The approval process is considered to be completed following a successful demonstration period. This is to ensure appropriate performance and reliability of the Category III system with that operators aircraft, procedures, maintenance, airports, and NAVAID’s. This process must be completed before operations down to lowest requested minima are authorized. Section 10.5 addresses appropriate demonstration process criteria.
In situations involving newly manufactured airplanes or where otherwise authorized by FAA, the operations demonstration and data collection process may be initiated prior to the issuance of Category III operations specifications. Sections 10.9 through 10.12 provide criteria that may be used to establish acceptable operations demonstration time periods, and demonstration program scope for different operator situations, aircraft variants, and low visibility operating experience history.
10.16. Operations Specification Amendments. The operator is responsible for maintaining current OpSpecs reflecting current approvals authorized by FAA. Once FAA has authorized a change for airborne systems, new runways, or other authorizations, appropriate and timely amendments to affected OpSpecs should be issued. Issuance of amendments to guidance or procedures in other related material such as the Flight Operations Manual or Training Program may also be required. When updated standard operations specification provisions are adopted by FAA, provisions of those updated operations specifications should normally be applied to each operator's program in a timely manner.
10.17. Use of Special Obstacle Clearance Criteria (e.g., RNP criteria). This paragraph addresses use of special criteria such as "Required Navigation Performance" (RNP) criteria. Pending implementation of RNP criteria for public use Standard Instrument Approach Procedures (SIAP’s), obstacle assessments using RNP criteria will be conducted on a case-by-case basis, and for Category III, only authorized as an element of special procedures for RNP qualified operators, using RNP qualified aircraft. Early application of RNP for special procedures is typically intended to apply to instrument procedure segments classified as a transition to a final approach segment, or to facilitate definition of suitable missed approach segments. Use of special obstacle clearance criteria or RNP criteria must be approved by AFS-400 for any Category III procedures.
If RNP procedures are used, the operator must have an acceptable method to assure that any waypoints which are considered critical to an instrument procedure (if any) are correctly defined, and are loaded into each applicable aircraft’s database, initially, and at each change cycle.
10.18. Proof-of-Concept Demonstration for New Systems/Methods. Proof-of-Concept [PoC] as used in this AC is defined as:
A generic demonstration in a full operational environment of facilities, weather, crew complement, airborne systems and any other relevant parameters is necessary to show concept validity in terms of performance, system reliability, repeatability, and typical pilot response to failures as well as to demonstrate that an equivalent level of safety is provided.
Proof-of-Concept may be established by a combination of analysis, simulation and/or flight demonstrations in an operational environment. PoC is typically a combined effort of FAA airworthiness and operational organizations with the applicant, with input from any associated or interested organizations.
A typical PoC program consists of the following elements:
1. Applicant submits a request to either FAA Aircraft Certification or Flight Standards.
2. Meetings are arranged to include all disciplines involved: Aircraft certification; Flight Standards;
National Resource Specialists (NRS’s); the applicant, and supporting personnel as necessary (e.g., Air Traffic and representative flightcrews, as appropriate).
3. A test plan is established which includes input from applicable FAA organizations, the applicant, and as applicable, industry user groups.
4. The test plan should include as a minimum: system definition, operations procedures, qualification, training, weather and environment definition, normal, rare-normal, and non-normal conditions to be assessed, flightcrew, test subject, and test crew requirements, test procedures, test safety constraints as applicable, assessment criteria, and analysis, simulator and test aircraft requirements, and a clear understanding of what constitutes a successful test and proof of concept.
5. PoC is conducted using agreed subject pilots, as appropriate.
6. PoC data is collected in a suitable simulator environment and validated in a realistic airplane environment.
7. FAA is responsible for assessing the PoC data which is typically provided to FAA as agreed by FAA and the applicant. FAA reports relevant findings to the applicant and if applicable, interested industry representatives.
8. FAA operations and airworthiness organizations use the data to develop criteria for approval of type designs, certification processes and procedures, operating concepts, facilities, flightcrew/aircraft dispatcher and maintenance qualification, operations specification, operations procedures, manuals, AFM’s, maintenance procedures, and any criteria necessary.
