Airworthiness Directives; The Boeing Company Airplanes, 86069-86072 [2023-27100]
Download as PDF
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules
AMS has not identified any relevant
Federal rules that duplicate, overlap, or
conflict with this proposed rule.
A small business guide on complying
with fruit, vegetable, and specialty crop
marketing agreements and orders may
be viewed at: https://
www.ams.usda.gov/rules-regulations/
moa/small-businesses. Any questions
about the compliance guide should be
sent to Richard Lower at the previously
mentioned address in the FOR FURTHER
INFORMATION CONTACT section.
After consideration of all relevant
material presented, including the
information and recommendations
submitted by the Committee and other
available information, USDA has
determined that this proposed rule is
consistent with and will effectuate the
purposes of the Act.
A 30-day comment period is provided
to allow interested persons to respond
to this proposed rule. All written
comments timely received will be
considered before a final determination
is made on this rule.
List of Subjects in 7 CFR Part 958
Marketing agreements, Onions,
Reporting and recordkeeping
requirements.
For the reasons set forth in the
preamble, the Agricultural Marketing
Service proposes to amend 7 CFR part
958 as follows:
PART 958—ONIONS GROWN IN
CERTAIN DESIGNATED COUNTIES IN
IDAHO, AND MALHEUR COUNTY,
OREGON
1. The authority citation for 7 CFR
part 958 continues to read as follows:
■
Authority: 7 U.S.C. 601–674.
■
Assessment rate.
ddrumheller on DSK120RN23PROD with PROPOSALS1
On and after July 1, 2023, an
assessment rate of $0.07 per
hundredweight is established for IdahoEastern Oregon onions.
Erin Morris,
Associate Administrator, Agricultural
Marketing Service.
[FR Doc. 2023–27213 Filed 12–11–23; 8:45 am]
BILLING CODE P
VerDate Sep<11>2014
16:23 Dec 11, 2023
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2023–2234; Project
Identifier AD–2023–00963–T]
RIN 2120–AA64
Airworthiness Directives; The Boeing
Company Airplanes
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
The FAA proposes to adopt a
new airworthiness directive (AD) for all
The Boeing Company Model 737–600,
–700, –700C, –800, –900, and –900ER
series airplanes. This proposed AD was
prompted by two engine fan blade-out
(FBO) events that resulted in the
separation of engine inlet cowl and fan
cowl parts from the airplane. In one
event, fan cowl parts damaged the
fuselage, which caused loss of
pressurization and subsequent
emergency descent. This proposed AD
would require replacing the fasteners on
the fan cowl support beam hinge fittings
for certain airplanes and, for all
airplanes, would require modifying the
radial restraint assembly and installing
an external doubler at the starter vent,
or as an option, installing a serviceable
fan cowl. This proposed AD would also
require revising the existing
maintenance or inspection program, as
applicable, to incorporate new
airworthiness limitations. The FAA is
proposing this AD to address the unsafe
condition on these products.
DATES: The FAA must receive comments
on this proposed AD by January 26,
2024.
SUMMARY:
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.
AD Docket: You may examine the AD
docket at regulations.gov under Docket
No. FAA–2023–2234; or in person at
Docket Operations between 9 a.m. and
ADDRESSES:
2. Revise § 958.240 to read as follows:
§ 958.240
DEPARTMENT OF TRANSPORTATION
Jkt 262001
PO 00000
Frm 00004
Fmt 4702
Sfmt 4702
86069
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.
Material Incorporated by Reference:
• For service information identified
in this NPRM, contact Boeing
Commercial Airplanes, Attention:
Contractual & Data Services (C&DS),
2600 Westminster Blvd., MC 110–SK57,
Seal Beach, CA 90740–5600; telephone
562–797–1717; website
myboeingfleet.com.
• You may view this service
information at the FAA, Airworthiness
Products Section, Operational Safety
Branch, 2200 South 216th St., Des
Moines, WA. For information on the
availability of this material at the FAA,
call 206–231–3195. It is also available at
regulations.gov by searching for and
locating Docket No. FAA–2023–2234.
