Document ID: FAA-2021-1169-0007
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2022-04-22T04:00Z

[Federal Register Volume 87, Number 78 (Friday, April 22, 2022)]
[Rules and Regulations]
[Pages 24034-24036]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-08543]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1169; Project Identifier AD-2021-01011-T; 
Amendment 39-22008; AD 2022-08-05]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 737-800 series airplanes. This AD was 
prompted by the determination that insufficient sealing may allow water 
to enter the lower lobe electronic equipment (EE) bay through the main 
deck floor structure at the rigid cargo barrier (RCB), which could 
cause damage to EE bay line replacement units (LRUs) in the E5 rack. 
This AD requires detailed inspections for the presence and condition of 
sealant at certain locations and applicable on-condition actions. This 
AD also requires replacing the moisture barrier tape at a certain 
location, replacing the weather seal at a certain location, and 
installing seat track fillers. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective May 27, 2022
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 27, 
2022.

ADDRESSES: For service information identified in this final rule, 
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 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 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-1169.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-1169; 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 final rule, any 
comments received, and other information. The 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: Courtney Tuck, Aerospace Engineer, 
Cabin Safety and Environmental Systems Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-
231-3986; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain The Boeing 
Company Model 737-800 series airplanes. The

[[Page 24035]]

NPRM published in the Federal Register on January 26, 2022 (87 FR 
3946). The NPRM was prompted by the determination that insufficient 
sealing may allow water to enter the lower lobe EE bay through the main 
deck floor structure at the RCB, which could cause damage to EE bay 
LRUs in the E5 rack. In the NPRM, the FAA proposed to require detailed 
inspections for the presence and condition of sealant at certain 
locations and applicable on-condition actions. The NPRM also proposed 
to require replacing the moisture barrier tape at a certain location, 
replacing the weather seal at a certain location, and installing seat 
track fillers. The FAA is issuing this AD to address water ingress in 
the lower lobe EE bay, which could result in water damage to the air 
data inertial reference units and flight management computers during 
flight, leading to a complete loss of data to primary flight displays 
and electronic navigation functions, which could prevent continued safe 
flight and landing.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Air Line Pilots Association, 
International (ALPA), Boeing, and an individual, who supported the NPRM 
without change.
    The FAA received an additional comment from Aviation Partners 
Boeing (APB). The following presents the comment received on the NPRM 
and the FAA's response to the comment.

Effect of Winglets on Accomplishment of the Proposed Actions

    APB stated that the installation of winglets per Supplemental Type 
Certificate (STC) ST00830SE does not affect compliance with the 
mandated actions in the proposed rule.
    The FAA agrees with the commenter. Therefore, the installation of 
STC ST00830SE does not affect the ability to accomplish the actions 
required by this AD. The FAA has not changed this AD in this regard.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Except for minor editorial changes, this AD is adopted as 
proposed in the NPRM. None of the changes will increase the economic 
burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 737-53A1401 RB, 
dated April 27, 2021. This service information specifies procedures for 
detailed inspections of the forward main deck cargo compartment floor 
to RCB, floor panel joints, drain troughs, seat track splices, and, for 
some airplanes, the lower lobe E5 rack drain pan shroud for sealant 
condition and application, and applicable on-condition actions. This 
service information also specifies procedures for replacing the main 
deck cargo door weather seal, replacing the moisture barrier tape on 
the forward main deck cargo compartment floor, and installing seat 
track fillers in the EE bay. On-condition actions include repair, 
removing existing sealant, and applying new sealant. 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.

Costs of Compliance

    The FAA estimates that this AD affects 7 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Action                          Labor cost                   Parts cost                Cost per product         Cost on U.S.  operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspect sealant.....................  Up to 12 work-hours x $85    $0.........................  Up to $1,020...............  Up to $7,140.
                                       per hour = Up to $1,020.
Remove/reinstall drain trough.......  Up to 15 hours x $85 per     Negligible.................  Up to $1,275...............  Up to $8,925.
                                       hour = Up to $1,275.
Replace weather seal................  Up to 7 work-hours x $85     $9,680.....................  Up to $10,275..............  Up to $71,925.
                                       per hour = Up to $595.
Replace barrier tape................  Up to 20 work-hours x $85    Negligible.................  Up to $1,700...............  Up to $11,900.
                                       per hour = Up to $1,700.
Install seat track filler...........  Up to 2 work-hours x $85     Negligible.................  Up to $170.................  Up to $1,190.
                                       per hour = Up to $170.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
               Action                          Labor cost                    Parts cost               product
----------------------------------------------------------------------------------------------------------------
Install or replace sealant..........  26 work-hours x $85 per hour  Negligible..................          $2,210
                                       = $2,210.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition actions specified in this AD.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this 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.

[[Page 24036]]

    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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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:

2022-08-05 The Boeing Company: Amendment 39-22008; Docket No. FAA-
2021-1169; Project Identifier AD-2021-01011-T.

(a) Effective Date

    This airworthiness directive (AD) is effective May 27, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-800 series 
airplanes, certificated in any category, as identified in Boeing 
Alert Requirements Bulletin 737-53A1401 RB, dated April 27, 2021.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by the determination that insufficient 
sealing may allow water to enter the lower lobe electronic equipment 
(EE) bay through the main deck floor structure at the rigid cargo 
barrier, which could cause damage to EE bay line replacement units 
in the E5 rack. The FAA is issuing this AD to address water ingress 
in the lower lobe EE bay, which could result in water damage to the 
air data inertial reference units and flight management computers 
during flight, leading to a complete loss of data to primary flight 
displays and electronic navigation functions, which could prevent 
continued safe flight and landing.

(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 737-53A1401 RB, dated April 27, 2021, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
737-53A1401 RB, dated April 27, 2021.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
737-53A1401, dated April 27, 2021, which is referred to in Boeing 
Alert Requirements Bulletin 737-53A1401 RB, dated April 27, 2021.

(h) Exceptions to Service Information Specifications

    (1) Where the Compliance Time column of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
53A1401 RB, dated April 27, 2021, uses the phrase ``the original 
issue date of Requirements Bulletin 737-53A1401 RB,'' this AD 
requires using ``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 737-53A1401 RB, 
dated April 27, 2021, 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 Courtney Tuck, 
Aerospace Engineer, Cabin Safety and Environmental Systems Section, 
FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; 
phone and fax: 206-231-3986; 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 737-53A1401 RB, dated 
April 27, 2021.
    (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; internet https://www.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, [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on April 4, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-08543 Filed 4-21-22; 8:45 am]
BILLING CODE 4910-13-P