The aircraft operating Ansett-ANA Flight 325 during the accident was a Vickers Viscount 720. This information is consistent across multiple sources, including a Facebook post from Airline Secrets Exposed, an article from Wikipedia on Ansett-ANA Flight 149, and an article from the Sydney Morning Herald. The Vickers Viscount 720 crashed into Botany Bay shortly after takeoff from Sydney on the evening of November 30, 1961.