FOR FURTHER INFORMATION CONTACT: Luis
Cortez-Muniz, Aviation Safety Engineer,
FAA, 2200 South 216th St., Des Moines,
WA 98198; telephone: 206–231–3958;
email: luis.a.cortez-muniz@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–2023–2234; Project Identifier AD–
2023–00963–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
E:\FR\FM\12DEP1.SGM
12DEP1
86070
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules
ddrumheller on DSK120RN23PROD with PROPOSALS1
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 Luis Cortez-Muniz,
Aviation Safety Engineer, FAA, 2200
South 216th St., Des Moines, WA 98198;
telephone: 206–231–3958; email:
luis.a.cortez-muniz@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 received two reports of
engine events that resulted in the
separation of engine inlet cowl and fan
cowl parts from the airplane. One event
occurred in August 2016 on a Boeing
Model 737–700 series airplane powered
by a CFM56–7B engine. The left engine
failed due to the FBO but the airplane
landed successfully. The second event
occurred on April 17, 2018, on a Boeing
Model 737–700 series airplane powered
by a CFM56–7B engine. In that event, an
FBO occurrence resulted in the release
of fan cowl parts and the engine cowling
departing the airplane. The fan cowl
parts damaged the fuselage, which
caused loss of pressurization and
subsequent emergency descent.
Although the airplane landed safely,
there was one passenger fatality. In that
event, the suspected cause of the FBO
occurrence was a low-cycle fatigue
crack in the dovetail of fan blade
number 13 of engine number 1. The
broken fan blade hit the engine fan case
at a critical location causing a
significant impulse, displacement, and
imbalance of the fan rotor effecting the
structural integrity of the engine
cowling.
In response to these events, the FAA
issued two AD actions for the CFM
International S.A. (CFM) Model
CFM56–7B engines. The FAA issued
emergency AD 2018–09–51,
Amendment 39–19287 (83 FR 23794,
May 23, 2018) (AD 2018–09–51), which
requires a one-time ultrasonic
inspection of the concave and convex
sides of the fan blade dovetail. The FAA
also issued AD 2018–26–01,
Amendment 39–19531 (83 FR 66090,
December 26, 2018) (AD 2018–26–01),
which requires initial and repetitive
inspections of the concave and convex
sides of the fan blade dovetail to detect
VerDate Sep<11>2014
16:23 Dec 11, 2023
Jkt 262001
cracking and replacement of any blades
found. The FAA issued AD 2018–09–51
to address fan blade failure due to
cracking, which could result in an
engine in-flight shutdown (IFSD),
uncontained release of debris, damage
to the engine, damage to the airplane,
and possible airplane decompression.
The FAA issued AD 2018–26–01 to
address failure of the fan blade, which
could result in the engine inlet cowl
disintegrating and debris penetrating the
fuselage, causing a loss of
pressurization, and prompting an
emergency descent.
Since AD 2018–09–51 and AD 2018–
26–01 were issued, the FAA has
determined further rulemaking is
necessary to reduce the probability of
unsecured nacelle components, should
an engine fan blade failure occur. As
evidenced by Exemption No. 19212,
dated July 13, 2022 (Docket No. FAA–
2023–2234), Boeing developed
modifications to the inlet cowl, fan
cowl, and exhaust nozzle that must be
accomplished prior to July 31, 2028.
Boeing petitioned and the FAA later
agreed to amend Exemption No. 19212
to 19212A, which added a requirement
that solutions to address potential
maintenance errors must be
incorporated prior to December 31,
2029. However, to implement these
design changes, the FAA must issue
rulemaking to address the unsafe
condition.
This proposed AD would address fan
cowls that are not strengthened, which
could, in the event of an FBO
occurrence, depart the nacelle
potentially damaging a stabilizer, or the
fan cowl could strike the fuselage and
window. The unsafe condition, if not
addressed, could result in loss of control
of the airplane, or in a rapid
decompression and hazard to windowseated passengers aft of the wing.
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.
