Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (SNPRM); reopening of comment period.

SUMMARY:

The FAA is revising an earlier proposal to supersede Airworthiness Directive (AD) 2013-07-09, which applies to certain The Boeing Company Model 737-700, -700C, -800, and -900ER series airplanes, Model 747-400F series airplanes, and Model 767-200 and -300 series airplanes. This action revises the notice of proposed rulemaking (NPRM) by adding airplanes to the applicability. The FAA is proposing this AD to address the unsafe condition on these products. Since these actions would impose an additional burden over that proposed in the NPRM, the FAA is reopening the comment period to allow the public the chance to comment on these proposed changes.

DATES:

The comment period for the NPRM published in the Federal Register on June 25, 2019 (84 FR 29818), is reopened.

The FAA must receive comments on this SNPRM by December 21, 2020.

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 Boeing service information identified in this SNPRM, 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. For Intertechnique service information identified in this SNPRM, contact Aerotechnics, 61 rue Pierre Curie BP 1, 78373 Plaisir, CEDEX, France; phone: +33 1 6486 6964; internet http://www.zodiacaerospace.com. You may view this referenced 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 on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0480.

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-2019-0480; 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 SNPRM, 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:

Eric Brown, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3563; email: Eric.M.Brown@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to participate in this rulemaking by submitting written comments, data, or views about this proposal. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should submit only one copy of the comments. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2019-0480; Product Identifier 2019-NM-041-AD” at the beginning of your 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, as well as a report summarizing each substantive public contact with FAA personnel concerning this proposed rulemaking. Before acting on this proposal, the FAA will consider all comments received by the closing date for comments. The FAA will consider comments filed after the comment period has closed if it is possible to do so without incurring expense or delay. The FAA may change this SNPRM because of those comments.

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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should be sent to Eric Brown, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3563; email: Eric.M.Brown@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.

Discussion

The FAA issued AD 2013-07-09, Amendment 39-17413 (78 FR 22178, April 15, 2013) (“AD 2013-07-09”). AD 2013-07-09 requires actions to address an unsafe condition on certain The Boeing Company Model 737-700, -700C, -800, and -900ER series airplanes, Model 747-400F series airplanes, and Model 767-200 and -300 series airplanes. AD 2013-07-09 requires a general visual inspection for affected serial numbers of the crew oxygen mask stowage box units, and replacement or re-identification as necessary.

The FAA issued an NPRM to amend 14 CFR part 39 by adding an AD to supersede AD 2013-07-09 that would apply to all The Boeing Company Model 737-700, -700C, -800, and -900ER series airplanes, Model 747-400F series airplanes, and Model 767-200 and -300 series airplanes. The NPRM published in the Federal Register on June 25, 2019 (84 FR 29818) (“the NPRM”). The NPRM was prompted by reports indicating that certain crew oxygen mask stowage box units were possibly delivered with a burr in the inlet fitting. The burr might break loose during test or operation, and might pose an ignition source or cause an inlet valve to jam. The NPRM was also prompted by a determination that the affected parts may be installed on airplanes outside the applicability of AD 2013-07-09. The NPRM proposed to require a general visual inspection for affected serial numbers of the crew oxygen mask stowage box units, and replacement or re-identification as necessary.

Actions Since NPRM Was Issued

Since the FAA issued the NPRM, it has been determined that the affected parts may be installed as rotable spares on airplanes outside of the applicability of the NPRM, thereby subjecting those airplanes to the unsafe condition. Therefore, the applicability in this proposed AD has been expanded to add all The Boeing Company Model 737-200, 300, -400, -500, -600, and -900 series airplanes; Model 737-8 and 737-9 airplanes; Model 747-200B, 747-200C, 747-200F, 747-400, and 747-400D series airplanes; Model 757-200, -200PF, -200CB, and -300 series airplanes; and Model 767-300F, and -400ER series airplanes.

Related Service Information Under 1 CFR Part 51

This proposed AD would require Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; and Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011; which the Director of the Federal Register approved for incorporation by reference as of May 20, 2013 (78 FR 22178, April 15, 2013). 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.

