Document ID: FAA-2023-0157-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2023-02-15T05:00Z

[Federal Register Volume 88, Number 31 (Wednesday, February 15, 2023)]
[Proposed Rules]
[Pages 9773-9776]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-03138]

 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 88 , No. 31 / Wednesday, February 15, 2023 / 
Proposed Rules  

[[Page 9773]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0157; Project Identifier AD-2022-01309-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 certain The Boeing Company Model 747-8 series airplanes. This 
proposed AD was prompted by a report of stress corrosion cracking in 
certain stringers and end stringer splice assemblies. This proposed AD 
would require repetitive inspections of the stringers and end stringer 
splice assemblies for any crack, shim, or gap, and applicable on-
condition actions. 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 March 31, 
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.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-0157; 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-2023-0157.

FOR FURTHER INFORMATION CONTACT: Stefanie N. Roesli, Aerospace 
Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th 
St., Des Moines, WA 98198; phone: 206-231-3964; 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-2023-0157; Project Identifier 
AD-2022-01309-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 
Stefanie N. Roesli, Aerospace Engineer, Airframe Section, FAA, Seattle 
ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-
3964; 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 has received a report indicating cracks found on end 
stringers of two Model 747-8 airplanes at station (STA) 2285, left and 
right sides, during foreign object debris (FOD) inspections in 
preparation for airplane modification. Boeing has also reported similar 
cracking on other Model 747-8 airplanes. The cracks were not visually 
detectable until the stringer splice assemblies were removed. The root 
cause was found to be stress corrosion cracking caused by excessive and 
sustained internal tensile stresses that were due to no shim being 
installed or shimmed gaps exceeding engineering limits at production. A 
crack in a stringer or end stringer splice assembly could grow in 
length and go undetected. This condition, if not addressed, could 
result in the inability of a structural element to sustain limit load 
and could adversely affect the structural integrity of the airplane.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or

[[Page 9774]]

develop on other products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 747-53A2909 RB, 
dated September 21, 2022. This service information specifies procedures 
for repetitive detailed inspections of the stringers and the end 
stringer splice assemblies at stringers S-17 to S-25 from STA 2285 to 
STA 2300 main entry door #5 cutout aft edge frame for any crack, any 
shim between a stringer and bear strap, and any gap within the 
fastener-joint-to-bear-strap joint, and applicable on-condition 
actions. On-condition actions include detailed inspections of the 
stringers and end stringers splice assemblies located between STA 2285 
and STA 2300 from stringers S-17L to S-25L/S-17R to S-25R, open hole 
high frequency eddy current (HFEC) inspection of the fastener holes of 
the skin common to the end stringer splice fitting for cracks, and 
repair of cracked stringer/end stringer splice fittings.
    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 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 by searching for and locating 
Docket No. FAA-2023-0157.

Clarification of Terminating Action

    Boeing Alert Requirements Bulletin 747-53A2909 RB, dated September 
21, 2022, contains a terminating action flagnote (b) in Tables 1 
through 4 of the Accomplishment Instructions that specifies ``Doing the 
detailed and High Frequency Eddy Current (HFEC) inspections and finding 
no crack as a result of the inspection is terminating action to 
Requirements Bulletin 747-53A2909 RB for that affected end stringer 
splice assembly.'' However, the flagnote ``(b)'' is located with 
certain conditions in Tables 1 through 4 and appears to be 
contradictory in certain locations, e.g., ``Condition 8.2: No crack 
found as a result of option 2 inspections'' specifies to do repetitive 
inspections; however the option 2 inspections are the detailed and HFEC 
inspections, which the flagnote specifies is terminating action. The 
FAA has clarified the terminating action in paragraphs (g)(1) through 
(4) of this proposed AD to confirm that no action is required for an 
end stringer splice assembly on which no cracking is found after the 
specified option 2 inspections are done.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 2 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
----------------------------------------------------------------------------------------------------------------
Detailed Inspection (S-17L to S-   4 work-hours x $85               $0  $340 per inspection  $680 per inspection
 25L) and (S-17R to S-25R).         per hour = $340                      cycle.               cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of the 
proposed inspection. The agency has no way of determining the number of 
aircraft that might need these on-condition actions:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Detailed Inspection and Open Hole (HFEC)        54 work-hours x $85 per hour =                $0          $4,590
 Inspection per side.                            $4,590.
Repair of cracked stringer/end stringer splice  13 work-hours x $85 per hour =               600           1,705
 fitting.                                        $1,105.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this proposed AD may be covered under warranty, thereby reducing the 
cost impact on affected operators.

