potentially adversely affecting the aircraft system operation, or the availability or suitability of Category III procedures at the airport of landing, or any alternate airport intended for Category III.
An operator may make the determination that a NOTAM does not apply to the aircraft system and procedures being used for a particular flight if the safety of the operation can be ensured, considering the NOTAM and situation (e.g., a NOTAM specifying Category III Not Available due to the ALS inoperative, for an aircraft that had previously been dispatched based on a Category III ETOPS or EROPS alternate airport flight plan, and no other suitable airport facility is available). In such instances, pilots must be advised of any relevant information to the decision, and any precautions to be taken.
8.9. Use of Military Facilities. Military facilities may be used for Category III if authorized by DoD, and if equivalent criteria are met as applicable to United States civil airports.
8.10. Special Provisions for Facilities Used for ETOPS or EROPS Alternates. ETOPS operations are extended range operations with twin-engine aircraft, typically conducted over oceanic or remote areas (see Appendix 1 for definitions, or see a current version of AC 120-42 and 14 CFR section 121.161 for requirements or criteria). EROPS operations are those “extended range operations” typically conducted in oceanic or remote areas, regardless of the number of installed engines.
An airport used as an ETOPS or EROPS alternate based on having available Category III engineinoperative capability should meet at least the following criteria:
Sufficient information about pre-threshold terrain, missed approach path terrain, and obstructions should be available so that an operator can assure that a safe Category III landing can be completed, and that an engine-inoperative missed approach can be completed from AH or DH as applicable, or at any time after passing the AH or DH at least to a point at the end of the landing touchdown zone (TDZ).
Sufficient meteorological and facility status information should be available so that a diverting flightcrew and the aircraft dispatcher can receive timely status updates on facility capability, weather/RVR, wind components, and braking action reports (if applicable), if conditions could or would adversely affect a planned Category III landing during the period of a diversion.
For any alternate airports not routinely used by that operator as a regular destination airport
(e.g., EGCC as an alternate for EGLL; BIKF as a North Atlantic alternate), sufficient information should be provided for aircraft dispatchers and pilots to be familiar with relevant low visibility and adverse weather characteristics of that airport that might have relevance to an engine-inoperative operation (e.g., unique lighting or markings, any nearby obstructions or frequently encountered local wind shear or turbulence characteristics, meteorological reports, braking reports, and NOTAM interpretation, appropriate ground taxi route and gate location information, emergency services available).
8.11. Alternate Minima. Use of alternate minima are specified in Standard OpSpecs Part C paragraph C055. For applicability of "engine inoperative Category III" capability see section 10.8, and in particular, 10.8.2 items (10) and (11).
Paragraph C055 is issued to all part 121 and part 135 operators who conduct IFR operations with airplanes. This paragraph provides a three-part table from which the operator, during the initial dispatch or flight release planning segment of a flight, determines applicable alternate airport IFR weather minimums for those cases where it has been determined that an alternate airport is required.
a. Standard Provisions. Standard provisions of the Part C paragraph C055 operationspecification are applicable to airports with at least one operational navigational facility, or for multiple navigation facilities providing straight-in instrument approach procedures other than precision, or a straight-in precision approach procedure, or a circling maneuver from an instrument approach procedure. The required ceiling and visibility is obtained by adding an increment to the landing minima
(e.g., adding 400 ft. to the Category I HAT or, as applicable, the authorized HAA, and by adding 1 statute mile to the authorized landing visibility.
b. Special Engine Inoperative Provisions. Special provisions for Category II and Category III engine-out capability are listed in the third part of the table for airports with at least two operational navigational facilities, each providing a straight-in precision approach, including a precision approach procedure to Category II or Category III minima. The required ceiling and visibility for this operational credit is obtained by adding 300 ft. or 200 ft. to the respective lowest Category II or Category III touchdown zone elevation of the two approaches considered, and by adding 1200 ft. to the lowest authorized RVR minimum (see Appendix 7 Part C paragraph C055).
