
[Federal Register Volume 81, Number 85 (Tuesday, May 3, 2016)]
[Proposed Rules]
[Pages 26490-26493]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-09794]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-6145; Directorate Identifier 2015-NM-056-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: We propose 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 fuel system reviews 
conducted by the manufacturer. This proposed AD would require modifying 
the fuel quantity indicating system (FQIS) to prevent development of an 
ignition source inside the center fuel tank due to electrical fault 
conditions. This proposed AD would also provide alternative actions for 
cargo airplanes. We are proposing this AD to prevent ignition sources 
inside the center fuel tank, which, in combination with flammable fuel 
vapors, could result in a fuel tank explosion and consequent loss of 
the airplane.

DATES: We must receive comments on this proposed AD by June 17, 2016.

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 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Boeing 
Commercial Airplanes, Attention: Data & Services Management, P.O. Box 
3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, 
extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. 
You may view this referenced service information at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information 
on the availability of this material at the FAA, call 425-227-1221. It 
is also available on the internet at http://www.regulations.gov by 
searching for and locating Docket No. FAA-2016-6145.

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-2016-
6145; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Jon Regimbal, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6506; fax: 425-917-6590; email: Jon.Regimbal@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite 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-2016-6145; 
Directorate Identifier 2015-NM-056-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

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, we issued a 
regulation 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, this rule 
included Special Federal Aviation Regulation No. 88 (``SFAR 88''), 
Amendment 21-78. 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 holders of certain type 
designs (i.e., type certificates (TCs) and supplemental type 
certificate (STCs)) 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

[[Page 26491]]

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, we have 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.
    We have 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.

Model 747 FQIS Design

    The design of the in-tank FQIS components and wiring has the 
potential for latent faults that could cause arcs, sparks, or resistive 
heating in the event of a hot short of an FQIS tank circuit to power 
wiring. The wiring of the FQIS is in some areas cobundled or closely 
adjacent to power wiring. An ignition source combined with flammable 
conditions in a center fuel tank could result in ignition of flammable 
vapor in the fuel tank, causing a structural failure of the wing and 
inflight breakup of the airplane.
    Under the policy contained in FAA Policy Memo PS-ANM100-2003-112-
15, SFAR 88--Mandatory Action Decision Criteria, dated February 25, 
2003 (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/
0/dc94c3a46396950386256d5e006aed11/$FILE/Feb2503.pdf), the FAA 
determined that this ignition source risk combined with the fleet 
average flammability for the center wing tank on Model 747-400, -400D, 
and -400F series airplanes created an unsafe condition for the center 
fuel tank. Applying that same policy, the FAA determined that due to a 
lower fleet average flammability, that same unsafe condition does not 
exist in the main (wing) or reserve tanks of Model 747-400, -400D, and 
-400F series airplanes.

Related Rulemaking

    On March 21, 2016, we issued AD 2016-07-07, Amendment 39-18452 (81 
FR 19472, April 5, 2016), for certain Boeing Model 757-200, -200PF, -
200CB, and -300 series airplanes. AD 2016-07-07 requires similar 
actions to those proposed in this NPRM. AD 2016-07-07 addressed the 
numerous public comments that were submitted on the proposal.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Service Bulletin 747-28-2340, dated June 6, 
2014. The service information describes procedures for a BITE check 
(check of built-in test equipment) of the FQIS. Refer to this service 
information for information on the procedures and compliance times. 
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

    We are 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 modifying the FQIS to prevent 
development of an ignition source inside the center fuel tank due to 
electrical fault conditions. As an alternative for cargo airplanes, 
this proposed AD would provide the alternative to modify the airplane 
by separating FQIS wiring routed between the FQIS processor and the 
center fuel tank, provided repetitive BITE checks (checks of built-in 
test equipment) of the FQIS are also performed.

