This Special Bulletin contains information on the progress of the investigation into identifying the cause of the 360º circumferential crack in the bevel gear vertical shaft on G-CHCN (AAIB Special Bulletin S6/2012). It also compares the findings with those recorded previously on another EC225 LP accident involving a similar failure on G-REDW on 10 May 2012 (AAIB Special Bulletin S3/2012) and provides a further update on the investigation into both accidents.

The Chief Inspector of Air Accidents has ordered that the investigations into the accident to G-REDW on 10 May 2012 and to G-CHCN on 22 October 2012 be combined, and to publish an Inspector’s Investigation Report.