Related Service Information Under 1
CFR Part 51
The FAA reviewed Boeing Special
Attention Requirements Bulletin 737–
71–1937 RB, dated July 27, 2023. This
service information specifies procedures
for replacing, for certain airplanes, the
fasteners on the fan cowl support beam
hinge fittings on the left and right
engine strut, and, for engine 1 and
engine 2 for all airplanes, modifying the
radial restraint assembly and installing
an external doubler at the starter vent,
PO 00000
Frm 00005
Fmt 4702
Sfmt 4702
or as an option, installing a serviceable
fan cowl.
The service information also requires
revision of the operator’s maintenance
or inspection program, as applicable, by
incorporating certain airworthiness
limitations (AWLs).
This service information is reasonably
available because the interested parties
have access to it through their normal
course of business or by the means
identified in ADDRESSES.
Proposed AD Requirements in This
NPRM
This proposed AD would require
accomplishing the actions specified in
the service information already
described, except as discussed under
‘‘Differences Between this Proposed AD
and the Service Information’’ and except
for any differences identified as
exceptions in the regulatory text of this
proposed AD. For information on the
procedures and compliance times, see
this service information at
regulations.gov under Docket No. FAA–
2023–2234.
This proposed AD would require
revisions to certain operator
maintenance documents to include new
airworthiness limitations. Compliance
with these limitations is required by 14
CFR 91.403(c). For airplanes that have
been previously modified, altered, or
repaired in the areas addressed by this
proposed AD, the operator may not be
able to accomplish the actions described
in the revisions. In this situation, to
comply with 14 CFR 91.403(c), the
operator must request approval for an
alternative method of compliance
according to paragraph (j) of this
proposed AD.
Differences Between This Proposed AD
and the Service Information
Boeing Special Attention
Requirements Bulletin 737–71–1937 RB,
dated July 27, 2023, identifies ‘‘System
Airworthiness Limitation NO. 2—Fan
Blade Out Conditions,’’ and ‘‘System
Airworthiness Limitation NO. 3—Fan
Blade Out Conditions’’ as the
airworthiness limitations that must be
incorporated. In addition to those
system limitations, the FAA has
determined that ‘‘System Airworthiness
Limitation NO. 4—Engine Nacelle
Maintenance Errors’’ must also be
incorporated as specified in paragraph
(h) of this proposed AD. System
Airworthiness Limitation NO. 4
specifically provides the limitation that
mandates solutions to maintenance
errors that must be accomplished prior
to December 31, 2029, as required by
Exemption No. 19212A.
E:\FR\FM\12DEP1.SGM
12DEP1
86071
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules
Costs of Compliance
The FAA estimates that this AD, if
adopted as proposed, would affect 1,979
airplanes of U.S. registry. The FAA
estimates the following costs to comply
with this proposed AD:
ESTIMATED COSTS
Action *
Labor cost
Parts cost
Cost per
product
Modification and Installation ........
140 work-hours × $85 per hour =
$11,900.
Up to 8 work-hour × $85 per hour
= $680.
$1,400 ........................
$13,300 ......................
$26,320,700.
Up to $2,300 ..............
Up to $2,980 ..............
Up to $5,897,420.
Fastener replacement ..................
Cost on U.S.
operators
* The option to install a serviceable fan cowl would cost up to $16,280 per product.
The FAA has determined that revising
the existing maintenance or inspection
program takes an average of 90 workhours per operator, although the agency
recognizes that this number may vary
from operator to operator. Since
operators incorporate maintenance or
inspection program changes for their
affected fleet(s), the FAA has
determined that a per-operator estimate
is more accurate than a per-airplane
estimate. Therefore, the agency
estimates the average total cost per
operator to be $7,650 (90 work-hours ×
$85 per work-hour).
Authority for This Rulemaking
Title 49 of the United States Code
specifies the FAA’s authority to issue
rules on aviation safety. Subtitle I,
section 106, describes the authority of
the FAA Administrator. Subtitle VII:
Aviation Programs, describes in more
detail the scope of the Agency’s
authority.
The FAA is issuing this rulemaking
under the authority described in
Subtitle VII, Part A, Subpart III, Section
44701: General requirements. Under
that section, Congress charges the FAA
with promoting safe flight of civil
aircraft in air commerce by prescribing
regulations for practices, methods, and
procedures the Administrator finds
necessary for safety in air commerce.
