[Federal Register Volume 86, Number 69 (Tuesday, April 13, 2021)]
[Proposed Rules]
[Pages 19160-19162]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-07544]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0258; Project Identifier AD-2020-01565-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 certain The Boeing Company Model 747-400, 747-400D, and 747-400F 
series airplanes. This proposed AD was prompted by reports of burned 
Boeing Material Specification (BMS) 8-39 urethane foam found in certain 
locations on the airplane; investigation revealed that the fire-
retardant properties degrade with age. This proposed AD would require 
inspecting the insulation blankets in certain areas of the forward 
cargo compartment for exposed BMS 8-39 urethane foam, not encapsulated 
by a protective fire resistant barrier, and for seal integrity, and 
replacing the BMS 8-39 urethane foam and seal if necessary. 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 28, 
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-
0258.

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-2021-
0258; 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: Julie Linn, Aerospace Engineer, Cabin 
Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3584; 
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-2021-0258; Project Identifier 
AD-2020-01565-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 
the 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 we receive, 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 we receive about this proposed AD.

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 Julie 
Linn, Aerospace Engineer, Cabin Safety and Environmental Systems 
Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 
98198; phone and fax: 206-231-3584; email: [email protected]. 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 reports of burned BMS 8-39 urethane foam, a 
material with fire-retardant properties. Investigation revealed that 
the fire-retardant properties degrade after five to ten years, and 
degraded BMS 8-39 urethane foam can be a fuel source for a fire if 
exposed to an ignition source. Foam and tape are used to make a seal at 
penetrations that go through the insulation blankets. The type of foam 
that is used, how that foam is installed, and how it is taped are all 
equally important for the integrity of the seal. Previously issued 
service information provided procedures for replacing the BMS 8-39 
urethane foam in most areas, but it did not include an area between 
body station (STA) 960 and STA 1000 on the left and right sides of the 
forward cargo compartment. Degraded BMS 8-39 urethane foam used in 
seals may fail to maintain sufficient halon concentrations in the cargo 
compartments to extinguish or contain fire or smoke, and may fail to 
prevent penetration of fire or smoke in areas of the airplane that are 
difficult to access for fire and smoke detection or suppression, which 
could result in loss of control of the airplane.

Related AD

    The FAA issued AD 2013-11-04, Amendment 39-17464 (78 FR 33193,

[[Page 19161]]

June 4, 2013) (AD 2013-11-04), for certain The Boeing Company 
airplanes, including the same Model 747-400, 747-400D, and 747-400F 
series airplanes identified in this NPRM. AD 2013-11-04 resulted from a 
report from Boeing indicating that various areas of the airplane 
(including flight deck and cargo compartments) were assembled with 
seals made of BMS 8-39 urethane foam; operators subsequently reported 
finding burned BMS 8-39 urethane foam in those locations. AD 2013-11-04 
requires replacing certain seals made of BMS 8-39 urethane foam. AD 
2013-11-04 resulted from operator or in-service reports of burned BMS 
8-39 urethane foam, and a report from the airplane manufacturer 
indicating that airplanes were assembled, throughout various areas of 
the airplane (including flight deck and cargo compartments), with seals 
made of BMS 8-39 urethane foam. The FAA issued AD 2013-11-04 to address 
the failure of urethane seals to maintain sufficient halon 
concentrations in the cargo compartments to extinguish or contain fire 
or smoke, and to prevent penetration of fire or smoke in areas of the 
airplane that are difficult to access for fire and smoke detection or 
suppression.
    This NPRM does not propose to supersede AD 2013-11-04. Rather, the 
FAA has determined that a stand-alone AD would be more appropriate 
because the expanded inspection area applies only to Model 747-400, 
747-400D, and 747-400F series airplanes, a small subset of the 
applicability of AD 2013-11-04.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Requirements Bulletin 747-25-3725 RB, dated 
October 27, 2020. The service information describes procedures for 
doing a general visual inspection of the insulation blankets in the 
area between STA 960 and STA 1000 on the left and right sides of the 
forward cargo compartment for exposed BMS 8-39 urethane foam, not 
encapsulated by a protective fire resistant barrier, and seal 
integrity, and replacing any BMS 8-39 urethane foam that is found 
exposed and any seal that does not have acceptable integrity for a 
smoke barrier. 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.

FAA's Determination

    The FAA is proposing this AD because the agency evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design.

Proposed AD Requirements

    This proposed AD would require accomplishment of the actions 
identified in Boeing Requirements Bulletin 747-25-3725 RB, described 
previously, 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-2021-0258.

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 proposed AD affects 109 airplanes of 
U.S. registry. The FAA estimates the following costs to comply with 
this proposed AD:

                                      Estimated Costs for Required Actions
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                                                                                    Cost per       Cost on U.S.
              Action                        Labor cost            Parts cost        product         operators
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Inspection........................  3 work-hours x $85 per                 $0             $255          $27,795
                                     hour = $255.
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    The FAA estimates the following costs to do any necessary on-
condition actions that would be required. The FAA has no way of 
determining the number of aircraft that might need these on-condition 
actions:

                 Estimated Costs of On-Condition Actions
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         Labor cost                Parts cost         Cost per  product
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1 work-hour x $85 per hour =  Minimal.............  $85 per finding.
 $85 per finding.
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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

[[Page 19162]]

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-2021-0258; Project Identifier AD-
2020-01565-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by May 28, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400, 747-400D, 
and 747-400F series airplanes, certificated in any category, as 
identified in Boeing Requirements Bulletin 747-25-3725 RB, dated 
October 27, 2020.

(d) Subject

    Air Transport Association (ATA) of America Code 25, Equipment/
furnishings.

(e) Unsafe Condition

    This AD was prompted by reports of burned Boeing Material 
Specification (BMS) 8-39 urethane foam found in certain locations on 
the airplane; investigation revealed that the fire-retardant 
properties degrade with age. The FAA is issuing this AD to address 
degraded BMS 8-39 urethane foam used in seals, which may fail to 
maintain sufficient halon concentrations in the cargo compartments 
to extinguish or contain fire or smoke, and may fail to prevent 
penetration of fire or smoke in areas of the airplane that are 
difficult to access for fire and smoke detection or suppression, 
which could result in loss of control 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 
Requirements Bulletin 747-25-3725 RB, dated October 27, 2020, do all 
applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Requirements Bulletin 747-25-
3725 RB, dated October 27, 2020.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Service Bulletin 747-25-
3725, dated October 27, 2020, which is referred to in Boeing 
Requirements Bulletin 747-25-3725 RB, dated October 27, 2020.

(h) Exception to Service Information Specifications

    Where Boeing Requirements Bulletin 747-25-3725 RB, dated October 
27, 2020, uses the phrase ``after the Original Issue date of 
Requirements Bulletin 747-25-3725 RB,'' this AD requires using ``the 
effective date 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)(1) 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

    (1) For more information about this AD, contact Julie Linn, 
Aerospace Engineer, Cabin Safety and Environmental Systems Section, 
FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; 
phone and fax: 206-231-3584; email: [email protected].
    (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.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-07544 Filed 4-12-21; 8:45 am]
BILLING CODE 4910-13-P