Aviation safety investigations & reports

Armstrong Whitworth Aircraft AW650-322 Argosy, VH-IPA, Melbourne Airport VIC, 3 May 1989

Investigation number:
Status: Completed
Investigation completed


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While taxiing after a normal landing, a rumbling noise was heard from the vicinity of the nosegear, the hydraulic low pressure light illuminated and nosegear steering authority was lost. The right hand nosewheel had separated from the aircraft due to fracturing of the axle. As the nosewheel departed it damaged the nosegear uplock assembly with consequent loss of hydraulic system integrity. It then continued under the fuselage causing skin damage. The nosewheel axle was recovered and subjected to metallurgical examination which showed that the fracture was due to fatigue. The fracture resulted from prior long term fatigue cracking which occupied approximately 75 of the cross sectional area of the axle. Stress corrosion cracks were present which were the most likely initiator of the fatigue cracks. A mandatory crack inspection requirement called up for this axle did not cover the specific area in which the stress corrosion was located. Consequently, during the axle refurbishment, the stress corrosion cracks were covered by a layer of electroplated chromium. Upon advice of the failure mode by the Bureau, the operator carried out an inspection of all inservice and spare axles, to remove any axles with stress corrosion under the electroplated chromium.

Download Final Report
[Download  PDF: 23KB]
General details
Date: 03 May 1989   Investigation status: Completed  
Time: 235    
Location: Melbourne Airport    
State: Victoria    
Release date: 16 February 1990   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Armstrong Whitworth Aircraft  
Aircraft model AW.650  
Aircraft registration VH-IPA  
Serial number 6803  
Type of operation Air Transport High Capacity  
Damage to aircraft Substantial  
Departure point Sydney NSW  
Departure time 0015  
Destination Melbourne Airport VIC  
Last update 21 March 2016