Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This proposed AD would require installing additional shielding of the hydraulic lines in the wing box area. This proposed AD is prompted by the determination that the additional hydraulic line shields will protect the lines from possible impact by tire debris if the tire tread fails. We are proposing this AD to prevent damage to the hydraulic lines and subsequent leakage from the two hydraulic systems, which could result in loss of braking capability on the affected side of the airplane, asymmetrical braking, and reduced directional control--particularly during a rejected takeoff.