8.12. Flight Planning to Airports That Have Weather Conditions Below Landing Minima. In certain instances an operator may flight plan (e.g., dispatch) an aircraft to a destination airport even though current weather is reported to be below, or may be forecast to be below landing minima. This is to permit aircraft to begin a flight if there is a reasonable expectation that at or near the expected time of arrival at the destination airport, weather conditions are expected to permit a landing at or above landing minima.
Flight Planning (e.g., dispatch) to such airports typically is considered acceptable if the following conditions are met:
1) All requirements are met to use the landing minima at the destination and at each alternate airport on which the flight plan (e.g., dispatch) is predicated (e.g., aircraft, crew, airport facilities, NAVAID’s).
2) If Alternate minima credit is applied based on availability of Category III capability, or Engine inoperative Category III capability, then each of the airborne systems otherwise applicable to use of that capability must be available at the time of flight planning (e.g., flight guidance system, anti skid, thrust reverse capability, as applicable to the aircraft type and Category III authorization for that operator)
3) ETA at the destination airport considers any necessary holding fuel that may be required while the aircraft waits for weather improvement.
4) Air Traffic conditions are considered for potential delay due to other aircraft arrivals or departures at the destination and at each alternate airport.
5) At least two qualifying alternates are available, the first of which considers the aircraft flying to the below minima intended destination, then holding for a time as determined by the operator awaiting approach or weather improvement, then flying to the closest alternate, then completing an approach and missed approach at that airport, and then flying to the second alternate and landing with appropriate reserve fuel.
9. CONTINUING AIRWORTHINESS/MAINTENANCE.
9.1. Maintenance Program. Unless otherwise approved by FAA, each operator should have an approved continuous airworthiness maintenance program (CAMP). The approved continuous airworthiness maintenance program should typically include any necessary provisions to address lower landing minima (LLM) or low visibility takeoff in accordance with the operator’s intended operation and the manufacturers recommended maintenance program, MRB requirements or equivalent requirements, or any subsequent FAA designated requirements (e.g., AD’s, mandatory service bulletins). Emphasis should be on maintaining and ensuring total system performance, accuracy, availability, reliability, and integrity for the intended operations.
9.2. Maintenance Program Provisions. The maintenance program should be compatible with an operator’s organization and ability to implement and supervise the program. Maintenance personnel should be familiar with the operators approved program, their individual responsibilities in accomplishing that program, and availability of any resources within or outside of the maintenance organization that may be necessary to assure program effectiveness (e.g., getting applicable information related to the manufacturer’s recommended maintenance program, getting information referenced in this AC such as service bulletin information).
Provision for low visibility operations may be addressed as a specific program or may be integrated with the general maintenance program.
Regardless whether the maintenance program is integrated or is designated as a specific program for Lower Landing Minima (LLM), the maintenance program should at least address the following:
1) Maintenance procedures necessary to ensure continued airworthiness relative to low visibility operations.
2) A procedure to revise and update the maintenance program.
3) A method to identify, record or designate personnel currently assigned responsibility in managing the program, performing the program, maintaining the program, or performing quality assurance for the program. This includes identification of any contractor or sub-contractor organizations, or where applicable, their personnel.
4) Verification should be made of the lower landing minima systems and configuration status for each aircraft brought into the maintenance or lower minimum program. Unless otherwise accepted by FAA, each aircraft should meet relevant criteria specified by the applicable aircraft manufacturer or avionics manufacturer for associated systems and equipment (e.g., Valid U.S. TC, appropriate STC records and compliance, assessment of status of any engineering orders, AD’s, service bulletins or other compliance).
5) Identification of modifications, additions, and changes which were made to qualify aircraft systems for the intended operation or minima, if other than as specified in the AFM, TC or STC.
6) Identification of additional maintenance requirements and log entries necessary to change minima status.
7) Any discrepancy reporting procedures that may be unique to the low visibility program. If applicable, such procedures should be compatibly described in maintenance documents and operations documents.
8) Procedures which identify, monitor and report lower minimum system and component discrepancies for the purpose of quality control and analysis.
9) Procedures which define, monitor and report chronic and repetitive discrepancies.
