Aircraft

Transport Canada says it plans to issue an airworthiness directive (AD) "at the earliest opportunity" to address faulty hydraulic accumulator end caps that can rip through systems and structures on Bombardier CRJ100 and CRJ200 aircraft.

The safety regulator last week issued a similar AD for several Bombardier business jets that use the same actuators, calling on operators to inspect the part numbers of the accumulators and replace certain units within 50h of the 10 November effective date of the AD.

Transport Canada plans to issue an AD applying to the CRJ200 (foreground)   ©John Croft

The directive was prompted by "seven cases of on-ground hydraulic accumulator screw cap or end cap failures" on CRJ aircraft, according to Transport Canada. The failures resulted in loss of the "associated hydraulic system and high-energy impact damage to adjacent systems and structure", according to the business jet AD.

Transport Canada says the lowest flight time on a failed unit was 6,991 cycles.

A worst case failure, according to the regulator, would involve the failure of a brake accumulator screw cap or end cap, "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".

Transport Canada says it is waiting for Bombardier to "supply the department with a service bulletin" before it can issue the CRJ AD.

Bombardier could not be immediately reached for comment.