Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Seven cases of on-ground hydraulic accumulator screw cap or end cap failure have been experienced on CL-600-2B19 (CRJ) aircraft, resulting in loss of the associated hydraulic system and high-energy impact damage to adjacent systems and structure. * * * * * * * *
A detailed analysis of the systems and structure in the potential line of trajectory of a failed screw cap/end cap for each accumulator * * * has been conducted. It has been identified that the worst case scenario would be failure of one of the brake accumulator screw caps/end caps, resulting in impact damage causing loss of both hydraulic systems No. 2 and No. 3, with consequent loss of both braking and nose wheel steering and the potential for a runway excursion [resulting in damage to the airplane and hazards to persons or property on the ground]. * * * * * The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.