SUMMARY: We are adopting a new airworthiness directive (AD) for CHI Model 107-II and Kawasaki Model KV107-II and KV107-IIA helicopters. This AD requires, before further flight, replacing certain upper collective pitch control yoke bolts. This AD is prompted by three failures of the affected bolts. These actions are intended to prevent failure of an upper collective pitch control yoke bolt (bolt), excessive vibration, migration of the shafts, and subsequent loss of control of the helicopter.
DATES: This AD becomes effective August 7, 2012.