Clothing ....................................................................8-28 Communication ........................................................8-29 Navigation Equipment..............................................8-29 Medical Equipment ..................................................8-29 Stowage ....................................................................8-30 Parachute ..................................................................8-30 Oxygen System Malfunctions ..................................8-30 Accident Prevention.....................................................8-30 Soaring Weather ..................................................9-1 Introduction  ....................................................................9-1 The Atmosphere.............................................................9-2 Composition ...............................................................9-2 Properties....................................................................9-2 Temperature  ............................................................9-2 Density....................................................................9-2 Pressure...................................................................9-2 Standard Atmosphere .................................................9-3 Layers of the Atmosphere ..........................................9-4 Scale of Weather Events ................................................9-4 Thermal Soaring Weather ..............................................9-6 Thermal Shape and Structure .....................................9-6 Atmospheric Stability.................................................9-7 Air Masses Conducive to Thermal Soaring ...................9-9 Cloud Streets ..............................................................9-9 Thermal Waves...........................................................9-9 Thunderstorms  ..........................................................9-10 Lifted Index ..........................................................9-12 K-Index .................................................................9-12 Weather for Slope Soaring .......................................9-14 Mechanism for Wave Formation..............................9-16 Lift Due to Convergence ..........................................9-19 Obtaining Weather Information...................................9-21 Preflight Weather Briefing........................................9-21 Weather-ReIated Information ..................................9-21 Forecasts  ......................................................................9-23 Graphic Weather Charts ...........................................9-23 Winds and Temperatures Aloft Forecast ..............9-23 Composite Moisture Stability Chart .....................9-24 Soaring Techniques ..........................................10-1 Introduction  ..................................................................10-1 Thermal Soaring...........................................................10-2 Locating Thermals....................................................10-2 Cumulus Clouds ...................................................10-2 Other Indicators of Thermals................................10-3 Wind .....................................................................10-4 The Big Picture .....................................................10-5 Towing ................................................................12-1 Introduction  ..................................................................12-1 Equipment Inspections and Operational Checks .........12-2 Tow Hook   ................................................................12-2 Schweizer Tow Hook ...........................................12-2 Considerations............................................................11-16 Glider Complexity..................................................11-16 Water Ballast ..........................................................11-17 Cross-Country Flight Using Other Lift Sources ........11-17 Cross-Country Soaring .....................................11-1 Introduction  ..................................................................11-1 Flight Preparation and Planning...................................11-2 Personal and Special Equipment..................................11-3 Navigation....................................................................11-5 Using the Plotter.......................................................11-5 A Sample Cross-Country Flight ...............................11-5 Navigation Using GPS .............................................11-8 Cross-Country Techniques...........................................11-9 Soaring Faster and Farther .........................................11-11 Height Bands ..........................................................11-11 Tips and Techniques...............................................11-12 Special Situations.......................................................11-14 Course Deviations ..................................................11-14 Lost Procedures ......................................................11-14 Cross-Country Flight in a Self-Launching Glider .....11-15 Entering a Thermal ..............................................10-5 Inside a Thermal  .......................................................10-6 Bank Angle ...........................................................10-6 Speed.....................................................................10-6 Centering...............................................................10-7 Collision Avoidance ................................................10-9 Exiting a Thermal.....................................................10-9 Atypical Thermals ..................................................10-10 Ridge/Slope Soaring ..................................................10-10 Traps   ......................................................................10-10 Procedures for Safe Flying .....................................10-12 Bowls and Spurs.....................................................10-13 Slope Lift................................................................10-13 Obstructions ...........................................................10-14 Tips and Techniques...............................................10-15 Wave Soaring.............................................................10-16 Preflight Preparation...............................................10-17 Getting Into the Wave ............................................10-18 Flying in the Wave .................................................10-20 Soaring Convergence Zones...................................10-23 Combined Sources of Updrafts ..............................10-24 Chapter 9 Chapter 11 Chapter 12 Chapter 10 x High-Performance Glider Operations and  Interpreting Weather Charts, Reports, and 