Look at the entries here — Page 661, Lesson 790

This is the index of the book — the alphabetical list of topics and the pages where they appear. I want to walk you through what this tells you, because learning to read an index is part of learning to use your reference material professionally. Look at the entries here. You have "Read Only Memory (ROM)" at page 309 — that's the computer memory that holds data permanently, the kind that doesn't lose its contents when power is removed. You have "READY NAV" at pages 240 and 242 — that's a flight management system annunciation telling you the navigation system is ready for use. "Real Wander" at page 142 — that's the actual drift of a gyroscope from its reference, as opposed to apparent wander caused by Earth's rotation. "Recovery Factor" at page 31 — that's the ratio used in temperature probe corrections, how much of the kinetic heating a probe actually recovers. "Rectified" at page 218 — that's the process of converting alternating current to direct current. "Red and Blue Poles" at page 106 — that's the colour coding on an artificial horizon, the red for the sky and blue for the ground, or in some instruments the reverse. "Red Radial Line" at page 45 — that's the maximum limit marking on an instrument dial. "Reference System" at page 337 — that's the inertial reference system that provides attitude and heading data. "Regional QNH" at page 64 — that's the altimeter setting for a specific region rather than a single aerodrome. "Remote Indicating Compass" at pages 204 and 211 — that's a compass system where the sensing element is mounted remotely, away from the cockpit, and the reading is transmitted to the display. "Remote Light Sensor" at page 283 and "Remote Light Sensor Unit" at page 281 — those are the photocell units that detect ambient light for automatic display dimming. "Remote Reading" at pages 26 and 27 — that's the principle of an instrument whose sensing element is separate from its indicator. "Remote Vertical Gyro" at page 178 — that's a vertical gyro mounted remotely that provides pitch and roll reference to other systems. "Frequency Modulated Continuous Wave (FMCW)" at page 263 — that's the radar technique used in radio altimeters, where the transmitted frequency is continuously varied and the height is derived from the frequency difference between transmitted and received signals. "Resistance Wire" at page 28 — that's the wire in a resistance temperature detector, whose resistance changes with temperature. "Resolution Advisories" at page 483 — those are the TCAS commands that tell the pilot what vertical manoeuvre to make to resolve a traffic conflict. "Restrictor" at page 74 — that's the calibrated restriction in a pneumatic instrument line that controls the rate of pressure change. "Reversion Modes" at pages 413 and 414 — those are the backup modes an autopilot or flight director falls back to when a primary mode is lost. "Rigidity" at pages 137, 140 and 176 — that's the gyroscopic property of resisting any change to its axis of rotation. "RIMC" at page 204 — that's the Remote Indicating Magnetic Compass, the full name for the system I mentioned earlier. "Ring Laser Gyros" at pages 145 and 257 — those are the optical gyroscopes that use laser beams travelling in opposite directions around a closed path to detect rotation. "Roll and Pitch Modes" at page 372 — those are the autopilot lateral and longitudinal control modes. "Roll Channel" at pages 337 and 364 — that's the axis of the autopilot or flight control system that controls the aircraft's roll. "Roll Error" at page 175 — that's the error in a gyro instrument caused by the aircraft's roll. And "Roll-out" — that's the phase of flight when the aircraft is aligned with the runway centreline after a turn, typically after an instrument approach. Now, I want you to notice something important about this index. It's not just a list — it's a map of the whole book. When you're studying for your ATPL, you'll use this to find a topic quickly. If you're asked about "Real Wander" and you're not sure where it's covered, you look here, you see page 142, and you go straight there. Also notice the page numbers. Some entries have a single page, like "Recovery Factor" at 31. Others have multiple pages, like "Rigidity" at 137, 140 and 176 — that tells you the topic is discussed in several places, and the most detailed treatment is usually the last one listed. And some entries, like "Remote Indicating Compass," have a range — 204, 211 — meaning the topic spans those pages. One more thing: the index uses the exact technical terms you'll need to know. "RIMC" is the acronym, and the full name is "Remote Indicating Magnetic Compass." When you see an acronym in the index, make sure you know what it stands for, because the exam will use both forms. So this is your reference tool. When you're revising, when you're looking for a specific fact, this is where you start. It tells you where everything lives in the book, and it gives you the official terminology you need to use.