This regulation is within the scope of
that authority because it addresses an
unsafe condition that is likely to exist or
develop on products identified in this
rulemaking action.
ddrumheller on DSK120RN23PROD with PROPOSALS1
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.
VerDate Sep<11>2014
16:23 Dec 11, 2023
Jkt 262001
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.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new airworthiness
directive:
■
The Boeing Company: Docket No. FAA–
2023–2234; Project Identifier AD–2023–
00963–T.
(a) Comments Due Date
The FAA must receive comments on this
airworthiness directive (AD) by January 26,
2024.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing
Company Model 737–600, –700, –700C,
–800, –900, and –900ER series airplanes,
certificated in any category.
(d) Subject
Air Transport Association (ATA) of
America Code 71, Powerplant.
PO 00000
Frm 00006
Fmt 4702
Sfmt 4702
(e) Unsafe Condition
This AD was prompted by two engine fan
blade-out (FBO) events that resulted in the
separation of engine inlet cowl and fan cowl
parts from the airplane. In one event, fan
cowl parts damaged the fuselage, which
caused loss of pressurization and
subsequential emergency descent. The FAA
is issuing this AD to address fan cowls that
are not strengthened, which, in the event of
an FBO occurrence, could depart the nacelle
potentially damaging a stabilizer, or the fan
cowl striking the fuselage and window. The
unsafe condition, if not addressed, could
result in loss of control of the airplane, or in
a rapid decompression and hazard to
window-seated passengers aft of the wing.
(f) Compliance
Comply with this AD within the
compliance times specified, unless already
done.
(g) Required Actions
Except as specified by paragraph (h) of this
AD: At the applicable times specified in the
‘‘Compliance’’ paragraph of Boeing Special
Attention Requirements Bulletin 737–71–
1937 RB, dated July 27, 2023, do all
applicable actions identified in, and in
accordance with, the Accomplishment
Instructions of Boeing Special Attention
Requirements Bulletin 737–71–1937 RB,
dated July 27, 2023.
Note 1 to paragraph (g): Guidance for
accomplishing the actions required by this
AD can be found in Boeing Special Attention
Service Bulletin 737–71–1937, dated July 27,
2023, which is referred to in Boeing Special
Attention Requirements Bulletin 737–71–
1937 RB, dated July 27, 2023.
(h) Exceptions to Service Information
Specifications
(1) Where the service information
referenced in paragraph (g) of this AD
specifies contacting Boeing or Collins
Aerospace for repair instructions: This AD
requires doing the repair before further flight
using a method approved in accordance with
the procedures specified in paragraph (j) of
this AD.
(2) Where Tables 1 through 4 of Boeing
Special Attention Requirements Bulletin
737–71–1937 RB, dated July 27, 2023, specify
incorporating 737–600/700/700C/800/900/
900ER Airworthiness Limitations (AWLs)
document D626A001–9–01 ‘‘System
Airworthiness Limitation NO. 2—Fan Blade
E:\FR\FM\12DEP1.SGM
12DEP1
86072
Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules
Out Conditions’’ and ‘‘System Airworthiness
Limitation NO. 3—Fan Blade Out
Conditions’’ into the operators’ maintenance
program, this AD requires revising the
existing maintenance or inspection program,
as applicable, by incorporating the
information specified in Figure 1 to the
introductory text of paragraph (h) of this AD
into the airworthiness limitations within 90
days after the effective date of this AD, or
before further flight after accomplishing the
(Option 1) or (Option 2) actions in Boeing
Special Attention Requirements Bulletin
737–71–1937 RB, dated July 27, 2023,
whichever occurs first.
