(1) All Category IIIb operations are conducted with an automatic or manual rollout control system. The accuracy and reliability of the rollout control system when considered in combination with the available visual cues and the characteristics of the ground support system will determine the lowest minima authorized for a particular operation. Additional criteria for approval of rollout control systems are contained in Appendix 2 and Appendix 3.
(2) Fail-passive rollout control systems which meet the criteria of Appendix 2 are necessary to conduct operations below 600 RVR (175 meters).
(3) Fail-operational rollout control systems which meet the criteria contained in Appendix 3 are necessary to conduct operations below 300 RVR (100 meters).
(4) Unless a fail-operational rollout control system is used, operations are not appropriate on runways with the runway centerline lights obscured by precipitation (i.e., snow or ice).
(3) An instrument, annunciator, or crew procedures to reliably detect and alert the pilot to abnormal lateral or vertical deviations during an approach or flare or an extended flare beyond the touchdown zone, or excessive lateral deviations during rollout.
c. Deceleration System(s)/Procedures for Category IIIb. A means to determine that a landing can be reliably completed within the available length of the runway is necessary to conduct Category IIIb operations (see Appendix 4). This means will be demonstrated to the FAA and, if acceptable, may be used to satisfy this requirement. At least one of the following means to assess stopping performance should be used:
(1) A "runway-remaining" indicator display showing length of remaining runway after touchdown.
(2) A deceleration display which can advise the pilot of the adequacy of aircraft deceleration to stop within the confines of the available runway.
(3) A groundspeed indicating system (i.e., inertial).
(4) An automatic braking system.
(5) A procedural means to assure a safe stop (not appropriate for minima less than 300 RVR (100 meters).
d. Airborne System Evaluation and Approval. Category Illa or Category IIIb airborne systems may be evaluated in accordance with the applicable airworthiness criteria contained in Appendices 1 and 2 or Appendix 3 during type certification, or they may be evaluated in conjunction with an FAA-approved program with an air carrier for aircraft in service with approved automatic landing systems.
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10. PILOT TRAINING AND PROFICIENCY PROGRAM.
a. Category III Ground Training (All Aircraft). The applicant's training program should provide training for the pilot in command and second in command in
(1) Ground Facilities.
(1) The operational characteristics, capabilities, and limitations as applied to Category III operations of:
(A) The instrument landing system and critical area protection.
(B) The visual approach aids; i.e., approach lights, touchdown zone and centerline lighting, signs, and markings.
(C) Transmissometer systems.
(D) Facility status, NOTAMS, or outage reports pertinent to use of Category III minima.
(2) The Airborne Category III System.
The operational characteristics, capabilities, and limitations appropriate to the Category III system(s) utilized such as:
(A) The automatic landing system.
(B) Automatic throttle system, if installed.
(C) The flight director system, if installed.
(D) Instrumentation and display systems.
(E) System and aircraft characteristics which determine the AH or DH, as applicable.
(F) Other systems and/or devices peculiar to the particular installation; i.e., computed go-around guidance equipment, failure warning systems, etc.
(G) Description of the limits to which acceptable system performance has been demonstrated for wind and wind shear.
(3) Other.
(1) Review of operations specifications applicable to Category III operations.
(ії) Policies and procedures concerning the conduct of Category III operations on icy or snow-covered runways, as well as those runways with braking action reported less than good.
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(iii) Pilot reporting of ILS anomalies, approach lights, runway lights, touchdown zone, or centerline light outages, or other discrepancies which may be pertinent to subsequent Category III approaches.
b. Flight Training Program.
(1) The following items are to be covered on both initial training and at least annually during recurrent training/proficiency checks for both pilot in command and second in command:
(1) Determination of the DH, if a DH applies, including use of radar altimeter.
Recognition of and proper reaction to significant failures encountered prior to and after reaching the AH or DH as applicable.
Missed approach technique and expected height loss as it relates to manual or automatic go-around and initiation altitude.
Runway visual range - its use and limitations, including the determination of controlling RVR and required transmissometers.
