Appendix D D-2 Representative levels of snowfall.
Representative levels of fog.
Haze.
Representative sun angles.
Representative airport lighting configurations.
Representative airport/runway surface conditions (dry, wet, standing water, snow cover).
Representative thermal crossover conditions.
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.).
Representative instrument approaches for the intended EFVS operations.
Note: A successful go-around due to lack of either enhanced vision from the DH/DA or natural vision at 100 ft above TDZE, does not constitute a faulted approach. A faulted approach is if:
o HUD or EFVS Approach System failure has occurred.
o 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.
o At 100 ft above TDZE the aircraft is not positioned so that the cockpit is within, and tracking so as to remain within, the lateral confines of the runway extended.
o Due to a confusing or misaligned image, the touchdown will be too short or too long.
o The EFVS Approach System image degrades the fly-ability of the display such that a successful approach to DA/DH or MDA/MDH is not possible.
D.3 Test Points Testing should include all phases of flight for which the applicant seeks approval of the system. In addition to the success criteria for approaches, the EFVS Approach System minimum performance standards require the assessment of the HUD/EFVS Approach System display when used in conjunction with the flight instrumentation required in 14 CFR § 91.176 and listed in chapter 4, paragraph 4.5.1.3 of this AC. The following evaluations should be performed in representative configurations. (The pilot evaluation matrix is at the end of this appendix.)
Appendix D D-3 D.4 Evaluation During Taxi D.4.1 Assess EFVS Approach System/HUD combination while taxiing and making identification of objects on runways, taxiways, parking aprons.
D.4.2 Verify the use of EFVS Approach System does not cause confusion or misleading information when viewing through the HUD/EVS all types of airport runway, taxiway, obstruction, and barrier lighting, marking and signage as well as the navigation, taxi, and landing lights of other aircraft.
D.4.3 Verify the HUD combiner, with the image displayed, does not significantly alter the color perception of the external scene.
D.4.4 Assess lack of burn-in or blooming from high intensity heat sources such as operating (running) engines, etc.
D.5 Take off Evaluation D.5.1 Ensure correct pitch angle is achieved using HUD pitch reference target.
D.5.2 Verify symbology in EFVS Approach System mode is clear, visible, and does not cause over-control or oscillations in acquiring and maintaining the required ground track.
D.5.3 Confirm the HUD with EFVS Approach System provides the pilot with a quick-glance (instant) sense of flight parameters.
D.5.4 Assess the transition to different selected vertical modes.
D.5.5 Evaluate the EFVS Approach System image during the take-off roll and throughout the climb segment, against the attributes listed in the pilot evaluation matrix.
D.6 Climb and Descent and Lateral Modes Evaluation D.6.1 Climb, descent, and lateral modes should be evaluated in day and night IMC and VMC to assess HUD/EFVS Approach System compatibility.
D.6.2 During vertical and lateral guidance maneuvers, evaluate the EFVS Approach System image against the attributes listed in the pilot evaluation matrix.
D.7 Instrument Approaches.
During any instrument approach for which approval is sought, HUD/EFVS Approach System compatibility should be evaluated against the attributes listed in the pilot evaluation matrix.
Appendix D D-4 D.8 Flare Landing and Go Around D.8.1 While using EFVS Approach System during final approach and through the flare (below 50 ft), touchdown roll or go-around, assess the transition to natural vision and compatibility of the guidance when following the HUD/EFVS Approach System flight cues.
D.8.2 Confirm 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.
D.8.3 Throughout the approach guidance maneuvers, evaluate the EFVS Approach System image against the attributes listed in the pilot evaluation matrix.
D.9 Copilot Monitor A copilot monitor 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.
D.9.1 Verify satisfactory display of imagery in all lighting and environmental conditions and that dimming controls of the display are adequate.
D.9.2 If the display has dual purposes, verify the means of switching the display to being the EFVS Approach System monitor and back is satisfactory and clearly evident.
D.9.3 Verify no flicker and/or jitter in the display.
D.9.4 Verify no objectionable glare or reflections are generated by the display or are visible in the display.
D.9.5 Verify the co-pilot’s use of the EFVS Approach System monitor does not require undue head/body movement away from his/her normal scan pattern or his/her normal seated position.
D.10 Failure Cases.
Failure cases to support the FHA should be assessed as required, for example, uncommanded full image brightness, misaligned image, frozen image, etc. during the approaches required in this appendix.
D.11 Ice Protection System Evaluation D.11.1 If the EFVS Approach System sensor installation has ice protection capability, the EFVS Approach System image must be evaluated with the ice protection on and off in representative environmental conditions.
