Airworthiness Directive · Amendment 39-16985 · Fuselage
Bombardier, Inc. Airplanes
This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes; certificated in any category; serial numbers 4161 through 4296 inclusive.
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted by reports of difficulties in opening the airstair door. This AD requires inspecting the structure and gearbox drain paths for blockages by sealant, and removing any blockages. We are issuing this AD to detect and correct drain paths blocked by sealant, resulting in an airstair door that is unable to be opened, which could hinder evacuation in the event of an emergency.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 600 flight hours after the effective date of this AD, do a general visual inspection of the structure and gearbox drain paths for blockages by sealant, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-53-48, dated December 2, 2010. If any blockages are found, before further flight, remove blockages, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-53-48, dated December 2, 2010.