Comments

The FAA gave the public the opportunity to comment on the NPRM. 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 blended or split scimitar winglets per Supplemental Type Certificate (STC) ST00830SE on Model 737NG airplanes (Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes), and blended winglets per STC ST01920SE on Model 767 airplanes, does not affect the accomplishment of the manufacturer's service instructions.

The FAA agrees with the commenter that STC ST00830SE and STC ST01920SE do not affect the accomplishment of the manufacturer's service instructions. Therefore, the installation of STC ST00830SE or STC ST01920SE does not affect the ability to accomplish the actions required by this proposed AD. The FAA has not changed this proposed AD in this regard.

Request To Expand the Applicability of the Proposed AD

United Airlines (UAL), Delta Airlines (DAL), American Airlines (AAL), and Boeing requested that the FAA expand the applicability of the proposed AD to include all Boeing airplane models on which the part could possibly be installed. Boeing noted that it permits installation of the affected oxygen mask boxes on several of their models. The commenters pointed out that the affected parts can be installed on more airplane models than are specified in the applicability of the proposed AD. AAL pointed out that adding additional airplane models on which the crew oxygen mask stowage box units could be installed to the proposed AD could prevent future additional regulatory action for the same part numbers of the crew oxygen mask stowage box units.

The FAA agrees with the request to expand the applicability of the proposed AD for the reasons provided. The FAA has revised paragraph (c) of this proposed AD to include all The Boeing Company Model 737-200, -300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series airplanes; Model 737-8 and 737-9 airplanes; Model 747-200B, 747-200C, 747-200F, 747-400, 747-400D, and 747-400F series airplanes; Model 757-200, -200PF, -200CB, and -300 series airplanes; and Model 767-200, -300, -300F, and -400ER series airplanes. This revision includes adding paragraphs (c)(4) and (5) of this proposed AD.

Request To Remove Paragraph (i)(3) of the Proposed AD

AAL requested that paragraph (i)(3) of the proposed AD be removed. AAL stated that it does not believe that re-installing the crew oxygen mask stowage box units after they have been inspected in accordance with paragraph (i)(1) of the proposed AD should be regarded as a mandatory regulatory item. AAL maintained that paragraph (i)(3) of the proposed AD does not appear to address any safety concern regarding the stowage boxes. AAL reasoned that removing paragraph (i)(3) of the proposed AD does not impact airplane safety and airworthiness and that the removal and reinstallation of the crew oxygen mask stowage box units can be done safely using the aircraft maintenance manual (AMM). AAL went on to recommend that if paragraph (i)(3) of the proposed AD is retained, it should be revised to include an option to install a new or serviceable crew oxygen mask stowage box unit.

The FAA agrees with the commenter's request to delete paragraph (i)(3) from this proposed AD for the reasons provided. The FAA notes that existing regulations require maintaining airplanes in an airworthy condition, which would include reinstalling removed parts. In addition, reinstalling a part does not directly address the unsafe condition identified in this AD. The FAA has deleted paragraph (i)(3) from this proposed AD.

Request To Remove Certain Required Service Information

AAL requested that the FAA remove Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; and Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; from the requirements in paragraph (i) of the proposed AD. All Nippon Airways (ANA) noted that the key point of the proposed AD is removing the crew oxygen mask stowage boxes identified in table 1 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011. ANA requested that operators be allowed to show compliance through referencing the service information only for serial number identification (the FAA infers ANA is requesting that the FAA revise the proposed AD to not require doing the inspections and replacements in accordance with the service information). AAL noted that it does not operate any of the airplanes identified in the effectivity of the specified service information, though the proposed AD would apply to its fleet. AAL noted that this discrepancy could cause confusion regarding showing compliance with the proposed AD and may lead to several alternative method of compliance (AMOC) approval requests. AAL stated that it does not believe that the phrase “for airplanes other than those identified in paragraph (g) of this AD” in paragraph (i) of the proposed AD is sufficient to address its concerns about showing compliance with the proposed AD. AAL went on to suggest that removing the service information would be an acceptable change to the proposed AD because the inspection for the part number and serial number of crew oxygen mask stowage boxes is a common and straightforward maintenance action. AAL noted that operators remove and replace the crew oxygen mask stowage boxes by using the instructions in AMMs and stated that the service information specified in the proposed AD does not contain instructions not already in the AMMs. AAL observed that many of the work instructions in the service information require the operator to reference its applicable AMM for additional instructions, and the AMMs define the general visual inspection of the crew oxygen mask stowage boxes for the serial number. Additionally, AAL pointed out that paragraph (i) of the proposed AD would mandate accomplishment of the general visual inspection of the crew oxygen mask stowage boxes for the serial number.