Appendix D D-5 D.11.2 Icing of the sensor fairing/radome must be appropriately assessed in accordance with the certified flight envelope.
D.12 Evaluation Matrix.
Table 6 contains the pilot’s evaluation matrix. The evaluation matrix should be used to support the testing described in this appendix. Additional evaluation points may be added to the test program depending on particular features and intended functions of the actual system being certified.
Table 6. EFVS Approach System Evaluation Matrix EFVS Approach System Evaluation Conditions A Confirm crew workload is not adversely affected by the HUD/ EFVS Approach System installation.
B Verify no adverse physiological effects from using the HUD/ EFVS Approach System (for example, fatigue, eye strain).
C Verify HUD/EFVS Approach System 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 diff erences in binocular view.)
D Verify no jitter or flicker of HUD/EFVS Approach System symbology/image.
E Verify the EFVS Approach System image does not have noise, local disturbances or artifacts that distract from the use of the system.
F If HUD symbol ogy has been modified to accommodate the EFVS Approach System image, assess HUD guidance and ensure that introduction of EFVS Approach System does not induce lag in control symbols inducing Pilot Induced Oscillation (PIO).
G Verify the system is not adver sely affected by aircraft maneuvering or changes in attitudes encountered during the referenced environmental conditions.
H Ensure 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 the total data presented by the EFVS Approach System imagery and HUD symbology does not over clutter the HUD combiner display area.
Appendix D D-6 EFVS Approach System Evaluation Conditions J Assess the degree of obscuration of the pilot’s outside vi ew or field of view through the cockpit window as a result of EFVS Approach System 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 Approach System imagery.
L Confirm there is no discrepancy between the conformal HUD symbols, sensor image, and the outside view through the windshield.
M Verify outside visibility as viewed through combiner sensor imagery is adequately aligned and conformal to the external scene and HUD symbology.
N Confirm the EFVS Approach System 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 Approach System 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.
R Determine whether the sensor image displayed on the HUD combin er 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 his/her task performance or safety.
T Verify identification of approach lights, runway threshold, touchdown zone etc. as per 14 CFR § 91.176(b)(3).
U Confirm the HUD EFVS Approach System image is suitable and performs its intended function.
V Confirm the sensor image on the co -pilot’s 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 pilot evaluation matrix.
Appendix D D-7 EFVS Approach System Evaluation Conditions X During vertical and lateral guidance maneuvers evaluate the EFVS Approach System image against the attributes listed in the attached pilot evaluation matrix.
Appendix E E-1 APPENDIX E. SAMPLE FLIGHT TEST CONSIDERATIONS FOR EFVS LANDING SYSTEM E.1 General Flight Test Considerations.
E.1.1 The objectives of the flight test program are to ensure that the system performs its intended function when installed, and to demonstrate that the EFVS Landing System is operationally acceptable and safe.
E.1.2 The flight test program should demonstrate that the EFVS Landing System is capable of providing enhanced flight visibility that is no less than the visibility required by the instrument approach, in conditions where actual flight visibility is less than the visibility required by the instrument approach. The EFVS Landing System flight demonstrations should prove that the system provides a satisfactory view of the required visual references for descent below DA/DH even when they are not visible using natural vision. The EFVS Landing System should enable the pilot to complete the instrument approach, landing, and rollout to a safe taxi speed using enhanced flight visibility when visual references would not otherwise be sufficiently visible using natural vision.
E.1.3 For EFVS Landing Systems installed on aircraft that are intended to conduct 14 CFR part 121,125, and 135 operations the applicant should document the demonstrated performance and the environmental conditions in which the performance was demonstrated. The additional documentation is necessary for the 14 CFR part 121,125, and 135 operators to be granted operational approval from Flight Standards to conduct EFVS touchdown and rollout. See AC 90-106 for further information regarding the operational approval process required for conducting EFVS operations. A summary of demonstrated performance and the associated environmental conditions should be documented in the AFM.
E.1.4 The flight test should demonstrate that the EFVS Landing System display of imagery and HUD symbology is satisfactory, so that both elements of information are readable and usable without mutual interference. The flight test should demonstrate that the brightness and contrast levels of the imagery and the symbology can be effectively controlled and provide satisfactory contrast between the two. Since flight deck and external light levels can affect the readability of the EFVS Landing System display and can change significantly throughout the approach and landing operation, the flight test should demonstrate that control of display brightness and contrast in dynamic conditions does not require excessive workload for the pilot.
E.1.5 Environmental conditions should be chosen to exercise both the automatic and manual control of items such as brightness, contrast, and gain, and any other parameter that affects the image displayed to the pilot.
