Summary
We propose to supersede Airworthiness Directive (AD) 2013-16- 14 for Eurocopter Deutschland GmbH (now Airbus Helicopters Deutschland GmbH) Model EC 135 P1, P2, P2+, T1, T2, and T2+ helicopters. AD 2013- 16-14 currently requires installing a washer in and modifying the main transmission filter housing upper part. Since we issued AD 2013-16-14, Airbus Helicopters Deutschland GmbH has extended the overhaul interval for the main transmission and determined that other models may have the same unsafe condition. This proposed AD would retain the requirements of AD 2013-16-14, add models to the applicability, and revise the required compliance time for the modification. The actions of this proposed AD are intended to correct an unsafe condition on these products.