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 certain The Boeing Company Model 777 airplanes. This proposed AD was prompted by significant changes, including new or more restrictive requirements, made to the airworthiness limitations (AWLs) and Critical Design Configuration Control Limitations (CDCCLs) related to fuel tank ignition prevention, the engine fuel suction feed system, and the nitrogen generation system. This proposed AD would require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. 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 May 10, 2021.

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 https://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 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; internet https://www.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.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0134; 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.

FOR FURTHER INFORMATION CONTACT:

Kevin Nguyen, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3555; email: kevin.nguyen@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-2021-0134; Project Identifier AD AD-2020-01254-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 the 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 https://www.regulations.gov,, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this proposed AD.

Confidential Business Information

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 that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Kevin Nguyen, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3555; email: kevin.nguyen@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The FAA has examined the underlying safety issues involved in fuel tank explosions on several large transport airplanes, including the adequacy of existing regulations, the service history of airplanes subject to those regulations, and existing maintenance practices for fuel tank systems. As a result of those findings, the FAA issued a final rule titled “Transport Airplane Fuel Tank System Design Review, Flammability Reduction, and Maintenance and Inspection Requirements” (66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements that rule included Amendment 21-78, which established Special Federal Aviation Regulation No. 88 (“SFAR 88”) to 14 CFR part 21. Subsequently, SFAR 88 was amended by: Amendment 21-82 (67 FR 57490, September 10, 2002; corrected at 67 FR 70809, November 26, 2002), Amendment 21-83 (67 FR 72830, December 9, 2002; corrected at 68 FR 37735, June 25, 2003, to change “21-82” to “21-83”), and Amendment 21-101 (83 FR 9162, March 5, 2018).

Among other actions, SFAR 88 requires certain type design (i.e., type certificate (TC) and supplemental type certificate (STC)) holders to substantiate that their fuel tank systems can prevent ignition sources in the fuel tanks. This requirement applies to type design holders for large turbine-powered transport airplanes and for subsequent modifications to those airplanes. It requires them to perform design reviews and to develop design changes and maintenance procedures if their designs do not meet the new fuel tank safety standards. As explained in the preamble to the final rule published on May 7, 2001, the FAA intended to adopt airworthiness directives to mandate any changes found necessary to address unsafe conditions identified as a result of these reviews.

In evaluating these design reviews, the FAA has established four criteria intended to define the unsafe conditions associated with fuel tank systems that require corrective actions. The percentage of operating time during which fuel tanks are exposed to flammable conditions is one of these criteria. The other three criteria address the failure types under evaluation: Single failures, single failures in combination with another latent condition(s), and in-service failure experience. For all four criteria, the evaluations included consideration of previous actions taken that may mitigate the need for further action.

The FAA issued AD 2008-11-13, Amendment 39-15536 (73 FR 30737, May 29, 2008) (AD 2008-11-13), which applies to certain The Boeing Company Model 777-200, -200LR, -300, and -300ER series airplanes. The applicability of AD 2008-11-13 did not include the Boeing Company Model 777F series airplane because those airplanes were not yet type certificated. AD 2008-11-13 requires incorporation of fuel system AWLs and also requires an initial inspection to phase in certain repetitive inspections, and repair if necessary. The fuel system AWLs were developed to satisfy SFAR 88 requirements and were included in the Airworthiness Limitations Section (ALS) of the manufacturer's Instructions for Continued Airworthiness. Since the FAA issued AD 2008-11-13, the ALS has been significantly revised by the manufacturer to correct technical and editorial errors and also to add new or more restrictive requirements. Many of those changes are related to fuel tank ignition prevention, the engine fuel suction feed system, and the nitrogen generation system. The FAA has determined that the specific revisions of the AWL mandated by AD 2008-11-13 (which applies to airplanes with an original standard airworthiness certificate or original export certificate of airworthiness issued before December 5, 2007) and the revisions of the AWL that have been delivered with airplanes as part of the type design and airworthiness certificate on or after December 5, 2007, are inadequate to provide information necessary to maintain critical design features and perform inspections.

