Aviation safety investigations & reports

Boeing Co 737-800, VH-VOA

Investigation number:
Status: Completed
Investigation completed


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.


The separation standard would not have been infringed if the crew of the B737 had complied with the 5,000 ft altitude requirement. At the time of the infringement, the B737 was being manually flown by the pilot in command who was distracted from his primary task of controlling the aircraft's flight path. The distraction occurred as he monitored the weather radar and assessed the meteorological conditions that the aircraft was encountering during the climb. The engagement of an autopilot would have reduced the pilot in command's workload and enabled him to monitor the weather situation while the auto-flight system levelled the aircraft at the assigned altitude. Crew coordination did not provide a defence against human error in this occurrence, as the co-pilot did not monitor the aircraft's flight path as it approached the assigned altitude.

Safety Action

Local Safety Action

As a result of this occurrence, the operator advised that the standard operating procedures detailed in the 737 Flight Crew Training Manual were amended to include:

"Altitude Restriction

Whenever there is a low level altitude restriction after takeoff, the autopilot will be engaged as soon as practical".

General details
Date: 20 February 2002   Investigation status: Completed  
Time: 0728 hours ESuT    
Location   (show map): 22 km E Sydney, Aero.    
State: New South Wales   Occurrence type: Loss of separation  
Release date: 21 October 2002   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer The Boeing Company  
Aircraft model 737  
Aircraft registration VH-VOA  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Sydney, NSW  
Departure time 0724 hours ESuT  
Destination Melbourne, VIC  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command ATPL 1158 17453

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer The Boeing Company  
Aircraft model 767  
Aircraft registration VH-OGP  
Serial number 28153  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Auckland, New Zealand  
Destination Sydney, NSW  
Last update 13 May 2014