The availability and limitations of visual cues encountered on approach both before and after DH, if applicable. This includes procedures for unexpected deterioration of conditions to less than minimum RVR encountered during approach, flare and rollout, demonstration of expected visual references with weather at minimum conditions, and the expected sequence of visual cues during an approach in which visibility is at or above landing minima.
(vi) The effects of vertical and horizontal wind shear (not required for recurrent training/proficiency checks).
(vii) Procedures for transitioning from nonvisual to visual flight.
(viii) Pilot recognition of the limits of acceptable aircraft position and flightpath tracking during approach, flare, and, if applicable, rollout.
(1x) Pilot recognition of and reaction to airborne or ground system faults or abnormalities, particularly after passing AH or DH.
Subparagraphs b(1)(1) through (ix) should be incorporated into the training program in sufficient detail to show how each item will be accomplished during initial and recurrent training. For instance, it could be stated that subparagraph b(1)(viii) will be accomplished by freezing the simulator at or below 50 feet with varying visibilities, wind components, runway lighting configurations, and offsets from centerline to demonstrate conditions that may be encountered on the line. The above listed items should be accomplished in an approved simulator unless the applicant can show that equivalent training is provided by the use of other training aids and/or devices.
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(2) Initial Category III Flight Training Requirements For a Pilot in Command • Each pilot in command initially should receive training in flight or in an approved simulator in conducting automatic landings (manual landings, if appropriate) and missed approaches from very low altitudes which, for some aircraft, may result in an inadvertent touchdown during the go-around maneuver. If a simulator is used, the automatic flight control system, instruments, and annunciator system should be able to realistically represent the Category Ill airborne system performance and failure modes. Also, if training is done in an approved simulator, at least two actual automatic landings should be conducted in the aircraft prior to conducting Category Ill approaches with weather conditions below Category II minima. This can be accomplished during normal line operations.
(11) Each pilot in command should satisfactorily demonstrate to either a company check pilot or an FAA inspector the following requirements in an approved simulator or in flight with a suitable view limiting device (e.g., variable density see-through training hood) in an aircraft configured with the appropriate Category III system and approved for these maneuvers:
(A) Two ILS approaches using the automatic landing system.
(B) An automatic landing from one of the approaches.
(C) A missed approach starting from a very low altitude which may result in a touchdown during the go-around maneuver.
(D) For those Category IIIb operations predicated on the use of a fail-passive rollout control system, a manual rollout using visual reference or a combination of visual and instrument references. This maneuver should be initiated by a fail-passive disconnect of the rollout control system, after main gear touchdown and prior to nose gear touchdown, in conditions representative of the most adverse lateral touchdown displacement and weather conditions anticipated in normal Category Illb operations with a fail-passive rollout control system.
(3) Second In Command Initial Flight Training Requirements. The flight training requirements for a second in command will depend on his/her assigned role during Category III approaches. Each second in command should satisfactorily demonstrate, to a company check pilot or an FAA inspector, his/her ability to perform his/her assigned duties. If a second in command is not expressly prohibited by his/her company from performing the duties of the pilot in command while under the supervision of the pilot in command during Category III approaches, he/she is to satisfactorily accomplish the additional requirements of subparagraph b(2).
(4) Recurrent Pilot In Command and Second In Command Proficiency Requirements.
(1) Pilot In Command. At least annually, the pilot in command is to satisfactorily demonstrate to a company check pilot or an FAA inspector the following requirements in an approved simulator or in flight with a view limiting 16 Par 10
device (e.g., variable density see-through training hood) suitable for Category III in an aircraft configured with the appropriate Category III systems and approved for these maneuvers:
(A) Two ILS approaches using the automatic landing system.
(B) An automatic landing from one of the approaches.
(C) A missed approach starting from a very low altitude which, for some aircraft, may result in an inadvertent touchdown during the go-around maneuver • (D) For those Category IIIb operations predicated on the use of a fail-passive rollout control system, a manual rollout using visual reference or a combination of visual and instrument references. This maneuver should be initiated by a fail-passive disconnect of the rollout control system, after main gear touchdown and prior to nose gear touchdown, in condition representative of the most adverse lateral touchdown displacement and weather conditions anticipated in normal Category IIlb operations with a fail-passive rollout control system.
