Airworthiness Directive · Amendment 39-18079 · Main landing gear
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 4454 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 two in-service incidents where one side of the main landing gear (MLG) did not achieve down-lock. This AD requires doing a detailed inspection of the apex joints of the stabilizer brace lock link in the MLG for clearance; rectifying and repairing the clearance gap, if necessary; and lubricating the apex joints of the stabilizer brace lock link in the MLG. We are issuing this AD to detect and correct insufficiently greased stabilizer brace lock linkage of the MLG and over-torqued lock linkage attachment bolts, which could lead to the failure to extend and down-lock the MLG, and could affect the safe landing of the airplane.
Within 1,000 flight hours or 6 months after the effective date of this AD, whichever occurs first: Do a detailed inspection of the apex joints of the stabilizer brace lock link in the main landing gear (MLG) for clearance, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-32-121, dated May 27, 2013.
(1) If the clearance gap is 0.001 inches (0.025 millimeters) or greater, do the action in paragraph (h) of this AD at the time specified in paragraph (h) of this AD.
(2) If the clearance gap is less than 0.001 inches (0.025 millimeters), before further flight, rectify the clearance gap, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-32-121, dated May 27, 2013; and do the action in paragraph (h) of this AD at the time specified in paragraph (h) of this AD. If the clearance gap cannot be rectified in accordance with Bombardier Service Bulletin 84-32-121, dated May 27, 2013: Before further flight, repair using a method approved by the Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.'s TCCA Design Approval Organization (DAO). After the repair is done, do the action in paragraph (h) of this AD at the time specified in paragraph (h) of this AD.
Note 1 to paragraphs (g) and (h) of this AD: Completion of the actions in this AD does not affect the actions specified in the existing maintenance review board (MRB) task number 320001-201.
Within 1,000 flight hours or 6 months after the effective date of this AD, whichever occurs first: Lubricate the apex joints of the stabilizer brace lock link in the MLG, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-32-121, dated May 27, 2013.
