We have Precession at pages 137, 139, and 140 — Page 661, Lesson 787

This is the index of the book — the alphabetical listing of topics with their page numbers. So we're looking at the "P" entries, and I want to walk you through what's here, because this tells you exactly what the book covers and where to find it. Let's start with the gyroscopic instruments, since those are core to your attitude and heading indications. We have Precession at pages 137, 139, and 140. Precession is the property of a gyroscope where an applied force produces movement at a point 90 degrees around from where the force is applied — it's fundamental to how gyroscopic instruments work. Then we have Primary Precession at page 185, and Primary Torque also at page 185 — these are the initial precession and torque in a gyro system. And Precession Rate at page 163 — that's how fast the gyro precesses, which matters for instrument accuracy. There's also a Precession Amplifier at pages 211 and 218, and a Precession motor at page 211 — these are components in gyro systems that drive or amplify the precession effect. Now, moving into the inertial navigation side. We have Principles of INS at page 228 — that's the fundamental theory of Inertial Navigation Systems. Platform at page 234 — that's the stabilized platform that holds the accelerometers and gyros. Platform tilt at page 238 — that's a source of error where the platform isn't perfectly level. Platform Alignment at page 257 — that's the process of aligning the platform to true north and level before flight. Plan Mode at page 294 — that's a navigation display mode. POS INIT at pages 273 and 274 — that's the position initialization, where you enter your starting position into the system. And Present Position at page 244 — that's your current computed position. Then we have the air data instruments. Pressure Altitude at page 53 — that's altitude indicated when the altimeter is set to the standard pressure of 1013.25 hectopascals. Position Error at pages 15, 42, and 85, and Position (or Pressure) Error at page 61 — these are errors in the pitot-static system caused by the position of the static ports and how airflow disturbs the pressure measurement. Pressure Error at page 15 is related. Pressure Transducer at page 98 — that's the device that converts pressure into an electrical signal. And Preflight Altimeter Checks at page 65, plus Preflight Checks at page 18 — those are the checks you do before flight to verify the instruments are working. Now the electrical and electronic components. Platinum at page 28 — that's the metal used in resistance temperature detectors, or RTDs, for measuring temperature. Poles of a Magnet at page 105 — that's the north and south poles, fundamental to how compasses and magnetic sensors work. Programmable Read Only Memory (PROM) at page 309, and PROM also at page 309 — that's a type of non-volatile memory that can be programmed once. Program at page 307 — that's the software or instructions loaded into a system. Power Control Unit (PCU) at page 407 — that's the unit that controls hydraulic or electrical power to actuators. Power Management Control (PMC) at page 393 — that's the system that manages engine power output. Power up BITE at page 100 — that's Built-In Test Equipment that runs automatically when the system is powered on. Then we have the display and traffic systems. Primary Flight Display (PFD) at pages 281 and 339 — that's the main electronic display showing attitude, airspeed, altitude, and heading. PRINTER at page 319 — that's the cockpit printer for printing flight plans and reports. Proximate Traffic at page 485 — that's traffic that's close to you, as shown on the traffic display, but not yet a collision threat. And finally, Polar Regions at page 317 — that's the areas near the poles where navigation is challenging because of magnetic and gyro errors. And Pound at page 2 — that's the unit of weight or force. So this index page is your map. When you're studying, you can use it to jump straight to the page where each topic is explained. Now, let's look at the actual gyroscope chapter, because that's where the precession concepts come to life.