The FAA agrees with the commenters' request. The service information referenced in the proposed AD does not include all airplanes on which the affected crew oxygen mask stowage units may be installed, and operators may have difficulty determining which part of the Accomplishment Instructions to comply with. In addition, as AAL noted, the service information refers operators to applicable AMM tasks for replacing affected parts. The FAA has determined that operators can use existing accepted procedures, including AMM tasks, to perform the inspections and replacements specified in paragraph (i) of this proposed AD. The FAA has therefore revised the introductory text of paragraph (i) and paragraphs (i)(1) and (2) of this proposed AD to remove the requirement to use certain service information to do the inspections and replacements specified in this proposed AD. As noted previously, the FAA has deleted paragraph (i)(3) from this proposed AD.

Request To Revise the Effectivity of the Service Information

DAL, ANA, and Cathay Pacific requested that Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; and Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; be revised to correctly reflect the applicability of the proposed AD. DAL also recommended that new service information be released to provide instructions for any models that might be added to the applicability of the proposed AD. ANA noted that it has airplanes not reflected in the effectivity of the service information and added that it cannot determine which instructions to follow for those airplanes because the service information lists groups by airplane variable numbers. Cathay Pacific Airways noted that it is not possible to satisfy the requirements of paragraph (i) of the proposed AD unless the effectivity of the service information is revised.

The FAA acknowledges the commenters' concern regarding the service information effectivity. As noted previously, the FAA has determined that the actions specified in the introductory text of paragraph (i) and paragraphs (i)(1) and (2) of this proposed AD can be done using existing accepted procedures, including AMM tasks. The FAA has revised the introductory text of paragraph (i) and paragraphs (i)(1) and (2) of this proposed AD to remove reference to the Boeing service information. This revision allows operators to use existing accepted procedures to perform the specified actions, negating the need to revise existing service information or create new service information for the models being added to this proposed AD.

Request To Allow Installation of Certain Crew Oxygen Mask Stowage Boxes

AAL requested that the FAA allow installation of crew oxygen mask stowage boxes if the serial number is illegible, but the date of manufacture can be determined to be outside of the range of July 12, 2007, through November 20, 2007, inclusive. AAL requested that this exception be included in the proposed AD, and recommended revising paragraph (i)(1) of the proposed AD. AAL reasoned that this change to the language in paragraph (i)(1) of the proposed AD would avoid possible misinterpretation of the compliance requirements of the proposed AD for airplanes on which the Boeing service information is not effective as well as prevent unnecessary removal of crew oxygen mask stowage boxes. AAL stated that the proposed new language would allow it to show compliance on its Boeing Model 757-200 airplanes and Model 737-8 airplanes, if those airplanes are added to the applicability of the proposed AD.

The FAA agrees that crew oxygen mask stowage box units manufactured outside of the range of July 12, 2007, through November 20, 2007, inclusive are not subject to the unsafe condition identified in this proposed AD. The FAA has revised paragraph (i)(1) of this proposed AD to state that “If any crew oxygen mask stowage box unit's serial number is unreadable or undetermined, but the manufacturing date can conclusively be determined to be outside the range of July 12, 2007, through November 20, 2007, inclusive, the crew oxygen mask stowage box unit does not need to be replaced.”

