Look at the entries under 'S' — Page 458, Lesson 583

We've just landed on the index page for the Powerplant volume of your Aircraft General Knowledge series. This is the map of the entire book, and I want to walk you through what's here, because it tells you exactly how the syllabus is structured. Look at the entries under 'S'. We have Safety Factor on page 28 — that's the ratio of a component's ultimate strength to the maximum load it's designed to carry. Then Saybolt Universal Systems on page 48 — that's a viscosity measurement scale for oils, named after the Saybolt viscometer. Scavenge Pump appears on pages 44 and 47 — that's the pump that returns oil from the sump back to the tank in a dry-sump lubrication system. Scraper Rings on page 27 — those are the lower piston rings that scrape excess oil off the cylinder wall. Notice the ignition section: Secondary Coil on page 67 is the coil that steps up voltage for the sparking plugs, and Step-up Transformer on page 67 is the device that increases that voltage. Sparking Plugs themselves are on page 28. Now the thermodynamics: Second Law on pages 4 and 5 — that's the law of thermodynamics governing entropy and heat flow direction. Specific Fuel Consumption (SFC) on pages 22 and 313 — that's the fuel mass flow per unit of thrust or power produced. The gas turbine section: Shrouded Stator Vanes on page 236 — stator vanes with a shroud at the tip to reduce leakage. Stator Blades on page 228 and Stator Vanes on page 235 — the stationary blades that direct airflow between compressor or turbine stages. Stresses in the Turbine on page 265 covers thermal and mechanical loading on turbine components. The propeller section: Single Acting Propeller on page 169 — a propeller that uses one force, like oil pressure, to move the blades in one direction and a spring or counterweight for the return. Sprag Clutch Ratchet on page 355 — a one-way clutch used in the starter system. Self-sustaining Speed on page 357 — the engine speed at which the gas turbine can continue accelerating without starter assistance. The lubrication section: Semi-synthetic Oils on page 49 and Straight Oil on page 49 — the two oil types; straight oil is mineral-based, semi-synthetic is a blend. Society of Automotive Engineers (SAE) on page 48 — the organization that sets oil viscosity grades. Sulphur Content — that's the sulphur percentage in fuel, which affects corrosion and deposits. The mechanical section: Spur Gear on page 31 — a gear with straight teeth parallel to the axis. Spur Gear Pump on page 46 — a positive displacement pump using two meshing spur gears. Small End on page 26 — the top end of the connecting rod that attaches to the piston pin. Stroke on page 14 — the piston's travel distance from top dead center to bottom dead center. Starter Motor on page 30 — the electric motor that cranks the engine. Start Cycle on page 356 — the sequence from starter engagement to self-sustaining speed. And finally Stability on page 78 and Stall on page 230 — stability is the engine's tendency to return to a steady operating point, and stall is the aerodynamic breakdown of airflow in the compressor. That's the full 'S' section of your index. It's a dense list, but each entry is a chapter you'll master. Ready to move on when you are.