1. A redundant flight control or guidance system, demonstrated in accordance with Appendix 3, or for aircraft types previously demonstrated acceptable earlier criteria described in previous versions of AC 120-28 as amended, or acceptable international criteria, such as the JAR AWO.
Acceptable flight guidance or control systems include the following:
a. A Fail Operational or Fail Passive automatic landing system at least to touchdown, or
b. A Fail Operational or Fail Passive manual flight guidance system providing suitable head-up or head-down command guidance, and suitable monitoring capability at least to touchdown, or
c. A hybrid system, using automatic landing capability as the primary means of landing at least to touchdown.
d. Other system which can provide an equivalent level of performance and safety.
NOTE: For system concepts not currently approved by FAA or system concepts not addressed by Appendix 3, a proof of concept demonstration is required prior to either airworthiness or operational consideration for approval.
2. An automatic throttle or automatic thrust control system which meets Appendix 3, or appropriate earlier criteria as specified in an FAA-approved AFM. However, for operations with a 50 foot Decision Height, or other operations that have specifically been evaluated such as for engine inoperative landing capability, automatic throttles may not be required if it has been demonstrated that operations can safely be conducted, with an acceptable work load, without their use.
3. At least two independent navigation receivers/sensors providing lateral and vertical position or displacement information, typically with the first pilot's station receiving information from one and the second pilot's station receiving information from the other. The navigation receivers/sensors must meet the criteria specified in Appendix 3 or equivalent, or must meet an earlier acceptable criteria as specified in an FAA AFM (e.g., 2 ILS localizer and glide slope receivers meeting performance requirements of AC 120-28C; Appendix 1, paragraph 7a & b).
4. At least two approved radio altimeter systems which meet the performance requirements outlined in Appendix 3, or acceptable earlier criteria, as specified in an FAA AFM, typically with the first pilot's station receiving information from one and the second pilot's station receiving information from the other.
5. Failure detection, annunciation, and warning capability, as described in Appendix 3, or as determined acceptable by earlier criteria, such as 120-28C; Appendix 1, paragraph 7c & 7g, and specified in an FAA AFM.
6. Missed approach guidance provided by one or more of the following means:
a. Attitude displays which include suitable pitch attitude markings, or a pre-established computed pitch command display.
b. An approved flight path angle display, or
c. An automatic or flight guidance go-around capability.
7. Suitable forward and side flight deck visibility for each pilot, as specified in 5.13.1.
8. Suitable windshield rain removal, ice protection, or defog capability as specified in 5.13.2.
5.3. Airborne Systems for Category III Minima Less Than RVR600.
5.3.1. Airborne Systems for Category III Minima Not Less than RVR400. The following equipment in addition to the instrument and navigation equipment required by part 91 for IFR flight is the minimum aircraft equipment considered necessary for Category III operations to minima less than RVR600 but not less than RVR400:
1. A redundant flight control or guidance system, demonstrated in accordance with Appendix 3, or for aircraft types previously demonstrated acceptable earlier criteria described in previous versions of AC 120-28 as amended, or acceptable international criteria, such as the JAR AWO.
Acceptable flight guidance or control systems include the following:
a. A Fail Operational landing system with a Fail Operational or Fail Passive automatic rollout system, or
b. A Fail Passive landing system (limited to touchdown zone RVR not less than RVR600) with Fail Passive rollout provided automatically or by a flight guidance system providing suitable head-up or head-down guidance, and suitable monitoring capability, or
c. A Fail Operational hybrid automatic landing and rollout system with compatible manual flight guidance system, using automatic landing capability as the primary means of landing.
d. Other system which can provide an equivalent level of performance and safety.
NOTE: For system concepts not currently approved by FAA or system concepts not addressed by Appendix 3, a proof of concept demonstration is required prior to either airworthiness or operational consideration for approval.
2. An automatic throttle or automatic thrust control system which meets Appendix 3, or appropriate earlier criteria as specified in an FAA-approved AFM. However, for operations with a 50
foot Decision Height, automatic throttles may not be required if it has been demonstrated that operations can safely be conducted, with an acceptable work load, without their use.
3. At least two independent navigation receivers/sensors providing lateral and vertical position or displacement information, typically with the first pilot's station receiving information from one and the second pilot's station receiving information from the other. The navigation receivers/sensors must meet the criteria specified in Appendix 3 or equivalent, or must meet an earlier acceptable criteria as specified in an FAA AFM (e.g., 2 ILS localizer and glide slope receivers meeting performance contained in AC 120-28C; Appendix 1, paragraph 7a & b).