Figure 1 to the Introductory Text of
Paragraph (h)—System Airworthiness
Limitations
SYSTEM .AIR.WORTHINESS LIMITATION No. 2
Fk~ BLADE OUT CONDmONS
All airaaihnustinstall the following modifications: (l)engine inlets \\iith new spacer design and
.increased fastener capability (2) fan cowls l\ith new radial testraiut fitting hooks. new radial restraint
clips. and an external doubler at the starter \'ent (3)f.m cowl support beam fastener changes (except for
7'57:-900ER. aircraft, bee.use the fan cowl support beam fastener changes are already incmporated). All .
aircraftthatha\.re not inootporated these modifkationscannotoperatepast July 31, 2028 unless upgraded
to new hardware that is fully compliant to §§25.901(e) and AppendixK25.1.1 to Part 25. Boeing u,ill
•release all sen.ice data to allow retrofit of hardware updates to the CFM56-1B nacelle prior to that date~
SYSTEM AIRWORTHINESS LIMITATION No. 3
FAN BLADE OUT CONDmONS
All aircraft delivered without the Penonnance Improvement Package (PIP) must install engine exhaust
nozzle stmctura1 stiffening: elements. All aircraft that have not incorporated these modifications cannot
operate past July 31~ 2028 unless upgraded to new hardware that is fully compliant to §§25.901{c) and
.Appendix K.25:1.1 to Part 25. Boeing "'ill release all sen'ice data to allow retrofit of hardware updates to
the CFM56-1Bnacelle prior to that date.
SYSTEMAIR.WORTHINESSLIMITATION No. 4
ENG~"E NACELLE :MAINTENANCE ERR.ORS
..\.11 aircraft must incmporate solutions to address potential maintenance errors. e.g., the failure to ..
completely latch the f.m cowl or the fan cowl integrated drive generator (IDG) door. All aircraft that have
not incotpOrated dlanges to become fully compliant 'INith §§25.901(c) and AppendixK.2S;Lt to Part 25
cannot be operated past December 31~ 20.29.
After the existing maintenance or
inspection program has been revised as
required by paragraph (h)(2) of this AD, no
alternative actions may be used unless the
actions are approved as an alternative
method of compliance (AMOC) in
accordance with the procedures specified in
paragraph (j) of this AD.
ddrumheller on DSK120RN23PROD with PROPOSALS1
(j) Alternative Methods of Compliance
(AMOCs)
(1) The Manager, AIR–520, Continued
Operational Safety Branch, FAA, has the
authority to approve AMOCs for this AD, if
requested using the procedures found in 14
CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector
or responsible Flight Standards Office, as
appropriate. If sending information directly
to the manager of the certification office,
send it to the attention of the person
identified in paragraph (k) of this AD.
Information may be emailed to: 9-ANMSeattle-ACO-AMOC-Requests@faa.gov.
(2) Before using any approved AMOC,
notify your appropriate principal inspector,
or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
(3) An AMOC that provides an acceptable
level of safety may be used for any repair,
modification, or alteration required by this
VerDate Sep<11>2014
16:23 Dec 11, 2023
Jkt 262001
AD if it is approved by The Boeing Company
Organization Designation Authorization
(ODA) that has been authorized by the
Manager, AIR–520, Continued Operational
Safety 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.
(k) Related Information
For more information about this AD,
contact Luis Cortez-Muniz, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des
Moines, WA 98198; telephone: 206–231–
3958; email: luis.a.cortez-muniz@faa.gov.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register
approved the incorporation by reference
(IBR) of the service information listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR
part 51.
(2) You must use this service information
as applicable to do the actions required by
this AD, unless the AD specifies otherwise.
(i) Boeing Special Attention Requirements
Bulletin 737–71–1937 RB, dated July 27,
2023.
(ii) [Reserved]
(3) For service information identified in
this AD, contact Boeing Commercial
PO 00000
Frm 00007
Fmt 4702
Sfmt 9990
Airplanes, Attention: Contractual & Data
Services (C&DS), 2600 Westminster Blvd.,
MC 110–SK57, Seal Beach, CA 90740–5600;
telephone 562–797–1717; website
myboeingfleet.com.
(4) You may view this service information
at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th
St., Des Moines, WA. For information on the
availability of this material at the FAA, call
206–231–3195.
(5) You may view this material at the
National Archives and Records
Administration (NARA). For information on
the availability of this material at NARA,
visit www.archives.gov/federal-register/cfr/
ibr-locations or email fr.inspection@nara.gov.