E.2 Minimum Flight Test Conditions Observed.
Appendix E E-2 E.2.1 Testing should include an appropriate number of fault-free approaches and landings in as many of the conditions listed below as practicable and as applicable to the systems intended function. The applicant should plan for no less than 50 fault free approaches and landings, of which at least 5 approaches will be needed to confirm satisfactory goaround performance. A sufficient number of approaches will be needed, with visibility conditions between 2400ft RVR and 1000ft RVR, to demonstrate that the EFVS Landing System can provide at least 2400 ft of enhanced flight visibility and enable the complete low visibility operation. The applicant and the FAA will agree on the minimum number of such approaches, but the number may change depending on demonstration results. The following list should be assessed against the EFVS Landing System Sensor(s), intended use and the specific installation. Additional tests may be specified. The environmental conditions to be tested must be agreed to by the FAA.
Night 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.
Representative sun angles.
Representative airport lighting configurations.
Representative airport/runway surface conditions (dry, wet, standing water, snow covered).
Representative thermal crossover conditions.
Representative wind conditions (e.g., crosswind, headwind, tailwind) and off-set conditions regarding lateral field of regard.
Representative runway surface types (dirt, asphalt, concrete, etc.).
Representative adjacent surfaces types (dirt, asphalt, concrete, etc.).
Representative runway widths.
Representative approach procedures and vertical approach angles.
Representative runway slopes (within the aircraft limitations).
E.2.2 A faulted approach occurs anytime the pilot is unable to complete a safe and successful approach, landing, rollout, and turnoff within the operational performance parameters detailed in Appendix D, or within additional operational performance standards as may be required by the certifying authority. However, a faulted approach does not occur due to the lack or loss of enhanced visibility due to the atmosphere, so long as a successful missed approach or rejected landing is executed. A faulted approach also does not occur due to ATC intervention, interference from other aircraft, interference from
Appendix E E-3 ground vehicles or persons, interference from animals (including birds), or any other reason not relating directly to the EFVS.
E.2.3 Final approach course offsets greater than 3 degrees require further flight test evaluation. The maximum allowable final approach course offset is to be established by flight test. These tests should include factors related to the offset, such as the HUD/EFVS field of view, crosswinds, and the maximum drift angle possible for a conformal flight path vector.
E.3 Test Points.
E.3.1 Testing should include all phases of flight in which EFVS Landing System operation will be permitted, approach types, approach course geometries, and aircraft configurations for which the applicant seeks approval of the system. In addition to the success criteria for the approach, landing, and rollout, the EFVS Landing System minimum performance standards require the assessment of the HUD/EFVS display when used in conjunction with the head up flight indications required in 14 CFR §
91.176 and listed in chapter 4, paragraph 4.5.1.3 of this AC. For effective post-flight analysis and evaluation of the results, past experience has shown that time-stamped video of exactly what is displayed on the HUD are recommended.
E.3.2 The test program should demonstrate that the EFVS Landing System image, with superimposed flight symbology, does not mislead, distract or jeopardize the safety of the landing and rollout. Without requiring exceptional pilot skill, alerting, strength, or workload, the image/symbology should allow and provide the visual cues for the pilot to perform:
E.3.2.1 Speed control 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.
E.3.2.2 A smooth transition through flare to landing.
E.3.2.3 Approach, flare, and landing at a normal sink rate for the aircraft.
E.3.2.4 Lateral touchdown performance shall be demonstrated to be the no worse than that achieved in visual operations for the specific aircraft.
Longitudinal touchdown performance shall be demonstrated within the first 1/3, or the first 3000 ft, of the runway, whichever is more restrictive, and demonstrated to be no worse than that achieved in visual operations for the specific aircraft.
E.3.2.5 Prompt and predictable correction of any lateral deviation away from the runway centerline to smoothly intercepted the centerline.
E.3.2.6 Touchdowns with a bank angle that is not hazardous to the airplane.
Appendix E E-4 E.3.2.7 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).
E.3.2.8 A normal de-rotation.
E.3.2.9 Satisfactory and smooth control of the airplane from touchdown to a safe taxi speed.
E.3.2.10 Satisfactory and smooth control of the path of the airplane along the runway centerline through rollout to a safe taxi speed.
E.3.2.11 A safe go around anytime including touchdown in all configurations to be certified.
E.4 Evaluation During Taxi E.4.1 Assess EFVS/HUD combination while taxiing and making identification of objects on runways, taxiways, and parking aprons.