9. FAA AC criteria for airworthiness and operational approval typically is a product of PoC assessment.
This process is presented pictorially in the following figure.
TECHNOLOGY DEVELOPMENT PROCESS
LETTER AND
APPLICATION TO ACO
APPLICANT
ACO INITIATES
PROJECT ACO
LETTER OF
INTENT TO
FAA-AFS
OPERATOR
DEVELOP
TECHNOLOGY TEAM
ACO, AFS
DETERMINE
APPLICATIONS
AND CONSTRAINTS
IN THE NATIONAL
OPERATIONAL SYSTEM AFS HQ Note 2)
DEVELOP PROOF OF
CONCEPT (POC)
TEST REQUIREMENTS
AND SUCCESS CRITERIA
ACO, AFS
CONDUCT POC
ACO, AFS
REPORT TEST
RESULTS
ACO, AFS
DEVELOP TYPE
DESIGN REQUIREMENTS
- Certification
- Operation
- Maintenance
ACO, TSS, AFS
DEVELOP USER
REQUIREMENTS
- Operation
- Maintenance
- Training Wash AFS, POI's Handbook DESIGN INDUSTRY Note 1)
ACO TYPE DESIGN
CERTIFICATION ACO ACO
AIRPLANE
FLIGHT MANUAL
DRAFT ADVISORY
CIRCULAR (AC)
ACO, TSS, AFS
POI AFS
OPS APPROVAL
OPS SPECIFICATIONS
FCOM-FLIGHT CREW
OPERATING MANUAL Note: 1) Futher modifications to the applicant's original Type Design may require additional technology revisions and/or follow on Proof of Concept testing.
2) The AFS group has the responsibility to coordinate with all Industry technology groups (ALPA, APA, ATA, ADF Industry, manufactures, vendors, DOD, NASA, etc.)
3) Both the FAA ACO and FAA AFS should be contacted to provide certification and operational data to the respective offices.
Index: ACO - Aircraft Certification Office (Including Aircraft Evaluation Group) AFS - Washington Flight Standards Policy Office TSS - Transport Standards Staff RRD7/19/94 Note 3)
11. FOREIGN AIR CARRIER CATEGORY III AT UNITED STATES AIRPORTS (PART 129 OPERATIONS SPECIFICATIONS).
11.1. Use of ICAO or FAA Criteria. International operators requesting or authorized for Category III at U.S. airports should meet criteria of 11.1.1 through 11.1.3 below.
11.1.1. Acceptable Criteria. Criteria Acceptable for use for assessment of international operator's applications for Category III at U.S. airports includes this AC, equivalent JAA criteria, or the ICAO Manual of All Weather Operations DOC 9365/AN910, as amended.
International operators previously approved by FAA in accordance with earlier criteria may continue to apply that earlier criteria. International operators seeking credit for operations addressed only by this revision of AC 120-28D (e.g., Category III HUD operations) must meet criteria of this AC, or equivalent criteria acceptable to FAA, for those applicable provisions.
11.1.2. Foreign Operator AFM Provisions. Unless otherwise authorized by FAA, aircraft used by international operators for Category III within the U.S. should have AFM provisions reflecting an appropriate level of Category III capability as demonstrated to or authorized by FAA, or demonstrated to or authorized by an authority recognized by FAA, as having acceptable equivalent Category III airworthiness criteria (e.g., European JAA, Canada MOT, UK CAA).
11.1.3. Foreign Operator Category III Demonstrations. International (Foreign) Air Carriers meeting FAA criteria, or criteria acceptable to FAA (e.g., European JAA, ICAO Criteria including Doc 9365/AN910), and having more than 6 months experience in use of Category III operations with the applicable aircraft type may be approved for Category III in accordance with provisions of their own regulatory authority, or in accordance with standard provisions of 14 CFR part 129 OpSpecs, which ever is the more restrictive. A separate demonstration period is not required for FAA if the “State of the Operator” does not require it. However, operators approved in accordance with this provision may nonetheless be subject to additional FAA demonstration for special situations, such as at airports with irregular underlying terrain (see 11.3), or for aircraft types not having flown to U.S. facilities having Category III procedures.
