Oliver Minchin, the son of Liberal senator Nick Minchin, was hit by the propeller of a boat while training at Lake Burrinjuck in NSW in February 2010.
Now the workplace safety regulator is taking legal action against the academy.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Comcare will argue that the Australian Defence Force contravened federal workplace safety laws by failing to take all reasonably practicable steps to protect the health and safety of its officer cadets," Comcare said in a statement on Monday.
Comcare's Neil Quarmby says the accident "could have been avoided".
"In Comcare's view, basic measures should have been taken, including the installation of a propeller guard and carrying out a better risk assessment of this activity".
The Federal Court is yet to set a date for the case to be heard.
The case joins a long list of legal problems facing the academy in the wake of the Skype scandal in which a first-year cadet was allegedly secretly watched while having sex.