However, if one of the required redundant operational systems is a manual system based on instrument displays, the pilot will be required at least annually to demonstrate proficiency, in flight or in an approved simulator, in the use of such a system. In the case of a pilot in command who is dual aircraft qualified, the proficiency requirements are to be accomplished at least annually for each aircraft type.
(ii) Second In Command. The proficiency requirements for a second in command will depend on his/her assigned role during Category III approaches.
During each required proficiency check, the second in command is to satisfactorily demonstrate to a company check pilot or an FAA inspector his/her ability to perform his/her assigned duties. If a second in command is not expressly prohibited from performing the duties of pilot in command during Category III approaches, he/she is to satisfactorily complete the additional requirements of paragraph 10(b)(4)(1).
(1i1) Ground and Flight Training - Aircraft Interchange. When equipment interchange is involved, the pilot in command and the second in command are to receive sufficient ground and flight training to ensure complete familiarity and competency with the particular airborne Category Ill system on the interchange aircraft. The amount of training required will depend on the differences in the flight control and display systems, and cockpit configuration.
Ground and Flight Training - Foreign Category Ill Airports.
If the operator has authorization for Category III operations at an airport in a foreign country which imposes procedures or limitations different from those in the United States, both the pilot in command and the second in command should receive sufficient ground and/or flight training to ensure familiarity and competence with these different conditions and requirements.
Category IIIa/b Evaluation on Line Checks. Operators should give consideration to requiring an approach utilizing Category Ill equipment and 17 Par 10
procedures appropriate to crew qualification and aircraft capability whenever Category IIla/b aircraft are utilized for line evaluations.
11. OPERATIONS MANUAL AND PROCEDURES. Procedures, instructions, and information to be used by flightcrews are to be developed by each air carrier to include, as applicable, at least the following:
a. Crewmember Duties. Crewmember duties during a Category III approach, flare, rollout, or missed approach are to be described in the operations manual.
These duties should at least contain a description of the responsibilities and tasks of the pilot flying the aircraft and the pilot not flying the aircraft during all stages of the approach, landing, and missed approach. The duties of the third crewmember, if required, should also be explicitly defined.
b. Training Information. Suitable information and company policies on subjects specified in paragraph 10 should be provided in the operator's manual or available to crews in an equivalent form for reference use.
12. MAINTENANCE PROGRAM. Each applicant is to establish a maintenance program, acceptable to FAA, to assure that the airborne equipment will continue at a level of performance and reliability established by the manufacturer or the FAA.
Applicants having existing FAA-approved maintenance/reliability programs for Category II equipment may extend their program to include Category Ill equipment.
The following are minimum requirements:
a. Maintenance Personnel Training. Each applicant is to establish an initial and recurrent training program acceptable to the FAA for personnel performing maintenance work on Category III airborne systems and equipment.
Training records for such personnel are to be kept current and made available to FAA for inspection.
b. Test Equipment and Standards. The applicant's program for maintenance of line (ramp) test equipment, shop (bench) test equipment, and a listing of all primary and secondary standards utilized during maintenance of test equipment which relates to Category III operation are to be submitted to the FAA for determination of adequacy. Emphasis will be placed on standards associated with ILS receivers, flight directors, automatic flight control systems, autothrottles, altimeter systems, hydraulic or electrical systems applicable, and maintenance techniques and procedures of associated redundant systems.
is are to be dusted to the Pal for receptance buford adopted.
d. Engineering Modifications. Titles and numbers of all modifications, additions, and changes which were made to qualify aircraft systems for
e. Autoland System Periodic Checks. Periodic 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. A system should 18 Par 10
APPROVAL OF CATEGORY III WEATHER MINIMA. Prior to approval of Category III weather minima, the applicant should submit documentation to the FAA Air Carrier District Office (ACDO) or Flight Standards District Office (FSDO) responsible for its operating certificate which demonstrates compliance with the appropriate provisions of these criteria in paragraphs 7 through 12. This documentation will be evaluated by the ACDO/FSDO and forwarded, with the recommended actions, to the Air Transportation Division, AFO-200, FAA Headquarters, Washington, D.C., for review and concurrence prior to approval of Category III minima. When an applicant has satisfactorily shown compliance with the appropriate provisions of these criteria, operations specifications authorizing Category Illa or Category IIIb minima with or without a DH, as applicable, may be issued (see Appendix 5).
