88 FR 88 pgs. 29555-29557 - Airworthiness Directives; The Boeing Company Airplanes
Type: PRORULEVolume: 88Number: 88Pages: 29555 - 29557
Pages: 29555, 29556, 29557Docket number: [Docket No. FAA-2023-0934; Project Identifier AD-2022-01443-T]
FR document: [FR Doc. 2023-09641 Filed 5-5-23; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-0934; Project Identifier AD-2022-01443-T]
RIN 2120-AA64
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 747-8F and 747-8 series airplanes. This proposed AD was prompted by a report of cracks in stringers, common to the end fittings, on the aft side of the bulkhead at station 2598. This proposed AD would require detailed inspections of the stringers, common to the end fittings, forward and aft of the bulkhead at a certain station for cracking and applicable on-condition actions. 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 June 22, 2023.
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 regulations.gov . Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• 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.
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2023-0934; 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, any comments received, and other information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
• 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 562-797-1717; website myboeingfleet.com .
• 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. It is also available at regulations.gov by searching for and locating Docket No. FAA-2023-0934.
FOR FURTHER INFORMATION CONTACT:
Stefanie Roesli, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3964; email: stefanie.n.roesli@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 ADDRESSES . Include "Docket No. FAA-2023-0934; Project Identifier AD-2022-01443-T" at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.
Confidential Business Information
[top] CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important
Background
The FAA has received a report indicating the presence of cracks in stringers, common to the end fittings, at stringer location S-42L/R and S-46L/R on the aft side of the bulkhead at station (STA) 2598. The airplane had accumulated 5,517 total flight cycles and 32,468 total flight hours at time the cracks were found. In addition, during foreign object debris (FOD) inspections Boeing found five cracks in stringers, common to the end fittings, at stringer locations S-2L, S-6L, S-8L, and S-2R on the forward side and S-5L on the aft side of the bulkhead at STA 2598 on two airplanes. The FAA has also received reports of similar cracks found on additional airplanes. In all cases, the cracks were found in the side walls of the stringers and had grown in longitudinal and transverse directions, but there was no other damage or deformation in the surrounding area. An investigation by Boeing found that during airplane assembly, un-shimmed or incorrectly shimmed gaps that were larger than engineering requirements caused excessive and sustained internal tensile stresses and resulted in stress corrosion cracking in the stringers. This condition, if not addressed, could lead to a failure of the skin adjacent to the bulkhead at STA 2598, which could adversely affect the structural integrity of the airplane.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022. This service information specifies procedures for repetitive detailed inspections of the stringers, common to the end fittings, forward and aft of the bulkhead at STA 2598, for any crack, and applicable on-condition actions. On-condition actions include repair.
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 ADDRESSES .
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified in the service information already described, 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 regulations.gov under Docket No. FAA-2023-0934.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 42 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|---|
| Detailed inspection | 91 work-hours × $85 per hour = $7,735 per inspection cycle | $0 | $7,735 per inspection cycle | $324,870 per inspection cycle. |
The FAA estimates the following costs to do any necessary repairs that would be required based on the results of the proposed inspection. The agency has no way of determining the number of aircraft that might need these repairs:
| Action | Labor cost | Parts cost | Cost per product |
|---|---|---|---|
| Repair | 13 work-hours × $85 per hour = $1,105 | $600 | $1,705 (per stringer). |
The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators.
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.
Regulatory Findings
[top] 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) Would not affect intrastate aviation in Alaska, and
(3) Would 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:
The Boeing Company: Docket No. FAA-2023-0934; Project Identifier AD-2022-01443-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by June 22, 2023.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 747-8F and 747-8 series airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by a report of cracks in stringers, common to the end fittings, on the aft side of the bulkhead at station (STA) 2598. The FAA is issuing this AD to address stress corrosion cracking in the stringers. This condition, if not addressed, could lead to a failure of the skin adjacent to the bulkhead at STA 2598, which could adversely affect the structural integrity of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Required Actions
Except as specified by paragraph (h) of this AD: At the applicable times specified in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022.
Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 747-53A2911, dated November 3, 2022, which is referred to in Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022.
(h) Exceptions to Service Information Specifications
(1) Where the Compliance Time column of the table in the "Compliance" paragraph of Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022, uses the phrase "the original issue date of Requirements Bulletin 747-53A2911 RB," this AD requires using "the effective date of this AD."
(2) Where Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (i) of this AD.
(i) 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 responsible Flight Standards 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 (j) of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards 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.
(j) Related Information
For more information about this AD, contact Stefanie Roesli, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3964; email: stefanie.n.roesli@faa.gov.
(k) Material Incorporated by Reference
(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 the AD specifies otherwise.
(i) Boeing Alert Requirements Bulletin 747-53A2911 RB, dated November 3, 2022.
(ii) [Reserved]
(3) 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 562-797-1717; website myboeingfleet.com .
(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.
(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, fr.inspection@nara.gov, or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued on April 13, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2023-09641 Filed 5-5-23; 8:45 am]
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