What is the purpose of door safety straps on cabin doors?

The purpose of door safety straps on cabin doors is primarily to warn individuals when the jet bridge or air stairs are not properly positioned. These safety straps act as a visual and physical notification that the door should not be opened, helping to prevent accidents that can occur if the door is opened while the aircraft is still connected to the terminal equipment. This is critical for ensuring the safety of both passengers and crew during boarding and deplaning.

While securing the door closed is important for aircraft safety, this particular function is typically managed by other mechanisms. Assisting with cabin door openings is not the primary role of safety straps, as these are safety features designed to indicate the status of the boarding equipment rather than assisting in the operation of the door itself. Additionally, preventing unauthorized access to the flight deck is achieved through other security measures, and safety straps do not serve this specific purpose.

Thus, the emphasis on communication regarding the proper position of boarding equipment makes option B the correct answer.