12/31/20 AIM Gulf of Mexico Grid System, 10 − 1 − 6 H Half − Way Signs, 7 − 6 − 5 Hand Signals, 4 − 3 − 28 Hazard Antenna Tower, 7 − 6 − 1 Bird, 7 − 5 − 1 Flight Obstructions to Flight, 7 − 6 − 1 Potential, 7 − 6 − 1 VFR in Congested Areas, 7 − 6 − 1 Ground Icing Conditions, 7 − 6 − 13 Mountain Flying, 7 − 6 − 3 Overhead Wires, 7 − 6 − 2 Thermal Plumes, 7 − 6 − 14 Unmanned Balloons, 7 − 6 − 2 Volcanic Ash, 7 − 6 − 7 HDTA.  See  High Density Traffic Airports Helicopter IFR Operations, 10 − 1 − 1 Landing Area Markings, 2 − 3 − 19 VFR Operations at Controlled Airports, 4 − 3 − 21 Special Operations, 10 − 2 − 1 Wake Turbulence, 7 − 4 − 6 High Density Traffic Airports, 4 − 1 − 18 Hold, For Release, 5 − 2 − 4 Holding, 5 − 3 − 19 Holding Position Markings, 2 − 3 − 1, 2 − 3 − 12 for Instrument Landing Systems, 2 − 3 − 12 for Intersecting Taxiways , 2 − 3 − 12 Holding Position Signs, Surface Painted, 2 − 3 − 13 Hypoxia, 8 − 1 − 3 I K L Icing Terms, 7 − 1 − 41 IFR, 4 − 4 − 4 Operations, To High Altitude Destinations, 5 − 1 − 28 Procedures, Use When Operating VFR, 5 − 1 − 2 IFR Approaches, 4 − 1 − 6 Military Training Routes, 3 − 5 − 1 Separation Standards, 4 − 4 − 7 ILS.  See  Instrument Landing System K − 9 Explosives Detection Team, 6 − 2 − 3 LAHSO.  See  Land and Hold Short Operations In − Runway Lighting, 2 − 1 − 6 Taxiway Centerline Lead − off Lights, 2 − 1 − 6 On Lights, 2 Touchdown Zone Lighting, 2 − 1 − 6 Incident, Aircraft, Reporting, 7 − 7 − 1 Inertial Navigation System, 1 − 1 − 18 Inertial Reference Unit (IRU), 1 − 1 − 18, 5 − 1 − 13 Initial Contact, 4 − 2 − 1 INS.  See  Internal Navigation System Instrument Departure Procedures (DP), 5 − 2 − 6 Instrument Landing System, 1 − 1 − 10 Category, 1 − 1 − 14 Compass Locator, 1 − 1 − 13 Course, Distortion, 1 − 1 − 14 Distance Measuring Equipment, 1 − 1 − 13 Frequency, 1 − 1 − 13 Glide Path, 1 − 1 − 12 Glide Slope, 1 1 Critical Area, 1 − 1 − 15 Holding Position Markings, 2 − 3 − 12 Inoperative Components, 1 − 1 − 14 Localizer, 1 − 1 − 11 Critical Area, 1 − 1 − 14 Marker Beacon, 1 13 Minimums, 1 − 1 − 14 Instrument Meteorological Conditions (IMC), 5 − 2 − 6 Integrated Terminal Weather System, 4 − 3 − 13 Intercept, 6 − 2 − 1 Interception Procedures, 5 − 6 − 8 Signals, 5 − 6 11 Interchange Aircraft, 4 − 2 − 4 International Flight Plan, IFR, Domestic, International, 5 − 1 − 18 International Flight Plan (FAA Form 7233 − 4) −  IFR Flights (For Domestic or International Flights), 5 − 1 − 18 Intersection Takeoffs, 4 − 3 − 16 IR.  See  IFR Military Training Routes IRU.  See  Inertial Reference Unit ITWS.  See  Integrated Terminal Weather System I − 6 Index