[Federal Register Volume 86, Number 67 (Friday, April 9, 2021)]
[Proposed Rules]
[Pages 18479-18481]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-07328]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0263; Project Identifier AD-2020-01702-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all The Boeing Company Model 777 airplanes. This proposed AD was 
prompted by a report that an operator found solid rivets with missing 
heads at the left buttock line 25 on the sloping pressure deck web. 
This proposed AD would require doing a detailed inspection of the left 
and right side sloping pressure deck at certain stations for any 
damaged solid rivets, 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 May 24, 
2021.

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 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; internet https://www.myboeingfleet.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-2021-
0263.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0263; 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: Luis Cortez, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: (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-2021-0263; Project Identifier 
AD-2020-01702-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 
https://www.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

[[Page 18480]]

should be sent to Luis Cortez, Aerospace Engineer, Airframe Section, 
FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; 
phone and fax: (206) 231-3958; email: Luis.A.Cortez-Muniz@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.

Background

    The FAA has received a report indicating that an operator found 
solid rivets with missing heads at the left buttock line 25 on the 
sloping pressure deck web. The Model 777-300 airplane had 23 solid 
rivet locations with missing manufactured heads; the airplane had 
accumulated 21,343 total flight cycles and 53,979 total flight hours at 
time of discovery. A fleet-wide multiple operator message (MOM) request 
found four more Model 777-300 airplanes and one retired Model 777-200 
airplane with missing solid rivet heads. Boeing analysis showed the 
root cause to be the 7050 aluminum solid rivets used on the sloping 
pressure deck web, which were inadequate for the complex tension 
loading environment, and led to premature fatigue cracking of the solid 
rivets. This condition, if not addressed, could result in undetected 
damaged or missing rivet heads on the sloping pressure deck web, which 
could result in loss of sloping pressure deck panels, causing 
decompression and pressure loss, and loss of the hydraulic systems in 
the area for wheel brakes (both normal and alternate) and steering, and 
potentially leading to runway departure and adversely affecting 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 develop on other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 777-53A0093 RB, 
dated November 24, 2020. This service information specifies procedures 
for doing a detailed inspection of the left and right side sloping 
pressure deck from station (STA) 1245 to STA 1287 for any damaged (i.e. 
missing solid rivet heads, cracking or deformation of the solid rivet, 
or gaps between the solid rivet head and the sloping pressure deck 
surface) solid rivets, and applicable on-condition actions. On-
condition actions include repeating the detailed inspection of the left 
and right side sloping pressure deck from STA 1245 to STA 1287 for any 
damaged solid rivet; repetitive detailed inspections of two rows of 
blind fasteners and solid rivets common to the affected stiffener for 
any damaged solid rivet or damaged blind fastener; replacing solid 
rivets or blind fasteners; and repair.
    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 https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0263.

Explanation of Requirements Bulletin

    The FAA worked in conjunction with industry, under the 
Airworthiness Directive Implementation Aviation Rulemaking Committee 
(AD ARC), to enhance the AD system. One enhancement is a process for 
annotating which steps in the service information are ``required for 
compliance'' (RC) with an AD. Boeing has implemented this RC concept 
into Boeing service bulletins.
    In an effort to further improve the quality of ADs and AD-related 
Boeing service information, a joint process improvement initiative was 
worked between the FAA and Boeing. The initiative resulted in the 
development of a new process in which the service information more 
clearly identifies the actions needed to address the unsafe condition 
in the ``Accomplishment Instructions.'' The new process results in a 
Boeing Requirements Bulletin, which contains only the actions needed to 
address the unsafe condition (i.e., only the RC actions).

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 224 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 inspections...........  Up to 384 work-hours x               $0  Up to $32,640.....  Up to $7,311,360.
                                  $85 per hour = Up to
                                  $32,640.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements or inspections 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 replacements or inspections:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
               Action                         Labor cost                Parts cost           Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement (solid fastener).......  338 work-hours x $85 per     Up to $3,200..........  Up to $31,930.
                                      hour = $28,730.
Replacement (blind fastener).......  328 work-hour x $85 per      Up to $450............  Up to $28,330.
                                      hour = $27,880.
Repetitive inspections of fastener   326 work-hours x $85 per     $0 per inspection       $27,710 per inspection
 rows.                                hour = $27,710 per           cycle.                  cycle.
                                      inspection cycle.
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[[Page 18481]]

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs 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) 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-2021-0263; Project Identifier AD-
2020-01702-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 24, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all The Boeing Company Model 777-200, -200LR, 
-300, -300ER, and 777F airplanes, certificated in any category.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report that an operator found solid 
rivets with missing heads at the left buttock line 25 on the sloping 
pressure deck web. The FAA is issuing this AD to address damaged or 
missing solid rivet heads on the sloping pressure deck web, which 
could result in loss of sloping pressure deck panels, causing 
decompression and pressure loss, and loss of the hydraulic systems 
in the area for wheel brakes (both normal and alternate) and 
steering, and potentially leading to runway departure and adversely 
affecting 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 777-53A0093 RB, dated November 24, 2020, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
777-53A0093 RB, dated November 24, 2020.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-53A0093, dated November 24, 2020, which is referred to in Boeing 
Alert Requirements Bulletin 777-53A0093 RB, dated November 24, 2020.

(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 777-53A0093 RB, 
dated November 24, 2020, uses the phrase ``the original issue date 
of 777-53A0093 RB'' or ``the original issue date of Requirements 
Bulletin 777-53A0093 RB,'' this AD requires using ``the effective 
date of this AD,'' except where Alert Requirements Bulletin 777-
53A0093 RB, dated November 24, 2020, uses the phrase ``the original 
issue date of Requirements Bulletin 777-53A0093 RB'' in a note or 
flag note.
    (2) Where Boeing Alert Requirements Bulletin 777-53A0093 RB, 
dated November 24, 2020, 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 Related Information. 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 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

    (1) For more information about this AD, contact Luis Cortez, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone and fax: (206) 231-
3958; email: Luis.A.Cortez-Muniz@faa.gov.
    (2) 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; internet https://www.myboeingfleet.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.

    Issued on March 30, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-07328 Filed 4-8-21; 8:45 am]
BILLING CODE 4910-13-P