Issued on December 1, 2023.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2023–27100 Filed 12–11–23; 8:45 am]
BILLING CODE 4910–13–P
E:\FR\FM\12DEP1.SGM
12DEP1
EP12DE23.002
(i) No Alternative Actions
Agencies
[Federal Register Volume 88, Number 237 (Tuesday, December 12, 2023)]
[Proposed Rules]
[Pages 86069-86072]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-27100]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-2234; Project Identifier AD-2023-00963-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 737-600, -700, -700C, -800, -900, and
-900ER series airplanes. This proposed AD was prompted by two engine
fan blade-out (FBO) events that resulted in the separation of engine
inlet cowl and fan cowl parts from the airplane. In one event, fan cowl
parts damaged the fuselage, which caused loss of pressurization and
subsequent emergency descent. This proposed AD would require replacing
the fasteners on the fan cowl support beam hinge fittings for certain
airplanes and, for all airplanes, would require modifying the radial
restraint assembly and installing an external doubler at the starter
vent, or as an option, installing a serviceable fan cowl. This proposed
AD would also require revising the existing maintenance or inspection
program, as applicable, to incorporate new airworthiness limitations.
The FAA is proposing this AD to address the unsafe condition on these
products.
DATES: The FAA must receive comments on this proposed AD by January 26,
2024.
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.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-2234; 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.
Material Incorporated by Reference:
For service information identified in this NPRM, contact
Boeing Commercial Airplanes, Attention: Contractual & Data Services
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600;
telephone 562-797-1717; website myboeingfleet.com.
You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200 South
216th St., Des Moines, WA. For information on the availability of this
material at the FAA, call 206-231-3195. It is also available at
regulations.gov by searching for and locating Docket No. FAA-2023-2234.
FOR FURTHER INFORMATION CONTACT: Luis Cortez-Muniz, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone:
206-231-3958; email: [email protected].
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-2023-2234; Project Identifier
AD-2023-00963-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
[[Page 86070]]
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 Luis Cortez-Muniz,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; telephone: 206-231-3958; email: [email protected]. 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 received two reports of engine events that resulted in the
separation of engine inlet cowl and fan cowl parts from the airplane.
One event occurred in August 2016 on a Boeing Model 737-700 series
airplane powered by a CFM56-7B engine. The left engine failed due to
the FBO but the airplane landed successfully. The second event occurred
on April 17, 2018, on a Boeing Model 737-700 series airplane powered by
a CFM56-7B engine. In that event, an FBO occurrence resulted in the
release of fan cowl parts and the engine cowling departing the
airplane. The fan cowl parts damaged the fuselage, which caused loss of
pressurization and subsequent emergency descent. Although the airplane
landed safely, there was one passenger fatality. In that event, the
suspected cause of the FBO occurrence was a low-cycle fatigue crack in
the dovetail of fan blade number 13 of engine number 1. The broken fan
blade hit the engine fan case at a critical location causing a
significant impulse, displacement, and imbalance of the fan rotor
effecting the structural integrity of the engine cowling.
In response to these events, the FAA issued two AD actions for the
CFM International S.A. (CFM) Model CFM56-7B engines. The FAA issued
emergency AD 2018-09-51, Amendment 39-19287 (83 FR 23794, May 23, 2018)
(AD 2018-09-51), which requires a one-time ultrasonic inspection of the
concave and convex sides of the fan blade dovetail. The FAA also issued
AD 2018-26-01, Amendment 39-19531 (83 FR 66090, December 26, 2018) (AD
2018-26-01), which requires initial and repetitive inspections of the
concave and convex sides of the fan blade dovetail to detect cracking
and replacement of any blades found. The FAA issued AD 2018-09-51 to
address fan blade failure due to cracking, which could result in an
engine in-flight shutdown (IFSD), uncontained release of debris, damage
to the engine, damage to the airplane, and possible airplane
decompression. The FAA issued AD 2018-26-01 to address failure of the
fan blade, which could result in the engine inlet cowl disintegrating
and debris penetrating the fuselage, causing a loss of pressurization,
and prompting an emergency descent.
Since AD 2018-09-51 and AD 2018-26-01 were issued, the FAA has
determined further rulemaking is necessary to reduce the probability of
unsecured nacelle components, should an engine fan blade failure occur.
