Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model DHC-8-400 series airplanes. This proposed AD was prompted by a report of a quality escape in the manufacturing of the advanced pneumatic detector (APD) switches, and the presence of contamination on the switch contact pin. This proposed AD would require identification and testing, and reidentification or replacement if necessary, of affected APDs. The FAA is proposing this AD to address the unsafe condition on these products.