Recommendation Date
Recipient Name
CAA
Text
The requirement for duplicate inspections after maintenance is performed on critical aircraft systems reduces the risk of a maintenance error remaining undetected and causing an accident. However, there are only a few specified control systems that are deemed critical and that require duplicate inspections. There are other important systems – for example, the landing gear and brakes – that are not subjected to the same level of scrutiny. This is a safety issue, particularly for aircraft used in air transport operations where the consequences of an accident could be greater.
The findings from 2 separate inquiries show that because duplicate inspections are currently confined to critical control systems only, the risk of undetected maintenance errors in important, but non-critical, aircraft systems is not sufficiently mitigated. This accident was a prime example of how maintenance errors that are made in an important system and that are not detected then or during subsequent maintenance can become causal factors in an accident. The risks were higher in this case because the relevant maintenance events had been performed by independent engineers on parts of an aeroplane sub-system that were not subject to duplicate inspections.
On 25 July 2013 the Commission recommended to the Director of Civil Aviation that he widen the range of aircraft systems that require duplicate checks after specified maintenance, at least for those aircraft used in air transport operations, in order to reduce the likelihood of recurring defects and incidents.
The findings from 2 separate inquiries show that because duplicate inspections are currently confined to critical control systems only, the risk of undetected maintenance errors in important, but non-critical, aircraft systems is not sufficiently mitigated. This accident was a prime example of how maintenance errors that are made in an important system and that are not detected then or during subsequent maintenance can become causal factors in an accident. The risks were higher in this case because the relevant maintenance events had been performed by independent engineers on parts of an aeroplane sub-system that were not subject to duplicate inspections.
On 25 July 2013 the Commission recommended to the Director of Civil Aviation that he widen the range of aircraft systems that require duplicate checks after specified maintenance, at least for those aircraft used in air transport operations, in order to reduce the likelihood of recurring defects and incidents.
Reply Text
The CAA considers that widening the scope of aircraft systems requiring duplicate inspections [is] not sufficiently supported by the Commission's investigation. In this regard, the CAA prefers to remain in keeping with current world regulatory practice and therefore will not implement the recommendation.
Related Investigation(s)