Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes. This proposed AD was prompted by a report of an in- flight event where isolation valve caution messages were received. This proposed AD would require inspecting the fuse/shuttle valve serial numbers, and replacing certain fuse/shuttle valves, as specified in a Transport Canada AD, which is proposed for incorporation by reference (IBR). The FAA is proposing this AD to address the unsafe condition on these products.