1974.......on base to rwy 17right , Moorabin, SI yells 'MY AIRCRAFT' , proceeds to aim straight at Princess of Tasmania on the near horizon ( Pt Phillip Bay), suddenly making ack, ack ,ack sounds , released about 1000 rounds in about 10 seconds, and then 'Your Aircraft' ............OK , turn final and plant a greaser , thankyou ! ( no headsets in those days , either)