The FAA also issued AD 2014-09-09, Amendment 39-17844 (79 FR 30005, May 27, 2014) (AD 2014-09-09), which applies to all The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. AD 2014-09-09 requires revising the maintenance program to incorporate a revision to the Airworthiness Limitations Section of the maintenance planning data (MPD) document. Since the FAA issued AD 2014-09-09, 28-AWL-101 has been revised, therefore, this proposed AD would require the incorporation of the revised 28-AWL-101. Incorporating the revision required by this proposed AD would terminate all the requirements of AD 2014-09-09.

The FAA has received a report indicating that significant changes, including new or more restrictive requirements, made to the AWLs and CDCCLs related to fuel tank ignition prevention, the engine fuel suction feed system, and the nitrogen generation system. The FAA is issuing this AD to address ignition sources inside the fuel tanks and the increased flammability exposure of the center fuel tank caused by latent failures, alterations, repairs, or maintenance actions, which could result in a fuel tank explosion and consequent loss of an airplane; and to address potential loss of engine fuel suction feed capability, which could result in dual engine flameouts, inability to restart engines, and consequent forced landing of the airplane.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Section 9, Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), of Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data (MPD) Document, D622W001-9, dated November 2019. This service information describes airworthiness limitations and CDCCLs tasks related to fuel tank ignition prevention, the engine fuel suction feed system, and the nitrogen generation system. 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 revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations.

This proposed AD would require revisions to certain operator maintenance documents to include new actions (e.g., inspections) and CDCCLs. Compliance with these actions and CDCCLs is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by this proposed AD, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (k) of this proposed AD.

Differences Between This Proposed AD and the Service Information

Paragraph (g) of this proposed AD would require operators to revise their existing maintenance or inspection program by incorporating, in part, AWL No. 28-AWL-11, “Fuel Quantity Indicating System (FQIS) and Auxiliary Fuel Tank (Cell) Electronic Fuel Level Indication System (EFLI)—Out Tank Wiring Installation Separation Requirement,” of Section 9, Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), of Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data (MPD) Document, D622W001-9, dated November 2019.

Paragraph (h) of this proposed AD would allow certain changes to be made to the requirements specified in AWL No. 28-AWL-11 as an option. Where AWL No. 28-AWL-11 identifies certain wire types for routing and installation of any new wiring under certain conditions, paragraph (h) of this proposed AD provides acceptable alternative wire types. Additionally, where AWL No. 28-AWL-11 identifies certain wiring sleeve material for new wiring installed under certain conditions, paragraph (h) of this proposed AD provides acceptable alternative wire sleeve materials.

Alternative Methods of Compliance (AMOCs) Previously Approved for AD 2008-11-13

The FAA has previously issued AMOC approvals for compliance with paragraph (g)(2) of AD 2008-11-13 to allow operators to incorporate alternative versions of AWL No. 28-AWL-11. AWL No. 28-AWL-11 includes the requirements for new wiring introduced by any alterations or changes to the type design, including STC modifications, in proximity to wiring that penetrates the fuel tank wall. Certain STCs that introduced new wiring near the fuel quantity indicating system (FQIS) wiring utilized design features that were different from the critical design features for fuel tank ignition prevention specified in the AD-mandated version of AWL No. 28-AWL-11. For those STCs, the FAA has approved alternative versions of AWL No. 28-AWL-11 that specified critical design features associated with STC modifications. The FAA has determined that certain critical design features specified in the AMOC-approved versions of AWL No. 28-AWL-11 are not acceptable to meet the intent of this AWL. Therefore, this proposed AD does not allow credit for AMOCs previously approved under AD 2008-11-13. However, based on the agency's assessment of critical design features, the FAA has provided options under paragraph (h) of this proposed AD to allow certain changes to be made to the requirements specified in AWL No. 28-AWL-11.

