On 17 January , Lerew was able to gain sufficient height in his Wirraway to confront a Japanese seaplane in a head - on attack .
Lerew 's . 303 machine - gun ammunition was not sufficient to bring it down .
On 17 January , Lerew was able to gain sufficient height in his Wirraway to confront a Japanese seaplane in a head - on attack , but his . 303 machine - gun ammunition was not sufficient to bring it down .