We Stopped at Palm Cove which was just up the road from trinity beach where you are stopping, and for the 5 nights we were there didnt hear a plane at all,i dont think you have anything to worry about,about plane noise its a lovely part of the world there. i dont think cairns airport is all that busy only got 1 runway so if you do hear the odd plane nothing to worry about wont spoil your holiday in a beautiful part of the world....
Not sure if your driving or not.....but theres a number 2 bus which takes you from trinity beach to the centre of cairns if you dont want to drive....have a wonderful time...
Just been reading reviews on Coral Sands on another Review site,nobody mentions plane noises,so i think nothing to worry about.