U.S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Criteria for Approval/Authorization of All Weather Operations (AWO) for Takeoff, Landing, and Rollout Date: 7/2/18 Initiated by: AFS-400 AC No: 120-118 Change:
This advisory circular (AC) provides an acceptable means, but not the only means, for obtaining and maintaining authorization of operations in Category (CAT) I, CAT II, and CAT III landing weather minima and instrument flight rules (IFR) lower-than-standard takeoff minima. This AC does not change, add, or delete regulatory requirements or authorize deviations from regulatory requirements. This AC addresses the operational authorizations formerly published in AC 120-28, Criteria for Approval of Category III Weather Minima for Takeoff, Landing, and Rollout, and AC 120-29, Criteria for Approval of Category I and Category II Weather Minima for Approach, and any subsequent developments.
ORIGINAL SIGNED by /s/ John S. Duncan Executive Director, Flight Standards Service
CONTENTS Paragraph Page
CHAPTER 1. INTRODUCTION1
1-1. Purpose1
a. Overview1
b. Regulatory Basis1
c. International Harmonization1
d. Nomenclature Changes1
e. CAT III Landing Minima1
f. All Weather Operations2
g. Responsible Flight Standards Office2
h. Dispatcher2
1-2. Where You Can Find This AC2
1-3. Relationship of This AC with AC 20-191 and Their Impact Upon AC 120-29A
and AC 120-28D2
1-4. Applicability2
1-5. Explanation of Content2
a. Takeoff, Approach, Landing and Rollout Operations3
b. Enhanced Flight Vision Systems (EFVS) and Synthetic Vision Guidance
Systems (SVGS)3
c. New Technology Demonstration (NTD)3
d. Operator Use Suitability Demonstration (OUSD) Changes3
e. Satellite-Based Augmentation System (SBAS)3
1-6. Related Regulations and References4
a. Title 14 CFR4
b. ACs, FAA Orders, and Operational Authorizations4
c. OpSpecs/MSpecs/LOAs5
CHAPTER 2. BACKGROUND7
2-1. Operational Authorizations Versus Airworthiness Demonstrations7
2-2. Explanation of Terms7
2-3. Approach Terminology7
CHAPTER 3. OPERATIONAL CONCEPTS9
3-1. Instrument Operations9
a. Airborne Systems9
b. Magnetic Variation (MagVar) Data and Onboard Database9
c. Airborne Databases and Interface11
3-2. Takeoff11
a. Takeoff Minima11
b. Pilot Assessment of Equivalent RVR11
3-3. Landing12
a. Approach and Landing Concepts12
b. Acceptable Instrument Approach Procedure (IAP) Basis13
c. Considerations for the Use of Procedures Other Than U.S.
Standard Procedures13
d. Special IAPs14
e. Glide Path Angle (GPA) and Vertical Descent Angle (VDA)14
Table 3-1. Maximum Standard Approach Design Glide Path Angles/Vertical
Descent Angles14
f. Steep Angle Approach14
3-4. Engine Inoperative CAT II/III15
3-5. Go-Around Safety15
a. CAT I Go-Around15
b. CAT II/III Go-Around15
c. Automatic Go-Around15
3-6. Requirements for CAT I Operations15
a. General Requirements15
b. CAT I Landing Minima with Reduced Lighting (RVR 1800)15
3-7. Requirements for Operations Below RVR 1800 to 100016
a. General Requirements16
b. Specification of CAT II DA/DH16
c. Eligibility for CAT II Minima Not Less Than 100 Feet DA/DH16
d. Use of IM16
e. SA CAT I17
f. SA CAT II18
g. CAT II Using RVR 1000 Minima18
Table 3-2. Special Authorization Category II and Category II Minima Matrix19
h. Application of a DA/DH or Equivalent (e.g., IM), for CAT II19
i. Visual Reference Requirements19
j. Precision Approach Radar (PAR)20
3-8. Requirements for Operations Below RVR 100020
