AC 120-28D July 13, 1999
CRITERIA FOR APPROVAL OF
CATEGORY III WEATHER MINIMA
FOR TAKEOFF, LANDING, AND ROLLOUT
1. Purpose. This advisory circular (AC) provides an acceptable means, but not the only means, for obtaining and maintaining approval of operations in Category III Landing Weather Minima and low visibility takeoff including the installation and approval of associated aircraft systems. It includes additional Category III criteria or revised Category III criteria for use in conjunction with Head-up Displays, satellite navigation systems, low visibility takeoff guidance systems, Wide-body Fail Passive operations and use of Category III during certain engine inoperative operations. This revision also updates and incorporates provisions of the former AC 20-57 into AC 120-28.
This revision incorporates changes resulting from the first steps toward international all weather operations (AWO) criteria harmonization taken by the Federal Aviation Administration (FAA), European Joint Aviation Authorities (JAA), and several other regulatory authorities. Subsequent revisions of this AC are planned as additional all weather operations harmonization items (AHI) are agreed and completed by FAA JAA, and other regulatory authorities.
L. Nicholas Lacey Director, Flight Standards Service
i
TABLE OF CONTENTS SEC # SECTION TITLES 1 PURPOSE 2 RELATED REFERENCES AND DEFINITIONS
2.1 Related References
2.2 Definitions 3 BACKGROUND
3.1 Major Changes Addressed in this Revision
3.2 Relationship of Operational Authorizations for Category III and Airborne System Demonstrations
3.3 Applicable Criteria 4 OPERATIONAL CONCEPTS
4.1 Classification and Applicability of Minima
4.2 Takeoff
4.3 Landing
4.3.1 Concepts and Objectives
4.3.2 Fail Operational Category III Operations
4.3.3 Alert Height
4.3.4 Fail Passive Category III Operations
4.3.5 Decision Altitude (Height)
4.3.6 Go-Around Safety
4.3.7 Category IIIa
4.3.8 Category IIIb
4.3.9 Runway Field-Length
4.3.10 Landing System Sensors (NAVAIDs) and Aircraft Position Determination
4.3.10.1 Instrument Landing System(ILS)
4.3.10.2 Microwave Landing System (MLS)
4.3.10.3 GNSS Landing System (GLS)
4.4 RNAV/Flight Management Systems (FMS)
4.5 Required Navigation Performance (RNP)
4.5.1 Standard RNP Types
4.5.2 Non-Standard RNP Types
4.6 Flight Path Definition
4.7 Engine Inoperative Category III Capability 5 AIRBORNE SYSTEMS
5.1 General
5.1.1 Airborne Systems
5.1.2 Non-Airborne Systems
5.1.3 Takeoff Guidance Systems
5.2 Airborne Systems for Category III Minima Not Less Than RVR600
5.3 Airborne Systems for Category III Minima Less Than RVR600
5.3.1 Airborne Systems for Category III Minima Not Less Than RVR400
ii
5.3.2 Airborne Systems for Category III Minima Not Less Than RVR300 (75 m)
5.3.3 Airborne Systems for Category III Minima Less Than RVR300
5.4 Automatic Flight Control Systems and Automatic Landing Systems
5.5 Flight Director Systems
5.6 Head-up Display Systems
5.7 Enhanced/Synthetic Vision Systems
5.8 Hybrid Systems
5.9 Instruments and Displays
5.10 Annunciations
5.11 Automatic Aural Alerts
5.12 Navigation Sensors
5.13 Supporting Systems and Capabilities
5.13.1 Flight Deck Visibility
5.13.2 Rain and Ice Removal
5.13.3 Miscellaneous Systems
5.14 Go-Around Capability
5.15 Excessive Deviation Alerting
5.16 Rollout Deceleration Systems or Procedures for Category III
5.16.1 Stopping Means
5.16.2 Antiskid Systems
5.17 Engine Inoperative Category III Capability
5.18 Airborne System Assessment for Irregular Pre-Threshold Terrain
5.19 Airworthiness Demonstrations of Airborne System Capability for Category III 6 PROCEDURES
6.1 Operational Procedures