Request To Remove Paragraph (i)(2) of the Proposed AD

AAL requested that the FAA remove paragraph (i)(2) of the proposed AD. AAL stated that it understands that all the crew oxygen mask stowage box units' serial numbers included in table 2 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, have been inspected and have already been determined to be compliant. AAL reasoned that paragraph (i)(2) of the proposed AD does not address any safety concerns and adds an undue burden on operators. AAL pointed out that Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, is included in the applicable component maintenance manual, and it is a mandatory inspection item within AAL's component maintenance program. AAL stated that it believes it is acceptable to re-identify the crew oxygen mask stowage box units included in table 2 of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, on attrition, as these stowage box units are removed from the airplane and sent for routine maintenance, without any safety impact.

The FAA disagrees with the commenter's request. Marking the acceptable parts is necessary so they can be easily identified and operators can verify that the actions specified by this proposed AD have been done on this part. In addition, the FAA notes that not all operators may have such a requirement in their component maintenance program, so an AD requirement is the appropriate means to ensure this action is done uniformly among operators. Therefore, the FAA has not changed this proposed AD regarding this issue.

Request To Revise Parts Installation Prohibition

AAL requested that the FAA revise paragraph (j) of the proposed AD to limit the prohibition to parts specified in table 1 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, as only those parts that present a safety risk. AAL and DAL requested that the FAA revise paragraph (j) of the proposed AD to exclude stowage boxes that have been corrected and re-identified as specified in Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011.

The FAA agrees with the request to revise paragraph (j) of the proposed AD. Only crew oxygen mask stowage box units with a serial number identified in table 1 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2 dated May 10, 2011, are prohibited from installation on an airplane. Crew oxygen mask stowage box units that are inspected and determined to have a serial number identified in table 2 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, may be installed on an airplane, provided they are modified as required by paragraph (i)(2) of this proposed AD. The FAA has revised paragraph (j) of this proposed AD accordingly, including restructuring the paragraph to add paragraphs (j)(1) and (2) of this proposed AD.

Request To Delay Start of Parts Installation Prohibition

UAL requested that the FAA delay the start of the parts installation prohibition specified in paragraph (j) of the proposed AD to “within 30 days after the effective date of this AD” as opposed to “as of the effective date of this AD.” UAL stated that restricting the installation of the crew oxygen mask box assemblies immediately after the effective date of the AD presents a logistical challenge that could disrupt supply chain balances. UAL pointed to the challenges presented by previous similar rulemaking regarding crew oxygen equipment, and argued that operators, the OEMs, and suppliers lost considerable time, effort, and material as operators ordered an over-abundance of parts prior to knowing the modification status of existing parts and crew oxygen equipment needs. UAL noted that it performs a system-wide inventory to determine its material requirements, then allocates the appropriate resources to inspect and modify a suitable number of components to begin its program, and that other carriers use similar processes. UAL stated that it does not believe that delaying the start of the parts installation prohibition would significantly increase any level of risk in relation to the total time allowed for operators to comply with the rest of the proposed AD.

The FAA disagrees with the commenter's request. This proposed AD specifies a parts installation prohibition with a timeline similar to that in AD 2013-07-09. The FAA notes that in developing appropriate compliance times for this proposed AD, the FAA considered the safety implications, parts availability, and normal maintenance schedules for the timely accomplishment of the proposed actions. Additionally, the FAA notes that the number of affected parts did not increase, only the range of airplane models on which those parts could possibly be installed.

Request To Change to an Appliance-Based AD

Boeing requested that the FAA consider issuing an appliance-based AD that is based on a component or appliance service bulletin. Boeing suggested that a component or appliance service bulletin would capture the applicability in the form of a serial number range, rather than expanding the scope of the proposed AD to all airplane line numbers. Boeing acknowledged the difference between the effectivity specified in the Boeing service information and the applicability of the proposed AD. Boeing stated it understands the FAA's concerns regarding the possibility of parts being rotated outside the effectivity contained in the Boeing service information. As a result, Boeing expressed its desire to seek an alternative solution to address the concerns of the FAA. Boeing recommended a collaboration between airline partners, other original equipment manufacturers (OEMs), and civil aviation authorities to develop an action to implement safe, fair, and consistent policy to address concerns on rotable parts for the industry.

