What does the Yellow color indicate in flight operations?

In flight operations, the color yellow signifies that ground personnel are engaged in the task of either engaging or disengaging equipment or aircraft. This is crucial for the safe and efficient handling of aircraft on the flight deck, as it directs the crew to be aware that actions are being taken that could impact the operation of aircraft, including the potential for aircraft propulsion systems being active or inactive.

Understanding this color code is essential for maintaining situational awareness during flight operations, as misinterpretation can lead to accidents or operational delays. Ground crew and flight deck personnel are trained to recognize these signals to ensure that all personnel on deck adhere to safety precautions, especially when working near moving aircraft and equipment.