The requirements for new wiring versus existing wiring are specified in AWL No. 28-AWL-11. Based on these requirements, any STC modifications that are installed after the incorporation of the version of AWL No. 28-AWL-11 required by paragraph (g) of this proposed AD must comply with AWL No. 28-AWL-11, including any mandatory rework, or the operator must request approval of an AMOC according to paragraph (k) of this proposed AD. Any STC modifications that are installed prior to the incorporation of the version of AWL No. 28 AWL-11 required by paragraph (g) of this proposed AD are not required to be reworked for compliance with the new wiring requirements of AWL No. 28-AWL-11, except that future repair and replacement of existing wiring must follow AWL No. 28-AWL-11.

Costs of Compliance

The FAA estimates that this proposed AD affects 219 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the FAA estimates the average total cost per operator to be $7,650 (90 work-hours × $85 per work-hour).

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

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.

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

The Boeing Company: Docket No. FAA-2021-0134; Project Identifier AD-2020-01254-T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) action by May 10, 2021.

(b) Affected ADs

This AD affects the ADs specified in paragraphs (b)(1) and (2) of this AD.

(1) AD 2008-11-13, Amendment 39-15536 (73 FR 30737, May 29, 2008) (AD 2008-11-13).

(2) AD 2014-09-09, Amendment 39-17844 (79 FR 30005, May 27, 2014) (AD 2014-09-09).

(c) Applicability

This AD applies to The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes having line numbers (L/Ns) 1 through 1609 inclusive, certificated in any category.

(d) Subject

Air Transport Association (ATA) of America Code 28, Fuel; 47, Inert Gas System.

(e) Unsafe Condition

This AD was prompted by significant changes, including new or more restrictive requirements, made to the airworthiness limitations (AWLs) and Critical Design Configuration Control Limitations (CDCCLs) related to fuel tank ignition prevention, the engine fuel suction feed system, and the nitrogen generation system. The FAA is issuing this AD to address ignition sources inside the fuel tanks and the increased flammability exposure of the center fuel tank caused by latent failures, alterations, repairs, or maintenance actions, which could result in a fuel tank explosion and consequent loss of an airplane; and to address potential loss of engine fuel suction feed capability, which could result in dual engine flameouts, inability to restart engines, and consequent forced landing of the airplane.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

Within 60 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information in Section D, “Airworthiness Limitations—Systems,” including Subsections D.1, D.2, and D.3, of Section 9, Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), of Boeing 777-200/200LR/300/300ER/777F Maintenance Planning Data (MPD) Document, D622W001-9, dated November 2019; except as provided by paragraph (h) of this AD. The initial compliance time for doing the airworthiness limitation instructions (ALI) tasks is at the times specified in paragraphs (g)(1) through (10) of this AD.

(1) For AWL 28-AWL-01, “External Wires Over Center Fuel Tank”: Within 16,000 flight cycles or 3,000 days, 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; or within 16,000 flight cycles or 3,000 days, whichever occurs first after the most recent inspection was performed as specified in 28-AWL-01; whichever occurs later.

(2) For AWL 28-AWL-03, “Fuel Quantity Indicating System (FQIS)—Out of Tank Wiring Lightning Shield to Ground Termination”: Within 16,000 flight cycles or 3,000 days, 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; or within 16,000 flight cycles or 3,000 days, whichever occurs first after the most recent inspection was performed as specified in 28-AWL-03; whichever occurs later.

(3) For AWL 28-AWL-18, “Over-Current and Arcing Protection Electrical Design Features Operation—AC Fuel Pump GFI and GFP”: Within 375 days after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 375 days after accomplishment of the actions specified in Boeing Service Bulletin 777-28A0037; or within 375 days after accomplishment of the actions specified in Boeing Service Bulletin 777-28A0038; or within 375 days after the most recent inspection was performed as specified in 28-AWL-18; whichever occurs latest.

(4) For AWL 28-AWL-21, “External Wires Over Auxiliary Fuel Tank (Cell)”: Within 16,000 flight cycles or 3,000 days, whichever occurs first after the date of issuance of the original airworthiness certificate or date of issuance of the original export certificate of airworthiness; or within 16,000 flight cycles or 3,000 days, whichever occurs first after the most recent inspection was performed as specified in 28-AWL-21; or within 365 days after the effective date of this AD; whichever occurs latest.

