Airworthiness Directives; Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

Résumé

We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. 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: Three cases of in-flight loss of cabin pressurization have been reported, resulting from failure of a bulkhead check valve in combination with failure of an air supply duct. In addition to mandating inspection, rework and/or replacement of the air supply ducts, Airworthiness Directive (AD) CF-2003-05 (subsequently revised to CF-2003-05R1) [which corresponds to FAA AD 2004-22-08] mandated the incorporation of a 4000 flight-hour repetitive inspection task for bulkhead check valves, Part Numbers (P/N) 92E20-3 and 92E20-4, into the approved maintenance schedule. However, this repetitive inspection task has since been superseded by a 3000 flight-hour periodic discard task for these bulkhead check valves. This directive mandates revision of the approved maintenance schedule to incorporate the discard task for bulkhead che