Airworthiness Directive · Amendment 39-23145 · Flight controls
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-8-401 and -402 airplanes, certificated in any category, as identified in Transport Canada AD CF-2024-10, dated March 1, 2024 (Transport Canada AD CF-2024-10).
The FAA is superseding Airworthiness Directive (AD) 2019-16- 09, which applied to certain De Havilland Aircraft of Canada Limited Model DHC-8-400 series airplanes. AD 2019-16-09 required one-time inspections for cracks and damage of the elevator power control unit (PCU) brackets and surrounding area, horizontal stabilizer rear spar, elevator front spar, and related investigative and corrective actions if necessary. Since the FAA issued AD 2019-16-09, new findings have been reported as a result of maintenance activities and/or inspections. This AD continues to require certain actions in AD 2019-16-09 and requires repeating the inspections one time and performing applicable on- condition actions. This AD also removes an airplane model from the applicability and provides optional terminating action for repetitive inspections. The FAA is issuing this AD to address the unsafe condition on these products.
Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, Transport Canada AD CF-2024-10.
(1) Where Transport Canada AD CF-2024-10 refers to the effective date of AD CF-2018-34 (December 31, 2018), this AD requires using October 9, 2019 (the effective date of AD 2019-16-09).
(2) Where Transport Canada AD CF-2024-10 refers to hours air time, this AD requires using flight hours.
(3) Where Transport Canada AD CF-2024-10 refers to “if cracks or damage”, this AD requires replacing that text with “if any crack or damage”.
(4) Where Transport Canada AD CF-2024-10 specifies actions if certain conditions are found on “rear spar assembly P/N 85517044 and/or elevator assembly P/N 85527021”, this AD requires replacing that text with “rear spar assembly P/N 85517044 or elevator assembly P/N 85527021”.
(5) Where Transport Canada AD CF-2024-10 specifies “after inspecting as required by AD CF-2018-34”, this AD requires replacing that text with “after inspecting as specified in Bombardier Service Bulletin 84-55-09 or de Havilland Aircraft of Canada Limited Service Bulletin 84-55-09”.
(6) Where paragraph B. of Part I and paragraph A. of Part II of Transport Canada AD CF-2024-10 specify a compliance time to do a repeat inspection, this AD allows the inspection to be done within 90 days after the effective date of this AD.
Although the material referenced in Transport Canada AD CF-2024-10 specifies to submit certain information to the manufacturer, this AD does not include that requirement.
(1) For airplane serial numbers 4001 and 4003 through 4058 inclusive on which any inspection specified in Section 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-55-09 or de Havilland Aircraft of Canada Limited Service Bulletin 84-55-09 has been done: Replacement of existing PCU fittings with redesigned PCU fittings in accordance with Part I, paragraph B., of Transport Canada AD CF-2025-19, dated March 24, 2025, terminates the requirements of paragraph (g) of this AD.
(2) For airplane serial numbers 4059 through 4580 inclusive on which any inspection specified in Section 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-55-09 or de Havilland Aircraft of Canada Limited Service Bulletin 84-55-09 has been done: Replacement of existing PCU fittings with redesigned PCU fittings in accordance with Part II, paragraphs B. and C., of Transport Canada AD CF-2025-19, dated March 24, 2025, terminates the requirements of paragraph (g) of this AD.
