Aviation safety investigations & reports

Runway excursion involving Boeing 737, VH-VUI, at Darwin Airport, Northern Territory, on 6 December 2016

Investigation number:
AO-2016-166
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

On 6 December 2016, with thunderstorm activity in the area, a Boeing 737-800 aircraft operated by Virgin Australia on a scheduled passenger flight from Melbourne, Victoria was on approach to runway 29 at Darwin Airport, Northern Territory. The flight crew established and maintained clear visual reference to the runway and surrounds until they encountered heavy rain shortly before reaching the runway threshold. Under the influence of a light but increasing crosswind, the aircraft drifted right without the flight crew being able to discern the extent of the drift.

The aircraft landed 21 m to the right of the runway centreline and, shortly after touchdown, the right landing gear departed the sealed surface of the runway, destroying six runway lights before the aircraft returned to the runway. The aircraft incurred minor damage from ground debris and there were no injuries.

What the ATSB found

A relatively small increase in crosswind resulted in a significant deviation from the runway centreline at a critical time during final approach. The absence of adequate visual cues influenced the flight crew’s ability to detect and correct the deviation.

International guidelines recommend, but do not mandate, the use of centreline lighting on wider runways. In recent years, two runway veer-offs have occurred at runway 29 at Darwin, which is the only runway in Australia that is wider than 50 m and not equipped with centreline lighting. No similar occurrence has happened at any other of the busier airports in Australia, where the runways are either narrower, or are a similar width but with centreline lighting.

A study of relevant occurrences world-wide found that the likelihood of a runway veer-off on landing increases significantly when using a runway that is wider than 50 m and does not have centreline lighting. This is likely due to limitations in the visual cues available in such circumstances.

There was no advisory information about this hazard in the operator’s manuals or in the aerodrome information provided to operators by Darwin Airport.

The ATSB also found limitations in the weather information provided to the flight crew while on approach to land.

What's been done as a result

The aircraft operator and airport operator initiated a number of safety actions as a result of the occurrence, including providing flight crews with information about the specific risks of approaches to Darwin Airport at night in conditions with reduced visibility.

The ATSB has issued a safety recommendation to the International Civil Aviation Organization and Darwin Airport to consider measures to reduce the safety risk identified in this report relating to wide runways without centreline lighting.

Safety message

Approaches in darkness and poor weather can be challenging. Centreline lighting greatly assists flight crews align the aircraft with the runway but many runways, including most in Australia, are not equipped with it. A wide runway without centreline lighting, such as that in Darwin, poses a particular challenge. Pilots and operators who are aware of any circumstances that are different to what is usually encountered and account for it in their planning are more likely to avoid being ‘caught out’ at a critical time.

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[Download  PDF: 1.85MB]
 
 
 

The occurrence

Context

Safety analysis

Findings

Safety issues and actions

Sources and submissions

Appendices

Safety Issues

Go to AO-2016-166-SI-01 - Go to AO-2016-166-SI-02 - Go to AO-2016-166-SI-03 - Go to AO-2016-166-SI-04 -

Standards for installation of runway centreline lighting on wider runways

Category I runways that are wider than 50 m and without centreline lighting are over-represented in veer-off occurrences involving transport category aircraft landing in low visibility conditions. The installation of centreline lighting on wider category I runways is recommended but not mandated by the International Civil Aviation Organization Annex 14.

Safety issue details
Issue number: AO-2016-166-SI-01
Who it affects: Operators using runways wider than 50 m without centreline lighting
Status: Safety action pending

Limited visual cues for approach at Darwin runway 11/29

The absence of centreline lighting and the 60-m width of runway 11/29 at Darwin result in very limited visual cues for maintaining runway alignment during night landings in reduced visibility.

Safety issue details
Issue number: AO-2016-166-SI-02
Who it affects: Pilots operating into Darwin airport
Status: Safety action pending

Operator guidance to flight crews

Virgin Australia did not have formal guidance for flight crews regarding the limited visual cues for maintaining alignment to runway 11/29 at Darwin during night landings in reduced visibility.

Safety issue details
Issue number: AO-2016-166-SI-03
Who it affects: Virgin Australia Airlines flight crews operating into Darwin airport
Status: Adequately addressed

En route supplement guidance to flight crews

The En Route Supplement Australia (ERSA) did not have formal guidance for flight crews regarding the limited visual cues for maintaining alignment to runway 11/29 at Darwin during night landings in reduced visibility.

Safety issue details
Issue number: AO-2016-166-SI-04
Who it affects: Pilots operating into Darwin airport
Status: Adequately addressed
General details
Date: 06 December 2016   Investigation status: Completed  
Time: 2303 CDT   Investigation level: Complex - click for an explanation of investigation levels  
Location   (show map): Darwin Airport   Investigation phase: Final report: Dissemination  
State: Northern Territory   Occurrence type: Runway excursion  
Release date: 15 May 2019   Occurrence category: Serious Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer The Boeing Company  
Aircraft model 737-800  
Aircraft registration VH-VUI  
Serial number 34441  
Operator Virgin Australia Airlines  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Minor  
Departure point Melbourne, Vic.  
Destination Darwin, NT  
Last update 15 May 2019