Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This AD was prompted by issuance of revised certification maintenance requirements for the horizontal stabilizer trim actuator (HSTA). This AD requires revising the maintenance or inspection program. We are issuing this AD to detect and correct premature wear and cracking of the HSTAs, which could result in reduced structural integrity and reduced control of the airplane due to the failure of system components.