52 RCACS Ground School Navigation PO 404 EO 1 “Definitions”

Introduction Teaching Points Teaching Points Basic Definitions Basic Definitions Types of Headings Types of Headings Variation Variation Compass Heading Compass Heading Bearing Bearing Distance Measurement Distance Measurement Speed Measurement Speed Measurement Track Track Review Review Reference: Reference: FTGU Chapter 7 FTGU Chapter 7 Section E Pages Section E Pages

Basic Definitions GREAT CIRCLE GREAT CIRCLE A circle on the surface of the earth whose plane passes through the center of the earth. It is also the shortest distance between two points on the surface of the earth. A circle on the surface of the earth whose plane passes through the center of the earth. It is also the shortest distance between two points on the surface of the earth. RHUMB LINE RHUMB LINE A curved line on the surface of the earth cutting all meridians at the same angle. A curved line on the surface of the earth cutting all meridians at the same angle. HEADING HEADING The direction that the aircraft nose (longitudinal axis) is pointing,measured clockwise from north. The direction that the aircraft nose (longitudinal axis) is pointing,measured clockwise from north.

Basic Definitions

Types of Headings TRUE HEADING TRUE HEADING The direction that the aircraft nose is pointing, measured clockwise from true north. The direction that the aircraft nose is pointing, measured clockwise from true north. MAGNETIC HEADING MAGNETIC HEADING The direction that the aircraft nose is pointing, measured clockwise from magnetic north. The direction that the aircraft nose is pointing, measured clockwise from magnetic north.

Variation (declination) VARIATION VARIATION The angle between true heading and magnetic heading. The angle between true heading and magnetic heading. ISOGONALS ISOGONALS Lines on a map joining places of equal variation. Lines on a map joining places of equal variation. AGONIC LINE AGONIC LINE Lines on a map joining places of zero variation Lines on a map joining places of zero variation

Declination Map

Compass Heading COMPASS HEADING COMPASS HEADING The direction that the needle in the compass is pointing. The direction that the needle in the compass is pointing. DEVIATION DEVIATION The angle between compass heading and magnetic heading. The difference is caused by the magnetic fields generated from the metal airframe and engine. The angle between compass heading and magnetic heading. The difference is caused by the magnetic fields generated from the metal airframe and engine.

Bearing BEARING BEARING The position of an object relative to your aircraft measured in degrees from north. This has nothing to do with aircraft heading. The position of an object relative to your aircraft measured in degrees from north. This has nothing to do with aircraft heading.

Distance Measurement NAUTICAL MILE NAUTICAL MILE Average length of one minute of latitude: Average length of one minute of latitude: 6080 feet feet. STATUTE MILE STATUTE MILE 5280 feet 5280 feet KILOMETER KILOMETER 1000 meters meters.

Speed Measurement KNOTS KNOTS Speed in nautical miles per hour. Speed in nautical miles per hour. MPH MPH Speed in statute miles per hour. Speed in statute miles per hour. KPH KPH Speed in kilometers per hour Speed in kilometers per hour

Speed Measurement INDICATED AIRSPEED INDICATED AIRSPEED Speed shown on the airspeed indicator. Speed shown on the airspeed indicator. TRUE AIRSPEED TRUE AIRSPEED Speed of the aircraft relative to the air. It is also calibrated airspeed corrected for airspeed indicator error due to density and temperature errors. Speed of the aircraft relative to the air. It is also calibrated airspeed corrected for airspeed indicator error due to density and temperature errors. GROUNDSPEED GROUNDSPEED Speed of the aircraft relative to the ground. Speed of the aircraft relative to the ground.

Track TRACK TRACK The direction the aircraft intended to take over the ground. (The line you draw on your map.) The direction the aircraft intended to take over the ground. (The line you draw on your map.) TRACK MADE GOOD TRACK MADE GOOD The actual track the aircraft flies over the ground. The actual track the aircraft flies over the ground. DRIFT DRIFT The angle between heading and track made good. The angle between heading and track made good.

Track

Questions? ?