6.1.1 Application of AFM Provisions
6.1.2 Crew Coordination
6.1.3 Monitoring
6.1.4 Use of the Decision Height or Alert Height
6.1.5 Call-outs
6.1.6 Aircraft Configurations
6.1.7 Compatibility with Category I and Category II Procedures
6.1.8 Flight Crew Response to Non-Normal Events
6.2 Category III Instrument Approach Procedures and Low Visibility Takeoff
6.2.1 Takeoff Guidance System Procedures
6.2.2 Acceptable Procedures for Category III Approach
6.2.3 Standard Obstacle Clearance for Approach and Missed Approach
6.2.4 Special Obstacle Criteria
6.2.5 Irregular Terrain Airports
6.2.6 Airport Surface Depiction for Category III Operations
6.2.7 Continuing Category III Approaches in Deteriorating Weather Conditions
6.2.8 Low Visibility Taxi Procedures
6.2.9 Navigation Reference Datum Compatibility (e.g.,WGS-84/Other Datum) 7 TRAINING AND CREW QUALIFICATION
7.1 Ground Training
7.1.1 Ground System and NAVAID’s for Category III
iii
7.1.2 The Airborne System
7.1.3 Flight Procedures and Associated Information
7.2 Flight Training (Aircraft or Simulator)
7.2.1 Initial Qualification
7.2.2 Recurrent Qualification
7.2.3 Recency of Experience
7.2.4 Re-qualification
7.2.5 Cockpit or Aircraft System Differences
7.2.6 Category III Operations with an Inoperative Engine
7.2.7 Training in Conjunction with Advanced Qualification Programs (AQP) or Exemptions for “Single Visit Training”
7.2.8 Credit for “High Limit Captains” (Reference section 121.562)
7.2.9 Enhanced or Synthetic Vision Systems (Independent Landing Monitor)
7.3 Checking or Evaluations
7.4 Experience with Line Landings
7.5 Crew Records
7.6 Dual Qualification
7.7 Interchange
7.8 Training For Use of Foreign Airports for Category III Operations or Low Visibility Takeoff
7.9 Line Checks 8 AIRPORTS, NAVIGATION FACILITIES AND METEOROLOGICAL CRITERIA
8.1 Use of Standard Navigation Facilities
8.2 Use of Other Navigation Facilities or Methods
8.3 Lighting Systems
8.4 Marking and Signs
8.5 Low Visibility Surface Movement Guidance and Control (SMGC) Plans
8.6 Meteorological Services and RVR Availability and Use
8.6.1 Meteorological Services
8.6.2 RVR Availability and Use
8.6.2.1 RVR Availability
8.6.2.2 RVR Use
8.6.3 Pilot Assessment of Takeoff Visibility Equivalent to RVR
8.7 Critical Area Protection
8.8 Operational Facilities, Outages, Airport Construction, and NOTAM’s
8.9 Use of Military Facilities
8.10 Special Provisions for Facilities Used for ETOPS or EROPS Alternates
8.11 Alternate Minima
8.12 Flight Planning to Airports That Have Weather Conditions Below Landing Minima 9 CONTINUING AIRWORTHINESS/MAINTENANCE
9.1 Maintenance Program
9.2 Maintenance Program Provisions
9.3 Initial and Recurrent Maintenance Training
9.4 Test Equipment/Calibration Standards
9.5 Return to Service Procedures
9.6 Periodic Aircraft System Evaluations
9.7 Reliability Reporting and Quality Control
iv
9.8 Configuration Control/System Modifications
9.9 Records
9.10 FAR 129 Foreign Operator Maintenance Programs
9.10.1 Maintenance of FAR 129 Foreign Registered Aircraft
9.10.2 Maintenance of FAR 129 Foreign Operated U.S. "N" Registered Aircraft 10 APPROVAL OF UNITED STATES OPERATORS
10.1 Operations Manuals and Procedures
10.2 Training Programs and Crew Qualification
10.3 Flight Planning (e.g., Dispatch, MEL, Alternate Airports, ETOPS or EROPS)
10.4 Formulation of Operations Specification
10.5 Operational/Airworthiness Demonstrations
10.5.1 Airborne System Suitability Demonstration
10.5.2 "Operator Use Suitability" Demonstration
10.5.2.1 Data Collection For Airborne System Demonstrations
10.5.2.2 Data Analysis
10.5.2.3 Approval of Landing Minima
