Our defence aircraft could soon be playing cat-and-mouse with submarines following a multibillion-dollar investment. 

The Governments putting $2.7 billion towards two new Airbus A321 planes to replace older planes. 

Five Seahawk helicopters are also being bought, equipped with anti-submarine torpedo systems.  

Retired Lieutenant Colonel and defence expert Josh Wineera told Ryan Bridge the helicopters will bring military combat to the next level. 

He says they're essentially a submarine-hunting aircraft, but can also carry out other tasks. 

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