O-2024 Navigation and Position Determination for Scanners Minnesota Wing Aircrew Training: Task O-2024 O-2024 Navigational Terms O-2024 Navigation Terms Course - planned or actual path of the aircraft over the ground – – True course Magnetic course Heading - direction the aircraft is pointing Drift - the effect of wind Drift correction - degrees added to or subtracted from aircraft heading Nautical mile (nm) - measurement used in air navigation Knots (kts) - nautical miles per hour O-2024 Longitude and Latitude O-2024 Latitude and Longitude Where they cross defines a point on the earth By convention, latitude is stated first • Latitude is Based on Earth’s motion • Axis of rotation defines poles and Equator • Arbitrary point of Greenwich, England was chosen for ‘prime meridian’. O-2024 North Latitudes Latitude Equator South Latitudes Parallels Measure How Far North or South of Equator Zero Degrees is Equator “90 Degrees North” is the North Pole “90 Degrees South” is the South Pole O-2024 West Longitude Prime Meridian East Longitude Longitude Half Great Circles Intersecting at the Poles Measure How Far East or West of England Zero Degrees is Prime Meridian (England) Numbers between 0 and 180 are either East or West Longitude 180 Degrees is opposite side of globe from England – near international date line in Pacific Ocean O-2024 Where’s Minnesota? Twin Cities – – Northern Minneapolis is at 45 Degrees North (half way between the Equator and North Pole!) 93 Degrees West is roughly the Eastern edge of St. Paul. The Northwest corner of the state: – – Exactly 49 Degrees North Roughly 97 Degrees West O-2024 How Big is One Degree? Degrees of Latitude are always the same distance apart, about 60 Nautical Miles Degrees of longitude vary in distance – near the poles the lengths are quite small. – In Minnesota, a degree of longitude is about 40 to 44 Nautical Miles across O-2024 Dividing Degrees into Smaller Units A ‘Minute’: 1/60th of a Degree – roughly a mile in size Minutes are usually broken down into tenths of minutes – Alternatively, a ‘Second’ is 1/60th of a minute O-2024 Expressing Latitude and Longitude in Degrees and Minutes Small high circle after number denotes degrees Apostrophe after number denotes minutes Example: Minneapolis Flying Cloud Airport 44o 49.63’ N 93o 27.43’ W read as… 44 degrees 49.63 minutes North 93 degrees 27.43 minutes West O-2024 Lines of latitude and longitude on sectional chart Lat/Long on chart O-2024 Determining Coordinates from a Chart O-2024 Magnetic Variation O-2024 Expressing Direction: The Compass Rose 360 330 30 N 300 270 60 W E 240 90 120 210 S 180 150 O-2024 Magnetic Variation PHYSICAL POLE The magnetic pole and physical pole are not co-located The difference in heading for the two poles is measured and referred to as magnetic variation Near the magnetic pole the difference can be substantial MAGNETIC POLE O-2024 Magnetic Variation in the US Westerly Variation Easterly Variation -15º -10º -5º -0º +25º +20º +15º +5º+10 º Agonic Line O-2024 Lines of Variation on a Sectional Chart O-2024 Converting True Course to Magnetic Course For East Variation, subtract from True Course True Course – Variation = Magnetic Course For West Variation, add to True Course True Course + Variation = Magnetic Course Mnemonic: “East is least, West is best” – – “Least” should make you think of subtraction Rule is reversed if one wishes to convert a Magnetic course to a True course. O-2024 Airspace O-2024 Special-Use Airspace Military Operating Area (MOA) – – Military Training Routes – – Military may be conducting high-speed operations VFR aircraft are not prohibited Instrument routes (IR) Visual routes (VR) Restricted Areas – – Military may be conducting air-to-ground bombing or gunnery practice No other aircraft are allowed O-2024 Sectional Charts O-2024 Chart Reading Sectional Aeronautical Charts – – 1 to 500,000 Medium to slow speed aircraft Types of Information – – – Topographical Aeronautical Legend O-2024 Sectional Charts Publication Schedule Legend changes somewhat over time Four Charts Needed to Cover Minnesota – – – – Twin Cities Omaha Green Bay Chicago O-2024 Sectional Chart Contents Physical Geographic Features – – – – – Areas: Water, Cities Lines: Roads, Power Lines, Railroads Landmarks: Race Tracks, Lookout Towers Vertical obstructions Maximum Elevation by Quadrangle O-2024 Sectional Chart Contents Aeronautical Features – – – Airports Airspace Boundaries Radio Navigation Facilities O-2024 Airport legend O-2024 Airport data O-2024 Radio Aids O-2024 Topographic,obstructions and miscellaneous O-2024 Chart Interpretation O-2024 Railroad Seaplane Base Power Line Airport 2 paved runways Weather on 118.375MHz Field elev. 1424 Traffic Frequency 123.0 MHz Fuel available Maximum Elevation Figure Vertical Obstruction (2549 Ft. MSL, 1192 Ft. AGL) O-2024 Airport with Control Tower Low Level Military Training Route Lookout Tower Parachute Jump Area O-2024 Airport Special Use Airspace no paved runways fuel available Restricted Airspace Military Airport With Control Tower O-2024 Class ‘B’ Airspace Class ‘D’ Airspace Ultralight Area O-2024 NDB O-2024 VOR/DME O-2024 Pilotage and Position Determination O-2024 Pilotage Navigation by visual cues Uses recognizable landmarks Correlate with sectional charts Takes practice – – – – – Familiar things look radically different from the air Seasons make a difference, especially winter Be careful using lakes – be sure of the shape and placement next to other features Difficult to use in sparse areas Difficult at night O-2024 Pilotage tricks Tricks: – Look for trees to find creeks, rivers, and towns O-2024 Position Determination Sectional or Map – – – – – Work from larger to smaller Work from a known location to present location Watch the scale on maps Remain suspicious if all points don’t seem to line up right Use groups of 3 characteristics to verify position O-2024 Keeping Track of Position Maintain positional awareness from takeoff to landing Finger on the map method using visual landmarks If necessary, ask the pilot or observer to determine position using GPS and/or VOR O-2024 Where are you? O-2024 Low Level Navigation O-2024 Low Level Navigation THE DANGER The biggest single problem is crew workload Your perception of speed varies with altitude SPECIAL ATTENTION Man-made obstructions Air crew duties These items should be covered during the briefing. O-2024 Obstacles and Other Dangers WAKE TURBULENCE O-2024 Obstacles and Other Dangers TALL TOWERS O-2024 Obstacles and Other Dangers POWER LINES O-2024 Obstacles and Other Dangers LOW-FLYING, HEAVY AIRCRAFT O-2024 CAP Grid System O-2024 CAP Grid System Overlays standard sectional maps Subdivides the map into distinct working areas Each grid is 1/4° of latitude by 1/4° of longitude (15 minutes square) and is assigned a number A grid is identified by a Sectional Chart name plus a number – Example: Twin Cities Grid 444 (St. Cloud Area) Grids are further divided into sub-grids labeled A, B, C, and D Each sectional has a standard for assigning grid numbers — for areas of overlap the grid number of the most westerly chart is used O-2024 Sectional Grid System 46 o 00’ N 30’ x 30’ Aeronautical Chart Divison 45 o 30’ N 94 o 00’ W 93 o 30’ W O-2024 Sectional Grid System 46 o 00’ N 15’ x 15’ 15’ x 15’ 45 o 45’ 15’ x 15’ 15’ x 15’ 45 o 30’ N 93 o 45’ 94 o 00’ W 93 o 30’ W O-2024 CAP Grid System A grid can be divided into quarter grids 7 ½ Minutes square in size Quarter-grids are labeled A, B, C, and D – Example: Twin Cities Grid 159A (The Northwest quarter of TC Grid 159) Letters are used to define sub-grids 159 ADB 159 A 102-15 W 102-00 W 36 15’ N A C B A B C D B 36-07.5’ N 102 11.25 W D C 36-00 N 102-07.5 W 102 15’ W 102-00 W O-2024 Standardized Latitude/Longitude Grid System This system does not require special numbering Lat-long of lower right corner defines the grid Letters are used to define sub-grids 36/102 AA 36/102 ADB 103-00 W 102-00 W 37-00 N A B C A B B C D 36-30 N 102-45 W D C 36-00 N 102-30 W 103-00 W 102-00 W O-2024 Making Grid Charts You can use a new sectional — normally not updated unless it gets worn out Use a hi-lighter (not pink) to mark grid boundaries on the chart using a long ruler Mark grid identification in black ink for easy visibility You should always keep a current sectional with you even if you have a sectional which is marked with grids