a. General CAT III Requirements20
b. Concepts and Objectives20
c. Fail Operational (FO) CAT III Systems21
d. Alert Height23
e. Fail Passive CAT III Systems24
f. Decision Height25
g. CAT III Operations with Not Lower than RVR 700 Landing Minima25
h. CAT III Operations with Landing Minima RVR 600 or Less26
i. CAT III Operations RVR Minima Rationale27
Table 3-3. Lowest Minima Currently Authorized for Fail Operational or Fail
Passive Landing Systems, or Landing and Rollout Systems28
j. Previously Approved CAT I/II/III Operations or Use of Previous or New
CAT I/II/III Criteria28
3-9. Visibility and RVR29
a. Meteorological Visibility29
b. Overseas Visibility Reporting29
c. Non-NWS Sources29
3-10. Runway Visual Range29
a. Controlling RVR29
b. Operating Minima30
c. Instrumentally Derived RVR Limitations30
d. Non-Instrumentally Derived RVR Reports30
3-11. Runway Field Length Requirements and Runway Contamination30
a. AFM Landing Distance Data30
b. Wet Runway Considerations30
c. Use of Autobrakes30
d. Emergency Return After Takeoff30
e. Alternate Airport Field Length31
f. Acceptable Field Length Factors and Considerations31
3-12. Rollout Deceleration Systems or Procedures for CAT II and/or III32
a. Stopping Means32
b. Antiskid Systems32
3-13. Vision Systems33
a. Synthetic Vision Systems (SVS)/Enhanced Vision Systems (EVS)
Situation Awareness33
b. Synthetic Vision Guidance Systems (SVGS)33
c. Enhanced Flight Vision Systems33
3-14. Hybrid Systems33
CHAPTER 4. PROCEDURES35
4-1. Operational Procedures35
a. Application of AFM Provisions35
b. Crew Coordination35
c. Monitoring35
d. Use of the MDA, DA, DH, or AH35
e. CAT I, II, and III Flightcrew Procedures Compatibility36
f. Flightcrew Response to Non-Normal Events36
4-2. AWO Takeoff And CAT II/III Instrument Approach Procedures (IAP)36
a. Takeoff Guidance System Procedures36
b. Standard Obstacle Clearance for Approach and Missed Approach37
c. Special Obstacle Criteria37
d. Irregular Terrain Airports37
4-3. Continuing Approaches in Deteriorating Weather Conditions37
a. Approach Ban38
b. Wind Constraint Applicability38
4-4. Low-Visibility Taxi Procedures38
a. Low-Visibility Taxi Procedures38
b. Day/Night Provisions39
c. Electronic Presentations39
d. Surface Movement Guidance and Control System (SMGCS)39
4-5. Assesment of Threshold Crossing Height (TCH), Approach Descent
Gradient, and Runway Slope39
a. Operator Assessment39
b. Runway Characteristics39
c. Airport Layout Plan (ALP)39
4-6. Metric Altitudes39
4-7. Approach NAVAID Requirements39
CHAPTER 5. TRAINING AND CREW QUALIFICATION41
5-1. General41
a. Ground Training and Flight Training41
b. Terminal Instrument Procedures (TERPS)41
5-2. Training and Checking for CAT I Qualification41
5-3. Ground Training41
a. Ground Systems and NAVAIDs41
b. The Airborne System43
c. Flight Procedures and Associated Information44
5-4. Flight Training for AWO (Aircraft or FFS)46
a. Types of Procedures and Conditions to be Addressed46
b. Combining Multiple Requirements47
c. Maneuvers47
d. Addressing Applicable Regulations49
5-5. Initial Qualification49
a. Ground Training49
b. Flight Training49
5-6. Recurrent Qualification49
a. Recurrent Ground Training49
b. Recurrent Flight Training49
c. Qualification in Conjunction with AQP50
5-7. Requalification50
5-8. Transition Qualification51
5-9. Upgrade Qualification51
5-10. Flight Deck or Aircraft System Differences51
5-11. Recency of Experience51
a. Requirements51
