Boeing Co 737-800, VH-VOA

The Boeing B737-800 (B737) was cleared to Melbourne via the
Sydney RWY 34R MARUB THREE standard instrument departure (SID) to
5,000 ft. The Boeing B767-338ER (B767) was inbound to Sydney from
Auckland, NZ, and had been cleared to descend to 6,000 ft with a
vector to a right downwind leg for RWY 34R. As the aircraft
approached each other 12 NM east of Sydney, an infringement of the
radar separation standard occurred.

The pilot in command of the B737 was the handling pilot for the
sector and was manually flying the aircraft while tracking via the
SID. He had recently completed retraining on the aircraft after
having not flown the type for 10 years.

After take-off, the B737 entered cloud and encountered
turbulence as it climbed through 3,500 ft. The pilot in command was
monitoring the aircraft's weather radar and stated that he became
distracted while assessing the meteorological conditions. Although
the co-pilot gave the 1,000 ft to assigned altitude call at 4,000
ft, he was also observing the weather situation and did not monitor
the flight instruments as the aircraft approached the assigned
altitude. The B737 continued to climb above 5,000 ft and reached
5,700 ft before the pilot in command descended the aircraft back to
the assigned level. During the descent the aircraft's traffic alert
and collision avoidance system issued a Traffic Alert.

The departure controller issued a turn instruction to the crew
of the B737 for avoidance action and an evasive turn instruction to
the crew of the B767, in addition to providing traffic information
on the B737. Recorded radar data indicated that lateral separation
between the aircraft reduced to 2.8 NM with a vertical separation
of 900 ft. The required radar separation standard was 3 NM
laterally or 1,000 ft vertically.