Presentation on theme: "Aeronautical Navigation"— Presentation transcript:
1 Aeronautical Navigation An IntroductionMaterials: Beachball globe, Nav Radios, Omniheads, Mercator/Gnomonic Chart Example, Handheld Radio, 4 Sticks for GPS demonstrationWritten for the Notre Dame Pilot InitiativeBy the Pilots of the University of Notre Dame“Teaching the Science, Inspiring the Art, Producing Aviation Candidates!”
2 Quote“For the execution of the voyage to the Indies, I did not make use of intelligence, mathematics or maps.”Christopher Columbus
4 Roadmap Terrestrial coordinates Concepts of position Chart projectionsConcepts of positionPiloting & dead reckoningRadio navigation systemsOther electronic navigation systemsCelestial navigationFoundations of Navigation
5 Terrestrial Coordinate System Great Circles – The largest circle that can be drawn on the surface of the earth & all like it.EquatorMeridiansEquatorMeridianGreat Circle
6 Terrestrial Coordinate System Small Circles-all other circlesParallels
7 Longitude/LatitudeParallels of latitude are small circles (with the exception of the equator)Meridians of longitude are great circlesLatitude is 90 degreesLongitude is 180 degrees
8 Desirable qualities of a chart projection: Maintain true shape of physical features.Maintain correct proportions of features relative to one another.True scale, permitting accurate measurement of distance.Rhumb lines plot as straight lines.Great circles plot as straight lines.No chart has all of these!
9 Mercator vs. Gnomonic Mercator Projection Gnomonic Projection This is the Great Circle Track that Charles Lindbergh flewOwl – Shortest distance between two points is a curve (great circle)Gnomonic Projection
10 Lambert Conformal Projection (Sectional Chart) Look at the front cover of a sectional chart to see how it unfolds curved
12 Airways Follow Great Circles Owl – Airways always follow great circlesV-12 from HAR to JST departs HAR westbound on a heading of 281, and departs JST eastbound on a heading of 096.
13 Navigational concepts A circle has 360 degreesA degree has 60 minutes1° of latitude is the same distance anywhere on the earth.How many miles is one minute of latitude?Ans. 1 min lat. = 1 nm = 2000 yds.Any questions on these conceptsNote that a NM is 15% longer than a SM
14 Where are we? At the ROTC Building -point On Juniper Road -LOP ½ mile from Golden Dome -LOP(circle)Near MeijerAmbiguous(which one?)Imprecise(how far?)We will be there in 5 minutesAnswer to: when will we arrive there?Draw these on the blackboard
15 Line of Position (LOP) A line that defines our position in 1-D Not necessarily straightArc, circle, hyperbola, intersection of spheresNeed a second line to define a fix in 2-DNeed a third to be sure
17 How do we get there? Plot a course Steer a heading Make a good track What’s a course?path of intended motionSteer a headingWhat’s a heading?the direction the aircraft is pointedMake a good trackWhat’s a track?the aircraft’s path over the ground
18 Course, Heading, & Track Big Bad Wind End of animation Plot a course, fly a heading, and make a track
19 Types of Navigation Systems PilotageDead ReckoningRadio NavigationADFVOR/DME/RNAVElectronic NavigationLoranGPSInertialCelestialTypes of Navigation:- Pilotage (Coastal) Navigation: employs the use of visual bearings and/or radar information to know landmarks to establish the ship's position and provide the information needed to safely and efficiently "drive" the ship.-Deduced ("Dead") Reckoning: a method of estimating the ship's position using the courses and speeds steered. First used when early mariners ventured out of sight of land, to enable them to get back home.
21 Nomenclature True & magnetic courses are given in 3 digits, e.g. 090 Relative bearings are given in degrees or clock position, e.g. 10º left of the nose, or 11 o’clock
22 Dead Reckoning DEN Big Bad Tower 1300 DR N E S W 1200 DR 1100 DR 070 ° Big Bad Mountain1000 DRNote how we know our position at every point in time because we know how fast we are flying and in what direction and for how long. We can safely navigate between hazards (called the Rockies).We always use BOTH dead reckoning and pilotage.PHX0900 DR0800 Fix
23 Types of Navigation Systems PilotageDead ReckoningRadio NavigationADFVOR/DME/RNAVElectronic NavigationLoranGPSInertialCelestialTypes of Navigation:-Radionavigation: Typically uses electromagnetic signals transmitted from ground stations to establish position.
24 The Radio Compass 1946 Stinson Voyager A Great 1 person airplane Geo Metro of the Air1946 Stinson Voyager
25 ADF/NDBThe ADF, or Automatic Direction Finder, is the receiver in the aircraftThe NDB, or Nondirectional Radio Beacon, is the transmitting antenna on the groundThe ADF is the receiver of the NDB’s transmissions
26 NDBThe NDB is a ground-based radio transmitter that emits a signal in every directionBenefitsEconomicEasy to maintainNot line of sightErrorsSusceptible to interference (T-Storms)Bounces around coastlines
27 NDB Operates on 190-535kHz Types Range is 190-1750kHz HH – watts; 75nm rangeH – watts; 50nm rangeMH – less than 50 watts; 25nm rangeCompass Locator – less than 25 watts; 15 nm rangeAM Radio Station
28 ADF The ADF determines the bearing from the aircraft TO the station Needle ALWAYS points to the stationIndicates relative bearingBearing, measured clockwise, from the nose of the aircraft TO the stationCard only indicates angle – has nothing to do with direction aircraft is pointedDifferences between fixed card and moveable card.
29 ADFUsing relative bearing and magnetic heading, magnetic bearing can be foundActual heading to fly to the stationMB = MH + RBExamples from Gleim (p. 272) – 13, 15, 16, 19, 25, 30
30 Homing the NDBHomingFlying the aircraft on any heading required to keep the needle pointed straight ahead (0° RB)Works great without windTakes longer and not direct with windDiagram homing on board
31 Tracking the NDBTracking – flying on a heading that maintains a constant, desired track to/from a stationFind heading/course that takes you to the stationOnce off by 10°, double the deflection and turn towards station (head of the needle)Once deflection equals correction, you are back on courseTurn 10° towards needleRepeat as necessary and become more precise with correction
32 Intercepting the NDB Parallel course Note deflection Double it Turn towards needleOnce deflection equals correction, you are on courseCorrect for wind (tracking)NOTE: very similar to tracking
33 Types of ADFs Fixed Card Moveable Card RMI – Radio Magnetic Indicator Always shows 0° at the topMoveable CardCan show magnetic heading at topBad ideaRMI – Radio Magnetic IndicatorSlaved to move with aircraftGREAT to have!