Broken Casualty Message and a Silent Net
At 1410 a platoon is 8 km from base in broken country. The VHF handheld runs 5 W with a whip antenna. The net was clear at 1400. A section reports a casualty at grid 421806. The message is broken: the operator gives another platoon's callsign, then says 'one casualty, need casevac, over'. At 1415 the net goes silent except for a constant carrier tone. The platoon commander wants to send a CASEVAC request and ask for fresh batteries. The signal operating instructions say the next radio check is at 1500 and that compromise procedures apply if the net is lost for more than 10 minutes. The operator has one spare battery at 40 percent charge.
1. What is wrong with the first message, and what should the operator have sent?
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The first message is poor because it uses another platoon's callsign, has no precedence, gives no number or type of casualty, no own location, and does not say what is needed. A correct initial transmission would be: 'Zero, this is One One, contact, over.' After the response, use the correct prowords: 'Zero, this is One One, CASEVAC, grid 421806, one casualty, gunshot wound, conscious, request urgent evacuation, over.' If the grid is the casualty's location, say so. Keep the message short and repeat the grid once. Do not guess or use another unit's identity, because that corrupts the net picture and may send help to the wrong place. Write the message down before transmitting so the order is precedence, callsign, location, casualty details, request.
2. What should the platoon do about the constant carrier and the lost net?
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A constant carrier after a lost net suggests jamming, a stuck transmitter, or a compromised frequency. Do not send the CASEVAC details or any sensitive information on that net. Try a radio check on the alternate frequency in the signal operating instructions, or ask a station on higher ground to relay. If the net remains lost for more than 10 minutes, implement the compromise procedures: stop using the current frequency and codes, report the loss through the alternate means, and treat the net as compromised. A runner or field telephone may be faster than waiting. Keep the original casualty message ready so it can be sent immediately on a clean channel. Do not keep pressing transmit to test the carrier; that wastes battery and may disclose your position.
3. How should the operator manage the 40 percent spare battery?
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Battery management is part of the plan. Keep the current battery in use for the emergency transmission if it has more charge, and hold the 40 percent battery as the reserve. Turn the set off between scheduled calls, use the lowest power that works, keep transmissions short, and avoid unnecessary radio checks. The 1500 check should be kept, but the CASEVAC message takes priority on an alternate net. Record the time each battery is used, and tell the commander the remaining capacity so he can decide whether to request resupply. A 40 percent battery may not last through a long evacuation net, so the operator should not spend it on administrative chatter.