For international (foreign) operators having current U.S. Category III authorization, the Category III demonstration period may be reduced or waived for addition of a new type aircraft to the existing Category III authority. The demonstration period may be reduced or waived to the extent that a successful demonstration has been accepted by FAA for that aircraft type for any other U.S. or international operator.
International (Foreign) Air Carriers not meeting above provisions may be subject to the demonstration described at 10.5.2 and 10.9 (equivalent to those necessary for U.S. operators) as determined applicable by FAA.
11.2. Issuance of Part 129 Operations Specifications. International (Foreign) Air Carriers operating to U.S. airports which meet applicable provisions above are approved for Category III through issuance of part 129 OpSpecs (see Appendix 7).
Operators intending Category III operations at U.S. designated irregular terrain airports, or airports otherwise requiring special assessments must successfully complete those assessments prior to use of those facilities.
11.3. Use of Certain United States Facilities. Foreign operators typically use Category III procedures in the U.S. which are available as unrestricted public use procedures. However, FAA may also authorize certain restricted public use procedures and special Category III approach procedures for non-U.S. Operators. Typically, these procedures require special airborne equipment capability, special training, or non-standard facility and obstacle assessments. These special procedures are identified on the Category II/III status checklist and are not usually published as a part 97 Category III SIAP.
Foreign operators may be eligible to use certain of these procedures if they meet the same special criteria as would apply to a U.S. operator, and if they are approved by their own authority specifically for the use of the procedure. Some procedures may not be eligible for foreign use because of other applicable restrictions such as a restriction placed on private facility use. Special or restricted procedures require both FAA authorization and specific authorization from the state of the operator's controlling authority for each procedure. This is to ensure that both the operator and foreign authority are aware of the special provisions needed, and to ensure equivalent safety to use of standard ICAO criteria.
Each foreign operator seeking Category III procedure authorization at a facility not published as a standard and unrestricted Category III SIAP, or at any other facilities identified as special or restricted on the FAA Category II/III Status checklist, and that operator's controlling authority must:
1. Be aware of the restrictions applicable to the procedure (e.g., facility status),
2. Provide evidence to FAA of the controlling authority's approval of the operator for each special procedure requested, and
3. Must have the applicable limitations and conditions included in that operator's part 129 OpSpecs for each procedure to be used.
Foreign operators shall not normally be authorized special Category III operations to minima lower than those specified in part 97 Category III SIAPS consistent with ICAO criteria.
12. OPERATOR REPORTING, AND TAKING CORRECTIVE ACTIONS.
12.1. Operator Reporting. The reporting of satisfactory and unsatisfactory Category III aircraft performance is a useful tool in establishing and maintaining effective maintenance and operating policy
and procedures. Information obtained from reporting data and its analysis is useful in recommending and issuing appropriate corrective action(s).
Accordingly, for a period of at least 1 year after an applicant has been advised that its aircraft and program meet Category III criteria, 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 ft. during operations in weather conditions below Category I minima.
4. Upon request, the certificate-holding district office will make this information available to AFS- 400 for overall Category III program management, or to assist in assessment of program or facility effectiveness.
This 1 year recording and reporting requirement applies to the initial Category III airplane, however, when maintained over longer periods of time the report data substantiates a successful program and can identify trends, or recurring problems that may not be related to aircraft performance.
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).
12.2. Operator Corrective Actions. In addition to the corrective actions contained in the operations and maintenance manuals, operators are expected to take appropriate corrective actions when they determine that conditions exist which could adversely affect safe Category III operations. Examples of situations for which an operator may need to take action restricting, limiting, or discontinuing Category III operations include:
Repeated aircraft system difficulties, repeated maintenance write-ups, chronic pilot reports of unacceptable landing performance, applicable service bulletin issuance, AD’s, NAVAID status or performance problems, applicable NOTAM’s, airport facility status change, air traffic procedure adjustment, lighting, marking, or standby power system status outages, airport construction, obstacle construction, temporary obstacles, natural disasters, adverse weather, snow banks, snow removal, icy runways or taxiways, deep snow in glide slope critical areas, inability to confirm appropriate critical area protection at non-United States airports, and other such conditions.