As evidenced by Exemption No. 19212, dated July 13, 2022 (Docket No.
FAA-2023-2234), Boeing developed modifications to the inlet cowl, fan
cowl, and exhaust nozzle that must be accomplished prior to July 31,
2028. Boeing petitioned and the FAA later agreed to amend Exemption No.
19212 to 19212A, which added a requirement that solutions to address
potential maintenance errors must be incorporated prior to December 31,
2029. However, to implement these design changes, the FAA must issue
rulemaking to address the unsafe condition.
This proposed AD would address fan cowls that are not strengthened,
which could, in the event of an FBO occurrence, depart the nacelle
potentially damaging a stabilizer, or the fan cowl could strike the
fuselage and window. The unsafe condition, if not addressed, could
result in loss of control of the airplane, or in a rapid decompression
and hazard to window-seated passengers aft of the wing.
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.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Special Attention Requirements Bulletin
737-71-1937 RB, dated July 27, 2023. This service information specifies
procedures for replacing, for certain airplanes, the fasteners on the
fan cowl support beam hinge fittings on the left and right engine
strut, and, for engine 1 and engine 2 for all airplanes, modifying the
radial restraint assembly and installing an external doubler at the
starter vent, or as an option, installing a serviceable fan cowl.
The service information also requires revision of the operator's
maintenance or inspection program, as applicable, by incorporating
certain airworthiness limitations (AWLs).
This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in ADDRESSES.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the service information already described, except as discussed under
``Differences Between this Proposed AD and the Service Information''
and except for any differences identified as exceptions in the
regulatory text of this proposed AD. For information on the procedures
and compliance times, see this service information at regulations.gov
under Docket No. FAA-2023-2234.
This proposed AD would require revisions to certain operator
maintenance documents to include new airworthiness limitations.
Compliance with these limitations is required by 14 CFR 91.403(c). For
airplanes that have been previously modified, altered, or repaired in
the areas addressed by this proposed AD, the operator may not be able
to accomplish the actions described in the revisions. In this
situation, to comply with 14 CFR 91.403(c), the operator must request
approval for an alternative method of compliance according to paragraph
(j) of this proposed AD.
Differences Between This Proposed AD and the Service Information
Boeing Special Attention Requirements Bulletin 737-71-1937 RB,
dated July 27, 2023, identifies ``System Airworthiness Limitation NO.
2--Fan Blade Out Conditions,'' and ``System Airworthiness Limitation
NO. 3--Fan Blade Out Conditions'' as the airworthiness limitations that
must be incorporated. In addition to those system limitations, the FAA
has determined that ``System Airworthiness Limitation NO. 4--Engine
Nacelle Maintenance Errors'' must also be incorporated as specified in
paragraph (h) of this proposed AD. System Airworthiness Limitation NO.
4 specifically provides the limitation that mandates solutions to
maintenance errors that must be accomplished prior to December 31,
2029, as required by Exemption No. 19212A.
[[Page 86071]]
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 1,979 airplanes of U.S. registry. The FAA estimates the
following costs to comply with this proposed AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action * Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Modification and Installation... 140 work-hours x $1,400............ $13,300........... $26,320,700.
$85 per hour =
$11,900.
Fastener replacement............ Up to 8 work-hour Up to $2,300...... Up to $2,980...... Up to $5,897,420.
x $85 per hour =
$680.
----------------------------------------------------------------------------------------------------------------
* The option to install a serviceable fan cowl would cost up to $16,280 per product.
The FAA has determined that revising the existing maintenance or
inspection program takes an average of 90 work-hours per operator,
although the agency recognizes that this number may vary from operator
to operator. Since operators incorporate maintenance or inspection
program changes for their affected fleet(s), the FAA has determined
that a per-operator estimate is more accurate than a per-airplane
estimate. Therefore, the agency estimates the average total cost per
operator to be $7,650 (90 work-hours x $85 per work-hour).
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.
Regulatory Findings
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
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 adding the following new airworthiness
directive:
The Boeing Company: Docket No. FAA-2023-2234; Project Identifier AD-
2023-00963-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by January 26, 2024.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any
category.
