Chapter 4 x  Approaches ................................................................................. 4-1 Introduction ................................................................................ 4-1 Approach Planning .................................................................. 4-2 Weather Considerations ........................................................ 4-2 Weather Sources .................................................................. 4-2 Broadcast Weather ............................................................... 4-4 Automated Terminal Information Service (ATIS) ....... 4-5 Automated Weather Observing Programs .................. 4-5 Automated Weather Observing System ....................... 4-5 Automated Surface Observing System (ASOS)/ Automated Weather Sensor System (AWSS) .............. 4-5 Center Weather Advisories (CWA)................................... 4-6 Weather Regulatory Requirements ............................... 4-6 Weather Requirements and Part 91 Operators .......... 4-6 Weather Requirements and Part 135 Operators........ 4-7 Weather Requirements and Part 121 Operators ....... 4-7 Aircraft Performance Considerations................................. 4-7 Aircraft Performance Operating Limitations .............. 4-7 Aircraft Approach Categories ........................................... 4-8 Instrument Approach Charts ................................................ 4-9 Approach Chart Naming Conventions ......................... 4-9 Straight-In Procedures ....................................................... 4-9 Circling-Only Procedures ................................................4-11 Communications ....................................................................4-11 Approach Control ..............................................................4-13 Air Route Traffic Control Center (ARTCC) ....................4-13 High or Lack of Minimum Vectoring Altitudes  (MVAs) .................................................................................4-14 Lack of Approach Control Terrain Advisories............4-15 Airports With an ATC Tower ............................................4-15 Airports Without A Control Tower ................................4-15 Primary NAVAID .......................................................................4-17 Equipment Requirements ....................................................4-17 Courses........................................................................................4-17 Traditional Courses ............................................................4-17 Area Navigation Courses .................................................4-18 Altitudes ....................................................................................4-19 Minimum Safe/Sector Altitude .....................................4-19 Final Approach Fix Altitude ............................................4-19 Minimum Descent Altitude (MDA), Decision Altitude (DA), And Decision Height (DH).....................................4-19 Enhanced Flight Vision Systems (EFVS) and Instrument Approaches ...........................................................................4-20 Vertical Navigation..................................................................4-23 Wide Area Augmentation System ................................4-25 Benefits Of WAAS In The Airport Environment.........4-25 Advantages Of WAAS Enabled LPV Approaches .....4-25 Ground-Based Augmentation System (GBAS)..........4-26 Required Navigation Performance (RNP) ...................4-30 RNAV Approach Authorization .....................................4-30 Baro-VNAV .............................................................................4-31 Hot and Cold Temperature Limitations.......................4-33 LNAV, LANV/VNAV and Circling Minimums...............4-34 Airport/Runway Information ..........................................4-34 Instrument Approach Procedure (IAP) Briefing............4-35 Navigation and Communication Radios ...................4-35 Flight Management System (FMS) ...............................4-35 Autopilot Modes .................................................................4-36 Descents .....................................................................................4-37 Stabilized Approach ..........................................................4-37 Descent Rates and Glidepaths for Nonprecision Approaches ..............................................................................4-37 Maximum Acceptable Descent Rates..........................4-37 Transition to a Visual Approach ....................................4-39 Missed Approach ...............................................................4-39 Example Approach Briefing ............................................4-42 Instrument Approach Procedure Segments .............4-42 Feeder Routes.......................................................................4-42 Terminal Routes ..................................................................4-42 DME Arcs ...............................................................................4-43 Course Reversal ..................................................................4-43 Initial Approach Segment ...............................................4-49 Intermediate Approach Segment ................................4-49 Final Approach Segment..................................................4-49 Missed Approach Segment ............................................4-50 Approach Clearance ..........................................................4-50 Vectors To Final Approach Course ...............................4-53 Nonradar Environment ....................................................4-54 Types of Approaches..............................................................4-54 Visual and Contact Approaches ....................................4-55 Visual Approaches .............................................................4-56 Contact Approaches .........................................................4-57 Charted Visual Flight Procedures .................................4-57 RNAV Approaches ..............................................................4-57 Terminal Arrival Areas .......................................................4-58 RNAV Approach Types ...........................................................4-60 GPS Overlay of Nonprecision Approach ....................4-60 GPS Stand-Alone/RNAV (GPS) Approach ...................4-60 RNAV (GPS) Approach Using WAAS .............................4-63 ILS Approaches ....................................................................4-63 ILS Approach Categories ..................................................4-63 CAT II and III Approaches .................................................4-63 Simultaneous Approaches To Parallel Runways .....4-64 Simultaneous Dependent Approaches.......................4-64 Simultaneous Independent Approaches ...................4-65 Simultaneous Close Parallel Precision Runway Monitor  (PRM) Approaches .........................................................4-65 Simultaneous Offset Instrument Approaches  (SOIAs) ................................................................................4-66 Converging ILS Approaches............................................4-66 VOR Approach .....................................................................4-66