What must crew members do before acting upon a mandatory directive?

Crew members must each have a written copy of the mandatory directive and confirm their understanding before taking any action. This requirement ensures that all crew members are fully aware of the directive's details and the implications it has for their operations. Having a written copy helps to prevent miscommunication and ensures that everyone is on the same page regarding the instructions received.

The confirmation of understanding is also vital as it provides an opportunity for any questions or clarifications to be addressed before proceeding. This procedure enhances safety and operational integrity, as crew members can then act confidently based on a shared comprehension of the directive. Additionally, it is a standard practice in rail operations to have documentation readily available, ensuring that crew members can reference the specific details necessary for safe train handling.