During the period (minimum of 6 months) following the issuance of these specifications, the operator will successfully complete the following operations demonstrations and data collection program in line service as part of the approval process to ensure continued performance and reliability of the system before operations down to the next succeeding lower minima are authorized. In unique situations involving newly manufactured airplanes where the air carrier's Category III maintenance program is approved for the proposed operation, this operations demonstration and data collection program may be initiated prior to the issuance of Category III operations specifications provided approval on a case-by-case basis is obtained from the Office of Flight Operations.
Airborne Systems Operational Demonstration. One-hundred (100) successful landings are to be accomplished in line operations, including training flights, using the Category Illa or Category IIIb system installed in each aircraft type.
If failures occur during the program, a determination will be made of the need for additional demonstration landings. The system should demonstrate reliability and performance in line operations consistent with the operational concepts specified in paragraph 7. 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, where ATC considerations significantly restrict the number of opportunities to utilize Type II/III ILS facilities, or to obtain ILS critical area protection during good weather conditions, reductions in the required number of landings will be considered on a case-by-case basis and requires approval from the Office of Flight Operations.
(1) The demonstration should be accomplished on U.S. Type II or Type III ILS facilities. However, at the operator's option, demonstrations may be made on other ILS facilities if sufficient data is recorded to determine the cause of unsatisfactory performance. However, no more than 50 percent of the demonstrations may be made on such facilities.
(2) If an operator has different models of the same type of aircraft utilizing 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 comply with the basic system performance criteria, but the operator need not conduct a full operational demonstration for each model.
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b. Data Collection During Airborne System Demonstration. Each applicant is to develop a form to be used by flightcrews to record the approach and landing performance. This form will be utilized whenever an approach and landing is attempted utilizing the Category III system, regardless of whether the approach is abandoned or concluded successfully. The completed forms and a summary of the demonstration results will be made available to the assigned FAA ACDO or FSDO for evaluation. The form 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.
(3) Touchdown or Touchdown and Rollout Performance. Describe whether or not the aircraft landed within the desired touchdown dispersion area with lateral velocity or crosstrack error which could be corrected by the pilot or automatic system so as to remain within the lateral confines of the runway without a requirement for unusual skills or techniques. The approximate lateral and longitudinal position of the actual touchdown point in relation to the runway centerline and the runway threshold, respectively, should be indicated in the report. This report should also include any Category III system abnormalities which required manual intervention by the pilot to ensure a safe touchdown or touchdown and rollout, as appropriate.
c. Data Analysis. Approaches on Type II or Type III ILS facilities where the pilot was assured that critical area protection was provided which do not result in a successful automatic landing are to be fully documented.
(1) ATC Factors. ATC factors which result in unsuccessful approaches should be reported. Examples include situations in which a flight is vectored too close in for adequate localizer and glide slope capture, lack of protection of IlS critical areas, or ATC requests the flight abandon the approach.
(2) Faulty Ground Station Signals. ILS beam irregularities, such as those caused by other aircraft taxiing, over-flying the antenna, or where a pattern of such faulty performance can be established should be reported.
