[Federal Register Volume 86, Number 156 (Tuesday, August 17, 2021)]
[Rules and Regulations]
[Pages 45855-45858]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-17681]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0670; Project Identifier AD-2021-00849-T; 
Amendment 39-21691; AD 2021-17-08]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 737-800 and -900ER series airplanes. 
This AD was prompted by reports that several of the fittings that 
provide attachment between the radome and fuselage were cracked to the 
point of failure on airplanes modified in accordance with a certain 
supplemental type certificate (STC). This AD requires demodification of 
the STC installation on the airplane by removing the external equipment 
installed during the STC modification (including the radome, antenna, 
and associated structure), installing doubler and fasteners, and system 
deactivation by pulling and collaring associated circuit breakers if 
installed. This AD also requires inspecting the external and feed-
through doublers, intercostals, skin, and frames in the area around the 
removed external equipment for cracking, and repair if necessary. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective August 17, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of August 17, 
2021.
    The FAA must receive comments on this AD by October 1, 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 final rule, contact 
Astronics Armstrong Aerospace, 804 S Northpoint Blvd., Waukegan, IL 
60085; telephone 847-244-4500; internet https://www.Astronics.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-2021-0670.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0670; 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 street address for the 
Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Surinder Sangha, Aerospace Engineer, 
Propulsion & Program Management Section, FAA, Chicago ACO Branch, Room 
107, 2300 East Devon Avenue, Des Plaines, IL 60018; telephone 847-294-
exception occurred on : 2021-17681.htm
exception occurred on : 2021-17681.htm
7010; fax 847-294-7834; email: suri[email protected].

SUPPLEMENTARY INFORMATION:

[[Page 45856]]

Background

    The FAA has received reports indicating that several of the 
fittings that provide attachment between the radome and fuselage were 
cracked to the point of failure. The radome to fuselage fittings were 
part of the ViaSat In-Flight Connectivity (IFC) System Antenna 
Provisions installed in accordance with FAA STC ST04096CH on Model 737-
800 and -900ER series airplanes. This failure of the attachment 
fittings, if not addressed, could result in loss of the radome and 
antennae, and consequent damage to the tail and damage to the fuselage 
in the vicinity of the radome, which could reduce the ability of the 
flightcrew to maintain safe flight and landing of the airplane. The FAA 
is issuing this AD to address the unsafe condition on these products.

FAA's Determination

    The FAA is issuing this AD because the agency has determined the 
unsafe condition described previously is likely to exist or develop in 
other products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Astronics Armstrong Aerospace Engineering Order, 
``ViaSat In-Flight Connectivity (IFC) System DE-MOD Boeing 737-800/-
900ER Series Aircraft,'' Document No. EO23-9642-02, Revision B, dated 
April 25, 2016. This service information specifies procedures for 
demodification of the STC installation by removing the external 
equipment (including radome, antenna, and associated structure) that 
was installed in accordance with FAA STC ST04096CH, and installing 
doubler and fasteners (de-mod kit), and system deactivation by pulling 
and collaring associated circuit breakers.
    The FAA also reviewed Astronics Connectivity Systems and 
Certification Service Bulletin SB44-9642-01, dated July 8, 2021. This 
service information specifies procedures for inspecting the external 
and feed-through doublers, intercostals, skin, and frames in the area 
around the removed external equipment for cracking. The inspections 
include an external low frequency eddy current (LFEC) inspection of the 
skin at the alteration installation area, doubler fastener holes in the 
first two rows of attachments between the doubler and fuselage skin, 
fastener and connector hole locations, the external doublers between 
fasteners at the area common to the stringers, and at the area common 
to the frame tees; an internal high frequency eddy current (HFEC) 
inspection of the intercostal at the fastener locations and the frames 
in the area of added frame segments; an internal detailed visual 
inspection of the frames between stringers 3L and 3R; an open hole HFEC 
rotating hole inspections of the stringer fastener holes where the 
doublers cover the stringer; a HFEC open-hole inspection of the 4X 
fitting base holes common to the external doublers at the 8X AR240-
1949-01 side fitting assembly locations; and an external HFEC 
inspection of the skin at the stringer fasteners, including all 
stringer fasteners which may be covered beneath the radome and adapter 
ring.
    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 the ADDRESSES section.

AD Requirements

    This AD requires accomplishing the actions specified in the service 
information already described. This AD also requires repairing any 
crack found during the inspections.

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and 
comment procedures for rules when the agency, for ``good cause,'' finds 
that those procedures are ``impracticable, unnecessary, or contrary to 
the public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty days, 
upon a finding of good cause.
    There are currently no U.S.-registered airplanes affected by this 
AD. Accordingly, notice and opportunity for prior public comment are 
unnecessary, pursuant to 5 U.S.C. 553(b)(3). In addition, for the 
foregoing reason(s), the FAA finds that good cause exists pursuant to 5 
U.S.C. 553(d) for making this amendment effective in less than 30 days.

