Summary
We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2C10 (Regional Jet Series 700, 701, & 702), Model CL-600-2D15 (Regional Jet Series 705), Model CL-600- 2D24 (Regional Jet Series 900), and Model CL-600-2E25 (Regional Jet Series 1000) airplanes. This proposed AD was prompted by a report that a number of rubber bull gear (RBG) wheels installed in the horizontal stabilizer trim actuator (HSTA) were manufactured using an incorrect material specification. This proposed AD would require replacement of the affected RBG wheels. We are proposing this AD to address the unsafe condition on these products.