When approaching an aircraft, what must be done?

Answer: B — Use caution and ensure the aircraft's engines are not running

When approaching an aircraft, it is essential to use caution and ensure that the aircraft's engines are not running. This is critical for safety reasons, as an aircraft with its engines running poses a significant danger due to high levels of noise, potential jet blast, and the risk of being struck by moving parts or objects. By confirming that the engines are not operating, a person can assess the environment more safely, minimizing the risk of accidents. Recognizing the aircraft's operational status also allows for safer communication with ground crew or pilots if necessary. In airfield operations, maintaining awareness of the aircraft's condition and the surrounding environment is paramount to ensure the safety of both personnel and aircraft operations. Other suggested actions, such as reducing speed to avoid noise, while considerate, do not address immediate safety concerns. Honking the horn could startle personnel on the flight line and is not an appropriate form of communication in such an environment. Pulling out emergency equipment would also be unnecessary unless a specific emergency situation arises, and is not a standard procedure when approaching an aircraft.