10.6 Eligible Airports and Runways
10.7 Irregular Pre-Threshold Terrain and Other Restricted Runways
10.8 Engine-Inoperative Operations and ETOPS or EROPS Alternates based on Category III
10.8.1 General Criteria for Engine Inoperative Category III Authorization
10.8.2 Engine Inoperative "Flight Planning"
10.8.3 Engine Inoperative En Route
10.8.4 Engine Failure During Approach, Prior to Alert Height or Decision Height
10.8.5 Engine Failure After Passing Alert Height or Decision Height
10.9 New Category III Operators
10.10 Credit for Experienced Category III Operators for New Authorizations
10.10.1 New Airports/Runways
10.10.2 New or Upgraded Airborne System Capabilities
10.10.3 Adding a New Category III Aircraft Type
10.11 Category III Program Status Following Operator Acquisitions/Mergers
10.12 Initiating New Combined Category II and Category III Programs
10.13 United States Carrier Category III Operations at Foreign Airports
10.14 Category III Operations on Off-Route Charters
10.15 Approval of Category III Minima and Issuance of Operations Specifications
10.16 Operations Specification Amendments
10.17 Use of Special Obstacle Clearance Criteria (e.g., RNP Criteria)
10.18 Proof-of-Concept Demonstration for New Systems/Methods 11 FOREIGN AIR CARRIER CATEGORY III AT UNITED STATES AIRPORTS (Part 129 OPERATIONS SPECIFICATIONS)
11.1 Use of ICAO or FAA Criteria
11.1.1 Acceptable Criteria
11.1.2 Foreign Operator AFM Provisions
11.1.3 Foreign Operator Category III Demonstrations
11.2 Issuance of Part 129 Operations Specifications
11.3 Use of Certain United States Facilities
v 12 OPERATOR REPORTING, AND TAKING CORRECTIVE ACTI ONS
12.1 Operator Reporting
12.2 Operator Corrective Actions APPENDIX 1 DEFINITIONS AND ACRONYMS APPENDIX 2 AIRWORTHINESS APPROVAL OF AIRBORNE SYSTEMS USED DURING A
TAKEOFF IN LOW VISIBILITY WEATHER CONDITIONS 1 APPENDIX 2 PURPOSE 2 APPENDIX 2 GENERAL 3 APPENDIX 2 INTRODUCTION 4 APPENDIX 2 TYPES OF TAKEOFF OPERATIONS 5 APPENDIX 2 TYPES OF TAKEOFF SERVICES
5.1 APPENDIX 2 ILS
5.2 APPENDIX 2 MLS
5.3 APPENDIX 2 GNSS [PoC]
5.3.1 APPENDIX 2 GNSS Flight Path Definition [PoC]
5.3.2 APPENDIX 2 GNSS Airplane Position Determination [PoC]
5.4 APPENDIX 2 Other
5.4.1 APPENDIX 2 Datalink [PoC] 6 APPENDIX 2 AIRWORTHINESS
6.1 APPENDIX 2 General Takeoff System
6.1.1 APPENDIX 2 Takeoff Performance Prior to 35 Ft. AGL
6.1.1.1 APPENDIX 2 ILS
6.1.1.2 APPENDIX 2 MLS
6.1.2 APPENDIX 2 Workload Criteria
6.2 APPENDIX 2 Takeoff System Integrity
6.3 APPENDIX 2 Takeoff System Availability
6.4 APPENDIX 2 Flight Deck Information, Annunciation and Alerting
6.4.1 APPENDIX 2 Flight Deck Information
6.4.2 APPENDIX 2 Annunciation
6.4.3 APPENDIX 2 Alerting
6.4.3.1 APPENDIX 2 Warnings
6.4.3.2 APPENDIX 2 Cautions
6.4.3.3 APPENDIX 2 Advisories
6.4.3.4 APPENDIX 2 System Status
6.4.3.5 APPENDIX 2 Engine Failures 7 APPENDIX 2 TAKEOFF SYSTEM EVALUATION
7.1 APPENDIX 2 Performance Evaluation
7.2 APPENDIX 2 Safety Assessment 8 APPENDIX 2 AIRBORNE SYSTEM
vi
8.1 APPENDIX 2 General
8.2 APPENDIX 2 Peripheral Vision Guidance Systems [PoC]
8.3 APPENDIX 2 Head Up Display Takeoff System
8.4 APPENDIX 2 Satellite Based Systems [PoC]
8.4.1 APPENDIX 2 Flight Path Definition
8.4.2 APPENDIX 2 On Board Database
8.4.3 APPENDIX 2 Datalink
8.5 APPENDIX 2 Enhanced Vision Systems [PoC] 9 APPENDIX 2 AIRPLANE FLIGHT MANUAL APPENDIX 3 AIRWORTHINESS APPROVAL FOR AIRBORNE SYSTEMS USED TO LAND
AND ROLLOUT IN LOW VISIBILITY CONDITIONS 1 APPENDIX 3 PURPOSE 2 APPENDIX 3 GENERAL 3 APPENDIX 3 INTRODUCTION 4 APPENDIX 3 TYPES OF LANDING AND ROLLOUT OPERATIONS 5 APPENDIX 3 TYPES OF LANDING AND ROLLOUT SERVICES
5.1 APPENDIX 3 ILS
