[Federal Register Volume 84, Number 217 (Friday, November 8, 2019)]
[Proposed Rules]
[Pages 60351-60354]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-24329]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0859; Product Identifier 2019-NM-114-AD]
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 747-100, 747-100B, 747-100B SUD, 
747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 
747SR, and 747SP series airplanes. This proposed AD results from fuel 
system reviews conducted by the manufacturer. This proposed AD would 
require replacement of the bonding jumpers on the auxiliary power unit 
(APU) fuel pump. This proposed AD would also require, for certain 
airplanes, installation of a second bonding jumper; an inspection of 
the override/jettison fuel pumps and transfer/jettison fuel pumps to 
determine if the bonding jumper has a one-piece braid or two-piece 
braid and replacement of the bonding jumper if necessary; and 
replacement of the bonding jumper on the electrical scavenge fuel pump. 
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 December 
23, 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 https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-

[[Page 60352]]

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 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 https://www.regulations.gov by searching 
for and locating Docket No. FAA-2019-0859.

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-2019-
0859; 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: Jeffrey Rothman, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3558; email: 
jeffrey.rothman@faa.gov.

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-2019-0859; 
Product Identifier 2019-NM-114-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 received, without change, to https://www.regulations.gov, including any personal information you provide. 
The FAA will also post a report summarizing each substantive verbal 
contact received 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'') at 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) and Amendment 21-83 (67 FR 
72830, December 9, 2002; corrected at 68 FR 37735, June 25, 2003, to 
change ``21-82'' to ``21-83'').
    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 final rule published on 
May 7, 2001, the FAA 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 has 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, single failures in 
combination with another latent condition(s), and in-service failure 
experience. For all four criteria, the evaluations included 
consideration of previous actions taken that may mitigate the need for 
further action.
    The FAA has determined that the actions identified in this proposed 
AD are necessary to reduce the potential of ignition sources inside 
fuel tanks, which, in combination with flammable fuel vapors, could 
result in fuel tank explosions and consequent loss of the airplane.
    The FAA has received data from the fuel tank inspection program 
indicating that the existing bond path design provides insufficient 
bond resistance margin between the fuel pump motor/impeller and 
structure. In the event of a fuel pump electrical fault, this condition 
might cause arcs at the existing fuel pump/tank interfaces and an 
ignition of fuel vapor in the wing fuel tank, which could result in a 
fuel tank explosion.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Service Bulletin 747-28-2228, Revision 1, 
dated September 27, 2001. This service information describes procedures 
for a replacement of the bonding jumpers on the APU fuel pump; an 
inspection of the six override/jettison fuel pumps and of the two 
transfer/jettison fuel pumps to determine if the bonding jumper has a 
one-piece braid or two-piece braid, and replacement of the existing 
bonding jumper if the bonding jumper has a one-piece braid; 
installation of a second bonding jumper; and replacement of the bonding 
jumper on the electrical scavenge fuel pump.
    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.

Other Relevant Rulemaking

    Boeing Service Bulletin 747-28-2228, Revision 1, dated September 
27, 2001, identifies ``Boeing Service Bulletin 747-28-2033'' as a 
concurrent requirement for certain airplanes. Boeing Alert Service 
Bulletin 747-28A2033, Revision 1, dated December 18, 2003, is the 
appropriate source of service information for accomplishing the 
installation required by AD 2005-01-07, Amendment 39-13931 (70 FR 1336, 
January 7, 2005) (``AD 2005-01-07''). The compliance time for 
accomplishing the installation required by AD 2005-01-07 has already 
passed; therefore, it is not necessary to include Boeing Alert Service 
Bulletin 747-28A2033 as a concurrent requirement in this proposed AD. 
The FAA issued AD 2005-01-07 to

[[Page 60353]]

ensure adequate electrical bonding between the housing of each fuel 
pump and airplane structure outside the fuel tanks. Inadequate 
electrical bonding, in the event of a lightning strike or fuel pump 
electrical fault, could cause electrical arcing and ignition of fuel 
vapor in the wing fuel tank, which could result in a fuel tank 
explosion.

