Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes

The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD- 500-1A11 airplanes. This proposed AD was prompted by a report of multiple in-service failures of pressure regulating shutoff valves (PRSOVs). This proposed AD would require revising the existing airplane flight manual (AFM) to incorporate procedures for reducing the thrust lever or shutting down the engine when the BLEED LEAK caution message is persistent, prohibit operation in known or forecasted icing conditions under certain minimum equipment list (MEL) provisions where the only operative PRSOV is an affected part, and require replacement of affected PRSOVs with improved PRSOVs. The FAA is proposing this AD to address the unsafe condition on these products.