(d) Subject
Air Transport Association (ATA) of America Code 71, Powerplant.
(e) Unsafe Condition
This AD was prompted by two engine fan blade-out (FBO) events
that resulted in the separation of engine inlet cowl and fan cowl
parts from the airplane. In one event, fan cowl parts damaged the
fuselage, which caused loss of pressurization and subsequential
emergency descent. The FAA is issuing this AD to address fan cowls
that are not strengthened, which, in the event of an FBO occurrence,
could depart the nacelle potentially damaging a stabilizer, or the
fan cowl striking the fuselage and window. The unsafe condition, if
not addressed, could result in loss of control of the airplane, or
in a rapid decompression and hazard to window-seated passengers aft
of the wing.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Except as specified by paragraph (h) of this AD: At the
applicable times specified in the ``Compliance'' paragraph of Boeing
Special Attention Requirements Bulletin 737-71-1937 RB, dated July
27, 2023, do all applicable actions identified in, and in accordance
with, the Accomplishment Instructions of Boeing Special Attention
Requirements Bulletin 737-71-1937 RB, dated July 27, 2023.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Special Attention Service
Bulletin 737-71-1937, dated July 27, 2023, which is referred to in
Boeing Special Attention Requirements Bulletin 737-71-1937 RB, dated
July 27, 2023.
(h) Exceptions to Service Information Specifications
(1) Where the service information referenced in paragraph (g) of
this AD specifies contacting Boeing or Collins Aerospace for repair
instructions: This AD requires doing the repair before further
flight using a method approved in accordance with the procedures
specified in paragraph (j) of this AD.
(2) Where Tables 1 through 4 of Boeing Special Attention
Requirements Bulletin 737-71-1937 RB, dated July 27, 2023, specify
incorporating 737-600/700/700C/800/900/900ER Airworthiness
Limitations (AWLs) document D626A001-9-01 ``System Airworthiness
Limitation NO. 2--Fan Blade
[[Page 86072]]
Out Conditions'' and ``System Airworthiness Limitation NO. 3--Fan
Blade Out Conditions'' into the operators' maintenance program, this
AD requires revising the existing maintenance or inspection program,
as applicable, by incorporating the information specified in Figure
1 to the introductory text of paragraph (h) of this AD into the
airworthiness limitations within 90 days after the effective date of
this AD, or before further flight after accomplishing the (Option 1)
or (Option 2) actions in Boeing Special Attention Requirements
Bulletin 737-71-1937 RB, dated July 27, 2023, whichever occurs
first.
Figure 1 to the Introductory Text of Paragraph (h)--System
Airworthiness Limitations
[GRAPHIC] [TIFF OMITTED] TP12DE23.002
(i) No Alternative Actions
After the existing maintenance or inspection program has been
revised as required by paragraph (h)(2) of this AD, no alternative
actions may be used unless the actions are approved as an
alternative method of compliance (AMOC) in accordance with the
procedures specified in paragraph (j) of this AD.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, AIR-520, Continued Operational Safety Branch,
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. In accordance with 14
CFR 39.19, send your request to your principal inspector or
responsible Flight Standards Office, as appropriate. If sending
information directly to the manager of the certification office,
send it to the attention of the person identified in paragraph (k)
of this AD. Information may be emailed to: [email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair, modification, or alteration required by this AD
if it is approved by The Boeing Company Organization Designation
Authorization (ODA) that has been authorized by the Manager, AIR-
520, Continued Operational Safety 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.
(k) Related Information
For more information about this AD, contact Luis Cortez-Muniz,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; telephone: 206-231-3958; email: [email protected].
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) Boeing Special Attention Requirements Bulletin 737-71-1937
RB, dated July 27, 2023.
(ii) [Reserved]
(3) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Contractual & Data Services
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; website myboeingfleet.com.
(4) You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200
South 216th St., Des Moines, WA. For information on the availability
of this material at the FAA, call 206-231-3195.
(5) You may view this material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on December 1, 2023.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2023-27100 Filed 12-11-23; 8:45 am]
BILLING CODE 4910-13-P