Background
The aircraft operator was contracted to provide regular transport of bank documents, medical pathology samples, and general freight between Wagga Wagga, Albury, and Corowa. On the day of the accident, a passenger accompanied the pilot for the day's flying.
Flight Details
The pilot commenced the flight from Corowa to Albury under Visual Flight Rules at about 500 ft above ground level. At Albury, he obtained the latest aerodrome weather report for Wagga Wagga, which indicated scattered cloud at 300 ft, broken cloud at 600 ft, visibility of 2,000 m in light rain, and a QNH of 1008 hPa. At 1715 Eastern Standard Time (EST), the aircraft departed Albury for Wagga Wagga under Instrument Flight Rules. The pilot contacted the Melbourne en-route controller at 1728, reporting he was maintaining 5,000 ft. The controller provided a flight information service with radar surveillance, but no transponder return was recorded. At 1732, the pilot reported transferring to the Wagga Wagga Mandatory Broadcast Zone (MBZ) frequency, which was his last contact with the controller. Transmissions on the MBZ frequency are recorded by AVDATA for landing charge calculations; this data was reviewed after the accident.
Accident Sequence
The pilot broadcast inbound on the MBZ frequency, indicating a GPS arrival. He communicated with another inbound aircraft and, at 9 NM from the aerodrome, broadcast his position descending through 2,900 ft. About 1 minute and 20 seconds later, he advised passing 2,000 ft but immediately corrected to state he was maintaining 2,000 ft. He added that it was "getting pretty gloomy" and that, according to the latest weather report, he should be visual at the procedure's minimum descent altitude. The aircraft was approximately 6 NM from the aerodrome at that time. This was the last transmission heard.
A resident south of Gregadoo Hill sighted the aircraft shortly before the accident. He observed the aircraft passing overhead at an unusually low height, then disappearing into cloud obscuring the hill, about 350 m from his position. Moments later, he heard an impact followed by a red flash. Engine noise seemed normal until impact. The aircraft collided with steeply rising terrain on the southern face of Gregadoo Hill, about 40 ft below the crest. The hill, 4 NM from the aerodrome, is marked on instrument approach charts as a spot height of 1,281 ft. The estimated accident time was 1739. The pilot and passenger sustained fatal injuries.
Post-Accident Analysis
The pilot had received an accurate appreciation of weather conditions near Wagga Wagga before departing Albury, indicating low cloud and poor visibility likely to affect arrival. The reported cloud base and visibility were below minimum criteria for the GPS procedure. The pilot's transmission about being visual at the minimum descent altitude suggested he had decided to continue below the minimum altitude to establish visual reference. Based on reports of broken low cloud near the aerodrome, the pilot would have needed to descend to 1,324 ft AMSL to be clear of cloud, within 50 ft of the last GPS-recorded altitude. Due to a difference between actual and forecast QNH, the left altimeter would have over-read by about 150 ft, showing approximately 1,400 ft. The right altimeter, set to the local QNH before departure, would have been more accurate but was likely not included in the pilot's instrument scan due to its co-pilot panel location. It was not possible to assess the extent to which illicit drugs may have influenced the pilot's performance.