The FAA and EASA recently issued emergency airworthiness directives (EAD) for Eurocopter’s popular twin-engine helicopter – the EC 135. There are some differences between FAA’s EAD 2012-10-51 and EASA’s AD 2012-0085-E, but both were implemented because cracks have been found in the hub-shaft flange of a main rotor hub. These cracks could result in the failure of the main rotor hub, which subsequently would make the helicopter uncontrollable.
The emergency ADs resulted from a previous AD issued by EASA in March, which required inspection of the same area. Since that AD, two additional cases of cracks were found, causing the agencies to issue the recent EADs.
