Aviation safety investigations & reports

Boeing Co 747-338, VH-EBX

Investigation number:
Status: Completed
Investigation completed


The crew of a Boeing 747 (B747), maintaining flight level (FL) 390, en route from Cairns to Nagoya, was contacted by the crew of a Boeing 767 (B767), en route from Auckland to Osaka. The B767 crew reported that they had been approved by air traffic control to climb from FL370 to FL390, and that their position was 44 NM south-east of ASEDA, which is located within the Tokyo oceanic control area. The B747 crew reported that they were 54 NM south-east of ASEDA at FL390. Subsequently, the B767 crew advised that they would limit their climb to FL385. Shortly after that exchange the sector controller instructed the crew of the B767 to descend to FL370 due to traffic.

An investigation found that the sector controller was managing five aircraft tracking north on air route A597, together with an aircraft crossing A597. The controller was concerned that the longitudinal separation between the B767 and another following aircraft at FL370 would reduce to less than the required standard, which was either 2,000 ft vertically or 15 minutes longitudinally. Consequently, the controller instructed the B767 crew to climb, but failed to appreciate that the B767 would conflict with the B747 at FL390. However, the controller subsequently recognised that an error had been made and issued alternative instructions.

General details
Date: 24 August 1998   Investigation status: Completed  
Time: 0756 hours UTC    
Location   (show map): 100 km SSE Aseda, (IFR)    
State: International   Occurrence type: Loss of separation  
Release date: 04 May 1999   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer The Boeing Company  
Aircraft model 747  
Aircraft registration VH-EBX  
Serial number 23688  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Cairns, QLD  
Destination Nagoya, JAPAN  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer Boeing  
Aircraft model 767  
Damage to aircraft Nil  
Departure point Auckland, NEW ZEALAND  
Destination Osaka, JAPAN  
Last update 13 May 2014