The FAA does not agree with the request to issue an appliance-based AD that applies to specific components or appliances. The FAA has determined that the affected parts are installed only on Boeing airplanes, so an appliance-based AD is not appropriate. In addition, the affected parts are rotable parts, and the FAA has determined that, regardless of operator diligence, these parts could later be installed on Boeing airplanes that were initially delivered with acceptable parts, thereby subjecting those airplanes to the unsafe condition. Therefore, the FAA has not changed this proposed AD in this regard.

Request To Extend the Compliance Time

DAL, UAL, and AAL requested that the compliance time for the inspection specified in paragraph (i) of the proposed AD be extended from 24 months to 36 months. UAL and DAL cited concern over parts availability due to the expansion of the applicability in the proposed AD. DAL noted there is a long lead time to obtain replacement parts. DAL and AAL stated that existing pre-flight checks provide a sufficient level of safety by accomplishing regular functional checks of the oxygen mask box assemblies, which would identify any units that are not functioning correctly. DAL maintained that the additional compliance time will allow sufficient time to adequately inspect all fleets. AAL stated that an extended compliance time would allow it to perform inspections in a main base environment where more ground time and manpower are available. AAL also noted that some of the older crew oxygen mask stowage boxes have parts data printed on the boxes instead of physical data plates; the printed data is more prone to scratches which cause difficulty in identifying the part information. AAL reasoned that this difficulty coupled with the large amount of boxes that must be inspected could cause operational disruptions.

The FAA does not agree with the commenters' request. In developing an appropriate compliance time for this action, the FAA considered the safety implications, parts availability, and normal maintenance schedules for the timely accomplishment of the inspection and replacement or re-identification as necessary. The FAA has determined an adequate number of replacement parts will be available within the compliance time specified in this proposed AD. Additionally, the number of affected parts did not increase, only the range of airplane models on which those parts could possibly be installed. In consideration of these items, the FAA has determined that a 24-month compliance time will ensure an acceptable level of safety. The FAA has not changed the proposed AD in this regard.

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. Certain changes described above expand the scope of the NPRM. As a result, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this SNPRM.

Proposed Requirements of This SNPRM

This SNPRM would require accomplishing the actions specified in the service information described previously. For information on the procedures and compliance times, see Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; and Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011; at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0480.

Costs of Compliance

The FAA estimates that this proposed AD affects 3,723 airplanes 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 providing cost estimates for the on-condition actions 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.

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

a. Removing Airworthiness Directive (AD) 2013-07-09, Amendment 39-17413 ( 78 FR 22178, April 15, 2013); and

b. Adding the following new AD:

The Boeing Company: Docket No. FAA-2019-0480; Product Identifier 2019-NM-041-AD.

(a) Comments Due Date

The FAA must receive comments on this AD action by December 21, 2020.

(b) Affected ADs

This AD replaces AD 2013-07-09, Amendment 39-17413 (78 FR 22178, April 15, 2013) (“AD 2013-07-09”).

(c) Applicability

This AD applies to all The Boeing Company airplanes, certificated in any category, as identified in paragraphs (c)(1) through (5) of this AD.

(1) Model 737-200, -300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series airplanes.

(2) Model 737-8 and 737-9 airplanes.

(3) Model 747-200B, 747-200C, 747-200F, 747-400, 747-400D, and 747-400F series airplanes.

(4) Model 757-200, -200PF, -200CB, and -300 series airplanes.

(5) Model 767-200, -300, -300F, and -400ER series airplanes.

(d) Subject

Air Transport Association (ATA) of America Code 35, Oxygen.

(e) Unsafe Condition

This AD was prompted by reports indicating that certain crew oxygen mask stowage box units were possibly delivered with a burr in the inlet fitting. The burr might break loose during test or operation, and might pose an ignition source or cause an inlet valve to jam. This AD was also prompted by a determination that the affected parts may be installed on airplanes outside the applicability of AD 2013-07-09. The FAA is issuing this AD to address this possible ignition source, which could result in an oxygen-fed fire; or an inlet valve jam in a crew oxygen mask stowage box unit, which could result in restricted flow of oxygen.

