Aviation safety investigations & reports

Loss of separation involving Boeing 777, N2333U and ATR 72, VH-FVQ, near Sydney Airport, New South Wales, on 22 January 2020

Investigation number:
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

Download final report
[Download  PDF: 522KB]

What happened

On 22 January 2020, a Boeing 777 was being operated by United Airlines as regular public transport flight UA870 from Sydney, Australia to San Francisco, United States.

At about the same time, a GIE Avions de Transport Régional ATR 72 was being operated by Virgin Australia as regular public transport flight VOZ1153 from Sydney to Tamworth, New South Wales.

Sydney Airport was configured for parallel runway operations, including simultaneous independent departures. VOZ1153 departed from runway 34R, to an assigned heading of 350º, just prior to UA870 departing from runway 34L. UA870 was required to maintain runway heading (335º) until reaching 1,500 ft, at which point the aircraft was cleared to turn left and track towards Richmond, northwest of Sydney. However, UA870 climbed straight ahead through to about 2,100 ft and then the aircraft turned to the right about 45º from the required heading, resulting in a loss of separation with VOZ1153. At their closest point of approach, the two aircraft were separated by 1,843 m (about 1.0 NM) laterally and 60 m (about 200 ft) vertically.

Air traffic control detected the loss of separation and issued interventional instructions to both aircraft. The required separation was re-established and both flights continued without further incident.

What the ATSB found

The ATSB found that the UA870 pilot flying was expecting a more simplistic procedure often provided to foreign crew departing Sydney for an oceanic route. The pilot flying then became confused regarding aspects of the flight management computer (FMC) coding generated to represent the actual departure clearance provided. This may have been due to an unfamiliarity with radar transitions from a standard instrument departure to an en route track. This led the pilot flying to incorrectly adjust the FMC prior to engine start, and resulted in the aircraft turning right after departure, bringing it into conflict with VOZ1153.

The pilot flying probably did not effectively communicate the changes made to the FMC to the crew. The FMC departure specific coding was also not effectively cross-checked by the pilot monitoring or relief pilots prior to take-off.

Safety message

The ATSB’s SafetyWatch program highlights broad safety concerns that come out of ATSB investigation findings and from the occurrence data reports by industry. One of these safety concerns is data input errors.

This occurrence illustrates the importance of procedural correctness, effective communication and crew coordination towards the conduct of safe flight operations. Any amendment to the flight management computer, particularly those applicable to the more critical phases of flight (departure and arrival procedures) should always be announced, and then carefully and independently verified by at least one other crew member. The incident also outlines that when possible, air traffic controllers can potentially further assist foreign crew by proactively factoring the crew’s unfamiliarity when providing airways clearances.

Download final report
[Download  PDF: 522KB]

The investigation

Crew details

General details
Date: 22 January 2020   Investigation status: Completed  
Time: 1425 AEDT   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): 2 km north Sydney Airport   Investigation phase: Final report: Dissemination  
State: New South Wales   Occurrence type: Loss of separation  
Release date: 28 July 2020   Occurrence category: Serious Incident  
Report status: Final   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer The Boeing Company  
Aircraft model 777-322ER  
Aircraft registration N2333U  
Serial number 62644 LN:1466  
Operator United Airlines  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Nil  
Departure point Sydney, New South Wales  
Destination San Francisco, United States  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer ATR-GIE Avions de Transport Régional  
Aircraft model ATR72-212A  
Aircraft registration VH-FVQ  
Serial number 1053  
Operator Virgin Australia Airlines  
Type of operation Air Transport High Capacity  
Sector Turboprop  
Damage to aircraft Nil  
Departure point Sydney, New South Wales  
Destination Tamworth, New South Wales  
Last update 25 September 2020