Where applicable, helicopters shall be equipped with seats for cabin crew members, which seats shall be forward or rearward facing within 15° of the longitudinal axis of the helicopter and located near floor-level emergency exits, where possible. Each cabin crew member required to satisfy the emergency evacuation criteria shall be provided a seat equipped with a safety harness: Provided that a safety belt with one diagonal shoulder strap is permitted if the fitting of a safety harness is not reasonably practical.