DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1479; Project Identifier AD-2022-00703-T]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all The Boeing Company Model 737-100, 737-200, 737-200C, 737-300,
737-400, 737-500, 737-600, 737-700, 737-700C, 737-800, 737-900, 737-
900ER, 757-200, 757-200PF, 757-200CB, 757-300, 767-200, 767-300, 767-
300F, and 767-400ER series airplanes. This proposed AD was prompted by
reports indicating premature aging of certain passenger chemical oxygen
generators. This proposed AD would require repetitively replacing
affected chemical oxygen generators with serviceable parts. This
proposed AD would also limit the installation of affected parts. The
FAA is proposing this AD to address the unsafe condition on these
products.

DATES: The FAA must receive comments on this proposed AD by January 23,
2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: 202-493-2251.
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.

Examining the AD Docket

You may examine the AD docket at regulations.gov by searching for
and locating Docket No. FAA-2022-1479; or in person at Docket
Operations between 9 a.m. and 5 p.m., Monday through Friday, except
Federal holidays. The AD docket contains this NPRM, any comments
received, and other information. The street address for Docket
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Nicole S. Tsang, Aerospace Engineer,
Cabin Safety and Environmental Systems Section, FAA, Seattle ACO
Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-
3959; email: nicole.s.tsang@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2022-1479; Project Identifier
AD-2022-00703-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Nicole S. Tsang, Aerospace Engineer, Cabin Safety and Environmental
Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des
Moines, WA 98198; phone: 206-231-3959; email: nicole.s.tsang@faa.gov.
Any commentary that the FAA receives that is not specifically
designated as CBI will be placed in the public docket for this
rulemaking.

Background

The FAA has been notified by the European Union Aviation Safety
Agency (EASA), which is the Technical Agent for the Member States of
the European Union, of an issue with the B/E Aerospace 117042-XX series
chemical oxygen generators installed on certain Airbus airplanes. The
units may fail to deliver oxygen to passengers during an emergency on
the airplane. To address this issue on certain Airbus airplanes, EASA
issued AD 2015-0117, dated June 24, 2015, corrected August 7, 2015, and
AD 2019-0140, dated June 12, 2019. The FAA issued corresponding AD
2016-16-02, Amendment 39-18600 (81 FR 53255, August 12, 2016), and AD
2020-04-18, Amendment 39-19855 (85 FR 14409, March 12, 2020),
respectively, which require the replacement of units older than 10
years and impose a 10-year life limit on all 117042-XX series
generators.
The FAA released Special Airworthiness Information Bulletin NM-17-
17, dated June 19, 2017, which indicated that the FAA and B/E Aerospace
Systems planned to conduct further investigation of chemical oxygen
generators in the 117080 series that are 10 to 15 years old since date
of manufacture, to determine if these generators have an issue similar
to the 117042 series generators.
The reduction of useful life was changed for 117080-02, 117080-03,
and 117080-04 series chemical oxygen generators from 15 years to 10
years. Collins Aerospace has Parts Manufacturer Approval (PMA) for
117080-02, 117080-03, and 117080-04 series chemical oxygen generators
on all Boeing Model 737-100, 737-200, 737-200C, 737-300, 737-400, 737-
500, 737-600, 737-700, 737-700C, 737-800, 737-900, 757-200, 757-200PF,
757-200CB, 757-300, 767-200, 767-300, 767-300F, and 767-400ER series
airplanes. However, the applicability of this proposed AD also includes
Boeing Model 737-900ER series airplanes. The FAA determined that Boeing
Model 737-900ER series airplanes are affected because there is concern
that operators might mistake the 737-900ER as a sub-model of the 737-
900, and the 117080-0X series of chemical oxygen generators might be
installed on Boeing Model 737-900ER series airplanes.
Collins Aerospace has observed that mis-actuations are possible 10
years after the manufacturing date and increase in likelihood as the
15-year life is approached. The mis-actuations are associated with the
tin-based chemistry used to manufacture the generators and specifically
appear to be caused by oxidation of tin fuel added to the chemical
core. Collins Aerospace's investigation and analysis concluded that the
chemical core oxidizes in a manner similar to the 117042-XX series
chemical oxygen generators. This condition, if not addressed, could
lead to failure of the generator to activate and consequently not
deliver oxygen during an emergency, possibly resulting in injury to
airplane occupants.

FAA's Determination

The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design. This product has been approved by the
aviation authority of another country, and is approved for operation in
the United States. Pursuant to the FAA's bilateral agreement with the
State of Design Authority, the FAA has been notified of the unsafe
condition described in the AD and service information referenced above.
The FAA is proposing this AD because the FAA evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop on other products of the same type design.

Related Service Information

Collins Aerospace Service Information Letter (SIL) 117080-SIL-002,
dated May 4, 2022, specifies procedures for replacing affected chemical
oxygen generators.

Proposed AD Requirements in This NPRM

This proposed AD would require inspecting the date of manufacture
of chemical oxygen generators having part numbers 117080-02, 117080-03,
and 117080-04, and replacing affected generators with serviceable
units. This proposed AD would also limit the installation of passenger
chemical oxygen generators to serviceable units.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 3,419 airplanes of U.S. registry. The FAA estimates the
following costs to comply with this proposed AD:

Estimated Costs

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.

Regulatory Findings

The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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

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

Sec. 39.13 [Amended]

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