Search and Rescue — Page 468, Lesson 630

Let’s pick this up right where the signals from the surface craft left off. I want to walk you through the manoeuvres an aircraft uses to talk to a ship or boat — what we call a surface craft — and then we’ll move into the ground-to-air visual signal code. First, 24.12 — Signals with Surface Aircraft. This is a defined sequence of manoeuvres. When an aircraft performs these in order, it means the aircraft wants to direct a surface craft toward another aircraft or a surface craft that is in distress. And here’s the key point: repeating the whole sequence carries the same meaning — it doesn’t change the message, it just reinforces it. The sequence is four steps. Step one: the aircraft circles the surface craft at least once. Step two: it crosses the projected course of the surface craft — that’s the line the craft is expected to travel — close ahead, and it does this at low altitude. While doing that crossing, the aircraft does one of three things: it rocks its wings, or it opens and closes the throttle, or it changes the propeller pitch. Any one of those three is acceptable. Step three: the aircraft heads in the direction in which the surface craft is to be directed. So the whole thing is: circle, cross ahead low with a signal, then point the way. Now 24.13 — Assistance No Longer Required. This is the opposite message. If the aircraft no longer needs assistance, it indicates that by crossing the wake of the surface craft — that’s the disturbed water trailing behind the craft — close astern, meaning just behind it, at low altitude. And again, it uses one of the same three signals: rocking the wings, opening and closing the throttle, or changing the propeller pitch. Notice the contrast: to direct, you cross ahead; to cancel, you cross astern. That’s a deliberate distinction you must remember. Then we move to 24.14 — SAR Signals. SAR stands for Search and Rescue. The rule here is strict: these signals, when used, shall have the meaning indicated, and they shall be used only for that purpose. No other signals that could be confused with them may be used. And when an aircraft observes any of these signals, it shall take whatever action the interpretation of the signal requires. So it’s a binding obligation, not a suggestion. 24.15 — Ground/Air Visual Signal Code. This is an internationally agreed system for ground parties to send basic messages and instructions to aircraft. There are two sets: signals from crash survivors, and signals from search teams. We’re going to focus on the survivor set now. 24.16 — Ground/Air Visual Signal Code for Use by Survivors. These signals can be set out in various forms — marked in snow, oil on sand, or burned grass in open areas — to ask for help. The code is a table of messages paired with symbols. Message one: Require assistance, symbol V. Message two: Require medical assistance, symbol X. Message three: No — that’s a negative — symbol N. Message four: Yes — affirmative — symbol Y. And message five: Proceeding in this direction, shown by an arrow pointing the way. So you have five survivor signals: V for help, X for medical help, N for no, Y for yes, and the arrow for direction of travel. These are the building blocks of ground-to-air communication when voice isn’t possible.