(3) Other Factors. Any other specific factors effecting the success of Category III operations that are clearly discernible to the flightcrew should be reported. An evaluation of reports discussed in subparagraphs b(1), b(2), and b(3) will be made to determine system suitability for further Category III operations
d. Approval of RVR Minima. When the data from the operational demonstration has been analyzed and found acceptable, an applicant for Category Illa initially authorized 1,000 RVR (300 meters) may be authorized to operate to minima of 700 RVR (200 meters). If the Category III rollout control system has been shown to meet the appropriate provisions of Appendix 2 or Appendix 3, an applicant for Category IIIb initially authorized 600 RVR (175 meters) may be authorized 300 RVR (100 meters) at airports having suitable ground facilities. Additional approvals 20 Par 13
for operations below 300 RVR (100 meters) may be authorized in the future if the airplane is suitably equipped and operational experience indicates that the airborne and ground support equipment are compatible with the lower minima.
e. Foreign Air Carriers. Operations specifications may be amended to authorize Category III landing minima provided the air carrier:
(1) Is authorized for these minima by the State of the Operator, and
(2) Certifies that its Category Illa or Category IIlb program is equivalent to that required by this AC for U.S. air carriers.
Foreign carriers having at least 6 months experience with Category Illa or Category IIlb with the specific type of aircraft and at least 6 months satisfactory experience at an appropriate U.S. facility in conducting automatic landings may be authorized the respective Category Illa minima as low as 700 RVR (200 meters) or Category IIIb minima as low as 300 RVR (100 meters). Foreign carriers not having the Category III or U.S. facility experience should complete the 6-month demonstration program with intermediate minima of 1,000 RVR (300 meters) for Category IIIa or 600 RVR (175 meters) for Category IIIb, but these carriers need not submit the documentation specified in this AC if the State of the Operator confirms to the FAA the authorization for the carrier to use Category III minima at U.S. facilities. However, until suitable facility upgrading is completed, foreign carriers desiring approval to conduct Category III operations on U.S. Type II ILS systems should submit documentation from the State of the Operator which confirms that the airborne equipment is compatible with operations on Type II facilities and the operator is specifically authorized Category III minima using these facilities. Following the 6-month demonstration program, the minima of 700 RVR (200 meters) for Category IIIa or 300 RVR (100 meters) for Category IIIb may be authorized if the program has been satisfactory.
14. OPERATIONAL REPORTING • a • For a period of 1 year after an applicant has been advised that its aircraft system meets Category III requirements, and reduced minima are authorized, the operator is to provide a monthly summary to the FAA of the following information:
(1) The total number of approaches where the equipment constituting the airborne portion of the Category III system was utilized to make satisfactory (actual or simulated) approaches to the applicable Category III minima (by aircraft type).
(2) The total number of unsatisfactory approaches by airport and aircraft registration number with explanations in the following categories - airborne equipment faults, ground facility difficulties, aborts of approaches because of ATC instructions, or other reasons.
(3) Notify the certificate-holding office as soon as possible of any system failures or abnormalities which require flightcrew intervention after passing 100 feet during operations in weather conditions below Category I minima.
The certificate-holding office will forward this information to the Office of Flight Operations as expeditiously as possible.
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b. For an Extended Period.
(1) For FAA facility review, the operator is encouraged to provide to the certificate-holding office an annual summary of the total number of approaches in weather conditions below Category II minima on which Category IIIa or Category IIIb procedures were used, listed by airport and aircraft type and the number of aborted approaches due to equipment failures or ATC.
(2) The operator is to notify the certificate-holding office as soon as possible of any system failures or abnormalities which require flightcrew intervention after passing 100 feet during operations in weather conditions below Category I minima. The certificate-holding office will forward this information to the Office of Flight Operations as expeditiously as possible.
NOTE: The reporting burden contained in this AC does not require Office of Management and Budget approval under the provisions of the Paperwork Reduction Act of 1980, according to Section 3502(4)(a).
Bennet 5. Aunt Kenneth S. Hunt Director of Flight Operations 22 Par 14
Appendix 1 APPENDIX 1. AIRWORTHINESS APPROVAL FOR CATEGORY III AIRBORNE SYSTEMS PURPOSE • This appendix contains criteria for the approval of airborne equipment and installations required for Category III operations.
GENERAL CRITERIA. The type certification approval for the equipment, system installations, and test methods should be based on a consideration of factors such as the intended function of the installed system, its accuracy, reliability, and fail-safe features, as well as the operational concepts in paragraph 7 of this AC.
