We are starting a new topic: Point of Safe Return, or PSR — Page 250, Lesson 261

We are starting a new topic: Point of Safe Return, or PSR. This is Chapter 14 in your book. Let me walk you through what this chapter covers. The Point of Safe Return is a critical fuel-management concept. It is the furthest point along a planned route from which you can still return to your departure aerodrome, given the fuel you have on board, without exceeding your fuel reserves. In other words, if you go beyond the PSR, you no longer have enough fuel to get back to where you started — you must continue to your destination or an alternate. So the PSR defines a time or distance limit for a go/no-go decision on the outbound leg. The chapter is structured to build your understanding step by step. It begins with an Introduction on page 259, which sets out the basic idea. Then it moves to the Derivation of the Formula on page 260 — that is where we will work out the mathematical relationship that lets you calculate the PSR. After that, on page 261, we cover Transposing the Formula to Navigation Computer — that means taking the formula and adapting it so you can solve it quickly using your flight computer (the circular slide rule you use in planning). Still on page 261, we look at The Effect of Wind on the Location of the PSR — wind changes your ground speeds outbound and inbound, so it shifts where the PSR falls along the route. Then we get into the Single Leg PSR on page 262 — that is the simplest case, where you have just one leg from departure to destination, and you want to know the PSR on that single leg. After that, there are Questions - Single Leg PSR on page 263, with Answers on page 265, so you can practise. The chapter then goes deeper: Derivation of the Formula for Variable Fuel Flows on page 266. This is important because in reality your fuel flow may not be constant — it changes with altitude, weight, and phase of flight. That section shows you how to handle that. Then there is an Example Variable Fuel Flows PSR - Single Sector on page 266, followed by Questions - PSR with Fuel on page 267 and Answers on page 268. Finally, there is a comprehensive set of Questions - All Types on page 269, with Answers on page 270, to tie everything together. So in this chapter, we are going to learn how to find the point on your route where you must turn back, or else you cannot make it home. That is the Point of Safe Return. Let's begin with the introduction.