First, let's look at the acronyms you'll encounter — Page 271, Lesson 381

I see we've landed on an index page — this is the back-of-the-book index for your Operational Procedures manual, covering entries from "Revised Clearance" through to "Single-pi" (cut off mid-word). Let me walk you through what's here and what it tells us about the book's content. First, let's look at the acronyms you'll encounter. RNP stands for Required Navigation Performance — it appears on pages 82 and 120, so it's a navigation accuracy standard we'll study. RVR is Runway Visual Range, referenced across many pages from 38 through 63 — that's a critical visibility measurement for takeoff and landing minima. RVSM means Reduced Vertical Separation Minimum, appearing on pages 40, 82, 122, 123, 125, and 134 — this is the system that allows aircraft to fly 1,000 feet apart vertically above Flight Level 290. Moving to communications and surveillance systems: SELCAL is Selective Calling, on pages 133 and 139 — that's the system that alerts the flight deck when ATC wants to contact you on HF radio. SATCOM is Satellite Communications, page 132. SARSAT is Search and Rescue Satellite-Aided Tracking, page 87 — part of the global distress alerting system. SAR is Search and Rescue, also page 87. For navigation and airspace: SIDs are Standard Instrument Departures, pages 39 and 95 — these are the published procedures you fly after takeoff. SCA appears on page 131 — that's Shannon Control Area, part of the North Atlantic airspace structure. Shanwick on page 120 is the oceanic control centre covering the eastern North Atlantic. Santa Maria and Reykjavik on page 120 are other oceanic control areas. The Shannon Oceanic Transition Area on page 131 is the airspace where you transition from domestic to oceanic control. Operational terms: Revised Clearance on page 137 and Revised Estimate on page 134 — these are ATC procedures for updating your flight plan or expected time. Routes and Areas of Operation on page 39 covers where you're permitted to fly. Separate Runways on pages 26 and 36 refers to runway configurations for simultaneous operations. Safety and security: Safety Management System (SMS) on page 5 is the systematic approach to managing safety risks. Security and Security Restricted Area on page 197 cover airport access control. Screening on page 197 is passenger and baggage security checks. Seat Belt on page 44 and Seats, Safety Belts and Harnesses on page 46 are cabin safety equipment. Senior Cabin Crew on pages 100 and 101 refers to the lead flight attendant. Weather: Rime on page 146 — that's rime ice, a type of ice accretion on aircraft surfaces. Navigation technology: Satellite Availability Prediction Programme on page 139 — this is a tool to predict when enough GPS satellites will be in view for your planned route. Finally, Single-engine Aeroplanes on page 40 covers operations with only one powerplant. This index is your roadmap — every page number tells you where to find the detailed material. We've just covered the entries from R through S