10) Procedures which ensure aircraft remain out of lower minimum status until successful corrective action has been verified for chronic and repetitive discrepancies.
11) Procedures which ensure the aircraft system status is placarded properly and clearly documented in the aircraft log book, in coordination with maintenance control, engineering, flight operations, and dispatch, or equivalent.
12) Procedures to ensure the downgrade of an aircraft low visibility capability status, if applicable, when maintenance has been performed by persons other than those trained, qualified, or authorized to use or approve procedures related to low visibility operations.
13) Procedures for periodic maintenance of systems ground check, and systems flight check, as applicable. For example, following a heavy maintenance, suitable checks may need to be performed prior to return to service.
14) Provisions for an aircraft to remain in a specific low visibility capability status (e.g., Category II, Category III, Fail-Operational, Fail Passive) or other designated operational status used by the operator.
15) Provision should be made for periodic operational sampling of suitable performance. Typically, at least one satisfactory approach should have been accomplished within a specified period approved for that operator, unless a satisfactory systems ground check has been accomplished. A recording procedure for both satisfactory and unsatisfactory results should be included. Fleet sampling is not typically acceptable in lieu of specific aircraft assessment. Typically at least one satisfactory low visibility system operational use, or a satisfactory systems ground check, should be accomplished within 30 days, for an aircraft to remain in Category III status. Any extension to an aircraft sampling period limit beyond 30 days, or use of statistical fleet sampling should be consistent with the manufacturer’s current sampling recommendations and be based on the demonstrated reliability of that operator’s aircraft flight guidance system performance in service. Failure of an operator to maintain an acceptable reliability record should result in timely and appropriate remedial action, and should lead to reconsideration of suitability of any sampling period extensions or fleet statistical sampling authorizations.
9.3. Initial And Recurrent Maintenance Training. Operator and contract maintenance personnel including mechanics, maintenance controllers, avionics technicians, personnel performing maintenance inspection or quality assurance, or other engineering personnel if applicable, should receive initial and recurrent training as necessary for an effective program. The training curriculum should include specific aircraft systems and operator policies and procedures applicable to low visibility operations. Recurrent training should typically be accomplished at least annually, or when a person has not been involved in the maintenance of the specified aircraft or systems for an extended period (e.g., greater than 6 months).
Training may lead to a certification or qualification (e.g., for lower landing minima “LLM”) if the operator so designates such qualification in that operator’s approved program.
The training should at least include, as applicable:
1) An initial and recurrent training program for appropriate operator and contract personnel.
Personnel considered to be included are maintenance personnel, quality and reliability groups, maintenance control, and incoming inspection and stores, or equivalent organizations. Training should include both classroom and at least some “hands-on” aircraft training for those personnel who are assigned aircraft maintenance duties. Otherwise, training may be performed in a classroom, by computer based training, in simulators, in an airplane or in any other effective combination of the above consistent with the approved program, and considered acceptable to FAA.
2) Subject areas for training should include: Operational concepts, aircraft types and systems affected, aircraft variants and differences where applicable, procedures to be used, manual or technical reference availability and use, processes, tools or test equipment to be used, quality control, methods for testing and return to service, signoffs required, proper Minimum Equipment List (MEL) application, general information about where to get technical assistance as necessary, necessary coordination with
other parts of the operator’s organization (e.g., flight operations, dispatch), and any other maintenance program requirements unique to the operator or the aircraft types or variants flown (e.g., human factors considerations, problem reporting).
3) Procedures for the use of outside vendors or vendor’s parts that ensures compatibility to program requirements and for establishing measures to control and account for parts overall quality assurance.
4) Procedures to ensure tracking and control of components that are “swapped” between systems for trouble shooting when systems discrepancies can not be duplicated. These procedures should provide for total system testing and/or removal of aircraft from lower minimum status.
5) Procedures to assess, track and control the accomplishment of changes to components or systems pertinent to low visibility operations (e.g., AD’s, service bulletins, engineering orders, FAR requirements).
6) Procedures to record and report lower minimum operation(s) that are discontinued/ interrupted because of system(s) malfunction.
7) Procedures to install, evaluate, control, and test system and component software changes, updates, or periodic updates.
