[Federal Register: July 10, 2007 (Volume 72, Number 131)]
[Proposed Rules]
[Page 37479-37484]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10jy07-18]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-28661; Directorate Identifier 2007-NM-013AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -
800, and -900 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 737-600, -700, -700C, -800, and -900 series
airplanes. This proposed AD would require installation of an automatic
shutoff system for the center tank fuel boost pumps, installation of a
placard in the airplane flight deck if necessary, and concurrent
modification of the P5-2 fuel control module assembly. This proposed AD
would also require revisions to the Limitations and Normal Procedures
sections of the airplane flight manual to advise the flightcrew of
certain operating restrictions for airplanes equipped with an automated
center tank fuel pump shutoff control. This proposed AD would also
require a
[[Page 37480]]
revision to the Airworthiness Limitations (AWLs) section of the
Instructions for Continued Airworthiness to incorporate AWL No. 28-AWL-
19 and No. 28-AWL-23. This proposed AD would also require installation
of two secondary override fuel pump control relays to each existing
primary override fuel pump control relay for the center fuel tank fuel
boost pumps. This proposed AD results from fuel system reviews
conducted by the manufacturer. We are proposing this AD to prevent
center tank fuel pump operation with continuous low pressure, which
could lead to friction sparks or overheating in the fuel pump inlet or
could create a potential ignition source inside the center fuel tank;
these conditions, in combination with flammable fuel vapors, could
result in a center fuel tank explosion and consequent loss of the
airplane.
DATES: We must receive comments on this proposed AD by August 24, 2007.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to http://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
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.
Fax: (202) 493-2251.
Hand Delivery: Room W12-140 on the ground floor of the
West Building, 1200 New Jersey Avenue SE., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for the service information identified in this
proposed AD.
FOR FURTHER INFORMATION CONTACT: Kathrine Rask, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Ave SW., Renton, Washington 98057-3356; telephone
(425) 917-6505; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
28661; Directorate Identifier 2007-NM-013-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments received by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of
that Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or you
may visit http://dms.dot.gov.
Examining the Docket
You may examine the AD docket on the Internet at http://dms.dot.gov
, or in person at the Docket Operations office between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The
Docket Operations office (telephone (800) 647-5527) is located on the
ground floor of the West Building at the DOT street address stated in
the ADDRESSES section. Comments will be available in the AD docket
shortly after the Docket Management System receives them.
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 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.
Boeing has found that certain failures will result in the center
tank fuel pumps continuing to run after the tank has been depleted.
Depending on the failure, pump low pressure may not be annunciated, or
power may not be removed from the pump when the pump has been commanded
``OFF.'' Operation of the center tank fuel pump with continuous low
pressure could lead to friction sparks or overheating in the fuel boost
pump inlet. This condition, if not corrected, could result in a fuel
tank explosion and consequent loss of the airplane.
Other Relevant Rulemaking
On April 18, 2001, we issued AD 2001-08-24, amendment 39-12201 (66
FR 20733, April 25, 2001), applicable to all Boeing Model 737
airplanes. That AD requires revising the airplane flight manual (AFM)
to prohibit extended dry operation of the center tank fuel pumps (with
no fuel passing through the pumps). Accomplishing the actions
[[Page 37481]]
specified in paragraphs (g), (h), (i), (j), and (k) of this proposed AD
would terminate the AFM revision required by paragraph (a) of AD 2001-
08-24 for Model 737-600, -700, -700C, -800, and -900 series airplanes
that have the automatic shutoff system installed.
On September 24, 2002, we issued AD 2002-19-52, amendment 39-12900
(67 FR 61253, September 30, 2002), applicable to all Boeing Model 737-
600, -700, -700C, -800, and -900 series airplanes, Model 747 airplanes,
and Model 757 airplanes. That AD requires revising the AFM to advise
the flightcrew of certain operating restrictions for maintaining
minimum fuel levels, prohibits use of the horizontal stabilizer tank on
certain airplanes, and prohibits the installation of certain fuel
pumps. That AD requires concurrent removal of the currently required
AFM revisions and insertion of new AFM revisions, requires installation
of placards to alert the flightcrew to the operating restrictions, and
prohibits installation of any un-inspected pumps. That AD permits the
AFM revision and placard to be removed under certain conditions.
Installation of a placard in accordance with paragraph (e) of AD 2002-
19-52, amendment 39-12900, is acceptable for compliance with paragraph
(h) of this AD.
On November 23, 2002, we issued emergency AD 2002-24-51, amendment
39-12992, applicable to all Boeing Model 737-600, -700, -700C, -800,
and -900 series airplanes, Model 747 airplanes, and Model 757
airplanes. (We issued a Federal Register version of AD 2002-24-51 on
December 23, 2002 (68 FR 10, January 2, 2003).) That AD requires
revising the AFM to require the flightcrew to maintain certain minimum
fuel levels in the center fuel tanks and, for certain airplanes, to
prohibit the use of the horizontal stabilizer fuel tank and certain
center auxiliary fuel tanks. Accomplishing the actions specified in
paragraphs (g), (h), (i), (j), and (k) of this proposed AD would
terminate the AFM revision specified in paragraph (b) of AD 2002-24-51
for Model 737-600, -700, -700C, -800, and -900 series airplanes that
have the automatic shutoff system installed.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 737-28A1206, dated
January 11, 2006. This service bulletin describes procedures for
installing an automatic shutoff system for the center tank fuel boost
pumps. Installation of the automatic shutoff system includes the
following actions:
In the J4 junction box, changing wiring and connector
termination positions and installing relays, transformers, markers, and
wires to a certain wire bundle.
In the J20 junction box, changing wiring and installing
relays, markers, and wires to a certain wire bundle.
