What physical sign is associated with rapid decompression?

The physical sign associated with rapid decompression is the presence of windblast or flying debris. When a rapid decompression occurs, the sudden change in pressure creates a forceful outflow of air and can result in any unrestrained objects or debris being propelled outward, which can create a hazardous environment. This phenomenon occurs because the external atmospheric pressure is suddenly lower than that inside the aircraft, leading to a rapid rush of air and any nearby particles being expelled.

Understanding the implications of rapid decompression is crucial for pilots, as it can significantly affect visibility and lead to potential injuries due to the impact of debris or the force of the wind. Recognizing the signs of rapid decompression, such as windblast, allows aircrew to react accordingly to maintain safety. The other choices, while potentially related to cabin altitude changes or other in-flight issues, do not specifically capture the immediate physical sign that one would experience during a rapid decompression incident.