Document ID: FAA-2020-0089-0007
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2021-06-24T04:00Z

[Federal Register Volume 86, Number 119 (Thursday, June 24, 2021)]
[Proposed Rules]
[Pages 33152-33153]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13133]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0089; Project Identifier 2019-NM-159-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: The FAA is withdrawing a notice of proposed rulemaking (NPRM) 
that proposed to adopt a new airworthiness directive (AD). That NPRM 
would have applied to certain The Boeing Company Model 737-700, -800, 
and -900ER series airplanes. The NPRM was prompted by a report of 
unshimmed gaps at a certain frame inner chord. The NPRM would have 
required a general visual inspection for repairs of a certain frame 
inner chord, a detailed inspection for unshimmed gaps of the frame 
inner chord, and applicable on-condition actions. Since issuance of the 
NPRM, the FAA determined that the proposed AD is inadequate to address 
the unsafe condition. The FAA intends to propose new rulemaking to 
incorporate changes to the proposed requirements and add airplanes that 
are also subject to the unsafe condition. Accordingly, the NPRM is 
withdrawn.

DATES: The FAA is withdrawing the proposed rule published on February 
4, 2020 (85 FR 6107), as of June 24, 2021.

ADDRESSES:

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0089; 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 AD action, any comments received, and other information. The 
street address for Docket Operations is U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Greg Rutar, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3529; email: 
Greg.Rutar@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued an NPRM that proposed to amend 14 CFR part 39 by 
adding an AD that would apply to certain Boeing Model 737-700, -800, 
and -900ER series airplanes. The NPRM was published in the Federal 
Register on February 4, 2020 (85 FR 6107). The NPRM was prompted by a 
report of unshimmed gaps at a certain frame inner chord.
    The NPRM proposed to require a general visual inspection for 
repairs of a certain frame inner chord, a detailed inspection for 
unshimmed gaps of the frame inner chord, and applicable on-condition 
actions. The proposed actions were intended to address gaps at a frame 
inner chord, which may initiate early cracking in fatigue critical 
baseline structure (FCBS) and result in the inability of a principal 
structural element (PSE) to sustain limit load and adversely affect the 
structural integrity of the airplane.

Actions Since the NPRM Was Issued

    Since issuance of the NPRM, the FAA determined that the proposed 
actions are inadequate to address the unsafe condition. In addition to 
identifying missing shims, Boeing has found a wrong type of shims, 
shanked fasteners, fastener head gaps, and incorrect fastener hole 
sizes. The unsafe condition and location of the problem are the same as 
those described in the NPRM. The FAA has identified additional Model 
737-700, -800, and -900ER airplanes as well as additional airplane 
models that are subject to the unsafe condition. The FAA has also 
determined that additional actions must be accomplished to address the 
unsafe condition on the affected airplanes. In light of these changes, 
the FAA intends to propose further rulemaking.
    Withdrawal of the NPRM constitutes only such action. The withdrawal 
does not preclude the FAA from further rulemaking on this issue or 
commit the FAA to any course of action in the future.

Comments

    The FAA received comments on the NPRM from four commenters, 
including Aviation Partners Boeing, Boeing, Delta Air Lines, and United 
Airlines. Although the FAA is withdrawing the NPRM because of new 
findings and not as a result of any of these comments, the following 
presents a brief discussion of the comments.
    United Airlines concurred with the NPRM.
    Aviation Partners Boeing and Delta Air Lines stated that the 
incorporation

[[Page 33153]]

of supplemental type certificate (STC) ST00830SE for installation of 
blended or split scimitar winglets does not affect compliance with the 
proposed actions, so a ``change in product'' alternative method of 
compliance (AMOC) would not be necessary. The FAA agrees with the 
commenters' assertions, but because the FAA is withdrawing the NPRM, 
the request is no longer necessary.
    Delta Air Lines noted that the service information recommended 
removing sealant squeeze-out that inhibits inserting the feeler gauge 
between the mating surfaces. The commenter was concerned that removing 
the sealant squeeze-out could damage the structure if a metallic tool 
is used. The FAA disagrees with the request; however, because the NPRM 
is being withdrawn, the commenter's requested change is unnecessary.
    Boeing requested several changes to the Discussion and Related 
Service Information Under 1 CFR part 51 sections and the description of 
the unsafe condition in the NPRM. The FAA disagrees with Boeing's 
requested changes. However, because the NPRM is being withdrawn, the 
commenter's requested changes are unnecessary.

FAA's Conclusions

    Upon further consideration, the FAA has determined that the NPRM 
does not adequately address the identified unsafe condition. 
Accordingly, the FAA is withdrawing the NPRM.

Regulatory Findings

    Since this action only withdraws an NPRM, it is neither a proposed 
nor a final rule. This action therefore is not covered under Executive 
Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979).

List of Subjects in 14 CFR Part 39

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

The Withdrawal

0
Accordingly, the notice of proposed rulemaking (Docket No. FAA 2020-
0089), which was published in the Federal Register on February 4, 2020 
(85 FR 6107), is withdrawn.

    Issued on June 15, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-13133 Filed 6-23-21; 8:45 am]
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