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include Docket No. FAA-2021-0670 and Project Identifier AD-
2021-00849-T at the beginning of your comments. The most helpful 
comments reference a specific portion of the final rule, 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 final rule 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 final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to 
Surinder Sangha, Aerospace Engineer, Propulsion & Program Management 
Section, FAA, Chicago ACO Branch, Room 107, 2300 East Devon Avenue, Des 
Plaines, IL 60018; telephone 847-294-7010; fax 847-294-7834; email: 
surinder.sangha@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.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because the FAA has determined 
that it has good cause to adopt this rule without notice and comment, 
RFA analysis is not required.

Costs of Compliance

    Currently, there are no affected U.S.-registered airplanes. For any 
affected airplane that is imported and placed on the U.S. Register in 
the future, the FAA provides the following cost estimates to comply 
with this AD:

[[Page 45857]]



                                                 Estimated Costs
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                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Removal and installation......................  24 work-hours x $85 per hour =            $2,000          $4,040
                                                 $2,040.
Inspections...................................  8 work-hours x $85 per hour =                  0             680
                                                 $680.
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    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs specified in this 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

    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, and
    (2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

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

Adoption of 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:

2021-17-08 The Boeing Company: Amendment 39-21691; Docket No. FAA-
2021-0670; Project Identifier AD-2021-00849-T.

(a) Effective Date

    This airworthiness directive (AD) is effective August 17, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-800 and -900ER 
series airplanes, certificated in any category, with ViaSat In-
Flight Connectivity (IFC) System Antenna Provisions installed in 
accordance with Astronics Armstrong Aerospace Supplemental Type 
Certificate (STC) ST04096CH.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports that several of the fittings 
that provide attachment between the radome and fuselage were cracked 
to the point of failure. The FAA is issuing this AD to address 
cracked fittings, which could result in loss of the radome and 
antennae, and consequent damage to the tail and damage to the 
fuselage in the vicinity of the radome, which could reduce the 
ability of the flightcrew to maintain safe flight and landing of the 
airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Demodification Part I (Removal of External Equipment)

    Before further flight, remove external equipment (including 
radome, antenna, and associated structure) that was installed in 
accordance with STC ST04096CH. Do the removal in accordance with 
steps 1 through 9 of paragraph 5.2.1., of Astronics Armstrong 
Aerospace Engineering Order, ``ViaSat In-Flight Connectivity (IFC) 
System DE-MOD Boeing 737-800/-900ER Series Aircraft,'' Document No. 
EO23-9642-02, Revision B, dated April 25, 2016.

(h) Inspection and Repair

    Before further flight after accomplishing the removal required 
by paragraph (g) of this AD, inspect the external and feed-through 
doublers, intercostals, skin, stringers, and frames in the area 
around the removed external equipment for any cracking in accordance 
with paragraph 3.3., ``Inspection,'' of Astronics Connectivity 
Systems and Certification Service Bulletin SB44-9642-01, dated July 
8, 2021. If any cracking is found, before further flight, repair 
using a method approved in accordance with the procedures specified 
in paragraph (j) of this AD.

(i) Demodification Part II (Installation and System Deactivation)

    Before further flight after accomplishing the actions required 
by paragraph (h) of this AD: Install doubler and fasteners and 
deactivate the system (including pulling and collaring associated 
circuit breakers if installed) in accordance with steps 10, 11, and 
12 of paragraph 5.2.1., of Astronics Armstrong Aerospace Engineering 
Order, ``ViaSat In-Flight Connectivity (IFC) System DE-MOD Boeing 
737-800/-900ER Series Aircraft,'' Document No. EO23-9642-02, 
Revision B, dated April 25, 2016.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Chicago 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.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.

 (k) Related Information

    For more information about this AD, contact Surinder Sangha, 
Aerospace Engineer, Propulsion & Program Management Section, FAA, 
Chicago ACO Branch, Room 107, 2300 East Devon Avenue, Des Plaines, 
IL 60018; telephone 847-294-7010; fax 847-294-7834; email: 
surinder.sangha@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.

[[Page 45858]]

    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Astronics Armstrong Aerospace Engineering Order, ``ViaSat 
In-Flight Connectivity (IFC) System DE-MOD Boeing 737-800/-900ER 
Series Aircraft,'' Document No. EO23-9642-02, Revision B, dated 
April 25, 2016.
    (ii) Astronics Connectivity Systems and Certification Service 
Bulletin SB44-9642-01, dated July 8, 2021. The issue date of this 
document is identified only on page 3 of the document.
    (3) For Astronics service information identified in this AD, 
contact Astronics Armstrong Aerospace, 804 S Northpoint Blvd., 
Waukegan, IL 60085; telephone 847-244-4500; internet https://www.Astronics.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 fr.inspection@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on August 11, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-17681 Filed 8-13-21; 11:15 am]
BILLING CODE 4910-13-P