8) Procedures related to the minimum equipment list (MEL) remarks section use which identify low visibility related systems and components, specifying limitations, upgrading and downgrading.
9) Procedures for identifying low visibility related components and systems as “required inspection items” (RII), to provide quality assurance whether performed in-house or by contract vendors.
9.4. Test Equipment/Calibration Standards. Test equipment may require periodic re-evaluation to ensure it has the required accuracy and reliability to return systems and components to service following maintenance. A listing of primary and secondary standards used to maintain test equipment which relate to low visibility operations should be maintained. It is the operator’s responsibility to ensure these standards are adhered to by contract maintenance organizations. Traceability to a national standard or the manufacturer’s calibration standards should be maintained.
9.5. Return To Service Procedures. Procedures should be included to upgrade or downgrade systems status concerning low visibility operations capability. The method for controlling operational status of the aircraft should ensure that flightcrews, maintenance and inspection departments, dispatch, and other administrative personnel as necessary are appropriately aware of aircraft and system status.
The appropriate level of testing should be specified for each component or system. The manufacturer’s recommended maintenance program or maintenance instructions should be considered when
determining the role built-in-test-equipment (BITE) should play for return to service (RTS) procedures, or for use as a method for low visibility status upgrade or downgrade.
Contract facilities or personnel should follow the operator’s FAA approved maintenance program to approve an aircraft for return to service. The operator is responsible for ensuring that contract organizations and personnel are appropriately trained, qualified, and authorized.
9.6. Periodic Aircraft System Evaluations. The operator should provide a method to continuously assess or periodically evaluate aircraft system performance to ensure satisfactory operation for those systems applicable to Category II or III. An acceptable method for assuring satisfactory performance of a low visibility flight guidance system (e.g., autoland or HUD) is to periodically use the system and note satisfactory performance. A reliable record such as a logbook entry or computer ACARS record showing satisfactory performance within the previous 6 months for Category II, or previous 30 days for Category III, is typically an acceptable method for assuring satisfactory system operation (see Section 9.2 item 15).
Periodic flight guidance system/autoland system checks should be conducted in accordance with procedures recommended by the airframe or avionics manufacturer, or by an alternate procedure approved by the FAA. For periodic assessment, a record should be established to show when and where the flight guidance/autoland system was satisfactorily used, and if performance was not satisfactory, to describe any remedial action taken.
Use of the flight guidance/automatic landing system should be encouraged to assist in maintaining its availability and reliability.
9.7. Reliability Reporting And Quality Control. For a period of 1 year after an applicant has been authorized reduced minima, a monthly summary should be submitted to the certificate holding office.
The following information should be reported:
a. The total number of approaches tracked, the number of satisfactory approaches tracked, by aircraft/system type, and visibility(RVR), if known or recorded.
b. The total number of unsatisfactory approaches, and reasons for unsatisfactory performance, if known, listed by appropriate category(e.g., poor system performance, aircraft equipment problem/failure;
ground facility problem, ATS handling, lack of critical area protection, or other).
c. The total number of unscheduled removals of components of the related avionics systems.
d. Reporting after the initial period should be in accordance with the operators established reliability and reporting requirements.
9.8. Configuration Control/System Modifications. The operator should ensure that any modification to systems and components approved for low visibility operations are not adversely
affected when incorporating software changes, service bulletins, hardware additions or modifications.
Any changes to system components should be consistent with the aircraft manufacturer’s, avionics manufacturer’s, industry or FAA accepted criteria or processes.
9.9. Records. The operator should keep suitable records (e.g., both the operator's own records and access to records of any applicable contract maintenance organization). This is to ensure that both the operator and FAA can determine the appropriate airworthiness configuration and status of each aircraft intended for Category III operation.
Contract maintenance organizations should have appropriate records and instructions for coordination of records with the operator.