b. Re-Establishing Recency of Experience51
5-12. Simultaneous Training for AWO51
5-13. Simultaneous Checking for AWO51
5-14. Checking for SA CAT I Qualification52
a. Additional SA CAT I Requirements52
b. Qualified CAT II Flightcrew Members52
5-15. Checking for CAT II Qualification52
5-16. Checking for CAT III Qualification53
a. Automatic Systems53
b. Manual Systems53
5-17. Checking for Low-Visibility Takeoff Qualification53
a. New/Reduced Minima53
b. No FFS Demonstration53
5-18. Experience with Line Landings53
a. Automatic Systems53
b. Manual Systems53
5-19. Crew Records53
5-20. Dual Qualification54
a. Appropriate Training54
b. Program Approval54
5-21. Interchange54
5-22. AWO Training for Use of Foreign Airports54
5-23. Line Checks54
5-24. Special Procedures and/or Special Qualification Airports54
5-25. Particular Approach System/Procedure Qualification54
a. Aircraft Equipment Dependent Approach System Qualification54
b. Approach and Landing with an Engine Inoperative55
c. Circling Approaches55
CHAPTER 6. AIRPORTS, NAVIGATION FACILITIES, AND
METEOROLOGICAL CRITERIA57
6-1. Airport Authorization57
a. Authorized. U.S. and Non-U.S. Airports and Runways57
b. Authorization Requests57
6-2. Use of CAT I/II/III Navigation Facilities57
a. Standard CAT I/II/III Navigation Facilities57
b. Non-Standard CAT I/II/III Facilities57
6-3. Lighting Systems58
a. CAT I Lighting Systems58
b. CAT II/III Lighting Systems58
c. Surface Lighting Below Runway Visual Range (RVR) 120058
d. Lighting Systems for SA CAT I/II58
e. Lighting Exceptions58
6-4. Meteorological Services and RVR Availability and Use58
a. Meteorological Services58
b. RVR Availability and Use Requirements59
c. Pilot Assessment of Takeoff Visibility Equivalent to RVR60
d. Alternate RVR Requirements for Short Field Length Operations60
e. International RVR Reporting and Use Equivalence Considerations60
6-5. ILS Critical Area Protection61
6-6. Operational Facilities: Outages and Notices to Airmen (NOTAM)61
a. Outages61
b. Notices to Airmen61
6-7. Special Provisions for Facilities Used for Extended Operations (ETOPS) of
Multi-Engine Aircraft or Alternates62
a. Airport Requirements62
b. Airport Information62
6-8. Alternate Minima62
6-9. Flight Planning to Airports that Have Weather Conditions Below
Landing Minima62
CHAPTER 7. CONTINUING AIRWORTHINESS/MAINTENANCE63
7-1. Maintenance Program General Provisions63
7-2. Maintenance Program Requirements63
a. AWO Operations63
b. Maintenance Program63
7-3. Initial and Recurrent Maintenance Training65
a. Training of Maintenance Personnel65
b. Training Requirements65
7-4. Test Equipment/Calibration Standards66
7-5. Return to Service Procedures66
a. Maintenance Procedures66
b. Testing66
c. Contract Maintenance67
7-6. Periodic Aircraft System Evaluations67
a. Evaluation Method67
b. Performance Evaluation67
c. FGS and/or Autoland System Checks67
7-7. Reliability Reporting and Quality Control67
a. Total Approaches67
b. Unsatisfactory Approaches67
c. Unscheduled Component Removals67
7-8. Configuration Control/System Modifications68
7-9. Records68
a. Operator Requirements68
b. Contract Maintenance Organization Requirements68
7-10. Part 129 Foreign Operator Maintenance Programs68
a. Maintenance of Part 129 Foreign Registered Aircraft68
b. Maintenance of Part 129 Foreign Operated U.S. N-Registered Aircraft68
CHAPTER 8. APPROVAL OF U.S. OPERATORS71
8-1. General71
8-2. Operations Manuals and Procedures71
