AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model DHC-8-401 and -402 airplanes. This proposed AD was prompted by a report that certain fuselages were delivered with non-conforming keel tension fittings and stringer end fittings. This proposed AD would require a detailed visual inspection of stringer end fittings and keel fittings for loose or working fasteners, signs of wear, and corrosion, and repair if necessary; and a general visual inspection of the keel tension fitting and stringer end fittings, as applicable and repairs and replacement of the keel and stringer end fittings if necessary. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by October 24, 2019.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For Bombardier, Inc., service information identified in this NPRM, contact De Havilland Aircraft of Canada Ltd., Q-Series Technical Help Desk, 123 Garratt Boulevard, Toronto, Ontario M3K 1Y5, Canada; phone: 416-375-4000; fax: 416-375-4539; email: thd@dehavilland.com; internet: https://dehavilland.com. 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.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0675; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, the regulatory evaluation, any comments received, and other information. The street address for Docket Operations is listed above. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Andrea Jimenez, Aerospace Engineer, Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7330; fax: 516-794-5531; email: 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2019-0675; Product Identifier 2019-NM-068-AD” at the beginning of your comments. The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of this NPRM. The FAA will consider all comments received by the closing date and may amend this NPRM because of those comments.

The FAA will post all comments received, without change, to http://www.regulations.gov, including any personal information you provide. The FAA will also post a report summarizing each substantive verbal contact received about this NPRM.

Discussion

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian AD CF-2019-06, dated February 18, 2019 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Bombardier, Inc., Model DHC-8-401 and -402 airplanes. The MCAI states:

A disclosure letter from a supplier identified a number of fuselages that were delivered with non-conforming keel tension fittings and stringer end fittings. Left unaddressed, these non-conformances can lead to premature cracking in several locations, corrosion, and compromise the structural integrity of the fuselage joints.

This [Canadian] AD requires a one-time inspection of the non-conforming fittings [and repair if necessary], and later [an inspection of the fittings and, if necessary,] replacement of the fittings [or repair].

You may examine the MCAI in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0675.

Related Service Information Under 1 CFR Part 51

Bombardier has issued the following service information.

• Service Bulletin 84-53-74, dated August 29, 2018. This service information describes procedures for a general visual inspection of the keel and stringer end fittings, repair, and replacement of the keel and stringer end fittings.
• Service Bulletin 84-53-75, dated August 29, 2018. This service information describes procedures for a detailed visual inspection of stringer end fittings and keel fittings, in the passenger compartment at stations X373.15 and X428.50, for loose or working fasteners, signs of wear, and corrosion.

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.

FAA's Determination

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to a bilateral agreement with the State of Design Authority, the FAA has been notified of the unsafe condition described in the MCAI and service information referenced above. The FAA is proposing this AD because the agency evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

The FAA estimates that this proposed AD affects 1 airplane of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA has received no definitive data that would enable the agency to provide cost estimates for the on-condition replacements specified in this proposed AD.

Authority for This Rulemaking

Title 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.

The FAA is issuing this rulemaking under 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.

This proposed AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes and associated appliances to the Director of the System Oversight Division.

Regulatory Findings

The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Will not affect intrastate aviation in Alaska; and

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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Bombardier, Inc.: Docket No. FAA-2019-0675; Product Identifier 2019-NM-068-AD.

(a) Comments Due Date

The FAA must receive comments by October 24, 2019.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Bombardier, Inc., Model DHC-8-401 and -402 airplanes, certificated in any category, serial numbers 4327, 4330, 4337, 4342, 4350, 4352, 4362, 4367, 4372, 4375, 4376, 4378, 4383, 4384, 4385, 4388, 4391, 4392, 4396, and 4397.

(d) Subject

Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Reason

This AD was prompted by a report that certain fuselages were delivered with non-conforming keel tension fittings and stringer end fittings. The FAA is issuing this AD to address non-conforming keel tension fittings and stringer end fittings which could lead to premature cracking in several locations, corrosion, and compromise the structural integrity of the fuselage joints.

