Centaurus, well done for bringing the EMAS issue to the attention of Australian airport authorities. One way of making sure they take your letter seriously is to prominently add cc's to eg the minister, leader of opposition, and press. This will make you unpopular, but as someone who takes a principled stand you know that life isn't a popularity competition. The other way of making our lazy bureaucrats do their job, as you're also doubtless aware, is to emphasize THEIR risk. Make them believe that the status quo puts them at risk.