What role does an Additional Crew Member (ACM) serve on an aircraft?

An Additional Crew Member (ACM) primarily serves as a supplementary flight attendant on an aircraft. This role involves assisting the flight crew in providing safety, service, and support to passengers during a flight. The ACM helps with various responsibilities such as conducting safety demonstrations, managing cabin service, and ensuring that all safety protocols are followed. This additional crew member acts to enhance passenger experience and safety, especially on longer flights where having extra personnel can improve efficiency and help manage onboard situations more effectively.

Other roles listed, like a backup pilot, maintenance technician, or air traffic controller, do not align with the responsibilities of an ACM. A backup pilot would be an additional pilot who takes on flight-related duties, a maintenance technician is responsible for aircraft upkeep rather than in-flight service, and an air traffic controller works on the ground, managing air traffic rather than being part of the in-cabin staff.