We are starting a new chapter: Chapter 16, titled Icing — Page 282, Lesson 271

We are starting a new chapter: Chapter 16, titled Icing. This is a critical topic for you as a professional pilot because ice on an aircraft is not just an inconvenience — it can fundamentally change the way your aircraft flies and how your engines perform. Let me walk you through what this chapter covers. First, the chapter opens with An Introduction to Icing and Its Basic Causes. That's where we'll begin: understanding why ice forms on an aircraft in the first place. Then we immediately move to a key concept — Supercooled Water Droplets, abbreviated as SWD. These are tiny droplets of liquid water that exist at temperatures below freezing, typically between 0°C and about -40°C. They are the primary ingredient for most in-flight icing. When an aircraft flies through a cloud of these supercooled droplets, the droplets strike the airframe and freeze on contact. From there, we look at The Effects of Icing — what ice does to your aircraft's performance, handling, and systems. Then the chapter breaks down the different types of ice you can encounter. There is Clear (or Glaze) Ice, which forms when larger supercooled droplets freeze slowly, spreading out into a smooth, transparent layer that can be very hard to see and can severely distort airflow. Then Rime Ice — that's the rough, milky-white, opaque ice that forms when smaller droplets freeze instantly on impact, trapping air bubbles. It builds up quickly on leading edges and is easier to detect but still dangerous. Next is Mixed Ice, which is exactly what it sounds like — a combination of clear and rime ice, often the most common type encountered in real flight. Then there is Rain Ice, which forms when an aircraft flies through freezing rain — rain that is liquid at sub-zero temperatures and freezes instantly on impact, creating a very rapid and severe clear ice accretion. There is also Pack Snow, which is snow that accumulates and compacts on the aircraft surfaces, and Hoar Frost, which forms when water vapour sublimates directly into ice crystals on a cold surface — this can happen on the ground or in flight. After the types, we cover Factors Affecting the Severity of Icing — things like the liquid water content of the cloud, the temperature, the droplet size, and the aircraft's speed and shape. Then Icing Forecasts — how meteorologists predict where and when icing will occur. That leads to the Freezing Level, which is the altitude where the temperature is 0°C — a critical reference point for your flight planning. We then move to Reporting of Icing — how pilots report icing encounters so that other crews and forecasters can be aware. Then we get into specific engine icing: Piston Engine Induction Icing — ice forming in the air intake of a piston engine, which can choke off the engine's air supply. And then Jet Engine Icing — ice forming inside a turbine engine, which can cause flameouts or damage. Finally, there is a section on Other Factors Affecting Jet Engine Operation in Icing Conditions, covering things like ice ingestion and the effects on compressor performance. The chapter ends with a set of Questions and then Answers for self-study. So, to summarise: this chapter takes you from the basic physics of supercooled water droplets, through every type of ice you might encounter, the factors that make it worse, how to forecast and report it, and finally how it affects both piston and jet engines. This is foundational knowledge for operating safely in any cold-weather or cloud-filled environment. Let's begin with the first section — the introduction to icing and its basic causes.