Summary
The pilot of a SAAB 340 aircraft which had been cruising at flight level 170, had been assigned flight level 130 for descent into Coffs Harbour, and was told to expect further descent at 45 miles. The aircraft was later observed on radar, 45 miles south of Coffs Harbour descending through flight level 127. Attempts were made to contact the pilot but there was no reply. After liaising with Coffs Harbour tower, the sector controller was informed that the pilot had reported on descent to flight level 110. The pilot had not been authorised for further descent nor had he received a frequency change instruction. There was no breakdown in separation.
