Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL- 601), and CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes. This proposed AD would require measuring to detect migration of the lower gimbal pin and inspecting for other discrepancies of the horizontal stabilizer trim actuator (HSTA). This proposed AD also would require replacing or modifying the HSTA, as applicable. This proposed AD results from reports of failure of the lower gimbal pin of the HSTA. We are proposing this AD to prevent migration of the lower gimbal pin of the HSTA, which could result in loss of the horizontal stabilizer and consequent loss of control of the airplane.