a. Manuals71
b. Procedures71
8-3. Training Programs and Crew Qualification71
8-4. Dispatch Planning71
8-5. OpSpecs71
a. OpSpec Contents72
b. OpSpec Maintenance72
c. OpSpec Amendments72
8-6. Operational Demonstrations72
a. Aircraft System Suitability Demonstration72
b. Operator Use Suitability Demonstration (OUSD)73
c. Use of Autoland or Head-Up Guidance at U.S. Type I Facilities
or Equivalent76
8-7. Determining the Proper OUSD for an Operator’s Requested Authorization77
a. Table Definitions77
b. Table Use78
c. Minimum Landings78
d. New Flight Control Equipment OUSD78
e. Six-Month Validation Phase Relief78
f. Small Fleet OUSD78
Table 8-1. Operator Use Suitability Demonstration Requirements79
8-8. CAT II/III Program Status Following Operator Acquisitions/Mergers80
8-9. Irregular Pre-Threshold Terrain and Other Restricted Runways80
8-10. U.S. Carrier AWO Operations at Foreign Airports80
a. Post-Approval Requirements80
b. Consistency with U.S. Standards80
8-11. Evaluation of New Technology and/or Operational Concepts80
a. New Technology Demonstration (NTD) Process80
b. NTD Methodology81
c. Process Illustration81
d. Conformity Inspections81
e. Post-NTD Operational Safety Assessment (OSA) or Review (OSR)81
f. Exclusive Benefit to Single Applicant81
g. Pre-Application or Advanced Research81
Figure 8-1. New Technology Demonstration Process83
CHAPTER 9. INTERNATIONAL (FOREIGN) OPERATORS CONDUCTING AWO AT
U.S AIRPORTS85
9-1. Acceptable Criteria85
a. Previously Approved Operators85
b. Airplane Flight Manual (AFM) Stated AWO Capability85
9-2. CAT II/III Authorization and Demonstrations85
a. Authorization85
b. Demonstration85
c. Addition of New Aircraft Type85
d. Additional Information85
9-3. Use of 14 CFR Non-Part 97 Procedures or Special Authorization
(SA) Procedures86
a. Non-Part 97 Instrument Approach Procedures (IAP)86
b. Procedures Requiring SA86
CHAPTER 10. OPERATOR REPORTING AND TAKING CORRECTIVE ACTIONS87
10-1. Operator Reporting87
a. Standard AWO Performance Reporting87
b. Additional Reporting Requirements87
10-2. CAT II/III Operator Corrective Actions87
a. AWO Corrective Action Responsibility87
b. Example Corrective Actions87
APPENDIX 1. DEFINITIONS AND ACRONYMS (18 pages)1
APPENDIX 2. ENGINE INOPERATIVE CATEGORY (CAT) II/III
APPROACH OPERATIONS (6 pages)1
APPENDIX 3. STANDARD OPERATIONS/MANAGEMENT SPECIFICATIONS (OPSPECS/MSPECS) AND LETTERS OF AUTHORIZATION
(LOA) (8 pages)1
APPENDIX 4. IRREGULAR TERRAIN ASSESSMENT (6 pages)1
Par 1-1 Page 1 CHAPTER 1. INTRODUCTION
1-1. PURPOSE. This AC provides an acceptable means, but not the only means, for obtaining and maintaining authorization of operations in Category (CAT) I, CAT II, and CAT III landing weather minima and instrument flight rules (IFR) lower-than-standard takeoff minima. Terms used in this AC such as “should” or “must” are used only in the sense of ensuring applicability of these particular methods of compliance when the acceptable means of compliance described herein is used. This AC does not change, add, or delete regulatory requirements or authorize deviations from regulatory requirements. This AC addresses the operational authorizations formerly published in AC 120-28, Criteria for Approval of Category III Weather Minima for Takeoff, Landing, and Rollout, and AC 120-29, Criteria for Approval of Category I and Category II Weather Minima for Approach, and any subsequent developments.
