Author: Wg Cdr Rajagopal

Navigation using the One in Sixty Rule Use of One in Sixty Rule One in a sixty rule is useful for pilots to quickly calculate alteration of heading One in sixty rule statement states that one unit off-track in 60 units along track mean a track error of 1 degree In other words, if you are 1 NM off-track after a flight of 60 NM, the track error would be 1 degree. Logic behind One in Sixty Rule Logic of One in Sixty Rule is based on an approximation with…

Triangle of Velocities or Vector Triangle or Wind Triangle Plotting Plotting is the means of keeping track of aircraft position at all times during a flight Pilots are legally mandated to be aware of their position at all times during a flight Track and Air Plot are the two means of keeping track of aircraft position Track Plot Track plot is maintained by connecting the ground positions of aircraft Track plot is the simplest means of keeping track of an aircraft position Planned track (PT)or Track Required (TR)is intended flight…

Earth Magnetism and Magnetic Compass Earth Magnetic Field Earth behaves as a large magnet with a Magnetic North and South Magnetic North is the direction indicated by the blue end of a freely suspended magnet Earth’s magnetic field is not exactly aligned to its polar axis since the Magnetic North is not co located with True north Magnetic north is approximately 400 NM away from True north and moves at at a slow rate of 22 NM per year Magnetic North and South poles are not diametrically opposite to each…

Measurement of Distance on Earth Surface Distance Measurement for Air Navigation Distance measurement is important for pilots to keep track of aircraft position Horizontal distances are measured in Nautical Miles, Kilometres or Statute Miles Vertical distances are measured in feet or meters Nautical Mile One nautical mile is the length of a meridian subtending an angle of 1 minute of arc at its centre of curvature At equator, curvature of earth is maximum Since highly curved lines require lesser distance per unit angle, the length of nautical mile is minimum…

Great Circle and Rhumb Line Tracks Vertex of a Great Circle Vertices are the northern and southern most points of a great circle Northern vertex is the point on the great circle that is closest to the north pole Southern vertex is the point on the great circle that is closest to the south pole The northern and southern vertices are antipodal or diametrically opposite points The distance between the vertices along the great circle track would be half the earth circumference Flight along a great circle would result in…

Position Reference System using Latitude and Longitude Requirement of Position Reference System Position Reference System to denote a place on earth without ambiguity It is similar to Cartesian co-ordinate system which uses X and Y axis Latitudes and longitudes are used in the position reference system Great Circles Great circles are imaginary lines or circles drawn on the surface of earth The centre and radius of a Great Circle are the same as that of earth Plane of a great circle cuts earth into two equal halves Only one great…