Airworthiness Directives; The Boeing Company Airplanes
| Published date | 25 June 2019 |
| Citation | 84 FR 29815 |
| Record Number | 2019-13049 |
| Section | Proposed rules |
| Court | Federal Aviation Administration |
Federal Register, Volume 84 Issue 122 (Tuesday, June 25, 2019)
[Federal Register Volume 84, Number 122 (Tuesday, June 25, 2019)]
[Proposed Rules]
[Pages 29815-29818]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-13049]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0440; Product Identifier 2019-NM-032-AD]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all The Boeing Company Model 737-300, -400, and -500 series
airplanes. This proposed AD was prompted by fuel system reviews
conducted by the manufacturer. This proposed AD would require applying
sealant to the fasteners in the fuel tanks, replacing wire bundle
clamps external to the fuel tanks and installing Teflon sleeving under
the clamps. 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 August 9,
2019.
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 http://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
[[Page 29816]]
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 service information at the FAA, Transport Standards 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 http://www.regulations.gov by searching
for and locating Docket No. FAA-2019-0440.
Examining the AD Docket
You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0440; 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, the regulatory evaluation, any comments received, and other
information. The street address for Docket Operations is listed above.
Comments will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Jeff Rothman, Aerospace Engineer,
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des
Moines, WA 98198; phone and fax: 206-231-3558; 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 the ADDRESSES section. Include ``Docket No. FAA-2019-0440;
Product Identifier 2019-NM-032-AD'' at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this NPRM. The FAA will
consider all comments received by the closing date and may amend this
NPRM because of those comments.
The FAA will post all comments we receive, without change, to
http://www.regulations.gov, including any personal information you
provide. The FAA will also post a report summarizing each substantive
verbal contact we receive about this NPRM.
Discussion
The FAA has examined the underlying safety issues involved in fuel
tank explosions on several large transport airplanes, including the
adequacy of existing regulations, the service history of airplanes
subject to those regulations, and existing maintenance practices for
fuel tank systems. As a result of those findings, the FAA issued a
final rule titled ``Transport Airplane Fuel Tank System Design Review,
Flammability Reduction, and Maintenance and Inspection Requirements''
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards
for transport airplanes and new maintenance requirements that rule
included Amendment 21-78, which established Special Federal Aviation
Regulation No. 88 (``SFAR 88'') to 14 CFR part 21. Subsequently, SFAR
88 was amended by: Amendment 21-82 (67 FR 57490, September 10, 2002;
corrected at 67 FR 70809, November 26, 2002), Amendment 21-83 (67 FR
72830, December 9, 2002; corrected at 68 FR 37735, June 25, 2003, to
change ``21-82'' to ``21-83''), and Amendment 21-101 (83 FR 9162, March
5, 2018).
Among other actions, SFAR 88 requires certain type design (i.e.,
type certificate (TC) and supplemental type certificate (STC)) holders
to substantiate that their fuel tank systems can prevent ignition
sources in the fuel tanks. This requirement applies to type design
holders for large turbine-powered transport airplanes and for
subsequent modifications to those airplanes. It requires them to
perform design reviews and to develop design changes and maintenance
procedures if their designs do not meet the new fuel tank safety
standards. As explained in the preamble to the rule, we intended to
adopt airworthiness directives to mandate any changes found necessary
to address unsafe conditions identified as a result of these reviews.
In evaluating these design reviews, the FAA established four
criteria intended to define the unsafe conditions associated with fuel
tank systems that require corrective actions. The percentage of
operating time during which fuel tanks are exposed to flammable
conditions is one of these criteria. The other three criteria address
the failure types under evaluation: single failures, combination of
failures, and unacceptable (failure) experience. For all three failure
criteria, the evaluations included consideration of previous actions
taken that may mitigate the need for further action.
This proposed AD was prompted by fuel system reviews conducted by
the manufacturer. Boeing has found that some fuel tank fasteners can be
an ignition source if a fault current or hot short occurs. A detailed
analysis of the fault current threats was done to find the
configuration necessary to safely conduct the fault current threats
without causing sparks in the fuel tanks. Application of sealant on the
fasteners in the fuel tanks at the wing rear spars, front spars and
upper wing rib shear ties decreases the risk of ignition sources at
those fuel tank fastener locations. In addition, external to the fuel
tanks at locations along the wing rear spars, front spars, the forward
cargo compartment station 540 bulkhead and the main wheel well station
663 bulkhead, installation of cushion clamps over Teflon sleeves on
wire bundles decreases metal-to-metal contact between the clamps and
their support brackets and will help prevent hot shorts. The FAA is
proposing this AD to address potential ignition sources inside the fuel
tank, which, in combination with flammable vapors, could result in a
fuel tank fire or explosion, and consequent loss of the airplane.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Service Bulletin 737-57A1321, dated
February 8, 2019. This service information describes procedures for
applying sealant to the fasteners in the fuel tanks at the wing rear
spars, front spars, and upper wing rib shear ties. This service
information also describes procedures for replacing wire bundle clamps
external to the fuel tanks and installing Teflon sleeving under the
clamps at locations along the wing rear spars, front spars, forward
cargo compartment station 540 bulkhead, and main wheel well station 663
bulkhead.
