Which of the following is critical to ensure when working near a helicopter?

Constant communication with the crew is essential when working near a helicopter because it helps ensure the safety of all personnel involved. Helicopters are often loud and can create significant wind, making it difficult to hear instructions or warnings, which is why maintaining direct communication is crucial. Clear communication allows ground personnel to be aware of any changes in the helicopter's operation or flight status, helping to prevent accidents and ensuring that everyone knows their roles and responsibilities.

This communication can involve using radios or hand signals, which ensure that information can be conveyed effectively, even in challenging conditions. Establishing a system of communication also allows for prompt responses to any emergencies or changes in the situation, which is especially important in an outdoor emergency care setting where quick decisions can save lives.