2019-13020. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737 series airplanes, except for Model 737-100, —200, -200C, -300, -400, and -500 series airplanes. This proposed AD was prompted by reports of separation of the lower aft wing-to-body fairing panel 194E (“fairing panel 194E”) during flight, due to worn or damaged nutplates on the support structure. This proposed AD would require repetitive inspections of fairing panel 194E, wheel well panel 193D, and support structure for discrepancies, and related investigative and corrective actions if necessary. This proposed AD would also require rework of the panels and support structure, which would terminate the repetitive inspections. 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 August 5, 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: [phone].
• 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 service information identified in this NPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone [phone]; internet https://www.myboeingfleet.com. You may view this referenced 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. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0399.

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-2019-0399; 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:

Alan Pohl, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: [phone]; email: [e-mail].

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-2019-0399; Product Identifier 2018-NM-149-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 agency will consider all comments received by the closing date and may amend this NPRM because of those comments.

The FAA will post all comments, 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 the agency receives about this NPRM.

Discussion

The FAA has received several reports of separation of the lower aft wing-to-body fairing panel 194E during flight. In two of these reports, damage from the separation of that panel was also found on an adjacent fairing panel. In another report, the panel was found loose. The airplanes with loose or missing panels had accumulated between 1,270 and 43,200 total flight hours, and between 550 and 15,800 total flight cycles. The FAA determined that the nutplates common to the forward edge of the panel could become worn or damaged. In addition, worn or damaged nutplates on the support structure for the wheel well panel 193D, which is adjacent to the 194E fairing panel, may also be a contributing factor to the loss of the 194E fairing panel. This condition, if not addressed, could result in separation of fairing panel 194E.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Boeing Service Bulletin 737-53-1307, dated January 12, 2012. This service information describes procedures for repetitive inspections of fairing panel 194E, wheel well panel 193D, and support structure for discrepancies (including incorrect torque at the fasteners and worn and damaged nutplates and fastener holes) and corrective actions (including repair and replacement of nutplates and fasteners). This service information also describes procedures for rework of the panels and support structure, including related investigative actions (general visual inspection of the panel and support structure for damage) and repair, which together would eliminate the need for the repetitive inspections.

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

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 in other products of the same type design.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between this Proposed AD and the Service Information,” and except for any differences identified as exceptions in the regulatory text of this proposed AD.

For information on the procedures and compliance times, see this service information at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-0399.

The phrase “related investigative actions” is used in this proposed AD. Related investigative actions are follow-on actions that (1) are related to the primary action, and (2) further investigate the nature of any condition found. Related investigative actions in an AD could include, for example, inspections.

The phrase “corrective actions” is used in this proposed AD. Corrective actions correct or address any condition found. Corrective actions in an AD could include, for example, repairs.

Differences Between This Proposed AD and the Service Information

The effectivity of Boeing Service Bulletin 737-53-1307, dated January 12, 2012, is limited to Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, line numbers 1 through 3532 inclusive. However, the applicability of this proposed AD includes all Model 737 airplanes except for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The FAA has determined, as has the design approval holder, that affected parts can be installed on future deliveries. Because the affected parts are rotable, the FAA has determined that these parts could later be installed on airplanes that were initially delivered with acceptable parts, thereby subjecting those airplanes to the unsafe condition.

Airplanes from line number 3533 through any airplane with an original airworthiness certificate or an original export certificate of airworthiness dated on or before the effective date of this AD would be subject to the initial inspection requirement of this proposed AD, but the inspection would not be required to be repeated if the airplane can be demonstrated to have the post-reworked configuration of Boeing Service Bulletin 737-53-1307, dated January 12, 2012, as specified in paragraph (h) of this AD. (Note that the “Parts Installation Limitation” specified in paragraph (i) of this AD would still apply.)

