Operational non-compliance involving a Airbus A320-211, VH-HYF, Melbourne, Aerodrome, VIC on 15 September 1997

The aircraft was departing from runway 16 and had been cleared via a RADAR THREE DEPARTURE CRENA to Perth, with an assigned heading of 290. This procedure requires the aircraft to turn after passing 4 DME. VH-HYF was observed on radar to commence a right turn at about 2 DME. The crew reported that the correct procedure had been briefed. As the aircraft passed 3 DME, the non-flying pilot was occupied on the radio and the flying pilot commenced the turn without checking the departure chart. The non-flying pilot noticed the error when he had completed the radio communications and advised the flying pilot.