You'll see TORA — Take-off Run Available — on page 23 — Page 537, Lesson 658

This is the index of the book — the map of the whole syllabus. I want to walk you through the key entries here, because this tells you exactly what we're going to cover in Mass and Balance and Performance. Let's start with the take-off distance concepts. You'll see TORA — Take-off Run Available — on page 23. That's the length of runway actually available for the aeroplane to accelerate along the ground during take-off. Right next to it is TODA — Take-off Distance Available — also on page 23. That's the total distance available for the take-off, which includes the runway plus any clearway beyond it. And you'll see both of these again on page 14, where they're introduced alongside their "required" counterparts — TORR and TODR — the Take-off Run Required and Take-off Distance Required. So you have what's available at the aerodrome versus what the aeroplane requires. Now, the clearway — that's the area beyond the runway that can be used for the initial climb. Look at Figure 2.1: clearways extend from the end of the runway with an upward slope not exceeding 1.25%. That's a specific limit you'll need to remember. And the stopway — Figure 2.2 — that's the area that must be able to support the aeroplane during a rejected take-off, and it's marked by large yellow chevrons. Figure 2.3 shows both stopways and clearways together at an aerodrome. Now let's look at the speed-related entries. V1 appears on pages 10, 14, and 250 — that's the Decision Speed. On page 250 you'll see it defined as V1 – Decision Speed, and on page 263 there's the V1 Range, which is the range of speeds within which V1 must be selected. V2 is on page 14 — that's the Take-off Safety Speed, and you'll see V2MIN on pages 14 and 256, which is the minimum allowable V2. And V3 appears at the end of the excerpt — that's the steady initial climb speed. You'll also see TOGA on page 14 — that's Take-off/Go-around thrust, the maximum thrust setting used for take-off. And TOSS on page 14 — that's Take-off Safety Speed, which is another term for V2. Now, the performance side. Thrust appears on pages 9 and 54, and Thrust Available on page 47. You'll see Turbojet on page 9 and Turboprop on page 10 — these are the two engine types whose thrust characteristics you'll compare. True Airspeed is on page 9, and then True Airspeed (TAS) appears again on page 114, with True Ground Speed (TGS) on page 115 — the difference being that ground speed accounts for wind. There's also the Total Drag Curve on page 52 — that's the curve showing how total drag varies with speed. And The Effect of Flaps on Climbing on page 49 — how flap settings change climb performance. Finally, on the mass side, you have TOW on page 14 — Take-off Weight. And there are two important limits: Tyre Speed Limit on page 256, and Tyre Speed Limit Mass on page 268 — the maximum mass at which the tyre speed limit applies. And Unbalanced Field on page 260 — that's the situation where the accelerate-stop distance and the take-off distance are not equal, which affects how you calculate the field length. So that's the map. The key relationships to hold onto: TORA and TODA are what the aerodrome gives you; TORR and TODR are what the aeroplane needs; V1 is your decision speed; V2 is your safety speed; and the tyre speed limit ties your mass to a maximum ground speed. We'll build all of this up properly as we go through the chapters.