Search and Rescue — Page 473, Lesson 632

Right, let's pick this up with the ground-to-air signals from search parties. We've covered the survivor signals, so now we're looking at how a ground search party communicates back up to the aircraft. I want to walk you through the code symbols. These are visual signals laid out on the ground, and each one has a specific meaning. The first one is "LLL" — that means "Operation completed." Three L's. Next, "LL" — two L's — means "We have found all personnel." Then we have "+ +" — two plus signs — which means "We have found only some personnel." So you can see the progression: LLL is the whole operation done, LL is all people found, and + + is only some found. Then we have "xx" — two X's — which means "We are not able to continue. Returning to base." That's a critical one for the pilot to understand, because it means the ground party is pulling out. Next, there's a signal with no code symbol listed — it's just described as "Have divided into two groups. Each proceeding in direction indicated." That's number 5. Then number 6: "Information received that aircraft is in this direction" — again, no code symbol, just the message. And finally, number 7 is "NN" — two N's — which means "Nothing found. Will continue to search." Now, here's the crucial part — the air-to-ground acknowledgment. This is in section 24.18. When the pilot sees these ground signals and understands them, they must acknowledge. During daylight hours, the pilot rocks the aircraft's wings. During the normal hours of darkness, the pilot flashes the landing lights on and off twice — or, if the aircraft isn't equipped with landing lights, by switching the navigation lights on and off twice. And here's the key limitation: if the aircraft does NOT give this signal, it tells the ground party that their signal has NOT been understood by the pilot. So the absence of the acknowledgment is itself a signal — a negative one. Let me show you the figure for this — it's Figure 24.3, which lays out these ground/air signals from search parties. Now, moving on to 24.19 — marking of droppable supplies. When packages are dropped to survivors from an aircraft, the content must be indicated by colour-coded streamers attached to the packages. This is specified in Doc 7333. Red streamers mean medical supplies and first aid equipment. Blue means food and water. Yellow means blankets and protective clothing. And black means miscellaneous equipment — things like stoves, axes, cooking utensils, and so on. So the colour tells the survivors exactly what's in each drop without them having to open everything. Finally, 24.20 — emergency frequencies. These are the dedicated radio frequencies used to communicate Distress, Urgency, and Safety messages, and you are required to know these. On VHF, it's 121.500 MHz — that's the aeronautical mobile emergency VHF. On UHF, it's 243.000 MHz — the aeronautical mobile emergency UHF. On HF, it's 2182 kHz — that's the international maritime distress and calling HF. And then there's SARSAT at 406 MHz — that's the SAR beacon frequency, and note it also radiates on 121.5. So those four frequencies — 121.5 VHF, 243.0 UHF, 2182 HF, and 406 MHz for SARSAT — are the ones you must commit to memory. That's the full picture for this section — the ground signals, the air acknowledgment, the supply colour coding, and the emergency frequencies.