In addition, approval should be based on demonstrated compatibility with ground facilities designated as U.S. Type II or Type III. The guidelines and procedures contained herein are considered acceptable methods of determining transport category airplane airworthiness for use in Category III operations.
EQUIPMENT APPROVAL CRITERIA. Airborne navigation instrument and/or flight control equipment may be eligible for installation approval as part of an installed system when it is:
order of Pound to competith the rea a. Found to comply with the requirements of an applicable technical standard
b. Found to comply with applicable FAR and approved as part of an airplane under a type certificate or supplemental type certificate.
c. Found to comply with other pertinent specifications adopted by the Administrator; e.g., military standards or a foreign government's validation which has been found to be compatible with the intent of the appropriate FAR.
4. SYSTEM EVALUATION. A flight test program should be conducted to determine that the pertinent systems installed are in accordance with the criteria of this document and agreement should be reached with the applicant on his proposed program to demonstrate compliance. Upon completion of an FAA engineering design review and supporting simulation studies, a type inspection authorization (TIA) should be issued to determine if the complete installation of equipment associated with Category III meets the criteria of this appendix.
This TIA will specify the necessary conformity inspections and tests to be conducted, both on the ground and in flight. It should include determination of satisfactory installation practices, freedom from interferences, compatibility with ground navigation facilities and the ATC system, and performance of intended functions. Performance testing in flight should cover representative and critical phases of both normal operations and malfunction simulation, including failure detection and warning.
Verification should be made of the safety of go-arounds from any point in the approach or landing prior to touchdown as described in paragraph la of this AC.
For aircraft in which a go-around from very low altitude may result in an inadvertent touchdown, the safety of such a procedure should be established. For fail-operational systems, in the event of an engine failure, the cockpit cues or indications after passing 100 feet ACL should not cause the flightcrew to attempt a go-around. Additionally, engine failure cues should not be overpowered by other cautions or warnings from the flight guidance system if the engine failure causes 1 Par 1
AC 120-28C 3/9/84 Appendix 1 the flight guidance system to disconnect. Clearly defined go-around procedures should be incorporated in the airplane flight manual.
5. FUNCTION AND RELIABILITY TESTING. In addition to the inspection and test program, a program of function and reliability flight testing may be required for the purpose of supplementing analytical and test data, such as fault analysis and reliability studies, with accelerated service experience (such testing if practicable may be done, by arrangement, during normal airline operations not predicated on use of the system undergoing test). The extent of the additional tests depends upon the complexity, number, nature of (or novel) design features incorporated in the system, and the record of previous tests and experience.
6. SYSTEM SAFETY CRITERIA. The Category III system and associated components, considered separately and in relation to other systems, should be designed to comply with FAR Section 25.1309, Amendment 25-23. For fail-operational systems, the airplane must be shown to be capable of completing the approach from 100 feet AGL to a safe landing within the touchdown zone and, if applicable, a safe rollout, except for failure conditions which are shown to be extremely improbable.
A safety analysis as described in AC 25.1309-1, System Design Analysis, should be accomplished. The safety analysis must show that:
The probability of an unsafe landing due to system malfunction is extremely improbable.
b. The probability of system malfunction which reduces the capability of the crew to cope with adverse operating conditions is improbable.
The exposure times for assessing probabilities for the Category III landing and rollout functions are:
(1) Category IIIa.
(i) Unsafe landing - the average time required to go from 100 feet AGL, or higher, to touchdown.
(ii) Availability of Function - the average time required to go from 1,500 feet AGL on approach to touchdown.
(2) Category IIIb.
(1) Unsafe landing - the average time required to go from 100 feet AGL, or higher, to a speed where safe manual control of the aircraft by the crew is assured in Category IIIb weather conditions.
(11) Availability of Function - the average time required to go from 1,500 feet AGL on approach to the speed where safe manual control of the aircraft by the crew is assured in Category IIIb weather conditions.
(3) Category 1IIc• Unsafe landing - the average time required to go from 100 feet AGL, or higher, to full stop on the runway.
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