2021-13097. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is superseding Airworthiness Directive (AD) 2016-25-29, which applied to certain The Boeing Company Model 767-200 and -300 series airplanes. AD 2016-25-29 required replacing the cargo compartment insulation blankets on the left and right sides with new insulation blankets that incorporate fire stops. This AD was prompted by a report of a fire in the bilge area of the cargo compartment that burned through the insulation blankets that were intended to prevent smoke from migrating behind the cargo compartment sidewall liners and upward into the main cabin. This AD continues to require the actions in AD 2016-25-29 for certain airplanes. This AD also adds airplanes to the applicability and requires a general visual inspection of the replacement insulation blankets to determine if the blankets are in serviceable condition and correctly installed, and applicable on-condition actions. For certain airplanes, this AD also requires an inspection to determine the insulation blanket part number installed; replacement of additional insulation blankets; and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective July 29, 2021.

The Director of the Federal Register approved the incorporation by reference of a certain publications listed in this AD as of July 29, 2021.

ADDRESSES:

For service information identified in this final rule, 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, 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 https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0680.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0680; 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 final rule, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Julie Linn, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2016-25-29, Amendment 39-18755 (81 FR 94956, December 27, 2016) (AD 2016-25-29). AD 2016-25-29 applied to certain The Boeing Company Model 767-200 and -300 series airplanes, and required replacing the cargo compartment insulation blankets on the left and right sides with new insulation blankets that incorporate fire stops. The NPRM published in the Federal Register on August 10, 2020 (85 FR 48122). The NPRM was prompted by a report of a fire in the bilge area of the cargo compartment that burned through the insulation blankets that were intended to prevent smoke from migrating behind the cargo compartment sidewall liners and upward into the main cabin. In the NPRM, the FAA proposed to continue to require the actions in AD 2016-25-29 for certain airplanes. The NPRM also proposed to add airplanes to the applicability and proposed to require a general visual inspection of the replacement insulation blankets to determine if the blankets are in serviceable condition and correctly installed, and applicable on-condition actions. For certain airplanes, the NPRM also proposed to require an inspection to determine the insulation blanket part number installed; replacement of additional insulation blankets; and applicable on-condition actions. The FAA is issuing this AD to address a fire in the bilge area of the cargo compartment, which if not contained could lead to a possible smoke and fire event in the passenger compartment.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from three commenters, including Aviation Partners Boeing, Delta Air Lines (DAL), and United Airlines (UAL). The following presents the comments received on the NPRM and the FAA's response to each comment.

Effect of Winglets on Accomplishment of the Proposed Actions

Aviation Partners Boeing stated that the installation of winglets per Supplemental Type Certificate (STC) ST01920SE does not affect the accomplishment of the manufacturer's service instructions.

The FAA agrees with the commenter that STC ST01920SE does not affect the accomplishment of the manufacturer's service instructions. Therefore, the installation of STC ST01920SE does not affect the ability to accomplish the actions required by this AD. The FAA has not changed this AD in this regard.

Request To Delay Rule Pending Revised Referenced Service Information

UAL concurs with the NPRM and requested that the FAA delay issuance of the final rule until the referenced Illustrated Parts Catalog (IPC) and airplane maintenance manual (AMM) specified in Boeing Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, are revised to ensure continued airworthiness and safety. UAL stated that the referenced service information will provide proper documentation support to maintain the insulation blanket changes specified in Boeing Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, prior to the release of the final rule. UAL also commented that the revised referenced service information can mitigate incorrect repairs and blanket installation, and minimize future alternative methods of compliance (AMOC) requests.

The FAA disagrees with delaying the final rule. Since the publication of the NPRM, the operator's existing IPC and AMM have been revised and provide accurate part numbers and corrective action procedures for missing insulation blankets. In addition, an operator unable to accomplish the actions in this AD for any reason may request approval of an AMOC under the provisions of paragraph (i)(1) of this AD, if sufficient data are submitted to substantiate that the change would provide an acceptable level of safety. The FAA has not changed this AD in this regard.

Request To Identify Proper Insulation Blankets

UAL expressed concern about the post-compliance maintenance configuration using Boeing Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, in the absence of a revised Boeing 767 IPC (i.e., Boeing 767 IPC sections 25-21-05; 25-52-03; 25-52-52; 25-52-62; 25-55-01) to identify the proper insulation blankets with integrated fire stops. UAL described disagreements in the service information for the identity of the insulation blanket installations and corresponding part numbers in the aft and forward cargo compartment of post-modification airplanes and missing insulation blankets from certain appendixes and figures. UAL stated that it is essential to identify post-service bulletin configurations in certain Boeing 767 IPCs to ensure that AD compliance is maintained and to avoid inadvertent demodification by maintenance technicians. UAL commented that the configuration control for the airplane is the IPC, which maintenance technicians use for proper part replacement, and would alert maintenance personnel of insulation blankets having the integrated fire stops to ensure continued airworthiness.