5.1.1 APPENDIX 3 ILS Flight Path Definition
5.1.2 APPENDIX 3 ILS Airplane Position Determination
5.2 APPENDIX 3 MLS
5.2.1 APPENDIX 3 MLS Flight Path Definition
5.2.2 APPENDIX 3 MLS Airplane Position Determination
5.3 APPENDIX 3 GNSS [PoC]
5.3.1 APPENDIX 3 GNSS Flight Path Definition [PoC]
5.3.2 APPENDIX 3 GNSS Airplane Position Determination [PoC]
5.3.3 APPENDIX 3 Datalink [PoC] 6 APPENDIX 3 AIRWORTHINESS
6.1 APPENDIX 3 General
6.2 APPENDIX 3 Approach Systems
6.3 APPENDIX 3 Landing and Rollout System Performance
6.3.1 APPENDIX 3 Landing System Performance
6.3.2 APPENDIX 3 Speed Control Performance
6.3.3 APPENDIX 3 Rollout System Performance
6.3.4 APPENDIX 3 Variables Affecting Performance
6.3.5 APPENDIX 3 Irregular Approach Terrain
6.3.6 APPENDIX 3 Approach and Automatic Landing with an Inoperative Engine
6.3.7 APPENDIX 3 Inoperative Engine Information
6.4 APPENDIX 3 Landing and Rollout System Integrity
6.4.1 APPENDIX 3 Landing System Integrity
6.4.2 APPENDIX 3 Rollout System Integrity
vii
6.4.3 APPENDIX 3 On Board Database Integrity [PoC]
6.5 APPENDIX 3 Landing and Rollout System Availability
6.5.1 APPENDIX 3 Landing System Availability
6.5.2 APPENDIX 3 Rollout System Availability
6.6 APPENDIX 3 Go-around
6.7 APPENDIX 3 Automatic Braking System
6.8 APPENDIX 3 Flight Deck Information, Annunciation and Alerting
6.8.1 APPENDIX 3 Flight Deck Information
6.8.2 APPENDIX 3 Annunciation
6.8.3 APPENDIX 3 Alerting
6.8.3.1 APPENDIX 3 Warnings
6.8.3.2 APPENDIX 3 Cautions
6.8.3.3 APPENDIX 3 Advisories
6.8.3.4 APPENDIX 3 System Status
6.9 APPENDIX 3 Multiple Landing Systems
6.9.1 APPENDIX 3 General
6.9.2 APPENDIX 3 Indications
6.9.3 APPENDIX 3 Annunciations
6.9.4 APPENDIX 3 Alerting 7 APPENDIX 3 LANDING AND ROLLOUT SYSTEM EVALUATION
7.1 APPENDIX 3 Performance Evaluation
7.1.1 APPENDIX 3 Validation of the Simulator
7.1.2 APPENDIX 3 Simulations for Automatic System Performance Demonstration
7.1.3 APPENDIX 3 Flight Test Performance Demonstration
7.1.4 APPENDIX 3 Demonstration of Approach and Automatic Landing with an Inoperative Engine
7.2 APPENDIX 3 Safety Assessment 8 APPENDIX 3 AIRBORNE SYSTEMS
8.1 APPENDIX 3 Automatic Flight Control Systems
8.2 APPENDIX 3 Autothrottle Systems
8.3 APPENDIX 3 Head Up Guidance
8.4 APPENDIX 3 Hybrid HUD/Autoland System [PoC]
8.4.1 APPENDIX 3 Hybrid HUD/Autoland System Fail Operational Equivalency Concept
8.4.2 APPENDIX 3 Hybrid System Go Around Capability
8.4.3 APPENDIX 3 Hybrid System Transition From Automatic to Manual Flight
8.4.4 APPENDIX 3 Hybrid System Pilot Not Flying (PNF)
8.5 APPENDIX 3 Satellite Based Landing Systems [PoC]
8.5.1 APPENDIX 3 Flight Path Definition
8.5.2 APPENDIX 3 Aircraft Database
8.5.3 APPENDIX 3 Differential Augmentation
8.5.4 APPENDIX 3 Datalink
8.6 APPENDIX 3 Enhanced Vision Systems [PoC] 9 APPENDIX 3 AIRPLANE FLIGHT MANUAL APPENDIX 4 WIND MODEL FOR APPROACH AND LANDING SIMULATION
viii APPENDIX 5 [RESERVED] APPENDIX 6 AFM PROVISIONS AND SAMPLE AFM WORDING
6.1 APPENDIX 6 Example Provision – AFM “Certificate Limitation” Section
6.2 APPENDIX 6 Example Provision - AFM “Normal Procedures” or “Normal Operation” [Typical Aircraft Type with Fail Operational and Fail Passive FGS]
6.3 APPENDIX 6 Example Provision - AFM “Normal Procedures” or “Normal Operation” [Typical Aircraft Type with Fail Passive FGS Capability] APPENDIX 7 STANDARD OPERATIONS SPECIFICATIONS - GENERAL APPENDIX 7 OPERATIONS SPECIFICATIONS - GENERAL APPENDIX 7 Para. A002 APPENDIX 7 Para. C051 APPENDIX 7 Para. C055 APPENDIX 7 Para. C05 6 APPENDIX 7 Para. C060 APPENDIX 7 Para. C078 APPENDIX 8 IRREGULAR TERRAIN ASSESSMENT APPENDIX 9 TAKEOFF SYSTEM PERFORMANCE AFTER LIFTOFF