Airworthiness Directive · Amendment 39-22142 · Fuel system
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 (S/Ns) 4001, 4003, and subsequent.
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 reports of broken P-clamps on the pressure relief line and the motive flow line in the fuel tanks, and a subsequent determination that certain service information lacked instructions for maintaining appropriate clearance between certain fuel tubes and their support brackets, and may also have led to incorrect installation of certain Teflon<SUP>TM</SUP> sleeves. This AD was also prompted by a determination that new or more restrictive airworthiness limitations are necessary. This AD requires inspecting the motive flow line, vent line, and related parts, and adding support or additional clearance if necessary. This AD also requires inspection, and replacement or relocation if necessary, of affected Teflon<SUP>TM</SUP> sleeves on the vent line, and installation of Teflon<SUP>TM</SUP> sleeves on the vent line at additional wing stations. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. The FAA is issuing this AD to address the unsafe condition on these products.
For the purposes of this AD, “prohibited tasks” are defined as any task identified in paragraph (l) of this AD and any procedure or task that specifies fuel tank access using non-manufacturer-approved procedures.
(1) For airplanes having S/N 4001 and 4003 through 4525 inclusive: Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first, increase the hole size in the collector tank partition wall, inspect the motive flow line for damage, and replace the associated grommet and motive flow line, in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-18, Revision B, dated April 20, 2017.
(2) For airplanes having S/N 4001 and 4003 through 4533 inclusive, on which Bombardier Service Bulletin 84-28-19, dated August 16, 2016; or Revision A, dated November 4, 2016; has not been done: Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first, replace the affected single nut plate brackets and standoffs at the affected left-hand (LH) and right-hand (RH) wing stations on the motive flow line and pressure relief line, in accordance with paragraphs 3.B. and 3.C. of Bombardier Service Bulletin 84-28-19, Revision D, dated February 16, 2018.
(3) Accomplishing Bombardier Repair Drawing 8/4-28-018, Issue 1, dated October 30, 2017; Issue 2, dated June 12, 2018; Issue 3, dated June 21, 2018; or Issue 4, dated July 27, 2018; is a method of compliance (MOC) only for the replacement of the affected single nut plate brackets and standoffs on the motive flow line and vent line at LH and RH wing stations Yw ± 209.019 and Yw ± 317.019 required by paragraph (h)(2) of this AD.
(4) Accomplishing Bombardier Repair Drawing 8/4-28-018, Issue 1, dated October 30, 2017; Issue 2, dated June 12, 2018; Issue 3, dated June 21, 2018; or Issue 4, dated July 27, 2018; prior to the effective date of this AD, along with the replacement of the affected single nut plate brackets and standoffs on the motive flow line, vent line, pressure relief line, and scavenge line at LH and RH wing stations Yw ± 209.019, Yw ± 317.019, and Yw ± 371.019, is acceptable for compliance for the actions required by paragraph (h)(2) of this AD.
(5) For airplanes having S/N 4001 and 4003 through 4533 inclusive, on which Bombardier Service Bulletin 84-28-19, dated August 16, 2016; or Revision A, dated November 4, 2016; has been done: Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first, inspect the motive flow line and vent line at wing stations -371.019 and 371.019 in the LH and RH fuel tanks, respectively, to ensure that these fuel tubes are adequately supported, and inspect the fuel tubes to verify that an appropriate clearance has been maintained between the fuel tubes and their support brackets, in accordance with paragraph 3.B., step (13), and paragraph 3.C., of Bombardier Service Bulletin 84-28-19, Revision D, dated February 16, 2018.
(6) For airplanes having S/N 4001 and 4003 through 4572 inclusive: Within 8,000 flight hours or 48 months after the effective date of this AD, whichever occurs first, install Teflon TM sleeves on the vent line at wing stations Yw ± 209.019 and Yw ± 371.019 in the LH and RH fuel tanks, inspect the Teflon TM sleeve installation on the vent line at wing stations Yw ± 317.019 in the LH and RH fuel tanks, and if any sleeve is incorrectly installed, reposition the Teflon TM sleeves before further flight, in accordance with paragraphs 3.B. and 3.C. of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-24, dated November 27, 2017.
(7) Prior to accomplishment of the actions required by paragraph (h)(6) of this AD, the applicable actions specified in paragraph (h)(2) or (5) of this AD must be done. For airplanes on which Bombardier Modification Summary (ModSum) 4Q113904 has been accomplished prior to accomplishment of the actions required by paragraph (h)(6) of this AD, no further action is required by this paragraph.
(8) For airplanes having S/N 4001 and 4003 through 4575 inclusive: Within 8,000 flight hours or 48 months after the effective date of this AD, whichever occurs first, inspect the Teflon TM sleeve installation on the vent line in the LH and RH fuel tanks for correct installation and damage, and if the sleeves are incorrectly installed or damage is found, before further flight, replace and reposition the Teflon TM sleeves, as applicable, in accordance with paragraphs 3.B. and 3.C. of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-25, dated November 27, 2017.
(9) Prior to accomplishment of the actions required by paragraph (h)(8) of this AD, the applicable actions specified in paragraph (h)(2) or (5) of this AD must be done. For airplanes on which Bombardier ModSum 4Q113904 has been accomplished prior to accomplishment of the actions required by paragraph (h)(8) of this AD, no further action is required by this paragraph.