9.10. FAR 129 Foreign Operator Maintenance Programs.
9.10.1. Maintenance of FAR 129 Foreign Registered Aircraft. For part 129 operators of Foreign registered aircraft (e.g., section 129.14 is not applicable), the cognizant CAA is the CAA of the operator. For those situations, FAA may implicitly accept that the maintenance program is considered to be acceptable if the cognizant CAA has approved it, and if the operator or CAA indicates that the program meets U.S. criteria, U.S. equivalent criteria (e.g., criteria such as JAA criteria), or ICAO criteria (e.g., Annex 6 and Doc 9365/AN910 "Manual of All Weather Operations"), and the cognizant CAA has authorized Category II or Category III U.S. operations.
FAA then issues the pertinent part 129 Category II/III OpSpec based on the other CAA’s approval for that operator. However, FAA reserves the prerogative to assure competence of both the operator and authorizing and supervising CAA, depending on whether the CAA or operator are considered to be from a category 1, 2, or 3 country (safety classification not a low visibility landing classification), and if there have been any reported problems with the operator or CAA. Evidence of the operator satisfying or being consistent with the manufacturer's recommended maintenance program should serve as evidence of an acceptable maintenance program, regardless of the capability of the CAA or the operator, unless FAA has specifically addressed maintenance requirements beyond those of the manufacturer for that aircraft type (e.g., required service bulletin compliance or Airworthiness Directive compliance related to the flight guidance system).
9.10.2. Maintenance of FAR 129 Foreign Operated U.S. “N” Registered Aircraft. Foreign operators of U.S. "N" Registered Aircraft (e.g., those operators to which section 129.14 is applicable) should have maintenance programs equivalent to that required for a U.S. part 121 operator. Use of the part 91 provisions for General Aviation are not applicable or appropriate.
Principal Operations Inspector Approval of Category II/III OpSpecs for a part 129.14 operator may implicitly be considered to also accept the maintenance program adequacy. Accordingly, coordination between the applicable POI and PMI is necessary before part 129 OpSpec authorization is completed. The FAA is ultimately the cognizant CAA for the maintenance program in this instance, if the aircraft is N registered. The FAA may however, accept the oversight of the operators CAA if that CAA is judged by FAA to have equivalent processes, criteria and procedures for oversight of maintenance programs (e.g., JAA countries). The basis for any such maintenance
program should be the recommended airframe manufacturer (or avionics vendor) program, considering any adjusted MRB requirements.
10. APPROVAL OF UNITED STATES OPERATORS.
Approval for Category I, II and III is through issuance of or amendments to Operations Specifications (OpSpecs). The authorizations, limitations, and provisions applicable to Category I, Category II or Category III are specified in Part C of the OpSpecs. Sample OpSpecs are provided in Appendix 7.
Operations specifications authorizing Category I operations that use ICAO standard NAVAID’s are normally approved by the certificate holding district office or regional flight standards office without further review and concurrence. All Category II or Category III operations normally require both regional flight standards and AFS-400 review and concurrence before approval.
10.1. Operations Manuals and Procedures.
a. Manuals. Prior to Category approval, appropriate flightcrew operating manuals, flight manuals, airline policy manuals, maintenance manuals, training manuals, and related aircraft checklists, quick reference handbooks, or other equivalent operator information, should satisfactorily incorporate pertinent Category III provisions.
Information covered in ground training, and procedures addressed in flight training should be available to pilots in an appropriate form for reference use.
b. Procedures. Prior to Category approval, provisions of section 6 of this AC for procedures, duties, instructions, or any other necessary information to be used by flightcrews and aircraft dispatchers should be implemented by the operator.
Crew member duties during the approach, flare, rollout, or missed approach should be described.
Duties should at least address responsibilities, tasks of the pilot flying the aircraft and the pilot not flying the aircraft during all stages of the approach, landing, rollout and missed approach. The duties of additional crewmembers, if required, should also be explicitly defined.
Specification of crewmember duties should address any needed interaction with the aircraft dispatcher or maintenance (e.g., addressing resolution of aircraft discrepancies and return to service).
The applicant's qualification program should incorporate specific Category II/III procedural responsibilities for the pilot in command and second in command in each of the ground training subject areas listed in paragraph 7.1, and each of the flight training subject areas listed in paragraph 7.2.