4. At least two approved radio altimeter systems which meet the performance criteria outlined in Appendix 3, or acceptable earlier criteria, as specified in an FAA AFM, typically with the first pilot's station receiving information from one and the second pilot's station receiving information from the other.
5. Failure detection, annunciation, and warning capability, as described in Appendix 3, or as determined acceptable by earlier criteria, such as 120-28C; Appendix 1, paragraph 7c & 7g, and specified in an FAA AFM.
6. Missed approach guidance provided by one or more of the following means:
a. Attitude displays which include calibrated pitch attitude markings, or a pre-established computed pitch command display,
b. An approved flight path angle display, or
c. An automatic or flight guidance go-around capability.
7. Suitable forward and side flight deck visibility for each pilot, as specified in 5.13.1.
8. Suitable windshield rain removal, ice protection, or defog capability as specified in 5.13.2.
5.3.2. Airborne Systems for Category III Minima Not Less than RVR300 (75 m). Visibility minima of RVR300 is applicable to those facilities reporting RVR in feet and which have appropriate reporting increments in feet. Visibility minima of 75m is applicable to those facilities reporting RVR in meters and which have appropriate reporting increments in meters.
In addition to the aircraft equipment specified in 5.3.1 above, the following equipment is required for Category III minima not less than RVR300 (75m):
1. A Fail Operational Automatic Flight Control System, or manual flight guidance system designed to meet fail operational system criteria, or a hybrid system in which both the fail-passive automatic system and the monitored manual flight guidance components provide approach and flare guidance to touchdown, and in combination provide full fail operational capability, and
2. A fail operational rollout guidance or control system that can assure safe rollout to taxi speed consisting of either:
a. A fail operational automatic rollout control system or fail operational manual flight guidance rollout system, or
b. A hybrid system consisting of at least a fail passive automatic rollout system and a compatible Fail Passive manual flight guidance rollout control system demonstrated in accordance with Appendix 3; (may be approved for operations not less than RVR300), or
3. Suitable flight instruments, annunciations, or crew procedures which can reliably detect and alert the flightcrew to abnormal lateral or vertical flight path performance during an approach to touchdown, or abnormal lateral performance during rollout.
5.3.3. Airborne Systems for Category III Minima Less than RVR300 (75 m). In addition to the aircraft equipment specified in 5.3.2 above, the following equipment is required for Category III minima less than RVR300 (75m):
1. A Fail Operational Automatic Flight Control System, or manual flight guidance system designed to meet fail operational system criteria, or a hybrid system in which both the fail-passive automatic system and the monitored manual flight guidance components provide approach and flare guidance to touchdown, and in combination provide full fail operational capability, and
2. A fail operational automatic, manual, or hybrid rollout control system.
5.4. Automatic Flight Control Systems and Automatic Landing Systems. Automatic Flight Control Systems or Autoland Systems considered acceptable for Category III, include:
1) Those systems meeting pertinent criteria of Appendix 3,
2) Those systems meeting acceptable earlier FAA criteria which have already been and currently are approved for use through operations specifications (whether or not specifically referenced in AFM provisions), or
3) Those systems meeting other equivalent criteria (e.g., JAR AWO), found acceptable to the FAA.
5.5. Flight Director Systems. Characteristics of Flight Director Systems (head down or head up) used for aircraft authorized for Category III should be compatible with any characteristics of the autopilot or autoland system used. Flight control systems which provide both autopilot control and flight director information may or may not display flight director commands as appropriate for the system design and operator requirements. Regardless of whether Flight Director commands are provided,
situational information displays of navigation displacement must also be provided to both flightcrew members. To assure that unacceptable deviations and failures can be detected, the displays must be appropriately scaled and readily understandable in the modes or configurations applicable.
"Flight director systems" may be considered as "fail passive" if after a failure, the flight path of the aircraft does not experience a significant immediate deviation due to the pilot following the failed guidance before the pilot detects the failure and discontinues using the guidance.
5.6. Head-up Display Systems. Head-up Display systems used as the basis for a suitable Category III authorization must provide guidance for one or both pilots as appropriate for the system design. If information is provided to only the flying pilot, then appropriate monitoring capability must be established for the non flying pilot. Monitoring tasks must be identified, and the non flying pilot must be able to assume control of the aircraft in the event of system failure or incapacitation of the pilot using the Head-up Display (e.g., for a safe go-around or completion of rollout). Head-up Display Systems acceptable for Category III must meet provisions of Appendix 3, or acceptable earlier criteria specified by the FAA and referenced in an AFM.
