Sep 2012 Lesson 5.3 Navigation Aeronautical Charts

Reference From the Ground Up Chapter 7.4: Aeronautical Charts Pages

Introduction Aeronautical charts are maps that show important information for air navigation.Aeronautical charts are maps that show important information for air navigation. Pilots need to know what kind of charts are available and how to read them.Pilots need to know what kind of charts are available and how to read them.

Outline Distance and Speed UnitsDistance and Speed Units Aeronautical ChartsAeronautical Charts Chart TypesChart Types Scale and ReliefScale and Relief

Distance Units Statute Mile (SM or Mi) = 5280 feetStatute Mile (SM or Mi) = 5280 feet Nautical Mile (NM) = 6080 feet = one minute of latitudeNautical Mile (NM) = 6080 feet = one minute of latitude Kilometer (km) = 1000 metersKilometer (km) = 1000 meters 66 NM = 76 SM = 122 km66 NM = 76 SM = 122 km

Speed Units Miles per Hour (MPH) = statute miles per hourMiles per Hour (MPH) = statute miles per hour Knots = nautical miles per hourKnots = nautical miles per hour Kilometers per hour (km/h)Kilometers per hour (km/h)

Speed Units Indicated Airspeed = speed on airspeed indicatorIndicated Airspeed = speed on airspeed indicator True Airspeed = Speed of aircraft relative to airTrue Airspeed = Speed of aircraft relative to air Groundspeed = Speed of aircraft relative to groundGroundspeed = Speed of aircraft relative to ground

Aeronautical Charts A Map is a small-scale, flat-surface representation of a part of the earth’s surfaceA Map is a small-scale, flat-surface representation of a part of the earth’s surface When designed for navigational information, it is called a ChartWhen designed for navigational information, it is called a Chart Four basic elements in map construction:Four basic elements in map construction: –Areas –Shapes –Bearings –Distances Mathematical basis on which maps are constructed are called projections; They show distortion because Earth is a sphereMathematical basis on which maps are constructed are called projections; They show distortion because Earth is a sphere

Conic Projection Lambert Conformal Conic ProjectionLambert Conformal Conic Projection –Cone superimposed over surface of a sphere; imprint made from where cone touches surface PropertiesProperties –Meridians converge toward nearer pole –Parallels are curves and concave toward nearer pole –Scale is constant –Straight line is an arc of a great circle

Mercator Projection Visualized as light shown from inside earth onto cylinder touching equatorVisualized as light shown from inside earth onto cylinder touching equator PropertiesProperties –Meridians and parallels are straight and parallel –No constant scale –Straight line on map is a rhumb line –Extreme exaggeration of areas in far north and south –Distances near equator are more precise Transverse MercatorTransverse Mercator –Cylinder rotated 90 degree to touch a meridian –Exaggeration at east and west areas –More accurate because closest meridian can be used

Chart Types VFR Navigation Charts (VNC)VFR Navigation Charts (VNC) –Lambert Conformal Conic Projection –1:500,000 scale World Aeronautical Charts (WAC)World Aeronautical Charts (WAC) –Lambert Conformal Conic Projection –1:1,000,000 scale VFR Terminal Area Charts (VTA)VFR Terminal Area Charts (VTA) –Transverse Mercator Projection –1:250,000 –Only made for high-traffic areas

Chart Types Enroute Charts (LO/HI)Enroute Charts (LO/HI) –Enroute Low Altitude (LO) for below 18,000 ft –Enroute High Altitude (HI) for above 18,000 ft –Used for IFR Canada Flight Supplement (CFS)Canada Flight Supplement (CFS) –Lists all aerodromes shown on VNC/WAC –Contains valuable information (runways, aerodrome lighting, services, radio frequencies etc)

Scale Relationship between unit of distance on map to distance on earth that unit representsRelationship between unit of distance on map to distance on earth that unit represents Representative FractionRepresentative Fraction –Most common method of expressing map scale –Ratio of unit of length of map to number of same units on earth Graduated ScaleGraduated Scale –Line drawn on part of map and graduated to show length of one mile on map

Relief Representation of ground elevation above sea levelRepresentation of ground elevation above sea level Ways of showing relief:Ways of showing relief: –Layer Tinting –Contour Lines –Spot Heights

Next Lesson 6.1 – Radio Radio From the Ground Up Chapter 8.1: Radio Pages