Kintyred. Legal limits on duty and flying hours are stipulated by EU regs, 900hrs a year and 100hrs a month (there are other limits). Local agreements may limit these to lower values. So if you are paid a salary for flying 900 hrs a year but only rostered for 500 hrs, the company is not getting full value from its contract with you. I flew with a holiday charter, where high monthly hours were achieved over the summer but winter work was pretty sparse so no more than 600 hrs was usual for us. With someone like BA/Virgin, who have more constant work across the year, 900/700 is achievable and therefore their pilots Achieve high productivity.