"Head-up Display systems" may be considered as "fail passive" if:
1. After a failure, the pilot using the system or pilot monitoring the system is made aware of the failure in a timely manner, and
2. The flight path of the aircraft does not experience a significant immediate deviation from the intended path due to the pilot following the failed guidance before the pilot flying or pilot monitoring detects the failure, and the pilot flying discontinues using the guidance.
5.7. Enhanced/Synthetic Vision Systems. Enhanced/Synthetic Vision Systems based on millimeter wave radar or other such sensors may be used to assure the integrity of other flight guidance or control systems in use during Category III operations. They must be demonstrated to be acceptable to FAA in a proof of concept evaluation and they must otherwise be in accordance with Appendix 3. Use of Enhanced/Synthetic Vision Systems for purposes other than establishing the accuracy or integrity of flight guidance system performance must be demonstrated to be acceptable through proof of concept testing prior to identification of specific airworthiness and operation criteria.
5.8. Hybrid Systems. Hybrid systems (e.g., a fail passive autoland system used in combination with a monitored HUD flight guidance system) may be acceptable for Category III if each element of the system alone is shown to meet its respective suitability for Category III, and if taken together, the components provide the equivalent performance and safety to a non-hybrid system as specified for the minima sought (e.g., fail operational Category IIIb).
Hybrid systems with automatic landing capability should be based on the concept of use of the automatic landing system as the primary means of control, with the manual flight guidance system serving as a backup mode or reversionary mode.
Manual rollout flight guidance capability must be provided for hybrid systems which do not have automatic rollout capability. Such manual rollout capability must have been shown to have performance and reliability at least equivalent to that of a fail passive automatic rollout system.
Any transition between hybrid system elements (e.g., control transition from autoland use to manual control HUD use, or for response to failures) must be acceptable for use by properly qualified flightcrews (e.g., qualified in accordance with part 121, SFAR 58, or equivalent JAA criteria, as applicable, and standard industry practices). Transitions should not require extraordinary skill, training, or proficiency.
For any system which requires a pilot to initiate manual control near or shortly after touchdown, the transition from automatic control prior to touchdown to manual control using the remaining element of the hybrid system (e.g., HUD) after touchdown must be shown to be safe and reliable.
For hybrid systems, operational procedures following failure of the automatic system or flight guidance system prior to touchdown may require that the pilot initiate a go-around, even though the aircraft using a hybrid system must have been demonstrated as being capable of safely completing a landing and rollout following a failure of one of the hybrid system elements below alert height.
A hybrid system may be approved for Category III if it is shown to meet the criteria specified in Appendix 3 when approved through an airworthiness demonstration process. Alternately, a hybrid system may be acceptable for Category III if it is determined to meet applicable airworthiness criteria for each element of the system separately (e.g., separately meets Category III criteria for autoland and HUD), and in addition, a successful operational suitability demonstration is completed using the individual system elements together as a hybrid system. If acceptability is determined through an operational demonstration process, the individual elements of the hybrid system must be shown to be compatible for both normal and nonnormal operations, and the combined system must be shown to have the necessary performance, integrity, and availability appropriate for the operations intended.
An operator may receive approval to use an automatic landing system and a manual flight guidance system as a Hybrid System provided, (a) each system individually meets appropriate airworthiness assessments, and (b), that operator conducts a successful operational demonstration showing the hybrid system's capability to meet applicable provisions of this section.
For hybrid systems used for Category III an Alert Height of 50' or higher should be used unless otherwise approved by the FAA AFS-400.
5.9. Instruments and Displays. Flight instrument and display presentations related to Category III, including attitude indicators, EADI’s, primary flight displays, EHSI’s, HIS’s, or other such navigation displays must provide pertinent, reliable and readily understandable information for both normal and nonnormal conditions related to Category III landing and missed approach.
Alert Height and/or Decision Height indications must be readily understandable, appropriately highlighted, and not be compromised by effects such as typical underlying terrain on the final approach path, and other annunciations or automatic audio call-outs. In addition, instruments and displays should provide appropriate indications considering terrain characteristics identified in Appendix 3 Section
6.3.4. Controls for altitude or height alerts used for minima determination or alert heights should use standard indications such as RH for radio height (or RA for radio altitude) and BARO for barometric altitude, rather than operational designations such as DH or MDA. Use of the designation RH or RA for height referenced values, or BARO for barometric altitude referenced values for controls or displays do not preclude related use of display symbology color changes or use of flashing alphanumeric symbology as the aircraft descends below a specifically referenced height or altitude value.
