantifiable measure of the EFVS visual advantage performance.
C.2 Quantified Visual Advantage Test Plan.
For determination of visual advantage, a data set demonstrating in-flight the relationship between slant range flight visibility and slant range enhanced flight visibility (visual advantage) with the reported visibility should be created and analyzed.
C.2.1 RTCA DO-390/EUROCAE ED-291, Test Procedures for Quantitative Visual Advantage.
Provides an industry consensus methodology for testing and documenting the quantitative visual advantage provided by the installed EFVS. The methodology in DO- 390/ED-291 has been deemed to be acceptable to FAA Flight Standards for the purposes of documenting the performance of the installed EFVS and supporting applications for operational approvals.
C.2.2 Alternate Methods.
An applicant may propose alternate methods of measuring and documenting the quantified visual advantage of the system. Should the applicant propose an alternate method to test the visual advantage for the installed EFVS, it is recommended that the applicant coordinate with the FAA’s Flight Standards Service to ensure that the results of the proposed quantitative visual advantage testing will be sufficient to support an operator’s application for operational approvals.
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AC 20-167B Appendix D APPENDIX D. SA MPLE AIRPLANE FLIGHT MANUAL (AFM) SUPPLEMENT D.1 Introduction.
Appendix D presents a sample below for the AFM supplement for Supplemental Type Certificate (STC) installations. This example may not be entirely applicable to airplane manufacturers when EVS, CVS, or EFVS are approved with the type certificate. The AIR certification branch will assist the applicant in developing an appropriate RFMS.
Installation Center/Repair Station Model XXX EVS/EFVS 123 Fourth Street Vision System Anytown, USA
FAA-APPROVED AIRPLANE FLIGHT MANUAL SUPPLEMENT
ABC MODEL XXX YYY VISION SYSTEM AIRPLANE MAKE:
AIRPLANE MODEL:
AIRPLANE SERIAL NO.:
REGISTRATION NO.:
This document must be carried in the airplane at all times. It describes the operating procedures for the ABC Model XXX YYY vision system when it has been installed in accordance with <manufacturer's installation manual number and date>.
For airplanes with an FAA-approved airplane flight manual, this document serves as the FAA Approved ABC Model XXX YYY Flight Manual Supplement. For airplanes that do not have an FAA-approved flight manual, this document serves as the FAA Approved ABC Model XXX YYY Supplemental Flight Manual.
The information contained herein supplements or supersedes the basic airplane flight manual dated <insert date> only in those areas listed herein. For limitations, procedures, and performance information not contained in this document, consult the basic airplane flight manual.
FAA-APPROVED ____________________ Title Office Federal Aviation Administration City, State D -1