Examples of appropriate corrective action could be an adjustment of Category III programs, procedures, training, modification to aircraft, restriction of minima, limitations on winds, restriction of NAVAID facility use, adjustment of payload, service bulletin incorporation, or other such measures necessary to ensure safe operation.
List of Appendices Appendix 1. - DEFINITIONS AND ACRONYMS Appendix 2. - AIRWORTHINESS APPROVAL OF AIRBORNE SYSTEMS USED
DURING A TAKEOFF IN LOW VISIBILITY WEATHER CONDITIONS Appendix 3. - AIRWORTHINESS APPROVAL FOR AIRBORNE SYSTEMS USED
TO LAND AND ROLLOUT IN LOW VISIBILITY CONDITIONS Appendix 4. - WIND MODEL FOR APPROACH AND LANDING SIMULATION Appendix 5. - AIRWORTHINESS DEMONSTRATION OF DECELERATION & BRAKING SYSTEMS OR DISPLAYS - [RESERVED] Appendix 6. - AFM PROVISIONS AND EXAMPLE AFM WORDING Appendix 7. - STANDARD OPERATIONS SPECIFICATIONS Appendix 8. - IRREGULAR TERRAIN ASSESSMENT Appendix 9. - TAKEOFF SYSTEM PERFORMANCE AFTER LIFTOFF
AC 120-28D 07/13/99 Appendix 1 APPENDIX 1
DEFINITIONS AND ACRONYMS This Appendix contains the definition of terms and acronyms used within this Advisory Circular (AC). The appendix also contains certain terms that are not used in this AC but are used in related AC’s and are included for convenient reference. Certain definition of terms and acronyms are also provided to facilitate common use of this Appendix for other related AC’s.
Definitions.
Actual Navigation Performance A measure of the current estimated navigation performance, excluding Flight Technical Error (FTE).
Actual Navigation Performance is measured in terms of accuracy, integrity, and availability of navigation signals and equipment.
Note: Also see Estimated Position Uncertainty [EPU].
Aeronautical Chart Critical data Data for Aeronautical charts determined in accordance with RTCA or ICAO Annex 4 criteria considered to have a very low probability of significant error and very high probability of validity [e.g., Perror per unit data element <1 X 10-8 ] Aeronautical Chart Essential data Data for Aeronautical charts determined in accordance with RTCA or ICAO Annex 4 criteria considered to have a low probability of significant error and high probability of validity [e.g., Perror per unit data element <1 X 10-5 ] Aeronautical Chart Routine data Data for Aeronautical charts determined in accordance with RTCA or ICAO Annex 4 criteria considered to have a routine possibility of significant error and routine validity [e.g., Perror per unit data element <1 X 10-3] Approach Intercept Waypoint (APIWP) Variable waypoint used only when intercepting the Final Approach Segment (FAS).
Automatic Dependent Surveillance (ADS) A surveillance technique in which aircraft automatically provide, via data link, data derived from on-board navigation and position fixing systems, including aircraft identification, four dimensional position and additional data as appropriate (ICAO - IS&RP Annex 6).
Alert Height A height above the runway based on the characteristics of the aircraft and its fail-operational landing system, above which a Category III approach would be discontinued and a missed approach initiated if a failure occurred in one of the redundant parts of the fail operational landing system, or in the relevant ground equipment. (ICAO - IS&RP Annex 6).
Airborne Navigation system The airborne equipment that senses and computes the aircraft position relative to the defined path, and provides information to the displays and to the flight guidance system. It may include a number of receivers and/or system computers such as a Flight Management Computer and typically provides inputs to the Flight Guidance System.
AC 120-28D Appendix 1 07/13/99 Automatic Go-Around A Go-Around which is accomplished by an autopilot following pilot selection and initiation of the "Go-Around" autopilot mode, when an autopilot is engaged in an "approach mode."