(f) Compliance

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

(g) Retained Inspection and Corrective Action, With No Changes

This paragraph restates the requirements of paragraph (g) of AD 2013-07-09 with no changes. For The Boeing Company Model 737 airplanes as identified in Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; The Boeing Company Model 747 airplanes as identified in Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; and The Boeing Company Model 767 airplanes as identified in Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011: Within 24 months after May 20, 2013 (the effective date of AD 2013-07-09); Do a general visual inspection to determine if the serial number of the crew oxygen mask stowage box unit is identified in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; or Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; as applicable. A review of airplane maintenance records is acceptable in lieu of this inspection if the serial number of the crew oxygen mask stowage box unit can be conclusively determined from that review.

(1) If any crew oxygen mask stowage box unit has a serial number identified in table 1 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011: Before further flight, replace the crew oxygen mask stowage box unit with a new or serviceable unit in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; or Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; as applicable.

(2) If any crew oxygen mask stowage box unit has a serial number identified in table 2 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011: Before further flight, add the letter “I” to the end of the serial number (identified as “SER”) on the identification label, in accordance with the Accomplishment Instructions of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011; and reinstall in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; or Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; as applicable.

(3) If no crew oxygen mask stowage box unit has a serial number identified in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011: Unless a records review was done to determine the serial number, before further flight, reinstall the crew oxygen mask stowage box unit, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011; Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011; or Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; as applicable.

(h) Retained Parts Installation Prohibition, With No Changes

This paragraph restates the requirements of paragraph (h) of AD 2013-07-09 with no changes. For airplanes identified in paragraph (g) of this AD: As of May 20, 2013 (the effective date of AD 2013-07-09), no person may install a crew oxygen mask stowage box unit with a serial number listed in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, on any airplane.

(i) New Inspection and Corrective Action

For airplanes other than those identified in paragraph (g) of this AD: Within 24 months after the effective date of this AD, do a general visual inspection to determine if the serial number of the crew oxygen mask stowage box unit is identified in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011. A review of airplane maintenance records is acceptable in lieu of this inspection if the serial number of the crew oxygen mask stowage box unit can be conclusively determined from that review.

(1) If any crew oxygen mask stowage box unit has a serial number identified in table 1 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011: Before further flight, replace the crew oxygen mask stowage box unit with a new or serviceable unit. If any crew oxygen mask stowage box unit's serial number is unreadable or undetermined, but the manufacturing date can conclusively be determined to be outside the range of July 12, 2007, through November 20, 2007, inclusive, the crew oxygen mask stowage box unit does not need to be replaced.

(2) If any crew oxygen mask stowage box unit has a serial number identified in table 2 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011: Before further flight, add the letter “I” to the end of the serial number (identified as “SER”) on the identification label, in accordance with the Accomplishment Instructions of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011; and reinstall the crew oxygen mask stowage box unit.

(j) New Parts Installation Prohibition

(1) For airplanes other than those identified in paragraph (g) of this AD: As of the effective date of this AD, no person may install a crew oxygen mask stowage box unit with a serial number identified in table 1 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, on any airplane.

(2) For airplanes other than those identified in paragraph (g) of this AD: As of the effective date of this AD, no person may install a crew oxygen mask stowage box unit with a serial number identified in table 2 of the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, on any airplane, unless that crew oxygen mask stowage box unit has been modified as required by paragraph (i)(2) of this AD.

(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 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 (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 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 2013-07-09 are approved as AMOCs for the corresponding provisions of this AD.

(l) Related Information

(1) For more information about this AD, contact Eric Brown, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3563; email: Eric.M.Brown@faa.gov.

(2) For Boeing 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.

(3) For Intertechnique service information identified in this AD, contact Aerotechnics, 61 rue Pierre Curie BP 1, 78373 Plaisir, CEDEX, France; phone: +33 1 6486 6964; internet http://www.zodiacaerospace.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.