Airworthiness Directive · Amendment 39-16986 · Doors
Bombardier, Inc. Airplanes
This AD applies to Bombardier, Inc. Model DHC-8-400, -401, and -402 airplanes, certificated in any category, serial numbers 4001 through 4361 inclusive.
We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. This AD was prompted by a report of the inability to open the airstair door while on the ground, because the airstair door seal did not deflate, which prevented the airstair door from opening. This AD requires changing the wiring that controls the pneumatic shut-off valve. We are issuing this AD to prevent the airstair door seal from not deflating, which could result in the airstair door not opening and could impede 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 6,000 flight hours after the effective date of this AD: Incorporate ModSum 4-126513, Seal System Shut Off Valve Control Logic Change, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-52-69, Revision C, dated June 28, 2011.
