Look at the range of entries — Page 346, Lesson 437

This is the index of the book — the alphabetical listing of topics with page numbers. I want to walk you through what this tells us about the structure of the course, because it gives you a map of the ground you'll cover. Look at the range of entries. We have Fuselage and Fuselage Design at page 11, and Hoop Stress also at page 11 — that's the structural theory right at the start. Then Hard Time Maintenance at page 39, which is a maintenance philosophy. Hand Pumps at page 58 — that's hydraulic systems. Fuses at page 70, Ground Servicing Couplings at page 73 — electrical and servicing. Now look at the landing gear section: Gear Selector Lock at page 108, GPWS — Ground Proximity Warning System at page 109, Ground Locks at page 109, Free Falls at page 110, Fusible Plugs at page 116. These are all landing gear systems and safety devices. Then we move to flight controls: Horn Balance at page 169, Frise Ailerons at page 173, High Lift Devices at page 156. And the fuel system: FSII — Fuel System Icing Inhibitor at page 312, Fungal Growth at page 312, Fuel Heater at page 313, HITEC — Lubricity Agent at page 313, Fuel Drains at page 317, Fuel Jettison at page 321, Fuel Quantity at page 323. And environmental systems: Gasper Air at page 214, Ground Cooling Fan at page 211, Heat Exchanger at page 211. Let me explain a few of these terms so you know what they mean before we dive in. Hoop Stress is the circumferential stress in a cylindrical pressure vessel — think of the fuselage as a tube under cabin pressure; the hoop stress is what tries to split it apart around its circumference. Fusible Plugs are safety devices that melt at a specific temperature to relieve pressure — often in landing gear struts or fire protection systems. Free Falls refers to a landing gear emergency extension where the gear drops and locks under gravity and airflow, not hydraulic power. Ground Locks are physical pins inserted into the landing gear on the ground to prevent accidental retraction. FSII is an additive that prevents ice crystals from forming in jet fuel. HITEC is a lubricity agent added to fuel to restore lubricating properties lost during refining. Gasper Air is the conditioned air supplied to the cabin for ventilation and pressurization. This index is your roadmap. Each of these entries is a topic we'll cover in detail. The page numbers tell you where in the book each subject lives, and the grouping — structural, hydraulic, electrical, landing gear, flight controls, fuel, environmental — shows you the major systems of the aircraft. We're starting at the very beginning of this journey. The first topic on this page is the Fuselage and Fuselage Design at page 11, along with Hoop Stress. That's where we'll begin — understanding the primary structure of the aircraft itself.