(1) For airplanes having S/N 4001 and 4003 through 4575 inclusive, on which the actions required by paragraph (h)(6) or (8) of this AD have been done before the effective date of this AD, or that have complied with paragraph (m)(4) of this AD: Within 60 days after the effective date of this AD, review the airplane maintenance records to confirm if any of the prohibited tasks (defined in paragraph (g) of this AD) were accomplished during or after compliance with paragraph (h)(6) or (8) of this AD or paragraph (m)(4) of this AD.
(i) If any of the prohibited tasks were accomplished during or after compliance with paragraph (h)(6) or (m)(4) of this AD, or if it cannot be conclusively confirmed that they were not accomplished during or after compliance with paragraph (h)(6) or paragraph (m)(4) of this AD: Within 8,000 flight hours or 48 months after the effective date of this AD, whichever occurs first, do the actions required by paragraph (h)(6) of this AD and, as applicable, comply with the requirements of paragraph (h)(7) of this AD.
(ii) If any of the prohibited tasks were accomplished during or after compliance with paragraph (h)(8) of this AD, or if it cannot be conclusively confirmed that they were not accomplished during or after compliance with paragraph (h)(8) of this AD: Within 8,000 flight hours or 48 months after the effective date of this AD, whichever occurs first, do the actions required by paragraph (h)(8) of this AD and, as applicable, comply with the requirements of paragraph (h)(9) of this AD.
(2) For airplanes having S/N 4573 and subsequent, with an airplane date of manufacture, as identified on the identification plate of the airplane, dated before the effective date of this AD: Within 60 days after the effective date of this AD, review the airplane maintenance records to confirm if any of the prohibited tasks (defined in paragraph (g) of this AD) were accomplished on or after the airplane date of manufacture. If any of the prohibited tasks were accomplished on or after the airplane date of manufacture, or if it cannot be conclusively confirmed that they were not accomplished on or after the airplane date of manufacture, within 8,000 flight hours or 48 months after the effective date of this AD, whichever occurs first, obtain and follow instructions for rework 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.
For all airplanes: Within 30 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in (Bombardier) Q400 Dash 8 Maintenance Requirements Manual (MRM) Temporary Revision (TR) ALI-0192 and TR ALI-0193, both dated April 24, 2018. The initial compliance time for doing the tasks in (Bombardier) Q400 Dash 8 MRM TR ALI-0192, dated April 24, 2018, is at the applicable time specified in paragraph (j)(1) or (2) of this AD, whichever occurs later:
(1) Prior to the accumulation of 18,000 total flight cycles or within 108 months since issuance of the original airworthiness certificate or original export certificate of airworthiness, whichever occurs first.
(2) Within 90 days after the effective date of this AD.
After the existing maintenance or inspection program has been revised as required by paragraph (j) of this AD, no alternative actions (e.g., inspections), intervals, or CDCCLs may be used unless the actions, intervals, and CDCCLs are approved as an AMOC in accordance with the procedures specified in paragraph (n)(1) of this AD.
For all airplanes: As of the effective date of this AD, comply with the prohibitions specified in paragraphs (l)(1) and (2) of this AD.
(1) It is prohibited to use the Bombardier airplane maintenance manual (AMM) tasks identified in paragraphs (l)(1)(i) through (v) of this AD, which are specified in the Bombardier Q400 Dash 8 AMM, PSM 1-84-2, Revision 59 dated October 5, 2017, or earlier revisions of these tasks. TRs including these AMM tasks, dated November 27, 2017, or earlier, are also prohibited for use except as specified in paragraph (l)(1)(i) through (v) of this AD.
(i) Task 28-10-00-280-806, Detailed Inspection of the Teflon TM Sleeve on the Fuel Tank Vent Line, LH and RH (FSL#284000-406), with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-145, dated November 21, 2017.
(ii) Task 28-12-06-000-801, Removal of the Outboard Vent Line, with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-146, dated November 21, 2017.
(iii) Task 28-12-06-400-801, Installation of the Outboard Vent Line, with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-147, dated November 21, 2017.
(iv) Task 28-12-01-000-801, Removal of the Inboard Vent Line, with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-148, dated November 24, 2017.
(v) Task 28-12-01-400-801, Installation of the Inboard Vent Line, with the exception of (Bombardier) Q400 Dash 8 AMM TR 28-149, dated November 27, 2017.
(2) It is prohibited to use the Bombardier Q400 Dash 8 Maintenance Task Card Manual (MTCM) task cards identified in paragraphs (l)(2)(i) and (ii) of this AD that are specified in the Bombardier Q400 Dash 8 MTCM, PSM 1-84-7TC, Revision 42, dated November 5, 2017, or earlier revisions or amendments of these task cards. MTCM task card revisions or amendments dated November 21, 2017, or earlier, are also prohibited for use, except as specified in paragraphs (l)(2)(i) and (ii) of this AD.
(i) Bombardier Q400 Dash 8 MTCM, Maintenance Task Card 000-28-520-704 (Config A01), Revision 42, Amendment 0002, dated November 21, 2017.
(ii) Bombardier Q400 Dash 8 MTCM, Maintenance Task Card 000-28-620-704 (Config A01), Revision 42, Amendment 0002, dated November 21, 2017.
