Aviation safety investigations & reports

Fairchild Industries Inc SA227-AC, VH-IAW

Investigation number:
200001657
Status: Completed
Investigation completed

Summary

The crew of the Fairchild Metroliner was conducting endorsement training in the Cowra area when they advised air traffic services (ATS) that their aircraft had a hydraulic failure and they were returning to Bankstown. An uncertainty phase was declared by ATS and the aircraft returned to Bankstown where a flapless landing was carried out.

The subsequent maintenance inspection found a cracked hydraulic pipe in the left landing gear wheel-well that had allowed the loss of the hydraulic oil contents from the power pack. The crack was in the bend radius of the pipe and was not visible to the naked eye. The crack only became apparent with the application of more than 800 psi of hydraulic pressure to the system during the maintenance inspection. The pipe was changed and the aircraft returned to service.

The pilot in command reported that he had experienced two similar hydraulic pipe failures in this aircraft type and the company fleet had five or six similar failures in the preceding twelve months. He also reported that he had a concern that the escaping oil in this situation could have started a wheel-well fire.

The design of the hydraulic system is such that, when a failure occurs in one of these hydraulic pipes, there is no redundancy. As a result, the leak drains the contents from the hydraulic reservoir, which is the common source of hydraulic fluid for both the left and right engine-driven hydraulic pumps. Without hydraulic services, nosewheel steering, anti-skid braking, flap operation and normal landing gear retraction and extension would not be available to the pilot.

Safety Action

As a result of the investigation into this and related occurrences, the Australian Transport Safety Bureau is currently investigating a safety deficiency involving the Fairchild SA-226/SA-227 type of aircraft that relates to replacement of certain hydraulic piping and ongoing inspection procedures for the hydraulic piping.

Any safety output issued, as a result of this analysis will be published in the Bureau's Quarterly Safety Deficiency Report.

General details
Date: 10 May 2000   Investigation status: Completed  
Time: 1623 hours EST    
Location   (show map): 1 km S Cowra    
State: New South Wales   Occurrence type: Hydraulic  
Release date: 02 April 2000   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Fairchild Industries Inc  
Aircraft model SA227  
Aircraft registration VH-IAW  
Serial number AC-600  
Type of operation Air Transport Low Capacity  
Damage to aircraft Nil  
Departure point Cowra, NSW  
Destination Cowra, NSW  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command ATPL 300.0 4000
Last update 13 May 2014