AD 2021-10-13

The FAA is superseding Airworthiness Directive (AD) 2015-17- 08, which applied to certain Bombardier, Inc. Model DHC-8-400 series airplanes. AD 2015-17-08 required installing new cable assemblies with a pull-down resistor. This AD requires modifications to the nose wheel steering (NWS) system. This AD was prompted by a report indicating that several failure modes of the NWS system may cause the loss of feedback from both rotary variable differential transformers to the steering control unit. The FAA is issuing this AD to address the unsafe condition on these products.

Final rule.

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by: 0 a. Removing Airworthiness Directive (AD) 2015-17-08, Amendment 39-18241 (80 FR 51459, August 25, 2015); and 0 b. Adding the following new AD: \n\n2021-10-13 De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.): Amendment 39-21546; Docket No. FAA-2021-0018; Project Identifier MCAI-2020-01214-T. \n\n(a) Effective Date \n\n\n\tThis airworthiness directive (AD) is effective July 1, 2021. \n\n(b) Affected ADs \n\n\n\tThis AD replaces AD 2015-17-08, Amendment 39-18241 (80 FR 51459, August 25, 2015) (AD 2015-17-08). \n\n(c) Applicability \n\n\n\tThis AD applies to De Havilland Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes, certificated in any category, serial numbers 4001, and 4003 through 4608 inclusive. \n\n(d) Subject \n\n\n\tAir Transport Association (ATA) of America Code 32, Landing gear. \n\n(e) Reason \n\n\n\tThis AD was prompted by a report indicating that several failure modes of the nose wheel steering (NWS) system may cause the loss of feedback from both rotary variable differential transformers to the steering control unit. The FAA is issuing this AD to address failure modes of the NWS system, which could lead to NWS runaway, loss of directional control of the airplane, and possible consequent runway excursion. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) New Requirement of This AD \n\n\n\tWithin 4,000 flight hours or 18 months, whichever occurs first after the effective date of this AD: Perform modifications to the NWS system, in accordance with paragraph 3.B of the Accomplishment Instructions of De Havilland Aircraft of Canada Limited Service Bulletin 84-32-162, Revision B, dated November 13, 2019, including UTC Aerospace Systems Service Bulletin 406300-32-142, dated June 24, 2019; and UTC Aerospace Systems Service Bulletin 406330-32-143, dated June 24, 2019. \n\n(h) Credit for Previous Actions \n\n\n\tThis paragraph provides credit for actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using De Havilland Aircraft of Canada Limited Service Bulletin 84-32-162, dated August 26, 2019, including UTC Aerospace Systems Service Bulletin 406300-32-142, dated June 24, 2019, and UTC Aerospace Systems Service Bulletin 406330-32-143, dated June 24, 2019; or De Havilland Aircraft of Canada Limited Service Bulletin 84-32-162, Revision A, dated October 18, 2019, including UTC Aerospace Systems Service Bulletin 406300-32-142, dated June 24, 2019, and UTC Aerospace Systems \n\n((Page 28481)) \n\nService Bulletin 406330-32-143, dated June 24, 2019. \n\n(i) Other FAA AD Provisions \n\n\n\t(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 responsible Flight Standards 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 responsible Flight Standards Office. \n\t(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. \n\n(j) Related Information \n\n\n\t(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) TCCA AD CF-2020-28, dated August 14, 2020, 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-2021-0018. \n\t(2) For more information about this AD, contact Siddeeq Bacchus, Aerospace Engineer, Mechanical Systems and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7362; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov. \n\t(3) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (k)(3) and (4) of this AD. \n\n(k) Material Incorporated by Reference \n\n\n\t(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. \n\t(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise. \n\t(i) De Havilland Aircraft of Canada Limited Service Bulletin 84- 32-162, Revision B, dated November 13, 2019, including UTC Aerospace Systems Service Bulletin 406300-32-142, dated June 24, 2019; and UTC Aerospace Systems Service Bulletin 406330-32-143, dated June 24, 2019. \n\t(ii) (Reserved) \n\t(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. \n\t(4)You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. \n\t(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. \n\n\n\tIssued on April 30, 2021. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service. (FR Doc. 2021-11088 Filed 5-26-21; 8:45 am) BILLING CODE 4910-13-P

Discussion \n\n\n\tTransport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued TCCA AD CF-2020-28, dated August 14, 2020 (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for certain De Havilland Aircraft of Canada Limited Model DHC-8-401 and -402 airplanes. You may examine the MCAI in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0018. \n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2015-17-08, Amendment 39-18241 (80 FR 51459, August 25, 2015) (AD 2015-17-08). AD 2015-17-08 applied to certain Bombardier, Inc. Model DHC-8-400 series airplanes. The NPRM published in the Federal Register on February 24, 2021 (86 FR 11175). The NPRM was prompted by a report indicating that several failure modes of the NWS system may cause the loss of feedback from both rotary variable differential transformers to the steering control unit. The NPRM proposed to require modifications to the NWS system. The FAA is issuing this AD to address failure modes of the NWS system, which could lead to NWS runaway, loss of directional control of the airplane, and possible consequent runway excursion. See the MCAI for additional background information. \n\nComments \n\n\n\tThe FAA gave the public the opportunity to participate in developing this final rule. The FAA has considered the comment received. The Air Line Pilots Association, International (ALPA) indicated its support for the NPRM. \n\n((Page 28480)) \n\nConclusion \n\n\n\tThe FAA reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for addressingthe unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tDe Havilland Aircraft of Canada Limited has issued Service Bulletin 84-32-162, Revision B, dated November 13, 2019, including UTC Aerospace Systems Service Bulletin 406300-32-142, dated June 24, 2019; and UTC Aerospace Systems Service Bulletin 406330-32-143, dated June 24, 2019. This service information describes procedures for modifying the NWS system (terminating wiring, reworking the left-hand console frame, and installing an NWS electronic control unit and NWS hand control). This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 54 airplanes of U.S. registry. \n\tThe FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs for Required Actions ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Modification.................. 13 work-hours x Up to $122......... Up to $1,227....... Up to $66,258. \n\t$85 per hour = \n\t$1,105. ---------------------------------------------------------------------------------------------------------------- \n\nAuthority for This Rulemaking \n\n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. \n\tThe FAA is issuing this rulemakingunder the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\n\tThe FAA determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under ExecutiveOrder 12866, \n\t(2) Will not affect intrastate aviation in Alaska, and \n\t(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.