
[Federal Register: October 13, 2009 (Volume 74, Number 196)]
[Proposed Rules]               
[Page 52431-52434]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13oc09-13]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0906; Directorate Identifier 2009-NM-075-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing 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

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 Boeing Model 747 series airplanes. This proposed AD would 
require replacing the power control relays for the main tank fuel boost 
pumps and jettison pumps, and the center tank scavenge pump, as 
applicable, with new relays having a ground fault interrupt (GFI) 
feature. The proposed AD also would require revising the maintenance 
program to incorporate Airworthiness Limitations (AWLs) No. 28-AWL-23 
(for Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-
200F, 747-300, 747SP, and 747SR series airplanes), and Nos. 28-AWL-28 
and 28-AWL-29 (for Model 747-400, 747-400D, and 747-400F series 
airplanes). This proposed AD results from fuel system reviews conducted 
by the manufacturer. We are proposing this AD to prevent damage to the 
fuel pumps caused by electrical arcing that could introduce an ignition 
source in the fuel tank, which, in combination with flammable fuel 
vapors, could result in a fuel tank explosion and consequent loss of 
the airplane.

[[Page 52432]]


DATES: We must receive comments on this proposed AD by November 27, 
2009.

ADDRESSES: You may send comments 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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; 
Internet https://www.myboeingfleet.com. You may review copies of the 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington. For information 
on the availability of this material at the FAA, call 425-227-1221 or 
425-227-1152.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; 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 (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Georgios Roussos, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone (425) 917-6482; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2009-0906; 
Directorate Identifier 2009-NM-075-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, and subsequent Amendments 21-82 and 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 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, 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, single failures in 
combination with a 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.
    We have determined that the actions identified in this AD are 
necessary to reduce the potential of ignition sources inside fuel 
tanks, which, in combination with flammable fuel vapors, could result 
in a fuel tank explosion and consequent loss of the airplane.
    As part of SFAR 88 analysis, Boeing determined that the power 
control relays for the main tank fuel boost pumps and jettison pumps 
and the center tank scavenge pump should be replaced with new relays 
having a ground fault interrupt (GFI) feature. The relays are located 
in the P414, P415, and P52 panels. The GFI feature is intended to 
protect the fuel pumps from damage caused from electrical arcing by 
removing electrical power from the pump if a ground fault is detected. 
Electrical arcing, if not prevented, could introduce an ignition source 
in the fuel tank, which, in combination with flammable fuel vapors, 
could result in a fuel tank explosion and consequent loss of the 
airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-28A2261, dated 
February 19, 2009. The service bulletin describes procedures for 
replacing the relays for the main tank fuel boost pumps and jettison 
pumps, and the center tank scavenge pump, as applicable, with new 
relays having a GFI feature. The replacement also includes reworking 
certain wiring and doing an operational test of the fuel boost pumps 
and new relays.
    We have also reviewed the following documents, which include a 
repetitive inspection (test) to verify continued functionality of the 
GFI relays:
     For Model 747-400, 747-400D, and 747-400F series 
airplanes: Subsection D, ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEMS,'' 
of Boeing 747-400 Maintenance Planning Data (MPD) Document, Document 
D621U400-9, Section 9, Revision April 2008. Subsection D of Revision 
April 2008 of the MPD includes new airworthiness limitations (AWLs) 28-
AWL-28 and 28-AWL-29. (These AWLs were first introduced in Revision 
October 2007 of the MPD document.) Incorporating these AWLs are an 
optional action in AD 2008-10-06, Amendment 39-15512 (73 FR 25990, May 
8, 2008).

[[Page 52433]]

     For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747SP, and 747SR series airplanes: Subsection 
D, ``AIRWORTHINESS LIMITATIONS--SYSTEMS,'' of Boeing 747-100/200/300/SP 
Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), Document D6-13747-CMR, Revision March 2008. 
Subsection D of Revision March 2008 of the AWLs includes new 
airworthiness limitation AWL 28-AWL-23. (This AWL was first introduced 
in Revision September 2007 of the AWLs/CMRs document.) Incorporating 
this AWL is an optional action in AD 2008-10-07, Amendment 39-15513 (73 
FR 25977, May 8, 2008).

