AD FAA-2011-1159

We are adopting a new airworthiness directive (AD) for Honeywell International Inc. LTS101-600A-2, -3, -3A, and LTS101-700D-2 turboshaft engines with certain power turbine governors (PTG) model AL- AB1, installed, that are marked with compliance symbol N or P, or with no compliance symbol, on the PTG identification plate. This AD requires initial and repetitive replacements of the affected PTGs. This AD was prompted by reports of two accidents where the engines suddenly lost power and the helicopters had to make emergency autorotation landings, leading to substantial damage to the helicopters. We are issuing this AD to prevent loss of engine power, leading to emergency autorotation landing and damage to the helicopter.