10.2. Training Programs and Crew Qualification. Training programs, AQP programs (if applicable), crew qualification and checking provisions and standards, differences qualification (AC 120-53) if applicable, check airmen qualification, line check, route check, and IOE programs should each
satisfactorily incorporate necessary Category III provisions, as applicable (see sections 7.2 through 7.4).
An acceptable method to track pertinent crewmember Category III qualification and recency should be established (see section 7.5).
For manually flown Category III systems (e.g., HUD FD’s, Hybrid HUD/Autoland) ensure that provisions are made for each flightcrew member to receive the appropriate training, qualification, and line experience before that particular crewmember is authorized to use the pertinent Category III minima.
10.3. Flight Planning (e.g., Dispatch, MEL, Alternate Airports, ETOPS or EROPS). MEL and CDL provisions should be addressed, as necessary, for Category III operations. The flight planning
(e.g., pilot or aircraft dispatcher) should ensure appropriate consideration of reported and forecast weather, field conditions, facility status, NOTAM information, alternate airport designation, engineinoperative missed approach performance, crew qualification, airborne system status, and fuel planning.
For ETOPS or EROPS operations, a satisfactory method to address item 8.10 above should be demonstrated.
10.4. Formulation of Operations Specification (e.g., RVR limits, DH or AH, equipment, field lengths). Proposed OpSpecs should list pertinent approved RVR limits, DH or AH use provisions, "Inner Marker based DH or AH" provisions (if applicable), required transmissiometers, airports/runways, aircraft equipment provisions for "normal" and, if applicable, "engine-inoperative" operations, landing field length provisions, and any other special requirements identified by the CHDO or AFS-400 (e.g., ETOPS or EROPS Category III). The operator's manuals, procedures, checklists, QRH’s, MEL’s, dispatch procedures and other related flightcrew information should be shown to be consistent with the proposed OpSpecs.
10.5. Operational/Airworthiness Demonstrations. Appropriate "airborne system suitability" and "operational use suitability" demonstrations must be completed as described in sections 10.5.1 and
10.5.2, unless otherwise specified by AFS-400. The purpose of these operational demonstrations is to determine or validate the use and effectiveness of the applicable aircraft flight guidance systems, training, flightcrew procedures, maintenance program, and manuals applicable to the Category III program being approved. Operators of aircraft having FAA approved AFM’s referencing AC 120-28D as the criteria used as the basis for Category III airworthiness demonstration already are considered to meet provisions of section 10.5.1, and typically need only address provisions of section 10.5.2. for verification of operational use suitability.
10.5.1. Airborne System Suitability Demonstration. Low visibility takeoff and landing requirements for Category I, Category II, and Category III are related to operating rules addressed by Standard OpSpecs and 14 CFR parts 1, 61, 91, 97, 121, 125, and 135. These provisions apply continuously, as defined at the time of a particular Category I, II, or III operation. Airworthiness rules (14 CFR parts 23, 25, etc.,) primarily apply at the time a "certification basis" is established for type certificate (TC) or supplemental type certificate (STC) and do not necessarily reflect "present" requirements, except through issuance of AD’s updated with an amended type certificate or new STC
application. Accordingly, operationally acceptable demonstrations addressing suitability of airborne systems for Category III, as applicable, must be successfully completed initially, and acceptable system status must be maintained by an operator to reflect compliance with current operating rules and airworthiness requirements, to initially operate or continue to operate to Category III minima.
To minimize the need for repeating initial airborne system operational suitability demonstrations for each operator, airborne system suitability is usually demonstrated in conjunction with airworthiness approval (TC or STC) of airborne system components such as flight guidance systems, autoland, flight directors, HUD’s, flight instrument and alerting systems, radio altimeters, inertial systems, and air data systems.
This approach to determination of airborne system suitability is taken to optimize use of analysis and flight demonstration resources for operators, aircraft manufacturers, avionics manufacturers, and the FAA. Accordingly, airborne system suitability is normally demonstrated through an initial airworthiness demonstration meeting applicable provisions of Appendices to this AC (or combined airworthiness/operational evaluation for new systems or concepts, or where otherwise necessary).
