First, we open with the Introduction and then immediately hit Limitations — Page 27, Lesson 34

This is the start of Chapter 2, "Definitions and Calculations," in your Mass and Balance syllabus. This chapter is the foundation for everything else in the subject, so I want to walk you through the roadmap of what we're about to cover, because the structure itself tells you what matters. First, we open with the Introduction and then immediately hit Limitations. In professional aviation, mass and balance isn't just about doing sums — it's about operating within certified limits. So we start by defining what those limits are. Then we look at the Effects of Overloading — what happens when you exceed the maximum mass. After that, the Effects of Out of Limit CG Position — and here CG means Centre of Gravity, the point where the aircraft would balance. Getting that point outside its certified range is a serious problem, and we'll examine why. We then move to the Movement of CG in Flight. This is crucial: the centre of gravity isn't fixed. As fuel burns off, as passengers move, as cargo is consumed, the CG shifts. You need to understand how and why. Next is Some Effects of Increasing Aeroplane Mass — how a heavier aircraft behaves differently in performance terms. Then we get to the heart of it: Definitions. This is where we nail down the exact professional terminology — terms like Basic Empty Mass, Maximum Ramp Mass, Zero Fuel Mass, and so on. You must know these cold, because every calculation in this chapter and every load sheet you'll ever sign depends on them. After definitions, we go through the practical mechanics. Weighing of Aircraft — how an aircraft is actually weighed on scales. Then the Weighing Schedule — the formal record of that weighing. Then the Minimum Equipment List, or MEL — the list of equipment that may be inoperative and still allow dispatch, and how that affects the mass figures. We then get into the calculations themselves. Calculation of Fuel Mass — converting fuel volume to mass, which depends on density. Then Calculation of the Basic Empty Mass and CG Position — working out where the empty aircraft's CG sits. Then Calculation of the Loaded Mass and CG Position for Light Aircraft — the step-by-step method for a small piston aircraft. We then look at CG Position as a Percentage of Mean Aerodynamic Chord (MAC). MAC is the Mean Aerodynamic Chord — the average chord of the wing, and expressing CG as a percentage of MAC is the standard way large aircraft specify their CG limits. Then we cover Repositioning of the Centre of Gravity — what you do when the CG is out of limits. There are two methods: by Repositioning Mass — moving existing mass within the aircraft — and by Adding or Subtracting Mass — changing the total mass to shift the CG. After that, Graphical Presentation — using graphs to solve mass and balance problems quickly. Then Cargo Handling, and within that, Floor Loading — how much weight the floor can take. We break that into Linear / Running Loads — load per unit length — and Area Load Limitations — load per unit area. We then apply all this to specific aircraft categories: Single-engine Piston / Propeller Aircraft (SEP1), Light Twin Piston / Propeller Aircraft (MEP1), and Medium Range Twin Jet (MRJT1). Each has its own characteristics and methods. Finally, we cover Calculation of the Loaded Mass and CG Position for Large Aircraft and end with Compiling a Document (Load Sheet) — the formal document that certifies the aircraft is within limits for dispatch. So that's the full map of this chapter. Every one of these topics builds on the ones before it, so we'll take them in order, starting with the introduction and limitations. Let's begin.