The aviation exercise will begin on Sunday and end on Friday, the army has warned.
Activity will take place between 9am and midnight around the island, home to specialised air defence units from 12 Regiment and 16 Regiment, Royal Artillery.
Up to eight helicopters, including Chinook, Merlin and Wildcat will be operating during the training event.
An army spokeswoman added: ‘Aircraft routing in and out of Thorney Island has been planned to minimise disruption as far as possible and the continued support of the local community is very much appreciated during this essential training.’
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