Aviation safety issues and actions

Expert review of statistical analysis in support of retrospective concessions

Issue number: AO-2010-089-SI-08
Who it affects: Engine manufacturer Rolls-Royce plc
Issue owner: Rolls-Royce
Transport function: Aviation: Air transport
Background: Investigation Report AO-2010-089
Issue release date: 27 June 2013
Current issue status: Adequately addressed

Safety issue description

The engine manufacturer did not have a requirement for an expert review of statistical analyses used in retrospective concession applications.

Proactive Action

Action number: AO-2010-089-NSA-044
Action organisation: Rolls-Royce
Date: 25 May 2011
Action status: Closed

On the 25 May 2011, Rolls-Royce advised the ATSB that a major corrective action, which arose from an internal major quality investigation, was to remove the existing retrospective concession procedures from their quality system, and replace them with a new Global Process titled Management of Undeclared Non-Conformance in Delivered Product.

The global process was developed to ensure an improved and more consistent approach across the company when it is identified that parts containing undeclared and non-conforming features have been released to the customer for entry into service. The global process included a technical review by a statistic expert.

The global process was incorporated into the engine manufacturer’s quality management system on 4 July 2011.

ATSB comment:

The ATSB is satisfied that the action taken by Rolls-Royce adequately addresses this safety issue and therefore makes no recommendation.

Last update 08 January 2014