Starting at the top: Diurnal — that's page 51 — Page 573, Lesson 571

This is the index of the General Navigation manual — the map of the whole book. Let me walk you through what's here, because an index tells you exactly what a professional navigator is expected to know, and in what order. Starting at the top: Diurnal — that's page 51. Diurnal means "daily," and in navigation it refers to the daily cycle of something, like the apparent movement of the Sun. Then Double Track Angle Error on page 200 — that's a specific error you'll meet in compass work, where the track you fly and the track you measure differ by twice the angle of some error source. Drift on page 125 — the angular difference between your heading and your actual track, caused by wind. Under E: Earth Convergence on page 241 — meridians converge toward the poles, and this is the rate at which they do so. Earth Rate on page 465 — the angular velocity of the Earth's rotation, a fundamental value for inertial systems. Equatorial Diameter on page 3 — the diameter of the Earth measured through the equator. European Datum 1950 Model (ED50) on page 3 — a reference model for the Earth's shape used in surveying and charting. Under F: Fix on page 477 — your determined position. Fixing Position on page 479 — the process of establishing that fix. Under G: Geodetic Latitude on page 10 — the latitude measured with respect to the geodetic model of the Earth. Geodosy on page 3 — note the spelling, that's the science of measuring the Earth's shape and size. Geoid on page 3 — the actual shape of the Earth's sea level surface, irregular due to gravity variations. Graduated Scale Line on page 223 — a scale line marked with divisions for measuring distances on a chart. Graticule appears twice — page 293 and page 8 — the network of meridians and parallels on a chart. Great Circle on page 7 — the shortest path between two points on a sphere. Great Circle Vertices on page 16 — the points of maximum latitude on a great circle. Greenwich Anti-meridian on page 13 — the meridian opposite Greenwich, at 180 degrees. Gridded Charts on page 458 — charts overlaid with a grid system. Grid Minimum Off-route Altitude (Grid Mora) on page 221 — the minimum safe altitude for off-route flight, expressed on a grid. Grid North on page 459 — the direction of the grid lines, not true north. Grid Ring Compass on page 494 — a compass with a grid ring for steering by grid directions. Under H: Hard Iron Magnetism on page 502 — permanent magnetism in the aircraft's structure affecting the compass. Heading on page 62 — the direction the aircraft's nose points. Horizontality on page 495 — the property of being level, relevant to compass mounting. Hour Angle on page 386 — the angular distance of a celestial body west of the meridian. Under I: Indicated Altitude on page 115 — what the altimeter shows, before corrections. Inertial Navigation System on page 45 — a self-contained navigation system using accelerometers and gyroscopes. Instrument Error on page 105 — error inherent in the instrument itself. Now, the key thing about this index: it's not random. It's arranged so that the Earth's shape and models come first — pages 3 to 16 — then chart work, then navigation techniques, then instruments, then inertial systems. That's the logical build-up of the whole syllabus. You'll see the same terms recur in the figures — for example, Figure 27.1 shows how True North is defined by the line joining a point to the North Pole, and Figure 27.7 shows the creation of a grid. Those will make sense when we reach those chapters. So this index is your roadmap. Every term here — from Diurnal to Instrument Error — is something you'll be expected to define precisely and apply in flight. We'll take them in order as we go through the book.