Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-400 series airplanes. This proposed AD was prompted by reports of flap power unit (FPU) pressure switch failures resulting in flap inoperative events. This proposed AD would require replacing the FPU pressure switch or the FPU. This proposed AD would also prohibit the installation of affected parts. The FAA is proposing this AD to address the unsafe condition on these products.