Availability An expectation that systems or elements required for an operations will be available to perform their intended functions so that the operation will be accomplished as planned to an acceptable level of probability.
Balked Landing A discontinued landing attempt. Term is often used in conjunction with aircraft configuration or performance assessment, as in "Balked landing climb gradient," Also see "Rejected Landing."
Catastrophic Failure Condition Failure Condition which would result in multiple fatalities, usually with the loss of the airplane.
Category I A precision instrument approach and landing with a decision height not lower than 60m (200 ft) and with either a visibility not less than 800m (2400 ft), or a runway visual range not less than 550m (1800 ft).
(ICAO - IS&RP Annex 6).
Category II A precision instrument approach and landing with a decision height lower than 60m (200 ft) but not lower than 30m (100 ft) and a runway visual range not less than 350m (1200 ft). (ICAO - IS&RP Annex 6).
Category IIIa A precision instrument approach and landing with a decision height lower than 30m (100 ft), or no decision height and a runway visual range not less than 200m (700 ft). (ICAO - IS&RP Annex 6).
Category IIIb A precision instrument approach and landing with a decision height lower than 15m (50 ft), or no decision height and a runway visual range less than 200m (700 ft) but not less than 50m (150 ft). (ICAO - IS&RP Annex 6).
FAA Note - the United States does not use Decision Heights for Category IIIb.
Category IIIc A precision instrument approach and landing with no decision height and no runway visual range limitations. (ICAO - IS&RP Annex 6).
Class I Navigation Navigation within the Service Volume of an ICAO Standard NAVAID.
Class II Navigation A flight operation or portion of a flight operation (irrespective of the means o f navigation) which takes place outside (beyond) the designated Operational Service Volume of an ICAO standard airway navigation facility or NAVAID
(e.g., VOR, VOR/DME, NDB).
Combiner The element of the head-up- display (HUD) in which the pilot simultaneously views the external visual scene along with synthetic information provided in symbolic form.
Command Information Information that directs the pilot to follow a course of action in a specific situation (e.g., Flight Director).
AC 120-28D 07/13/99 Appendix 1 Conformal Information Information which correctly overlays the image of the real world, irrespective of the pilots viewing position.
Datum Crossing Height [DCH] The height (in feet or meters) of the Flight Path Control Point above the Runway Datum Point.
Decision Altitude (DA) A specified altitude in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. (Adapted from ICAO - IS&RP Annex 6).
Decision Altitude (Height) DA(H) For Category I, a specified minimum altitude in an approach by which a missed approach must be initiated if the required visual reference to continue the approach has not been established. The "Altitude" value is typically measured by a barometric altimeter or equivalent (e.g., Inner Marker) and is the determining factor for minima for Category I Instrument Approach Procedures. The "Height" value specified in parenthesis is typically a radio altitude equivalent height above the touchdown zone (HAT) used only for advisory reference and does not necessarily reflect actual height above underlying terrain.
For Category II and certain Category III procedures (e.g., when using a Fail- Passive autoflight system) the Decision Height (or an equivalent IM position fix) is the controlling minima, and the altitude value specified is advisory.
The altitude value is available for cross reference. Use of a barometrically referenced DA for Category II is not currently authorized for 14 CFR part 121, 129 or 135 operations at U.S. facilities (Adapted from ICAO - IS&RP Annex 6).
Decision Height (DH) A specified height in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established (Adapted from ICAO - IS&RP Annex 6).
Design Eye Box The three dimensional volume in space surrounding the Design Eye Position from which the HUD information can be viewed.
Design Eye Position The position at each pilot's station from which a seated pilot achieves the optimum combination of outside visibility and instrument scan.
Defined Path The path that is defined by the path definition function.
Desired Path The path that the flightcrew and air traffic control can expect the aircraft to fly.
Enhanced Vision System An electronic means to provide the flightcrew with a synthetic image of the external scene.
Estimate of Position Uncertainty [EPU], or Estimated Position Error [EPE] A measure based on a scale which conveys the current position estimation performance - Also called Estimated Position Error (EPE)