Which of the following is NOT a responsibility of the TDP signalman?

The responsibility that is not associated with the TDP (Tactical Deployment Point) signalman is ensuring safety belt usage. The primary duties of a TDP signalman are focused on communication and coordination for the safe landing and takeoff of aircraft. This role includes providing guidance to the aircrew, managing personnel involved in the loading and unloading of cargo, and overseeing ground-to-air communications. Ensuring safety belt usage, while critical to overall operational safety, falls under the responsibilities of the crew and personnel involved with the loading and unloading operations rather than being a direct duty of the signalman. This differentiation highlights the specific nature of each role in a helicopter landing zone operation.