Recommendation: 2011-004

Basis for Recommendation

The hazard log was found to be ineffective in addressing the hazards relating to the over-inflation of the secondary suspension. The hazard log addresses the over-inflation of the secondary suspension due to failure of a single levelling valve and provides operational and maintenance controls to mitigate the hazard. These controls were found to be ineffective as the operational control was not in place and the maintenance control relied on robust maintenance controls that were not in place. Therefore the RAIU make the following safety recommendation:

Recommendation

IÉ should review its process of managing the hazard log in relation to the Class 29000s to ensure the adequacy of this process and verify that implementation of closure arguments in the hazard log is effective.