Airworthiness Directive · Amendment 39-19732 · Landing gear
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 4001 through 4585 inclusive, and 4587.
The FAA is adopting a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Model DHC-8-400 series airplanes. This AD was prompted by reports of the nose landing gear (NLG) locking in a partially extended position due to loose bushings on the lock link of the NLG locking mechanism. This AD requires repetitive inspections of the bushings and the lower lock link of the NLG for discrepancies, and corrective actions if necessary. This AD also requires replacement of the lower lock link of the NLG, which terminates the repetitive inspections. The FAA is issuing this AD to address the unsafe condition on these products.
Except as provided by paragraphs (h) and (i) of this AD: Do a general visual inspection for the NLG lower lock link part number and discrepancies of the bushings and of the lower lock link of the NLG locking mechanism, at the applicable time specified in paragraph (g)(1) or (2) of this AD, in accordance with paragraphs 3.A. and 3.B., or 3.A. and 3.D., as applicable, of the Accomplishment Instructions of Bombardier Service Bulletin 84-32-153, Revision A, dated February 27, 2018. If any discrepancy is found, before further flight, repair or replace the NLG lower lock link, as applicable, in accordance with paragraphs 3.B. or 3.D, as applicable, of Bombardier Service Bulletin 84-32-153, Revision A, dated February 27, 2018. Repeat the inspection thereafter at intervals not to exceed 1,600 flight cycles on any NLG lower lock link.
(1) For airplanes on which an NLG lower lock link has accumulated 7,200 or fewer total flight cycles as of the effective date of this AD: Before the accumulation of 8,000 total flight cycles on the NLG lower lock link.
(2) For airplanes on which an NLG lower lock link has accumulated more than 7,200 total flight cycles as of the effective date of this AD: Within 800 flight cycles on the NLG lower lock link after the effective date of this AD.
For airplanes with an NLG lower lock link that is repaired or replaced as specified in any one of paragraphs (h)(1) through (4) of this AD: The next inspection specified by paragraph (g) of this AD is required for the NLG lower lock link on the airplane at the applicable time specified in figure 1 to the introductory text of paragraph (h) of this AD.
| Flight cycles | Compliance time |
|---|---|
| Airplanes on which the NLG lower lock link has accumulated 7,200 or fewer flight cycles since the NLG lower link was repaired or replaced | Before the accumulation of 8,000 flight cycles on the NLG lower lock link since the repair or replacement. |
| Airplanes on which the NLG lower lock link has accumulated more than 7,200 flight cycles since the NLG lower link was repaired or replaced | Within 800 flight cycles on the NLG lower lock link after the effective date of this AD. |
(1) Repaired as specified in Bombardier Repair Drawing 8/4-32-0338;
(2) Repaired as specified in the Goodrich Aerospace Canada Ltd. Component Maintenance Manual, Part Number (P/N) 47300, 32-21-03;
(3) Replaced with a serviceable lock link having P/N 47324-1 (SCR-093-17-B); or
(4) Replaced with a new lock link having P/N 47324-1.
The inspections specified in this AD are not required for any new NLG lower lock link having P/N 47324-3.