(5) For AWL 28-AWL-26, “Auxiliary Fuel Tank (Cell) AC Fuel Pump Uncommanded ON/Automatic Shutoff Circuit”: Within 375 days after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 375 days after the most recent inspection was performed as specified in 28-AWL-26; or within 30 days after the effective date of this AD; whichever occurs latest.

(6) For AWL 28-AWL-32, “Cushion Clamps and Teflon Sleeving Installed on Out-of-Tank Wire Bundles Installed on Brackets that are Mounted Directly on the Fuel Tanks”: For airplanes having L/N 1 through 503 inclusive, within 3,750 days after accomplishment of the actions specified in Boeing Service Bulletins 777-57A0050, or within 60 months after the effective date of this AD, whichever occurs later. For airplanes having L/N 504 and subsequent, within 3,750 days after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 60 months after the effective date of this AD; whichever occurs later.

(7) For AWL 28-AWL-101, “Engine Fuel Suction Feed Operational Test”: Within 7,500 flight hours after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 7,500 flight hours after the most recent inspection was performed as specified in AWL No. 28-AWL-101; whichever occurs later.

(8) For AWL 47-AWL-04, “NGS—Thermal Switch”: Within 108,000 flight hours after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 108,000 flight hours after accomplishment of the actions specified in Boeing Service Bulletin 777-47-0002; or within 108,000 flight hours after the most recent inspection was performed as specified in 47-AWL-04; whichever occurs latest.

(9) For 47-AWL-05, “NGS—Cross Vent Check Valve”: Within 10,682 flight hours after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 10,682 flight hours after accomplishment of the actions specified in Boeing Service Bulletin 777-47-0002; or within 10,682 flight hours after the most recent inspection was performed as specified in 47-AWL-05; whichever occurs latest.

(10) For AWL 47-AWL-06, “NGS—NEA Distribution Ducting Integrity”: Within 10,682 flight hours after the date of issuance of the original airworthiness certificate or the date of issuance of the original export certificate of airworthiness; or within 10,682 flight hours after accomplishment of the actions specified in Boeing Service Bulletin 777-47-0002; or within 10,682 flight hours after the most recent inspection was performed as specified in 47-AWL-06; whichever occurs latest.

(h) Additional Acceptable Wire Types and Sleeving

As an option, when accomplishing the actions required by paragraph (g) of this AD, the changes specified in paragraphs (h)(1) and (2) of this AD are acceptable.

(1) Where AWL No. 28-AWL-11 identifies wire types BMS 13-48, BMS 13-58, and BMS 13-60, the following wire types are acceptable: MIL-W-22759/16, SAE AS22759/16 (M22759/16), MIL-W-22759/32, SAE AS22759/32 (M22759/32), MIL-W-22759/34, SAE AS22759/34 (M22759/34), MIL-W-22759/41, SAE AS22759/41 (M22759/41), MIL-W-22759/86, SAE AS22759/86 (M22759/86), MIL-W-22759/87, SAE AS22759/87 (M22759/87), MIL-W-22759/92, and SAE AS22759/92 (M22759/92); and MIL-C-27500 and NEMA WC 27500 cables constructed from these military or SAE specification wire types, as applicable.

(2) Where AWL No. 28-AWL-11 identifies TFE-2X Standard wall (manufactured as specified in MIL-I-23053) for wire sleeving, the following sleeving materials are acceptable: Roundit 2000NX and Varglas Type HO, HP, or HM.

(i) No Alternative Actions, Intervals, or Critical Design Configuration Control Limitations (CDCCLs)

After the existing maintenance or inspection program has been revised as required by paragraph (g) 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 (k) of this AD.

(j) Terminating Actions

Accomplishment of the revision required by paragraph (g) of this AD terminates the requirements specified in paragraphs (j)(1) and (2) of this AD for that airplane.

(1) All requirements of AD 2008-11-13 for Model 777-200, -200LR, -300, and -300ER series airplanes only.

(2) All requirements of AD 2014-09-09.

(k) 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 (l)(1) 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.

(l) Related Information

(1) For more information about this AD, contact Kevin Nguyen, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3555; email: kevin.nguyen@faa.gov.

(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 562-797-1717; internet https://www.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.