AD 2020-04-20

This AD is effective May 4, 2020.

None.

This AD applies to De Havilland Aircraft of Canada Limited Model DHC-8-400, -401, and -402 airplanes, certificated in any category, manufacturer serial numbers 4001, 4003, and subsequent.

Air Transport Association (ATA) of America Code 28, Fuel.

This AD was prompted by reports of wear on fuel couplings, bonding springs, and sleeves as well as fuel tube end ferrules and fuel component end ferrules. The FAA is issuing this AD to address such wear, which could reduce the integrity of the electrical bonding paths through the fuel line and components, and ultimately lead to fuel tank ignition in the event of a lightning strike.

Comply with this AD within the compliance times specified, unless already done.

For airplanes having serial numbers 4001 and 4003 through 4575 inclusive that, as of the effective date of this AD, have not done the actions specified in Bombardier Service Bulletin 84-28-21: At the applicable times specified in paragraph (g)(1) or (2) of this AD, do the actions specified in paragraphs (h)(1) and (2) of this AD.

(1) For all airplanes except those identified in paragraph (g)(2) of this AD: Within 6,000 flight hours or 36 months, whichever occurs first after the effective date of this AD.

(2) For airplanes with an original airworthiness certificate or original export certificate of airworthiness issued on or after the effective date of this AD: Within 6,000 flight hours or 36 months, whichever occurs first after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness.

For airplanes having serial numbers 4001 and 4003 through 4575 inclusive that, as of the effective date of this AD, have not done the actions specified in Bombardier Service Bulletin 84-28-21: At the applicable times specified in paragraph (g)(1) or (2) of this AD, do the actions specified in paragraphs (h)(1) and (2) of this AD. Repeat the actions thereafter at intervals not to exceed 6,000 flight hours or 36 months, whichever occurs first.

(1) Do a detailed inspection of the clamshell coupling bonding wires, fuel couplings, and associated sleeves for discrepancies that meet specified criteria, as identified in, and in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-20, Revision D, dated November 23, 2018. If any conditions are found meeting the criteria specified in Bombardier Service Bulletin 84-28-20, Revision D, dated November 23, 2018, before further flight, replace affected parts with new couplings and sleeves of the same part number, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-20, Revision D, dated November 23, 2018.

(2) Do a detailed inspection of the fuel tube end ferrules, fuel component end ferrules, and ferrule O-ring flanges for damage and wear, and rework (repair, replace, or blend, as applicable) the parts, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-20, Revision D, dated November 23, 2018.

For airplanes having serial numbers 4001 and 4003 through 4575 inclusive: Doing a detailed inspection of the fuel tube end ferrules, fuel component end ferrules, and ferrule O-ring flanges for damage and wear, and reworking (repair, replace, or blend, as applicable) the parts; and doing a retrofit (structural rework) of the fuel couplings, isolators, and structural provisions, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-21, Revision C, dated July 13, 2018, terminates the inspections specified in paragraphs (h)(1) and (2) of this AD.

For airplanes having serial numbers 4001, 4003 through 4489 inclusive, and 4491 through 4575 inclusive that, as of the effective date of this AD, have done the actions specified in Bombardier Service Bulletin 84-28-21, Revision A, dated September 29, 2017; and airplanes having serial numbers 4576 through 4581 inclusive: Within 6,000 flight hours or 36 months after the effective date of this AD, whichever occurs first, do the actions specified in paragraph (j)(1) or (2) of this AD.

(1) Accomplish electrical bonding checks of all threaded couplings on the inboard vent lines in the left and right wings, in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-26, Revision A, dated November 29, 2018.

(2) Do a detailed inspection of the fuel tube end ferrules, fuel component end ferrules, and ferrule O-ring flanges for damage and wear, and rework (repair, replace, or blend, as applicable) the parts; and a retrofit (structural rework) of the fuel couplings, isolators, and structural provisions in accordance with paragraph 3.B., “Procedure,” of the Accomplishment Instructions of Bombardier Service Bulletin 84-28-21, Revision C, dated July 13, 2018.

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 Q400 Dash 8 (Bombardier) Temporary Revision ALI-0192, dated April 24, 2018; and Q400 Dash 8 (Bombardier) Temporary Revision ALI-0193, dated April 24, 2018. Except as specified in paragraph (l) of this AD, the initial compliance time for doing the tasks in Q400 Dash 8 (Bombardier) Temporary Revision ALI-0192, dated April 24, 2018, is at the time specified in Q400 Dash 8 (Bombardier) Temporary Revision ALI-0192, dated April 24, 2018, or within 30 days after the effective date of this AD, whichever occurs later.

