During the post-flight inspection of a Saab 340B passenger aircraft, the number-two outboard main landing gear wheel was observed to have sustained noticeable damage. The flight crew reported that there was no prior indication of the failure, as the aircraft had handled normally during the landing and taxiing phase of the flight.
Subsequent examination found that the wheel inner rim had fractured away from the hub for approximately one-half of the total circumference. A circumferential fatigue crack had initiated at a location at the bead seat radius, and had propagated until a final ductile overload failure caused a section of the wheel rim to separate.
During the course of the investigation, it was found that the particular wheel design was being phased out due to recognised fatigue problems identified at the bead seat area.
Both the manufacturer and operator were aware of the increased fatigue susceptibility of the earlier wheel design, and had established increased inspection regimes for those wheels remaining in service.
|Date:||06 February 2009||Investigation status:||Completed|
|Time:||1435 ESuT||Investigation level:||Complex - click for an explanation of investigation levels|
|State:||New South Wales||Occurrence type:||Landing gear/indication|
|Release date:||17 February 2010||Occurrence category:||Incident|
|Report status:||Final||Highest injury level:||None|
|Aircraft manufacturer||S.A.A.B. Aircraft Co|
|Type of operation||Air Transport Low Capacity|
|Damage to aircraft||Minor|
|Departure point||Orange, NSW|