Now, a few of these deserve a quick definition because they're core… — Page 661, Lesson 791

This is the index of the book — the alphabetical list of topics and the page numbers where they appear. So we're looking at the entries under "R" and "S." Let me walk you through what's here, because even an index teaches you the structure of the subject. Under "R," we have Roll Error at page 175, Roll-out at 383, ROM at 309, Rotor at 137, Rotor Bearing Friction at 142, Rotor RPM at 140, RTE at pages 273 and 274, RTE DATA at 286, Runway Alignment at 383, Runway Awareness and Advisory System at 471, and Runway Visual Range — abbreviated RVR — at 386. Now, a few of these deserve a quick definition because they're core instrumentation terms. Roll Error is the error in a gyroscopic heading or attitude instrument caused by the aircraft's roll — the instrument precesses and shows a false reading. Roll-out is the phase of a turn when the aircraft returns to wings-level. ROM stands for Read-Only Memory — the non-volatile storage in a computer that holds fixed data. Rotor is the spinning element of a gyroscope, and Rotor RPM is its rotational speed — critical because a gyro needs a minimum RPM to maintain rigidity in space. Rotor Bearing Friction is the mechanical resistance in the gyro's bearings, which causes precession and drift. RTE is the route — the flight plan — and RTE DATA is the route data entered into the navigation computer. Runway Alignment is the process of aligning the aircraft's heading with the runway centerline, and Runway Awareness and Advisory System is a warning system that alerts the crew if the aircraft is not aligned with the correct runway. Runway Visual Range, RVR, is the horizontal distance a pilot can see down the runway, used for landing minima. Then under "S," we have Safety Criticality at 310, SAGNAC at 255, SAGNAC effect at 256, SAT at pages 30 and 97, SATCOM at 317, Satellite Communication at 317, Schuler Oscillation at 238, Schuler Period at 237, Schuler Tuning at 257, Scripting Language at 310, Secondary Precession at 185, Secondary Torque at 185, Secondary Winding at 217, Second Integrator at 230, Seconds at page 2, Second Stage of Integration at 238, Sensitive at 120, Sensitive Altimeter at 56, Sensitivity at 121, and Series at 358. Let me define the important ones. Safety Criticality is the degree to which a system failure could endanger the aircraft — it determines the redundancy and certification level required. SAGNAC is the effect named after the physicist — the Sagnac effect is the principle behind ring laser gyros: two beams of light travel in opposite directions around a closed loop, and rotation causes a measurable difference in their path lengths. SAT is Static Air Temperature — the actual temperature of the air outside the aircraft, unaffected by compressibility. SATCOM is Satellite Communication — the system for voice and data via satellite. Schuler Oscillation, Schuler Period, and Schuler Tuning all relate to the 84-minute natural period of a pendulum that is tuned so that an inertial navigation system's accelerometer errors do not grow unbounded — the platform oscillates about the vertical with an 84-minute period. Scripting Language is a programming language used to automate tasks in a system. Secondary Precession and Secondary Torque refer to the gyroscopic effect where an applied torque produces precession at right angles — the secondary effect. Secondary Winding is the output coil of a transformer or synchro. Second Integrator and Second Stage of Integration refer to the double integration of acceleration to get velocity and then position in an inertial system. Sensitive Altimeter is the precision altimeter with a sensitive mechanism that reads small altitude changes, and Sensitivity is the degree of response of an instrument to a change in the measured quantity. Series refers to a circuit configuration where components are connected end to end. So this index is your map — it tells you where each concept lives in the book, and it gives you the vocabulary you'll need. When we get to the actual chapters, we'll define each of these properly. For now, you know what the terms mean at a glance.