Let's start at the top — Page 657, Lesson 768

This is the index of the book — the alphabetical list of topics and the page numbers where they appear. It's not a lesson in itself, but it's a map of the territory we're about to cover, and I want to walk you through what's here so you know what's coming. Let's start at the top. SI — that's the International System of Units, the metric system — appears on page 75. Then E-type — that's a type of thermocouple, a temperature sensor — on page 119. EU-OPS Requirements — the European operating rules for commercial air transport — on page 357. Now here's a cluster of related terms. Expanded Arc, EXP ARC, Expanded ILS, and Expanded VOR — these are all display modes on an Electronic Flight Instrument System, or EFIS. The Expanded Arc is on page 286, EXP ARC is the same thing abbreviated, also on page 286. Expanded VOR is on page 290, and Expanded ILS on page 292. These are the different ways the navigation display can present your position relative to a VOR or an ILS — the expanded modes show a wider picture of the surrounding area. Expansion on page 122 is a different concept — that's about how a gyroscope behaves as it warms up. Eye Reference Point on page 8 — that's the design point where the pilot's eye is positioned for the instrument panel to be correctly aligned. Then we move into the F section. FADEC — Full Authority Digital Engine Control — on page 397. That's the system that controls the engine's fuel and thrust automatically. Fahrenheit on page 2 — the temperature scale. FAIL on page 278 — that's the annunciation, the warning you'd see on a display when something has failed. Now here's an important pair. Fail-operational, also called Fail-active, on page 380 — that means after a failure, the system continues to operate fully, with no loss of function. And Fail-passive, also called Fail-soft, also on page 380 — that means after a failure, the system reverts to a safe state, it stops controlling but doesn't cause a hazard. There's also Fail-passive Operation on page 380 — same concept, the operation of that fail-passive mode. And Fail Safe Autopilot on page 352 — an autopilot designed so that any failure leaves the aircraft in a safe condition. Failure Annunciation on page 295 — that's the visual or audible warning that a failure has occurred. Failure Warning on page 99 — similar, the warning of a failure, but in a different context. FANS on page 325 — that's Future Air Navigation System, the data-link communication system. FANS A on page 325 and FANS B on page 328 — these are two versions or levels of that system. Faraday's Law on page 216 — that's the electromagnetic principle that a changing magnetic field induces a voltage in a conductor — fundamental to how many instruments generate signals. Fast Erection System on page 178 — that's a mechanism in a gyroscopic instrument that quickly brings the gyro to its operating speed. FCC on page 294 — Flight Control Computer, the brain of the autopilot and flight director. FD Fail Indications on page 342 — the indications you'd see when the Flight Director has failed. FD Go-around (GA) on page 346 — the flight director's guidance for a go-around, when you abort the landing and climb away. FDIU on page 499 — Flight Data Interface Unit, which connects the flight data recorder to the aircraft's systems. FD Manoeuvre Protection on page 346 — the flight director's function that prevents the aircraft from exceeding its limits during a manoeuvre. And FDR on page 497 — Flight Data Recorder, the device that records flight parameters for accident investigation. So this index is telling you the full scope of the instrumentation syllabus — from basic units and temperature scales, through gyroscopes and electromagnetic principles, to the modern electronic displays, autopilot systems, and data recording. Each of these page numbers is a topic we'll cover in depth as we go through the book.