As the FAA stated previously, since the NPRM was issued, relevant sections of the IPC have been revised. The operator's existing IPC contains the accurate part numbers and corrects missing insulation blankets. For clarification, the part numbers for the insulation blankets specified in Boeing Special Attention Service Bulletin 767-25-0550, dated January 15, 2015, and Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, are acceptable for installation; the new part numbers requires less work to install. The FAA has revised paragraph (h)(4) of this AD accordingly.

In addition, Boeing found that the insulation blankets at certain locations were not affected by the integrated fire stop issue that are addressed in Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019. Therefore, these insulation blankets were removed from Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019. Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, includes work to re-inspect the installation of the insulation blankets that were installed in Boeing Special Attention Service Bulletin 767-25-0550, dated January 15, 2015. Since those insulation blankets that are not affected by the fire stop issue were removed from Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, there is no need for instructions in Revision 1 to inspect the work that was performed in Boeing Special Attention Service Bulletin 767-25-0550, dated January 15, 2015. The FAA has not changed this AD in this regard.

Request To Correct the Date of the Service Information

UAL commented that, in the toolbox on https://www.myboeingfleet.com,, there are two versions of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1: One version is dated December 4, 2019, and one version is dated December 5, 2019. UAL also commented that the header of the toolbox states that Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, is not the current version. UAL stated that the proper service information date needs to be addressed in the NPRM.

The FAA has confirmed that the correct date of the service information is December 4, 2019, and that there is currently only one version of the service information cited on https://www.myboeingfleet.com. The FAA has not changed this AD in this regard.

Request for Correct Figure Reference

DAL commented that figure 42-A of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, refers to item 4 between stations 434 through 456, but it should be item 3. DAL stated this citation has been confirmed by Boeing in Service Request 3-4634446605.

The FAA agrees that the correct reference for figure 42-A between stations 434 through 456 of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, is item 3. In addition, figure 42 is a RC step. The FAA has added paragraph (h)(2) of this AD to identify the correct item number.

Request To Correct Insulation Blanket Location

DAL commented that in figure 51 of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, there should be an insulation blanket depicted between station (STA) 1395 and STA 1417. DAL also commented that appendixes D, E, F, G, H, and I of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, show the insulation blanket part numbers between STA 1395 and STA 1417. DAL reported that Boeing confirmed that the insulation blanket was missing from that figure.

The FAA agrees with the commenter's statement. The FAA has added paragraph (h)(3) of this AD to specify that Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, figures 49, 50, and 51, between STA 1395 and STA 1417, should indicate that an insulation blanket is installed.

Request To Allow Stoppage Options Due to the Pandemic

For airplanes that have been in mass parking due to the worldwide pandemic, DAL requested clock stoppage options such as those offered to operators by the manufacturer for scheduled maintenance program tasks. DAL stated that this request is for airplanes that meet the following conditions:

• Airplanes that are currently undergoing storage, or airplanes that will enter storage during the compliance time of the proposed AD.
• Airplanes that were preserved with instructions in close reference to the AMM procedures.

DAL also commented that an airplane in a preserved state does not experience the following risk factors that are taken into consideration for the proposed AD:

• Passenger Safety: The newly installed insulation blankets are meant to prevent smoke from migrating behind the cargo compartment sidewall liners and upward into the main cabin, where it could affect passengers. If the airplane does not have passengers during the time in which it is preserved, there is no increased risk to the public.
• Potential fire in the cargo compartments: Since the airplane is not in operation, there is no cargo being stored in the cargo compartments, meaning it is highly unlikely that there will be a fire initiated to cause smoke.

In addition, DAL asserted that the safety risk associated with the inferior insulation blankets installed on the airplane is either a small consideration or not a consideration at all in the calculation of overall fleet risk because the concern is not with degradation of insulation blanket material, or any other factor in which an increase in compliance time would increase the risk.