Demonstration to an acceptable earlier version of AC 120-28 or equivalent criteria may continue to be used for demonstration of aircraft/airborne systems initially type certificated prior to issuance of this AC 120-28D revision as applicable to the particular aircraft or airborne system (e.g., current production aircraft using earlier AC’s 120-28/A/B/C.)
However, previously demonstrated aircraft or airborne systems seeking Category III credits specified only in provisions of revised AC 120-28D (e.g., Hybrid Autoland/HUD Category III) must meet criteria specified in this AC.
Acceptable results of such airworthiness evaluations are usually described in section 3 (Normal and Non- Normal Procedures) of the FAA approved AFM or AFM Supplement. Certificate Holding District Offices should ensure that aircraft proposed for Category III have completed such an appropriate airborne system operational suitability demonstration, and that result should normally be reflected in the approved AFM or AFM Supplement, unless otherwise specified by AFS-400.
For aircraft certified by FAA through section 21.29 (Certain Non-United States manufactured aircraft), AFM provisions applicable to Category III may vary. In certain instances AFM provisions may not be consistent with United States policy or rules applicable to Category III. In such instances, CHDO prior coordination with AFS-400 is appropriate to provide appropriate guidance to operators regarding applicability of various AFM provisions (e.g., DH and RVR limitations, acceptable NAVAID use, alerting system use, and required versus recommended crew procedures).
In the event of special circumstances such as FAA Category III acceptance of an aircraft certificated by a Non-United States airworthiness authority which has only foreign AFM Category III approval, or acceptance of additional credit for existing systems, operational assessments in accordance with criteria in this AC, or equivalent criteria, may be necessary. In such instances, AFS-400 specifies applicable criteria.
10.5.2. "Operator Use Suitability" Demonstration. At least one-hundred (100) successful landings should be accomplished in line operations using the low visibility landing system installed in each aircraft type applicable to the Category III authorization. Demonstrations may be conducted in line operations, during training flights, or during aircraft type or route proving runs.
If an excessive number of failures (e.g., unsatisfactory landings, system disconnects) occur during the landing demonstration program, a determination should be made for the need for additional demonstration landings, or for consideration of other remedial action (e.g., procedures adjustment, wind constraints, or system modifications).
The system should demonstrate reliability and performance in line operations consistent with the operational concepts specified in section 4. In unique situations where the completion of 100 successful landings could take an unreasonably long period of time due to factors such as a small number of aircraft in the fleet, limited opportunity to use runways having Category II/III procedures, or inability to obtain ATS critical area protection during good weather conditions, and equivalent reliability assurance can be achieved, a reduction in the required number of landings may be considered on a case-by-case basis.
Reduction of the number of landings to be demonstrated requires a justification for the reduction, and prior approval from the Technical Programs Division (AFS-400).
Landing demonstrations should be accomplished on U.S. facilities or international facilities acceptable to FAA which have Category II or III procedures. However, at the operator's option, demonstrations may be made on other runways and facilities if sufficient information is collected to determine the cause of any unsatisfactory performance (e.g., critical area was not protected). No more than 50 percent of the demonstrations may be made on such facilities.
If an operator has different models of the same type of aircraft using the same basic flight control and display systems, or different basic flight control and display systems on the same type of aircraft, the operator should show that the various models have satisfactory performance, but the operator need not conduct a full operational demonstration for each model or variant.
10.5.2.1. Data Collection For Airborne System Demonstrations. Each applicant should develop a data collection method (e.g., form to be used by flightcrew) to record approach and landing performance. Data should be collected whenever an approach and landing is attempted using the Category III system, regardless of whether the approach is abandoned, unsatisfactory, or is concluded successfully. The resulting data and a summary of the demonstration data should be made available to the CHDO for evaluation. The data should, as a minimum, include the following information:
1. Inability to Initiate an Approach. Identify deficiencies related to airborne equipment which preclude initiation of a Category III approach.
2. Abandoned Approaches. Give the reasons and altitude above the runway at which approach was discontinued or the automatic landing system was disengaged.