Document ID: FAA-2019-0480-0010
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2020-11-05T05:00Z

[Federal Register Volume 85, Number 215 (Thursday, November 5, 2020)]
[Proposed Rules]
[Pages 70526-70531]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-24346]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0480; Product Identifier 2019-NM-041-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

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

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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

[[Page 70527]]

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)

[[Page 70528]]

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.

[[Page 70529]]

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

[[Page 70530]]

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:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection (retained action from AD     1 work-hour x $85 per                 $0             $85          $3,400
 2013-07-09) (40 airplanes).             hour = $85.
Inspection (new action) (3,683          1 work-hour x $85 per                  0              85         313,055
 airplanes).                             hour = $85.
----------------------------------------------------------------------------------------------------------------

    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

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by
0
a. Removing Airworthiness Directive (AD) 2013-07-09, Amendment 39-17413 
(78 FR 22178, April 15, 2013); and
0
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

[[Page 70531]]

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.

    Issued on October 14, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-24346 Filed 11-4-20; 8:45 am]
BILLING CODE 4910-13-P