a. Overview. This AC is the basis for AWO flight operations and should be used in conjunction with AC 20-191, which provides airworthiness criteria for aircraft system certification. Authorization for operators to act in compliance with their standard CAT II and III operations specifications (OpSpecs), management specifications (MSpecs), and letters of authorization (LOA) are also discussed at length in this AC.
b. Regulatory Basis. CAT II and III operations conducted by Title 14 of the Code of Federal Regulations (14 CFR) part 91 operators are done primarily in accordance with part 91, §§ 91.189, 91.191, 91.193, and part 91 appendix A, Category II Operations: Manual, Instruments, Equipment, and Maintenance; 14 CFR part 61, §§ 61.66, 61.67 and 61.68; and further provisions as authorized by the FAA Administrator in the operator’s LOA.
Section 91.189(g) states that CAT II and III operations conducted by certificate holders operating under 14 CFR part 121, 125, 135, part 129 foreign air carriers, or holders of MSpecs issued in accordance with part 91 subpart K (91K), may conduct CAT II or CAT III operations only in accordance with their OpSpecs or MSpecs.
c. International Harmonization. This new AC also incorporates information pertaining to international AWO criteria harmonization between the Federal Aviation Administration (FAA), European Aviation Safety Agency (EASA), and several other regulatory authorities.
Subsequent revisions of this AC will be published as additional AWO harmonization items are agreed upon by FAA, EASA, and other regulatory authorities.
d. Nomenclature Changes. This AC reflects the changes which occurred in 2011 when the FAA removed the definitions of CAT IIIa, IIIb, and IIIc operations and discontinued the use of this nomenclature in subsequent documentation. Some FAA instrument procedures may still retain CAT IIIa nomenclature until these procedures are updated or amended. These definitions are outdated and no longer utilized for aircraft certification or operational authorization. Any references to these terms in this AC are used for historical context.
e. CAT III Landing Minima. The CAT III landing minima at a particular runway are currently based on the demonstrated qualities and capabilities of the signal utilized for approach on that runway. The approach charts now show only the lowest possible CAT III landing minima on a runway. For example, the approach chart for a landing at an airport may only state that the Runway Visual Range (RVR) is 600 and will not make any reference to the CAT IIIb operations
Par 1-1 Page 2 definition. Operators now use the published minima in conjunction with their OpSpecs/MSpec to determine the lowest landing minima allowed to them.
f. All Weather Operations. The term AWO, as used in this AC, is meant to include operations during low-visibility takeoff and landing conditions. This encompasses takeoff below standard weather minima and instrument approach procedures (IAP) for CAT I, II and III, to include Special Authorization (SA) CAT I and II.
g. Responsible Flight Standards Office. There are numerous instances in this AC where the term “responsible Flight Standards office” is used. The intent of this phrase is to direct the operator to the proper office/organization with authorization authority based upon the type of operation referenced.
h. Dispatcher. For the purposes of this document, the term “dispatcher” refers to a person or persons exercising operational control over a flight other than the flightcrew.
1-2. WHERE YOU CAN FIND THIS AC. You can find this AC on the FAA’s website at http://www.faa.gov/regulations_policies/advisory_circulars.
1-3. RELATIONSHIP OF THIS AC WITH AC 20-191 AND THEIR IMPACT UPON AC 120-29A AND AC 120-28D. This AC contains the revised operational authorization information previously found in AC 120-28D, Criteria for Approval of Category III Weather Minima for Takeoff, Landing, And Rollout, dated July 13, 1999, and AC 120-29A, Criteria for Approval of Category I and Category II Weather Minima for Approach, dated August 12, 2002.
