licence requirement
This is a revenue flight on B777 and it is an 6 hours flight leg into the night. There are a captain and 2 flight officers. One flight officer carries a CPL licence with about 100 hours on type and total 600 hours. The other one CPL with 400 hours on type and total 900 hour. Both without ATPL. Can the captain take a rest outside cockpit? Is there any rule and regulation regarding active crew on duty?