Situation information displays of navigation displacement must be available to both flightcrew members, and must be appropriately scaled and readily understandable in presentations or mode of display used.
Instrument and panel layouts must follow accepted principles of flight deck design.
5.10. Annunciations. Annunciations must be clear, unambiguous, and appropriately related to the flight control mode in use. The mode annunciation labels should not be identified by landing minima classification. For example, LAND 2, LAND 3, Single Land, Dual Land, etc., are acceptable mode annunciation labels, whereas, Category II, Category III, etc., should not be used. Aircraft previously demonstrated for Category III which do not meet this criteria may require additional operational constraints to assure the correct use of minima suited to the aircraft configuration. In addition, mode annunciation labels must be consistent with other annunciations in the cockpit, and with the airplane documentation.
5.11. Automatic Aural Alerts. Automatic Aural Alerts (e.g., automatic call-outs, voice callouts) of radio altitude, or call-outs approaching landing minimums, or call-outs denoting landing minimums must be consistent with the design philosophy of the aircraft in question. However, any automatic call-outs used should not be of a volume or frequency that interferes with necessary flightcrew communications or normal crew coordination procedures. Recommended automatic call-outs include a suitable alert or tone as follows:
1. At 500 ft. (radio altitude), approaching minimums and at minimums, and
2. Altitude call-outs during flare, such as at "50" ft., "30" ft. and "10" ft., or altitudes appropriate to aircraft flare characteristics. Low altitude radio altitude call-outs, if used, should appropriately address the situation of higher than normal sink rate during flare, or an extended flare which may be progressing beyond the touchdown zone.
5.12. Navigation Sensors. Various navigation sensors may be acceptable to support Category III operations as specified in Section 4.3.10. ILS localizer and glideslope signals are the primary means currently used for the determination of deviation from the desired path for Category III operations.
Criteria for acceptable ILS and MLS localizer and glide-slope receivers are included in Appendix 3 or in earlier acceptable criteria used by FAA for previous demonstrations of systems for Category III. Other
navigation sensors, such as GNSS, or DGNSS, may be used individually or in combination to satisfy the necessary accuracy, integrity and availability for Category III if proof of concept demonstrations are successfully completed and operational experience at Category I and Category II minimums is acceptable.
Navigation sensors other than ILS must meet equivalent ILS performance or appropriate RTCA or EUROCAE criteria, unless otherwise authorized.
Appropriate marker beacon information, or equivalent, must be displayed to each pilot for the outer, middle and inner markers. Appropriate substitutes for marker beacons may be authorized by the FAA for Category III based upon the use of suitable GNSS/DGNSS capabilities, or DME.
5.13. Supporting Systems and Capabilities.
5.13.1. Flight Deck Visibility. Suitable forward and side flight deck visibility for each pilot should be provided as follows:
a. The aircraft should have a suitable visual reference cockpit cutoff angle over the nose for the intended operations, at the intended approach speeds, and for the intended aircraft configurations, as applicable (e.g., flap settings),
b. The aircraft's flight deck forward and side windows should provide suitable visibility for taxi and ground operations in low visibility, and
c. Placement of any devices or structure in the pilots visual field which could significantly affect the pilot's view for low visibility operations must be acceptable (e.g., HUD drive electronics, sunvisor function or mountings).
5.13.2. Rain and Ice Removal. Suitable windshield rain removal, ice protection, or defog capability should be provided as specified below:
a. Installation of rain removal capability is required (e.g., windshield wipers, windshield bleed air).
b. Installation and use of windshield hydrophobic coatings, or use of equivalent rain repellent systems which meet pertinent environmental standards are recommended.
c. Installation of windshield anti-ice or de-ice capability is required for aircraft intended to operate in known icing conditions during approach and landing.
d. Installation of at least forward windshield defog capability is recommended for aircraft subject to obscuration of the pilot's view during humid conditions.
Aircraft subject to obscuration of the windshield due to rain, ice, or fogging of the pilot's view which do not have protection, or which do not have adequate protection may require operational limitations on the conditions in which low visibility operations are conducted.
