Airworthiness Directive · Amendment 39-21589 · Nacelles/pylons
De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
This AD applies to De Havilland Aircraft of Canada Limited (type certificate previously held by Bombardier, Inc.) Model DHC-8-400, -401, and -402 airplanes, certificated in any category, serial numbers 4081 through 4591 inclusive.
The FAA is adopting a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-400 series airplanes. This AD was prompted by a report that a number of nacelle A- frames were not manufactured in accordance with engineering drawings. This AD requires, depending on airplane configuration, removing the fasteners on the nacelle A-frame side brace sub-assemblies, doing an eddy current inspection for cracking, cold-working the holes, installing oversize fasteners, re-identifying the reworked side brace fitting and A-frame, and repair if necessary. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within the compliance time specified in paragraph (g)(2) of this AD, do the applicable actions specified in paragraphs (g)(1)(i) and (ii) of this AD.
(i) For airplanes having serial numbers 4081 through 4582 inclusive: Remove the fasteners on the nacelle A-frame side brace sub-assemblies, do an eddy current inspection for cracking on airplanes having 30,000 total flight cycles or more, cold-work the holes, and install oversize fasteners, in accordance with Part A of paragraph 3.B. of the Accomplishment Instructions of De Havilland Aircraft of Canada Limited Service Bulletin 84-54-32, dated October 10, 2019. If any cracking is found, before further flight, repair the cracking using a method approved by the Manager, New York ACO Branch, FAA; or Transport Canada Civil Aviation (TCCA); or De Havilland Aircraft of Canada Limited's TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.
(ii) For all airplanes: Re-identify the reworked side brace fitting and A-frame, in accordance with Part B of paragraph 3.B. of the Accomplishment Instructions of De Havilland Aircraft of Canada Limited Service Bulletin 84-54-32, dated October 10, 2019.
(2) At the earlier of the times specified in paragraphs (g)(2)(i) and (ii) of this AD, do the applicable actions specified in paragraph (g)(1) of this AD.
(i) Within 48 months or 8,000 flight hours after the effective date of this AD, whichever occurs first.
(ii) At the later of the times specified in paragraphs (g)(2)(ii)(A) and (B) of this AD.
(A) Before accumulating 40,000 total flight cycles.
(B) Within 12 months or 1,290 flight cycles after the effective date of this AD, whichever occurs first.