E.4.2 Verify that the use of EFVS Landing System does not cause confusion or misleading information when viewing through the HUD/EFVS Landing System appropriate types of airport runway, taxiway, obstruction, and barrier lighting and signage as well as the navigation, taxi, and landing lights of other aircraft.
E.4.3 Verify 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 required task.
E.4.4 Assess the impact of burn-in or blooming (if applicable) on the EFVS Landing System image from high intensity heat sources such as running engines, stationary lights, etc.
E.5 Take off Evaluation.
E.5.1 Ensure correct pitch angle is achieved using HUD pitch symbology.
E.5.2 Verify symbology in EFVS Landing System mode is clear, visible, and does not cause over-control or oscillations in acquiring and maintaining the required ground track.
E.5.3 Confirm that the HUD with EFVS Landing System provides the pilot with a quickglance (instant) sense of flight parameters.
E.5.4 Assess the transition to different selected vertical modes.
E.5.5 Evaluate the EFVS Landing System image during the take-off roll and throughout the climb segment, against the attributes listed in the pilot evaluation matrix.
Appendix E E-5 E.6 Climb and Descent and Lateral Modes Evaluation.
E.6.1 Climb, descent, and lateral modes should be evaluated in day and night IMC and VMC to assess HUD/EFVS Landing System compatibility.
E.6.2 During vertical and lateral guidance maneuvers, evaluate the E(F)VS image against the attributes listed in the pilot evaluation matrix.
E.7 Instrument Approaches to the DA(H) E.7.1 During any instrument approach for which approval is sought, HUD/EFVS Landing System compatibility should be evaluated against the attributes listed in the pilot evaluation matrix.
E.7.2 Final approach course offsets greater than 3 degrees require further flight test evaluation. The maximum allowable final approach course offset is to be established by flight test. These tests should include the factors related to the offset, such as the HUD/EFVS Landing System field of view, crosswinds, and the maximum drift angle possible for a conformal flight path vector. Since 14 CFR § 91.176 permits EFVS to touchdown for approaches which could be offset up to 15 degrees, flight test evaluation should factor this offset into potential limitations and airworthiness approvals.
E.8 Final Approach from the DA/DH, Flare, Landing and Rollout to Safe Taxi Speed.
E.8.1 While using EFVS Landing System during an enhanced visual final approach and through the flare (below 50ft), touchdown, rollout, and turn-off, assess the performance of the EFVS Landing System image and displayed symbology against the attributes listed in the pilot evaluation matrix.
E.8.2 Confirm that a landing and rollout to a safe taxi speed that is primarily performance based on the EFVS Landing System image and displayed symbology does not cause over-control or oscillations in acquiring and maintaining the required ground track.
E.9 Rejected Landing Confirm that at any time during the EFVS Landing System based approach between DA/DH and touchdown, a safe rejected landing can be conducted.
E.10 Pilot Monitoring (PM) Display.
E.10.1 Verify the display is location meets the requirements of 14 CFR §§ 23/25/27/29.1321 and any symbology displayed should not adversely obscure the sensor imagery of the runway environment.
Appendix E E-6 E.10.2 Verify satisfactory display of imagery in all lighting and environmental conditions and that dimming controls of the display are adequate.
E.10.3 If the display has dual purposes, verify the means of switching the display to being the EFVS Landing System monitor and back is satisfactory and clearly evident.
E.10.4 Verify that the pilot monitoring use of the PM display monitor does not require undue head/body movement away from his/her normal scan pattern or his/her normal seated position.
E.10.5 Verify 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. The PM’s display should be shown to be acceptable for the pilot monitoring to see and identify visual references and to verify that all visual requirements for the approach and landing are satisfied.
E.11 Failure Cases.
Failure cases to support the FHA shall be assessed and tested as required (e.g., uncommanded full image brightness, misaligned image, frozen image, failed image, etc.) during the approaches required in this appendix.
E.12 Ice Protection System Evaluation.
E.12.1 If the EFVS Landing System sensor installation has ice protection/de-misting capability, the EFVS Landing System image should be evaluated with the ice protection/de-misting on and off in representative environmental conditions.
E.12.2 Icing of the sensor fairing should be appropriately assessed in accordance with the aircraft’s certified flight envelope.
E.13 Evaluation Matrix Table 7 below is the test evaluation matrix that should be used to support the testing described above. Additional evaluation points may be added to the test program depending on particular features and intended functions of the actual system being certified.
Table 7. EFVS Landing System Evaluation Matrix EFVS Landing System Evaluation Matrix A Confirm that crew workload is not adversely affected by the HUD/EFVS Landing System installation.