5.13.3. Miscellaneous Systems. Other supporting systems should meet appropriate criteria compatible with Category III Operational Objectives. Applicable criteria may include criteria as specified in Appendix 3, criteria as specified in basic airworthiness requirements applicable to U.S.
certificated aircraft, or equivalent, or operational criteria for IFR flight. Regarding supporting systems, “In-service aircraft” or “new production” aircraft may meet or continue to meet criteria previously found acceptable for Category III operation for supporting systems for those aircraft. Supporting systems for Category III are considered to include, as applicable: Instruments, radar altimeters, air data computers, inertial reference units, attitude and heading gyros, instrument switching, flight deck night lighting, landing lights and taxi lights, position lights, turnoff lights, recognition lights, GPWS or EGPWS, flight data recorders or other low visibility related aircraft systems pertinent to a particular type.
Any GPWS or EGPWS systems interfaces (e.g., glide slope deviation warning) should be compatible with and should not interfere with the Category III Operations to be conducted (e.g., for engine inoperative Category III Configurations). For multimode capable systems for Category III (e.g., MMR), interfaces with GPWS or EGPWS for each MMR mode (e.g., ILS, MLS or GLS) should be consistent.
For Flight Data Recorders (FDR’s) or Quick Access Recorders (QAR’s), it is recommended that operators consider appropriate flight data recorder requirements for incident or event analysis when addressing provisions for Category III. It is recommended that any data recorders installed provide sufficient capability for recording of parameters applicable to flight guidance system performance for use with Category III operations. Typical parameters of interest and appropriate sample rates are those found in Appendix 8 applicable to Irregular Terrain Assessment.
5.14. Go-Around Capability. Regardless of the flight guidance system used an appropriate goaround mode/capability should be provided. A go-around mode/capability must be able to be selected at any time during the approach to touchdown. The go-around mode/capability should provide information for a safe discontinuance of the approach at any point to touchdown, if activated prior to touchdown. If activated at a low altitude where the aircraft inadvertently touches the ground, the goaround mode should provide adequate information to accomplish a safe go around and not exhibit unsafe characteristics as a result of an inadvertent touchdown. Inadvertent selection of go-around after touchdown should have no adverse effect on the ability of the aircraft to safely rollout and stop.
5.15. Excessive Deviation Alerting. An acceptable method should be provided to detect excessive deviation of the aircraft laterally and vertically during approach, and laterally during rollout, as applicable.
The method used should not require excessive workload or undue attention. This provision does not require a specified deviation warning method or annunciation, but may be addressed by parameters displayed on the ADI, EADI, or PFD. When a dedicated deviation warning is provided, its use must not cause excessive nuisance alerts.
5.16. Rollout Deceleration Systems or Procedures for Category III.
5.16.1. Stopping Means. A means to determine that an aircraft can be reliably stopped within the available length of the runway is necessary to conduct Category III operations. At least one of the following means to assess stopping performance should be used:
1. An automatic braking system which includes information for the flightcrew about appropriate auto brake settings to be used for landing or which provides landing distance information suitable for use by the flightcrew to determine which auto brake setting may or may not be appropriate.
2. A ground speed indicating system based on inertial information or other equivalent source such as GNSS, together with acceptable procedures for its use.
3. A deceleration display or other indication which can advise the pilot of the adequacy of aircraft deceleration to stop within the available runway length.
4. A runway remaining indicator display reliably showing the length of remaining runway after touchdown.
5. A procedural means to assure a safe stop acceptable to FAA. However, a procedural means to ensure a safe stop is not appropriate for minima less than RVR300 (75 m).
5.16.2. Antiskid Systems. Unless otherwise determined to be acceptable to the FAA, aircraft authorized for Category III should have an operable anti-skid system installed and operative per the applicable FAA MMEL and MEL.
The authorization for aircraft to operate using Category III minima without anti-skid is determined by the POI for each aircraft type, considering the following factors:
1. Extra field length margin of runways to be authorized, compared with field lengths necessary for the aircraft type, and
2. The braking system characteristics of the aircraft regarding susceptibility to tire failure during heavy braking, and susceptibility to tire failure during operations with reduced or patchy runway surface friction.
5.17. Engine Inoperative Category III Capability. The following criteria are applicable to aircraft systems intended to qualify for "engine inoperative Category III" authorizations. Aircraft demonstrated to meet "engine inoperative" provisions of Appendix 3 that have an appropriate reference to engine inoperative Category III capability in the FAA approved AFM are typically considered to meet the provisions listed below.
