Aviation safety investigations & reports

Main landing gear wheel failure during taxi involving Boeing 737, VH-VUH, at Brisbane Airport, Queensland, on 4 January 2017

Investigation number:
AO-2017-003
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

Download final report
[Download  PDF: 630KB]
 

What happened

On 4 January 2017, a Boeing 737-8FE, registered VH-VUH (VUH) and operated by Virgin Australia Airlines Pty Ltd (Virgin) was holding on B3 taxiway at Brisbane Airport, Queensland, when the crew heard a loud noise from what they thought was a burst tyre on the left main landing gear wheel. The crew attempted to return the aircraft to the gate, but were held short of the gate when an attending engineer observed that the number one main wheel assembly (left hand outboard wheel) had failed.

What the ATSB found

The ATSB found that the number one main wheel ruptured due to tie bolt assemblies that had loosened while in service. This allowed the two wheel halves to move relative to each other, resulting in a fatigue crack and eventual wheel rupture. The loosening was most likely due to the presence of anti-seize compound between the wheel halves, which affected the clamping forces.

The ATSB also found that while tie bolt assemblies on this wheel-type (single-web) were more prone to in-service loosening than dual-web wheels, there were no mandated inspections suitable for detecting such loosening. There were also no mandated risk controls to prevent loosening or subsequent rupture.

What's been done as a result

Virgin advised that following this occurrence, regular inspections were implemented to identify and prevent the loosening of tie bolt assemblies.

The wheel manufacturer updated the wheel’s component maintenance manual with more detailed instructions for applying anti-seize compound.

Boeing has advised the 737 NG fleet of the issue and suggested two possible courses of action. These were based on two optional service bulletins that the manufacturer had in place prior to the occurrence:

  • incorporation of a new inner half-wheel that allows for safe deflation if tie bolt assemblies loosen (Service Bulletin C20626-32-014)
  • the addition of lockwire to the tie bolt nuts, to prevent loosening in the first place (Service Bulletin C20626-32-016).

Safety Message

This incident highlights the importance of compliance with all aspects of manufacturers’ maintenance procedures, including the appropriate application of anti‑seize. This is especially important if, as in this case, there is no simple means of detecting the effect that such excess product can have on fastener security.

Download final report
[Download  PDF: 630KB]
 
 
 

The occurrence

Context

Safety analysis

Findings

Sources and submissions

General details
Date: 04 January 2017   Investigation status: Completed  
Time: 1710 AEST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): Brisbane Airport   Investigation phase: Final report: Dissemination  
State: Queensland   Occurrence type: Landing gear/indication  
Release date: 30 March 2020   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer The Boeing Company  
Aircraft model 737-8FE  
Aircraft registration VH-VUH  
Serial number 34440  
Operator Virgin Australia Airlines  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Minor  
Departure point Brisbane, Queensland  
Destination Melbourne, Victoria  
Last update 30 March 2020