EC135 M/R hub crack
 

EMERGENCY
FAA AIRWORTHINESS DIRECTIVE
Aviation Safety
DATE: May 18, 2012
Aircraft Safety Alerts
AD #:
2012-10-53
This emergency airworthiness directive (EAD) No. 2012-10-53 is being sent to owners and operators of Eurocopter Deutschland GmbH (ECD) Model EC135 P1, EC135 P2, EC135 P2+, EC135 T1, EC135 T2, and EC135 T2+ helicopters. This EAD supersedes EAD No. 2012-10-51, dated May 15, 2012 (EAD 2012-10-51).
Background
On May 15, 2012, we issued EAD 2012-10-51 for the ECD Model EC135 series helicopters to detect a crack on the main rotor hub (MRH) shaft flange. That EAD requires a pilot check of the lower MRH shaft flange for a crack or deformed blade attachment bolt safety pins before the first flight of each day, inspecting the upper and lower MRH shaft flanges for a crack within 5 hours time- in-service (TIS), and replacing the MRH shaft if there is a crack.