Costs of Compliance

The FAA estimates that this proposed AD would affect 983 airplanes of U.S. registry. The agency estimates the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection	8 work-hours × $85 per hour = $680 per inspection cycle	$0	$680 per inspection cycle	Up to $668,440 per inspection cycle.
Rework	25 work-hours × $85 per hour = $2,125	0	$2,125	Up to $2,088,875.

The FAA has received no definitive data that would enable the agency to provide cost estimates for the on-condition repairs 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 has 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.

§ 39.13

[Amended]

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

The Boeing Company: Docket No. FAA-2019-0399; Product Identifier 2018-NM-149-AD.

(a) Comments Due Date

The FAA must receive comments by August 5, 2019.

(b) Affected ADs

None.

(c) Applicability

This AD applies to The Boeing Company Model 737 series airplanes, certificated in any category, except for Model 737-100, -200, -200C, -300, -400, and -500 series airplanes.

(d) Subject

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

(e) Unsafe Condition

This AD was prompted by reports of separation of lower aft wing-to-body fairing panel 194E (“fairing panel 194E”) during flight, due to worn or damaged nutplates on the 193D wheel well panel and support structure. The FAA is issuing this AD to address separation of fairing panel 194E.

(f) Compliance

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

(g) Repetitive Inspections and Corrective Actions

(1) For airplanes with an original airworthiness certificate or an original export certificate of airworthiness dated on or before the effective date of this AD: Within 24 months after the effective date of this AD, do a general visual inspection for discrepancies of fairing panel 194E, wheel well panel 193D, and support structure, and do all applicable related investigative and corrective actions, in accordance with Part 1 and Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 737-53-1307, dated January 12, 2012. All applicable related investigative and corrective actions must be done before further flight. Repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles.

(2) For airplanes having line numbers 3533 and subsequent with an original airworthiness certificate or an original export certificate of airworthiness dated on or before the effective date of this AD: If the initial inspection required by paragraph (g)(1) shows that fairing panel 194E, wheel well panel 193D, and the support structure have the number and type of attachments specified in the post-reworked configuration of Boeing Service Bulletin 737-53-1307, dated January 12, 2012, then the repetitive inspections required by paragraph (g)(1) of this AD are terminated. The requirements of paragraph (i) of this AD continue to apply.

(h) Terminating Action

For airplanes with an original airworthiness certificate or an original export certificate of airworthiness dated on or before the effective date of this AD: Within 72 months after the effective date of this AD, do the actions required by paragraph (h)(1) or (h)(2) of this AD, as applicable. Accomplishing the actions in paragraph (h)(1) or (h)(2) of this AD terminates the repetitive inspections required by paragraph (g)(1) of this AD. The requirements of paragraph (i) of this AD continue to apply.

(1) Rework fairing panel 194E, wheel well panel 193D, and the support structure, including accomplishment of all applicable related investigative actions and repair, in accordance with Part 3 of the Accomplishment Instructions of Boeing Service Bulletin 737-53-1307, dated January 12, 2012. All applicable related investigative actions and repairs must be done before further flight.

(2) Verify that fairing panel 194E, wheel well panel 193D, and the support structure have the number and type of attachments specified in the post-reworked configuration of Boeing Service Bulletin 737-53-1307, dated January 12, 2012.

(i) Parts Installation Limitation

As of the effective date of this AD, no person may install a fairing panel 194E on any airplane identified in paragraph (c) of this AD, unless fairing panel 194E, wheel well panel 193D, and the support structure have the number and type of attachments specified in the post-reworked configuration of Boeing Service Bulletin 737-53-1307, dated January 12, 2012.

(j) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Seattle 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 the attention of the person identified in paragraph (k)(1) of this AD. Information may be emailed to: [e-mail].

(2) 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.

(3) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO Branch, FAA, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(k) Related Information

(1) For more information about this AD, contact Alan Pohl, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: [phone]; email: [e-mail].

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone [phone]; internet https://www.myboeingfleet.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.

Issued in Des Moines, Washington, on June 14, 2019.

Michael Kaszycki,

Acting Director, System Oversight Division, Aircraft Certification Service.