Prior to the publication of this AC, operational authorization and aircraft certification information was consolidated in either AC 120-29A (for CAT I and II), or AC 120-28D (for CAT III).
Aircraft certification information currently contained in AC 120-28D and AC 120-29A remains in effect until revised by the publication of AC 20-191. The publication of AC 20-191 will subsequently cancel AC 120-28D and AC 120-29A.
1-4. APPLICABILITY. The intent of this AC is to provide information for all operators, including part 91, considering or currently operating under AWO. New operational authorizations (e.g., C052, C060, C078, etc.) should use the criteria of this AC. Operations approved based upon earlier criteria may continue or operators may seek additional operational credit provided by this AC. Airworthiness criteria and demonstrations are addressed in AC 20-191.
1-5. EXPLANATION OF CONTENT. The AC includes incorporation and significant revision of information previously contained in AC 120-29 and AC 120-28 into a single document, the extraction of airworthiness criteria and relocation into AC 20-191, and the removal of information pertaining to Required Navigation Performance (RNP) and microwave landing system (MLS). Many changes to the content of those previous ACs have been made to improve clarity, accuracy, completeness, and consistency. It is suggested that this AC be read in its entirety due to the new presentation of this subject matter.
Par 1-5 Page 3
a. Takeoff, Approach, Landing, and Rollout Operations. This new AC discusses takeoff, approach, landing, and rollout operations which involve ground-based Navigational Aids (NAVAID) used for AWO approach operations. The AC includes information on AWO takeoff guidance systems, expanded SA CAT I guidance, updated CAT II/III guidance for use in conjunction with Head-Up Display (HUD) systems, Ground Based Augmentation System (GBAS) Landing System (GLS), and use of CAT II/III during certain engine inoperative operations.
b. Enhanced Flight Vision Systems (EFVS) and Synthetic Vision Guidance Systems (SVGS). Additional information is included addressing operations utilizing EFVS and SVGS during AWO operations, as well as operations involving hybrid approach and landing systems.
Expanded information and guidance on EFVS and its authorized use are located in AC 90-106, Enhanced Flight Vision Systems. The EFVS rule, § 91.176, effective March 21, 2017, and associated EFVS operational authorizations (e.g., OpSpecs) contain unique operational capabilities and regulatory exceptions that are not addressed in this document. Readers must refer to AC 90-106 for a complete understanding of differences which may apply when conducting EFVS operations or using EFVS during conduct of operations discussed in this AC
(e.g., CAT II or III operations).
c. New Technology Demonstration (NTD). A new term, NTD, is introduced in this AC as a process of generic demonstration of technology, providing an equivalent or acceptable level of safety to the current operation. The NTD was formerly known as Proof of Concept (PoC) in AC 120-28 and AC 120-29. An NTD is typically initiated by an operator or manufacturer after consultation with the Flight Technologies and Procedures Division.
d. Operator Use Suitability Demonstration (OUSD) Changes. Changes to the topic of OUSD are also contained in this AC. Operators should pay particular attention to several updated minimum requirements for demonstration of appropriate performance, automation, and technology involved in an acceptable OUSD. Changes to the equipage, training, and maintenance requirements for SA CAT I authorization and operations are included in this new AC. Finally, steep angle approach operational approval is examined and authority for operational authorization is established.
e. Satellite-Based Augmentation System (SBAS). This AC does not discuss operations based upon SBAS. Operations relating to this subject are discussed in the most current versions of AC 90-101, Approval Guidance for RNP Procedures with AR, AC 90-105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace, AC 90-107, Guidance for Localizer Performance with Vertical Guidance and Localizer Performance without Vertical Guidance Approach Operations in the U.S. National Airspace System and AC 90-108, Use of Suitable Area Navigation (RNAV) Systems on Conventional Routes and Procedures.