Let's pick this up right where the procedure gets concrete — Page 421, Lesson 514

Let's pick this up right where the procedure gets concrete. We're looking at the "increased V2 take-off" technique — the method that lets you legally raise your V2 speed to buy yourself better climb performance, which in turn lets you carry more mass. Here's the logic chain we just established: if you fly faster than the minimum V2, your climb gradient improves. That improved climb performance means the climb limit mass can go up. A higher climb limit mass raises the performance limited take-off mass, and that gives you a better regulated take-off mass. So the whole point of this procedure is to trade a higher take-off speed for a higher allowable take-off weight. Now, the actual working method. I want you to think of this as a two-graph exercise, both taken from CAP 698, section 4, pages 29 and 30. The left-hand graph is the "improved climb performance field length limit" graph, and it's split by flap setting — so step (a) is simply to select the set of graphs that matches your flap setting. Step (b) is where the calculation starts. You take the field length limit mass and subtract the climb limit mass. That difference is your entry value. You enter the left-hand graph with that value on the horizontal axis, and travel vertically upward until you hit the normal 'climb limit' mass line. Step (c) is the read-off. From that intersection, you move horizontally in two directions. To the left, you read the climb mass improvement off the vertical axis — that's how much extra mass you've gained. To the right, you read the increase to apply to V1. So one intersection gives you two outputs: a mass gain and a V1 speed increase. Step (d) carries you across to the right-hand graph. You continue horizontally right from that same intersection until you reach the reference line of the right-hand graph. From there, you interpolate and follow the grid lines to reach a vertical input in the right-hand graph — and that vertical input is the normal climb limit mass. So the right-hand graph is entered with the climb limit mass itself. Finally, step (e): from that intersection, travel horizontally right to the vertical axis, and you read the increase to apply to VR and V2. Note that this is a single value applied to both VR and V2 — the rotation speed and the take-off safety speed both get the same increment. So the full picture: the left graph gives you the V1 increment and the climb mass improvement; the right graph gives you the VR and V2 increment. The climb mass improvement is what feeds back into your performance limited take-off mass, and the speed increments are what you actually fly. One practical note before you go into the exam: CAP 698 itself, at the top of page 28 of section 4, gives a very clear introduction to what this procedure is for. If you're ever unsure what the procedure entails, that introduction is your anchor — read it first, then apply the methodology. Let me show you the actual graphs so you can see how the two sides connect.