Costs of Compliance

    We estimate that this proposed AD affects 54 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

                                        Estimated Costs--Required Actions
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                                                                                     Cost per      Cost on U.S.
            Action                         Labor cost               Parts cost        product        operators
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Modification.................  1,200 work-hours x $85 per hour =        $200,000        $302,000    $16,308,000.
                                $102,000.
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                                      Estimated Costs--Alternative Actions
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                Action                            Labor cost               Parts cost        Cost per product
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BITE check...........................  1 work-hour x $85 per hour = $85              $0  $340 per year (4 checks
                                        per check.                                        per year).
Wire separation......................  230 work-hours x $85 per hour =          $10,000  $29,550.
                                        $19,550.
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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.
    We are 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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This

[[Page 26492]]

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) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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-2016-6145; Directorate Identifier 
2015-NM-056-AD.

(a) Comments Due Date

    We must receive comments by June 17, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400, -400D, and 
-400F series airplanes, certificated in any category, excluding 
airplanes equipped with a flammability reduction means (FRM) 
approved by the FAA as compliant with the Fuel Tank Flammability 
Reduction (FTFR) rule (73 FR 42444, July 21, 2008) requirements of 
section 25.981(b) or section 26.33(c)(1) of the Federal Aviation 
Regulations (14 CFR 25.981(b) or 14 CFR 26.33(c)(1)).

(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. We are issuing this AD to prevent ignition sources 
inside the center fuel tank, which, in combination with flammable 
fuel vapors, 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) Modification

    Within 60 months after the effective date of this AD, modify the 
fuel quantity indicating system (FQIS) to prevent development of an 
ignition source inside the center fuel tank due to electrical fault 
conditions, using a method approved in accordance with the 
procedures specified in paragraph (i) of this AD.

(h) Alternative Actions for Cargo Airplanes

    For airplanes used exclusively for cargo operations: As an 
alternative to the requirements of paragraph (g) of this AD, do the 
actions specified in paragraphs (h)(1) and (h)(2) of this AD. To 
exercise this alternative, operators must perform the first 
inspection required under paragraph (h)(1) of this AD within 6 
months after the effective date of this AD. To exercise this 
alternative for airplanes returned to service after conversion of 
the airplane from a passenger configuration to an all-cargo 
configuration more than 6 months after the effective date of this 
AD, operators must perform the first inspection required under 
paragraph (h)(1) of this AD prior to further flight after the 
conversion.
    (1) Within 6 months after the effective date of this AD, record 
the existing fault codes stored in the FQIS processor and then do a 
BITE check (check of built-in test equipment) of the FQIS, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-28-2340, dated June 6, 2014. If any nondispatchable 
fault code is recorded prior to the BITE check or as a result of the 
BITE check, before further flight, do all applicable repairs and 
repeat the BITE check until a successful test is performed with no 
nondispatchable faults found, in accordance with the Accomplishment 
Instructions of Boeing Service Bulletin 747-28-2340, dated June 6, 
2014. Repeat these actions thereafter at intervals not to exceed 650 
flight hours. Modification as specified in paragraph (h)(2) of this 
AD does not terminate the repetitive BITE check requirement of this 
paragraph.
    (2) Within 60 months after the effective date of this AD, modify 
the airplane by separating FQIS wiring that runs between the FQIS 
processor and the center tank wing spar penetrations, including any 
circuits that might pass through a main fuel tank, from other 
airplane wiring that is not intrinsically safe, using methods 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
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 ACO, send it to the 
attention of the person identified in paragraph (j) 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 Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO, 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.
    (4) 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) 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. 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 Jon Regimbal, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle ACO, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6506; 
fax: 425-917-6590; email: Jon.Regimbal@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, WA. For information on the availability of this 
material at the FAA, call 425-227-1221.


[[Page 26493]]


    Issued in Renton, Washington, on April 15, 2016.
Victor Wicklund,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-09794 Filed 5-2-16; 8:45 am]
BILLING CODE 4910-13-P