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 we 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 accomplishing the actions specified
in the service information described previously. For information on the
[[Page 29817]]
procedures and compliance times, see this service information at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0440.
Costs of Compliance
The FAA estimates that this proposed AD affects 268 airplanes of
U.S. registry. We estimate the following costs to comply with this
proposed AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Apply sealant, replace clamps, Up to 516 Up to $200....... Up to $44,060.... Up to $11,808,080.
install Teflon sleeving. work[dash]hours x $85
per hour = $43,860.
----------------------------------------------------------------------------------------------------------------
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.
This proposed AD is issued in accordance with authority delegated
by the Executive Director, Aircraft Certification Service, as
authorized by FAA Order 8000.51C. In accordance with that order,
issuance of ADs is normally a function of the Compliance and
Airworthiness Division, but during this transition period, the
Executive Director has delegated the authority to issue ADs applicable
to transport category airplanes and associated appliances to the
Director of the System Oversight Division.
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) 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 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 (AD):
The Boeing Company: Docket No. FAA-2019-0440; Product Identifier
2019-NM-032-AD.
(a) Comments Due Date
We must receive comments by August 9, 2019.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 737-300, -400,
and -500 series airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by fuel system reviews conducted by the
manufacturer. The FAA is issuing this AD to address potential
ignition sources inside the fuel tank, which, in combination with
flammable vapors, could result in a fuel tank fire or explosion, and
consequent loss of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Apply Sealant, Replace Clamps, and Install Teflon Sleeving
Except as specified in paragraph (h) of this AD: At the
applicable times specified in paragraph 1.E., ``Compliance,'' of the
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
57A1321, dated February 8, 2019, do all applicable actions
identified as ``RC'' (required for compliance) in, and in accordance
with, the Accomplishment Instructions of Boeing Alert Service
Bulletin 737-57A1321, dated February 8, 2019.
(h) Exceptions to Service Information Specifications
(1) For purposes of determining compliance with the requirements
of this AD: Where Boeing Alert Service Bulletin 737-57A1321, dated
February 8, 2019, uses the phrase ``the original issue date of this
service bulletin,'' this AD requires using ``the effective date of
this AD.''
(2) Where Boeing Alert Service Bulletin 737-57A1321, dated
February 8, 2019, specifies contacting Boeing: This AD requires
doing actions 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, Los Angeles 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 local Flight Standards
District 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)(2) 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 local flight standards district office/certificate holding
district 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, Los
Angeles ACO Branch, FAA, to
[[Page 29818]]
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.
(4) Except as specified by paragraph (h)(2) of this AD: For
service information that contains steps that are labeled as Required
for Compliance (RC), the provisions of paragraphs (i)(4)(i) and
(i)(4)(ii) of this AD apply.
(i) The steps labeled as RC, including substeps under an RC step
and any figures identified in an RC step, must be done to comply
with the AD. If a step or substep is labeled ``RC Exempt,'' then the
RC requirement is removed from that step or substep. An AMOC is
required for any deviations to RC steps, including substeps and
identified figures.
(ii) Steps not labeled as RC may be deviated from using accepted
methods in accordance with the operator's maintenance or inspection
program without obtaining approval of an AMOC, provided the RC
steps, including substeps and identified figures, can still be done
as specified, and the airplane can be put back in an airworthy
condition.
(j) Related Information
(1) For more information about this AD, contact Jeff Rothman,
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch,
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3558; email: [email protected].
(2) For information about AMOCs, contact Serj Harutunian,
Aerospace Engineer, Propulsion Section, FAA, Los Angeles ACO Branch,
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5254; fax: 562-627-5210; email: [email protected].
(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. You may view this service information at the
FAA, Transport Standards Branch, 2200 South 216th St., Des Moines,
WA. For information on the availability of this material at the FAA,
call 206-231-3195.
Issued in Des Moines, Washington, on June 10, 2019.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification
Service.
[FR Doc. 2019-13049 Filed 6-24-19; 8:45 am]
BILLING CODE 4910-13-P