The initial compliance time for task 284000-419 is at the time specified in paragraph (l)(1) or (2) of this AD, as applicable, or within 30 days after the effective date of this AD, whichever occurs later.

(1) For airplanes having serial numbers 4001 and 4003 through 4575, inclusive: Within 18,000 flight hours or 108 months, whichever occurs first, after the earliest date of embodiment of Bombardier Service Bulletin 84-28-21 on the airplane.

(2) For airplanes having serial numbers 4576 and subsequent: Within 18,000 flight hours or 108 months, whichever occurs first, from the date of issuance of the original airworthiness certificate or original export certificate of airworthiness.

After the existing maintenance or inspection program has been revised as required by paragraph (k) 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 alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (p)(1) of this AD.

Although Bombardier Service Bulletin 84-28-20, Revision D, dated November 23, 2018, specifies to submit certain information to the manufacturer, this AD does not include that requirement.

(1) This paragraph provides credit for the actions required by paragraphs (h)(1) and (2) of this AD, if those actions were performed before the effective date of this AD using the service information specified in paragraph (o)(1)(i), (ii), or (iii) of this AD.

(i) Bombardier Service Bulletin 84-28-20, Revision A, dated December 14, 2016.

(ii) Bombardier Service Bulletin 84-28-20, Revision B, dated February 13, 2017.

(iii) Bombardier Service Bulletin 84-28-20, Revision C, dated April 28, 2017.

(2) For the airplane having serial number 4164, this paragraph provides credit for the initial inspections required by paragraphs (h)(1) and (2) of this AD, if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 84-28-20, dated September 30, 2016.

(3) This paragraph provides credit for the actions specified in paragraph (i) of this AD if those actions were performed before the effective date of this AD using the service information specified in paragraph (o)(3)(i), (ii), or (iii) of this AD.

(i) Bombardier Service Bulletin 84-28-21, dated August 31, 2017.

(ii) Bombardier Service Bulletin 84-28-21, Revision A, dated September 29, 2017.

(iii) Bombardier Service Bulletin 84-28-21, Revision B, dated June 8, 2018.

(4) This paragraph provides credit for the actions required by paragraph (j)(1) of this AD if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 84-28-26, dated August 14, 2018.

(5) This paragraph provides credit for the actions required by paragraph (j)(2) of this AD if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 84-28-21, Revision B, dated June 8, 2018.

(6) For airplanes having serial numbers 4001, 4003 through 4489 inclusive, and 4491 through 4575 inclusive, and that are post Bombardier Service Bulletin 84-28-21, Revision A, dated September 29, 2017: This paragraph provides credit for the actions required by paragraph (j) of this AD if those actions were performed prior to the effective date of this AD using the service information specified in paragraph (o)(6)(i) or (ii) of this AD.

(i) Bombardier Modification Summary Package (ModSum) IS4Q2800032, dated February 1, 2018.

(ii) Any airworthiness limitation change request (ACR) specified in figure 1 to paragraph (o)(6)(ii) of this AD.

[graphic omitted; see the official PDF]

The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, New York ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the certification office, send it to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; fax 516-794-5531. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(2) Contacting the Manufacturer: For any requirement in this AD to obtain instructions from a manufacturer, the instructions must be accomplished 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.

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) Canadian Airworthiness Directive CF-2017-04R2, dated September 25, 2018, for related information. This MCAI may be found in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0726.

(2) For more information about this AD, contact Joseph Catanzaro, Aerospace Engineer, Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7366; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

(3) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (r)(3) and (4) of this AD.

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise.

(i) Bombardier Service Bulletin 84-28-20, Revision D, dated November 23, 2018.

(ii) Bombardier Service Bulletin 84-28-21, Revision C, dated July 13, 2018.

(iii) Bombardier Service Bulletin 84-28-26, Revision A, dated November 29, 2018.

(iv) Bombardier Q400 Dash 8 (Bombardier) Temporary Revision ALI-0192, dated April 24, 2018.

(v) Q400 Dash 8 (Bombardier) Temporary Revision ALI-0193, dated April 24, 2018.

(3) For service information identified in this AD, contact De Havilland Aircraft of Canada Limited, Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; telephone 416-375-4000; fax 416-375-4539; email thd@dehavilland.com; internet https://dehavilland.com.

(4) You may view this service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.

(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email fedreg.legal@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.