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design. 
This proposed AD would require accomplishing the actions specified in 
the service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 258 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                                     Table--Estimated Costs
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                                                                                                                                           Number of U.S.-
               Action                        Work hours         Average labor              Parts                   Cost per product          registered                  Fleet cost
                                                                rate per hour                                                                 airplanes
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Replacement.........................  10 to 14 \1\...........             $80  $16,800 to $36,200 \1\......  $17,600 to $37,320 \1\......             258  $4,540,800 to $9,628,560 \1\.
Revision of Airworthiness             1......................             $80  None........................  $80.........................             258  $20,640.
 Limitations section.
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\1\ Depending on airplane configuration.

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 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), 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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

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

    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 AD:

Boeing: Docket No. FAA-2009-0906; Directorate Identifier 2009-NM-
075-AD.

Comments Due Date

    (a) We must receive comments by November 27, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to 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; as 
identified in Boeing Alert Service Bulletin 747-28A2261, dated 
February 19, 2009.

    Note 1:  This AD requires a revision to a certain operator 
maintenance document to include new inspections. Compliance with 
these inspections is required by 14 CFR 43.16 and 91.403(c). For 
airplanes that have been previously modified, altered, or repaired 
in the areas addressed by these limitations, the operator may not be 
able to accomplish the actions described in the revisions. In this 
situation, to comply with 14 CFR 43.16 and 91.403(c), the operator 
must request approval for an alternative method of compliance 
according to paragraph (j) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued operational safety of the airplane.

Subject

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

Unsafe Condition

    (e) This AD results from fuel system reviews conducted by the 
manufacturer. The Federal Aviation Administration is issuing this AD 
to prevent damage to the fuel pumps caused by electrical arcing that 
could introduce an ignition source in the fuel tank which, in 
combination with flammable fuel vapors, could result in a fuel tank 
explosion and consequent loss of the airplane.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

[[Page 52434]]

Replacement

    (g) Within 60 months after the effective date of this AD: 
Replace the power control relays for the main tank fuel boost pumps 
and jettison pumps, and the center tank scavenge pump, as 
applicable, with new relays having a ground fault interrupt feature, 
in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-28A2261, dated February 19, 2009.

Maintenance Program Revision

    (h) Concurrently with the actions required by paragraph (g) of 
this AD: Revise the maintenance program by incorporating the 
applicable information in paragraphs (h)(1) and (h)(2) of this AD. 
The inspection interval for AWLs 28-AWL-23, 28-AWL-28, and 28-AWL-29 
starts on the date the replacement required by paragraph (g) of this 
AD is done.
    (1) For Model 747-400, 747-400D, and 747-400F series airplanes: 
Incorporate new airworthiness limitations 28-AWL-28 and 28-AWL-29 of 
Subsection D, ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEMS,'' of Boeing 
747-400 Maintenance Planning Data (MPD) Document, Document D621U400-
9, Section 9, Revision April 2008. (These AWLs were first introduced 
in Revision October 2007 of the MPD document.)
    (2) For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747SP, and 747SR series airplanes: 
Incorporate new airworthiness limitation 28-AWL-23 of Subsection D, 
``AIRWORTHINESS LIMITATIONS--SYSTEMS,'' of Boeing 747-100/200/300/SP 
Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), Document D6-13747-CMR, Revision March 2008. 
(This AWL was first introduced in Revision September 2007 of the 
AWLs/CMRs document.)

No Alternative Inspection or Inspection Intervals

    (i) After accomplishing the action required by paragraph (h) of 
this AD, no alternative inspections or inspection intervals may be 
used, unless the inspections or intervals are approved as an 
alternative method of compliance (AMOC) in accordance with the 
procedures specified in paragraph (j) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(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. Send information to 
Attn: Georgios Roussos, Aerospace Engineer, Systems and Equipment 
Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 
Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 917-
6482; fax (425) 917-6590. Or, e-mail information to 9-ANM-Seattle-
ACO-AMOC-Requests@faa.gov.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.

    Issued in Renton, Washington, on September 25, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-24490 Filed 10-9-09; 8:45 am]

BILLING CODE 4910-13-P
