When transmitting a medevac request over the radio, what is the appropriate way to start?

Starting a medevac request with "I have a medevac request, over" is the appropriate approach because it clearly and specifically communicates the nature of the transmission right from the beginning. This phrasing provides essential information to the receiving party that there is a medical evacuation need, which is critical for prioritizing the response.

By stating you have a medevac request, the recipient immediately understands that this communication is urgent and pertains to medical support, allowing them to allocate resources and prepare for the situation appropriately. Clear communication is vital in emergency situations, as it reduces confusion and ensures that the necessary response can be mobilized quickly.

The other options lack specificity regarding the type of assistance required or may create uncertainty about the urgency of the situation. While they might convey a need for help, they do not convey the specific nature of the request as effectively as the correct choice.