(f) Compliance

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

(g) Detailed Visual Inspection of the Stringer End Fittings and Keel Fittings and Repair

Within 8,000 flight hours or 5 years after the effective date of this AD, whichever occurs first: Do a detailed visual inspection of the stringer end fittings and keel fittings at fuselage stations X373.15 and X428.50 for loose and working fasteners, signs of wear, and corrosion in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-75, dated August 29, 2018. If any loose or working fasteners, signs of wear, or corrosion are found during any inspection required by this paragraph, before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.'s TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature. Doing the actions specified in Bombardier Service Bulletin 84-53-66 does not constitute compliance with the actions specified in this paragraph.

(h) General Visual Inspection, Repair, and Replacement of the Stringer End Fittings and Keel Fittings

Except for airplanes identified in paragraph (i) of this AD: Before accumulating 40,000 total flight cycles or within 12 months after the effective date of this AD, whichever occurs later, do the inspections specified in paragraphs (h)(1) and (2) of this AD.

(1) Do a general visual inspection of the keel tension fittings at fuselage stations X373.15 and X428.50 for non-conformance conditions (oversize, elongated, and off angle conditions) in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-74, dated August 29, 2018. If any non-conformance condition is found, before further flight, replace the keel tension fittings at fuselage stations X373.15 and X428.50, including doing all applicable repairs, in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-74, dated August 29, 2018; except where Bombardier Service Bulletin 84-53-74, dated August 29, 2018, specifies to contact Bombardier, before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature.

(2) Do a general visual inspection of the stringer end fittings at fuselage stations X373.15 and X428.50 for non-conformance conditions (i.e., excessive depth Hi-Lite fastener hole chamfers and installation too close to the fillet radius), in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-74, dated August 29, 2018. If any non-conformance condition is found, before further flight, replace the stringer end fittings at fuselage stations X373.15 and X428.50, including doing all applicable repairs and an eddy current or fluorescent dye penetrant inspection for cracks of all blended areas and fasteners, in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-74, dated August 29, 2018; except where Bombardier Service Bulletin 84-53-74, dated August 29, 2018, specifies to contact Bombardier, before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature.

(i) Rework for Airplanes That Have Accomplished Bombardier Service Bulletin 84-53-69 Prior to the Effective Date of This AD

For airplanes on which the actions specified in Bombardier Service Bulletin 84-53-69 have been accomplished prior to the effective date of this AD: Before accumulating 40,000 total flight cycles or within 12 months after the effective date of this AD, whichever occurs later, do a general visual inspection of the stringer end fittings at fuselage stations X373.15 and X428.50 for non-conformance conditions (i.e., excessive depth Hi-Lite fastener hole chamfers and installation too close to the fillet radius) in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-74, dated August 29, 2018. If any non-conformance condition is found, before further flight, replace the stringer end fittings at fuselage stations X373.15 and X428.50, including doing all applicable repairs and an eddy current or fluorescent dye penetrant inspection for cracks of all blended areas and fasteners, in accordance with paragraph 3.B. of the Accomplishment Instructions of Bombardier Service Bulletin 84-53-74, dated August 29, 2018; except where Bombardier Service Bulletin 84-53-74, dated August 29, 2018, specifies to contact Bombardier, before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature.

(j) Corrective Action for Eddy Current and Fluorescent Dye Penetrant Inspections

If, during any eddy current or fluorescent dye penetrant inspection required by paragraph (h)(2) or (i) of this AD, any cracking is found, before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature.

(k) Other FAA AD Provisions

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; phone: 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 corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature.

(l) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) Canadian AD CF-2019-06, dated February 18, 2019, for related information. This MCAI may be found in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0675.

(2) For more information about this AD, contact Andrea Jimenez, Aerospace Engineer, Airframe and Propulsion Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7330; fax: 516-794-5531; email: 9-avs-nyaco-cos@faa.gov.

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