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:

[[Page 9775]]

    (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

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

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

Sec.  39.13  [Amended]

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

The Boeing Company: Docket No. FAA-2023-0157; Project Identifier AD-
2022-01309-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by March 31, 2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-8 series 
airplanes, certificated in any category, as identified in Boeing 
Alert Requirements Bulletin 747-53A2909 RB, dated September 21, 
2022.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by a report of stress corrosion cracking in 
the stringers and end stringer splice assemblies located between 
station (STA) 2285 and STA 2300 from stringers S-17 to S-25 on the 
left and right sides of the airplane caused by excessive and 
sustained internal tensile stresses that were due to no shim being 
installed or shimmed gaps exceeding engineering limits at 
production. A crack in a stringer or end stringer splice assembly 
could grow in length and go undetected. The unsafe condition, if not 
addressed, could result in the inability of a structural element to 
sustain limit load and could adversely affect the structural 
integrity of the airplane.

(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 
Alert Requirements Bulletin 747-53A2909 RB, dated September 21, 
2022, do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 747-53A2909 RB, dated September 21, 2022. For this AD, 
terminating action for certain end stringer springer splice 
assemblies are specified in paragraphs (g)(1) through (4) of this 
AD.

    Note 1 to paragraph (g):  Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
747-53A2909 RB, dated September 21, 2022, which is referred to in 
Boeing Alert Requirements Bulletin 747-53A2909 RB, dated September 
21, 2022.

    (1) For any end stringer splice assembly on which no cracking is 
found after accomplishing CONDITION 3 (OPTION 2) (ACTION 1) and 
CONDITION 3 (OPTION 2) (ACTION 2) inspections specified in Table 1 
of the Accomplishment Instruction of Boeing Alert Requirements 
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action 
is required by this AD for that end stringer splice assembly.
    (2) For any end stringer splice assembly on which no cracking is 
found after accomplishing CONDITION 6 (OPTION 2) (ACTION 1) and 
CONDITION 6 (OPTION 2) (ACTION 2) inspections specified in Table 2 
of the Accomplishment Instruction of Boeing Alert Requirements 
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action 
is required by this AD for that end stringer splice assembly.
    (3) For any end stringer splice assembly on which no cracking is 
found after accomplishing CONDITION 8 (OPTION 2) (ACTION 1) and 
CONDITION 8 (OPTION 2) (ACTION 2) inspections specified in Table 3 
of the Accomplishment Instruction of Boeing Alert Requirements 
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action 
is required by this AD for that end stringer splice assembly.
    (4) For any end stringer splice assembly on which no cracking is 
found after accomplishing CONDITION 10 (OPTION 2) (ACTION 1) and 
CONDITION 10 (OPTION 2) (ACTION 2) inspections specified in Table 4 
of the Accomplishment Instruction of Boeing Alert Requirements 
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action 
is required by this AD for that end stringer splice assembly.

(h) Exceptions to Service Information Specifications

    (1) Where the Compliance Time column and certain notes of the 
tables in the ``Compliance'' paragraph of Boeing Alert Requirements 
Bulletin 747-53A2909 RB, dated September 21, 2022, use the phrase 
``the original issue date of Requirements Bulletin 747-53A2909 RB,'' 
this AD requires using ``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 747-53A2909 RB, 
dated September 21, 2022, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair using a method 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or 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 (j) 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, 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.

(j) Related Information

    For more information about this AD, contact Stefanie N. Roesli, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone: 206-231-3964; email: 
[email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 747-53A2909 RB, dated 
September 21, 2022.
    (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 service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA,

[[Page 9776]]

[email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on January 27, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-03138 Filed 2-14-23; 8:45 am]
BILLING CODE 4910-13-P