Airworthiness Directive · Amendment 39-17445 · Fire protection
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 4382 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 chafing found on the main landing gear (MLG) yoke. The chafing was attributed to contact between the nacelle fire detection wires and the MLG yoke. This AD requires inspections of the nacelle fire detection wires and the MLG yoke for damage; replacing nacelle fire detection wires, if necessary; repairing the MLG yoke, if necessary; and installing brackets and associated hardware to secure the fire detection wires. We are issuing this AD to prevent chafing between the nacelle fire detection wires and the MLG yoke. Chafing could lead to cracking and subsequent failure of the MLG yoke, which could adversely affect the safe landing of the airplane. In addition, chafing of the nacelle fire detection wires could cause them to fail and prevent the detection of a fire in the nacelle assembly.
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 or 36 months after the effective date of this AD, whichever occurs first, accomplish the actions specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-26-11, Revision A, dated January 25, 2012.
(1) Do a detailed inspection of the left and right nacelle fire detection wires for damage (i.e., chafing). If damage is found on any nacelle fire detection wire: Before further flight, remove and replace the damaged wire with a new wire, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-26-11, Revision A, dated January 25, 2012.
(2) Do a detailed inspection of the MLG yoke for damage (e.g., chafing, nicks, cracking).
(i) If any damage is found within the limitations specified in Figure 8 of Bombardier Service Bulletin 84-26-11, Revision A, dated January 25, 2012: Before further flight, repair the MLG yoke, in accordance with Figure 9, steps 1 through 10, of Bombardier Service Bulletin 84-26-11, Revision A, dated January 25, 2012.
(ii) If any damage exceeds the limitations specified in Figure 8 of Bombardier Service Bulletin 84-26-11, Revision A, dated January 25, 2012: Before further flight, repair the MLG yoke using a method approved by either the Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA; or Transport Canada Civil Aviation (or its delegated agent).
(3) Install brackets and associated hardware, in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 84-26-11, Revision A, dated January 25, 2012.