The FAA disagrees with having stoppage options due to the unsafe condition. In developing an appropriate compliance time, the FAA considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the actions in this AD. Further, the FAA arrived at the proposed compliance time with Boeing's concurrence. It is difficult to plan for every possible storage scenario, and currently, the FAA does not have procedures that would address every possible scenario to ensure that all airplanes will be addressed in a timely manner once the airplanes are back in service. If an operator is unable to accomplish the actions in this AD for whatever reason or has the airplane in storage, it may request approval of an AMOC under the provisions of paragraph (i)(1) of this AD, if sufficient data are submitted to substantiate that the change would provide an acceptable level of safety. The FAA has not changed this AD in this regard.

Conclusion

The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019. The service information describes procedures for replacement of cargo compartment insulation blankets between stringers 29 and 33, on the left and right sides, with new insulation blankets that incorporate fire stops; an inspection to determine the insulation blanket part number installed between stringers 29 and 33, on the left and right sides; a general visual inspection of the replacement insulation blankets between stringers 29 and 33, on the left and right sides to determine if the insulation blankets are in serviceable condition and correctly installed; and applicable on-condition actions. On-condition actions include repair, replacement, and correction of insulation blanket installations. 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.

Costs of Compliance

The FAA estimates that this AD affects 329 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs for Required Actions

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Replacement (retained actions from AD 2016-25-29)	Up to 54 work-hours × $85 per hour = Up to $4,590	(*)	Up to $4,590	Up to $1,510,110.
Inspections and replacements (new proposed action)	Up to 62 work-hour × $85 per hour = Up to $5,270	Up to $35,900	Up to $41,170	Up to $13,944,530.
* The FAA has received no definitive data that would enable providing parts cost estimates for the retained actions specified in this AD.

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

According to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. The FAA does not control warranty coverage for affected operators. As a result, the FAA has included all available costs in our cost estimate.

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

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.

For the reasons discussed above, I certify that this AD:

(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 Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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:

a. Removing Airworthiness Directive (AD) 2016-25-29, Amendment 39-18755 ( 81 FR 94956, December 27, 2016); and

b. Adding the following new AD:

2021-12-11 The Boeing Company: Amendment 39-21598; Docket No. FAA-2020-0680; Project Identifier 2020-NM-079-AD.

(a) Effective Date

This airworthiness directive (AD) is effective July 29, 2021.

(b) Affected ADs

This AD replaces AD 2016-25-29, Amendment 39-18755 (81 FR 94956, December 27, 2016) (AD 2016-25-29).

(c) Applicability

This AD applies to The Boeing Company Model 767-200, -300, -300F, and -400ER series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019.

(d) Subject

Air Transport Association (ATA) of America Code 25, Equipment/furnishings.

(e) Unsafe Condition

This AD was prompted by a report of a fire in the bilge area of the cargo compartment that burned through the insulation blankets that were intended to prevent smoke from migrating behind the cargo compartment sidewall liners and upward into the main cabin. The FAA is issuing this AD to address a fire in the bilge area of the cargo compartment, which if not contained could lead to a possible smoke and fire event in the passenger compartment.

(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 paragraph 1.E., “Compliance,” of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, do all applicable actions identified as “RC” (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019.

(h) Exceptions and Clarifications to Service Information Specifications

(1) Where Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, uses the phrase “the Revision 1 date of this service bulletin,” this AD requires using “the effective date of this AD.”

(2) Where Figure 42-A of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, identifies item 4 between stations 434 through 456, the correct item between stations 434 through 456 is item 3.

(3) Figures 49, 50, and 51 of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, are missing the depiction of an insulation blanket, and an installation blanket must be installed between station (STA) 1395 and 1417.

(4) The part numbers for the insulation blankets specified in Boeing Special Attention Service Bulletin 767-25-0550, dated January 15, 2015, and Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, are acceptable for installation; the new part numbers specified in Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, require less work to install.

(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 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 (j) 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.

(4) AMOCs approved previously for AD 2016-25-29 are approved as AMOCs for the corresponding provisions of Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019, that are required by paragraph (g) of this AD.

(5) For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (i)(5)(i) and (ii) of this AD apply.

(i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or substep is labeled “RC Exempt,” then the RC requirement is removed from that step or substep. An AMOC is required for any deviations to RC steps, including substeps and identified figures.

(ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition.

(j) Related Information

For more information about this AD, contact Julie Linn, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: [phone]; email: [e-mail].

(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 Special Attention Service Bulletin 767-25-0550, Revision 1, dated December 4, 2019.

(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 [phone]; internet https://www.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, email [e-mail], or go to: https://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on June 3, 2021.

Gaetano A. Sciortino,

Deputy Director for Strategic Initiatives, Compliance & Airworthiness Division, Aircraft Certification Service.