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 accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    The FAA estimates that this proposed AD affects 74 airplanes of 
U.S. registry. The FAA estimates the following costs to comply with 
this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                   Labor cost          Parts cost       Cost per  product       operators
----------------------------------------------------------------------------------------------------------------
Replacement, Installation, and    Up to 15 work-      Up to $2,000......  Up to $3,275......  Up to $242,350.
 Inspection.                       hours x $85 per
                                   hour = Up to
                                   $1,275.
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    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
proposed inspection. The FAA has no way of determining the number of 
aircraft that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost               Parts cost            Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement..........................  Up to 6 work-hours x     Up to $950.............  Up to $1,460.
                                        $85 per hour = Up to
                                        $510.
----------------------------------------------------------------------------------------------------------------

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-2019-0859; Product Identifier 
2019-NM-114-AD.

(a) Comments Due Date

    The FAA must receive comments by December 23, 2019.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-100, 747-100B, 
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-
400D, 747-400F, 747SR, and 747SP series airplanes, certificated in 
any category, line numbers (L/Ns) 1 through 1229 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by fuel system reviews conducted by the 
manufacturer indicating that the existing bond path design

[[Page 60354]]

provides insufficient bond resistance margin between the fuel pump 
motor/impeller and structure. The FAA is issuing this AD to address 
insufficient bond resistance margin between the fuel pump motor/
impeller and structure. In the event of a fuel pump electrical 
fault, this condition might cause arcs at the existing fuel pump/
tank interfaces and an ignition of fuel vapor in the wing fuel tank, 
which could result in a fuel tank explosion and consequent loss of 
the airplane.

(f) Compliance

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

(g) Definitions

    For the purposes of this AD, the definitions specified in 
paragraphs (g)(1) through (4) of this AD apply.
    (1) Group 1 airplanes: L/Ns 1 through 167 inclusive.
    (2) Group 2 airplanes: L/Ns 168 through 971 inclusive.
    (3) Group 3 airplanes: L/Ns 972 through 1161 inclusive.
    (4) Group 4 airplanes: L/Ns 1162 through 1229 inclusive.

(h) Replacement, Installation, and Inspection

    Within 60 months after the effective date of this AD, do the 
applicable actions specified in paragraphs (h)(1) through (4) of 
this AD, in accordance with the Accomplishment Instructions of 
Boeing Service Bulletin 747-28-2228, Revision 1, dated September 27, 
2001.
    (1) For Groups 1, 2, and 3 airplanes: Do the actions specified 
in paragraphs (h)(1)(i) and (ii) of this AD.
    (i) Do a general visual inspection of the six override/jettison 
fuel pumps to determine if the bonding jumper has a one-piece braid 
or two-piece braid. If the bonding jumper has a one-piece braid, 
within 60 months after the effective date of this AD, replace the 
existing bonding jumper.
    (ii) Install a second bonding jumper.
    (2) For Groups 1, 2 and 3 airplanes with horizontal stabilizer 
fuel tanks: Do the actions specified in paragraphs (h)(2)(i) and 
(ii) of this AD.
    (i) Do a general visual inspection of the two transfer/jettison 
fuel pumps to determine if the bonding jumper has a one-piece braid 
or a two-piece braid. If the bonding jumper has a one-piece braid, 
within 60 months after the effective date of this AD, replace the 
existing bonding jumper.
    (ii) Install a second bonding jumper.
    (3) For all airplanes: Replace the bonding jumpers on the 
auxiliary power unit (APU) fuel pump.
    (4) For Groups 1 and 2 airplanes: Replace the bonding jumper on 
the electrical scavenge fuel pump.

(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 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)(1) of this AD. Information may be 
emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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, 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 Jeffrey Rothman, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3558; email: jeffrey.rothman@faa.gov.
    (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 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 October 29, 2019.
Dionne Palermo,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2019-24329 Filed 11-7-19; 8:45 am]
 BILLING CODE 4910-13-P