The AFM or equivalent reference must suitably describe demonstrated approach and missed approach performance for the engine inoperative configuration, and the aircraft must meet pertinent criteria otherwise required for all-engine Category III or equivalent criteria. This performance data should also be available in the automated flight planning, performance and weight and balance systems normally used by the air carrier so as to be readily available to the pilot and, if applicable, the aircraft dispatcher.
Exceptions to all-engine Category III, or equivalent criteria, may be authorized for engine inoperative Category III as follows:
a. The effects of a second engine failure when conducting Category III operations with an engine inoperative need not be considered, except for a demonstration that the airplane remain controllable when the second engine fails,
b. Crew intervention to re-trim the aircraft to address thrust asymmetry following engine loss may be permitted,
c. Alternate electrical and hydraulic system redundancy provisions may be acceptable, as suited to the type design (e.g., bus isolation and electrical generator remaining capability must be suitable for the engine out configuration),
d. Requirements to show acceptable landing performance may be limited to demonstration of acceptable performance during engine out flight demonstrations (e.g., a safe landing on the runway), and
e. Landing system "status" should accurately reflect the aircraft configuration and capability.
2. Suitable information must be available to the flightcrew at any time in flight, and particularly at the time of a "continuation to destination" or "diversion to alternate” decision. This is to determine that the aircraft can have an appropriate Category III approach capability when the approach is initiated (e.g., Non-normal checklist specification of expected configuration during approach, autoland status annunciation of expected capability).
3. Performance should be demonstrated in appropriate weather conditions considering winds and any other relevant factors.
5.18. Airborne System Assessment for Irregular Pre-Threshold Terrain. Not withstanding that airworthiness demonstrations may consider irregular terrain in the pre-threshold area, special operational evaluations are nonetheless required for certain airports having difficult pre-threshold terrain conditions (see Section 6.2.5). Criteria for the operational evaluation of irregular pre-threshold terrain airports is contained in Appendix 8. This criteria may be used both for operational authorizations and in conjunction with airworthiness demonstrations for type certification (TC) or supplemental type certification (STC).
5.19. Airworthiness Demonstrations of Airborne System Capability for Category III.
Airworthiness demonstrations of airborne systems not previously approved for Category III should be in accordance with the provisions of Appendices 2 through 6. Aircraft which have previously completed airworthiness demonstrations in accordance with earlier criteria may continue to reference the demonstrations against earlier criteria in their AFM and may elect to continue to use earlier criteria for continued production or demonstration of new production derivative aircraft. The criteria of this AC must be used when seeking credit not provided by the earlier criteria, for new aircraft types, or for significantly modified systems proposed to FAA for derivative aircraft after the date of the issuance of this revised AC. Category III aircraft systems may be evaluated in accordance with the applicable criteria contained in the Appendices of this AC during airworthiness demonstrations, or they may be evaluated in conjunction with an FAA approved program with an operator, for aircraft that are "in service" using the equivalent criteria and evaluation methods, to those specified in the Appendices to this AC. Operational demonstrations will not be conducted based on criteria prior to this AC.
6. PROCEDURES.
6.1. Operational Procedures. Appropriate operational procedures based on the approved operator program should be addressed. Operational procedures should consider the pilot qualification and training program, airplane flight manual, crew coordination, monitoring, appropriate takeoff and landing minima including specification of either a Decision Height or an Alert Height (as applicable) for landing, crew call-outs, and assurance of appropriate aircraft configurations. Suitable operational procedures must be used by the operator and be used by flightcrews prior to conducting low visibility takeoff or Category III landing operations.
6.1.1. Application of AFM Provisions. The operator's procedures for low visibility takeoff or Category III landing should be consistent with any AFM provisions specified in the normal or nonnormal procedures sections (e.g., Section 3 of the AFM) during airworthiness demonstrations.
Adjustments of procedures consistent with operator requirements are permitted when approved by the POI. Operators should assure that no adjustments to procedures are made which invalidate the applicability of the original airworthiness demonstration.
Where navigation performance for a specific RNP can only be achieved by specific system modes (e.g., coupled flight director or autopilot), the specific modes and associated RNP levels should be applied consistent with the AFM.
Where operations are based on RNP, suitable flight manual provisions for RNP capability and use should be provided. If not available in the AFM or Flight Crew Operating Manual (FCOM), RNP operations may be approved on a case by case basis, consistent with “fleet qualification” for RNP criteria such as found in RTCA DO-236 Appendix D, or equivalent FAA criteria.
6.1.2. Crew Coordination. Appropriate procedures for crew coordination should be established so that each flightcrew member can carry out their assigned responsibilities. Briefings prior to the