jollyrog gives good advice about not trying again until you are really ready.
Get your instructor to help you to understand where you went wrong.
As well as the subject content think carefully about your exam strategy. Read all the questions first. Answer the ones you know. Answer all the questions (even the ones you haven't a clue about - you may guess right and the pass mark is set assuming you will do this).
Incidentally when you say you got 70%, what do you mean exactly? In UK CAA PPL airlaw exams 70% is a pass (just, but it is a pass). So I'm a bit confused by that bit of your post.
Last edited by Heston; 13th Apr 2013 at 09:07.