At the P5 overhead panel in the flight compartment,
replacing the P5-2 fuel control module with a reworked P5-2 fuel
control module.
In the flight compartment, installing the P61-8 fuel test
panel and installing circuit breakers and markers in the P6-3 circuit
breaker panel.
Adding wiring to certain wire bundles in the P6 circuit
breaker panel, between the flight and electronics compartment, in the
J4 and J20 junction boxes, in the E2-1 and E4-2 electronics shelves in
the electrical compartment, between the E2-1 electronics shelf and the
P5-2 fuel control panel, between the E4-2 electronics shelf and the P5-
2 fuel control panel, between the E2-1 electronics shelf and the J20
junction box, and between the E4-2 electronics shelf and the J4
junction box.
We have also reviewed Boeing Alert Service Bulletin 737-28A1248,
dated December 21, 2006. This service bulletin describes procedures for
installing two secondary override fuel pump control relays to each
existing primary override fuel pump control relay for the center fuel
tank fuel boost pumps. The installation includes installing a new
overlay marker and Brady label, changing and adding certain wires, and
connecting the new relays to the power distribution panel.
We have also reviewed Revision December 2005 and Revision May 2006
of Section 9 of the Boeing 737-600/700/700C/700IGW/800/900 Maintenance
Planning Data (MPD) Document, D626A001-CMR (hereafter referred to as
``the MPD''). Subsection F, ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEM
AWLs,'' of the MPD describes new airworthiness limitations (AWLs) for
fuel tank systems. The AWLs include:
AWL inspections, which are periodic inspections of certain
features for latent failures that could contribute to an ignition
source.
Critical design configuration control limitations
(CDCCLs), which are limitation requirements to preserve a critical
ignition source prevention feature of the fuel tank system design that
is necessary to prevent the occurrence of an unsafe condition. The
purpose of a CDCCL is to provide instruction to retain the critical
ignition source prevention feature during configuration change that may
be caused by alterations, repairs, or maintenance actions. A CDCCL is
not a periodic inspection.
Subsection F of the MPD, Revision December 2005, adds new fuel
system AWL No. 28-AWL-19, which is a repetitive inspection of the
automatic shutoff system for the center tank fuel boost pumps to verify
functional integrity. Subsection F of the MPD, Revision May 2006, adds
new fuel system AWL No. 28-AWL-23, which is a repetitive inspection of
the power failed on protection system for the center tank fuel boost
pumps to verify functional integrity.
Boeing Alert Service Bulletin 737-28A1206 recommends concurrent
accomplishment of Boeing Component Service Bulletin 233A3202-28-03,
dated January 12, 2006. Boeing Component Service Bulletin 233A3202-28-
03 describes procedures for replacing the left and right center boost
pump switches of the P5-2 fuel control module assembly with new
switches and changing the wiring of the P5-2 fuel control module
assembly.
Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. For this reason, we are proposing this AD,
which would require the following actions:
Installation of an automatic shutoff system for the center
tank fuel boost pumps.
Installation of a placard in the airplane flight deck, if
necessary. (Placards are necessary only for ``mixed fleet operation,''
which means that some airplanes in an operator's fleet are equipped
with automatic shutoff systems while other airplanes are not.)
Concurrent modification of the P5-2 fuel control module
assembly.
Revisions to the Limitations and Normal Procedures
sections of the AFM to advise the flightcrew of certain operating
restrictions for airplanes equipped with an automated center tank fuel
pump shutoff control.
Revision to the AWLs section of the Instructions for
Continued Airworthiness to incorporate AWL No. 28-AWL-19, which would
require repetitive inspections of the automatic shutoff system for the
center tank fuel boost pumps to verify functional integrity.
[[Page 37482]]
Installation of two secondary override fuel pump control
relays to each existing primary override fuel pump control relay for
the center fuel tank fuel boost pumps.
Revision to the AWLs section of the Instructions for
Continued Airworthiness to incorporate AWL No. 28-AWL-23, which would
require repetitive inspections of the power failed on protection system
for the center tank fuel boost pumps to verify functional integrity.
This proposed AD would also allow accomplishing the revision to the
AWLs section of the Instructions for Continued Airworthiness in
accordance with later revisions of the MPD as an acceptable method of
compliance if they are approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA.
Costs of Compliance
There are about 2,109 airplanes of the affected design in the
worldwide fleet. The following table provides the estimated costs, at
an average labor rate of $80 per work hour, for U.S. operators to
comply with this proposed AD. The estimated cost of parts for
installing an automatic shutoff system depends on the configuration of
an airplane.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Number of
U.S.-
Action Work hours Parts Cost per airplane registered Fleet cost
airplanes
----------------------------------------------------------------------------------------------------------------
Installation of the automatic 89 $23,072 to $30,192 to 616 $18,598,272 to
shutoff system. $34,559. $41,679. $25,674,264.
Placard installation, if 1 $10.............. $90.............. 616 $55,440.
necessary.
Concurrent modification of 9 $3,815........... $4,535........... 616 $2,793,560.
fuel control module assembly.
AFM revision.................. 1 None............. $80.............. 616 $49,280.
AWL revision to add 28-AWL-19. 1 None............. $80.............. 616 $49,280.
Installation of secondary pump 65 $2,964........... $8,164........... 726 $5,927,064.
control relays.
AWL revision to add 28-AWL-23. 1 None............. $80.............. 726 $58,080.
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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 have 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 that the 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.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket. See the
ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2007-28661; Directorate Identifier 2007-NM-
013-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by August
24, 2007.
Affected ADs
(b) Accomplishing certain paragraphs of this AD terminates
certain requirements of AD 2001-08-24, amendment 39-12201, and
terminates certain requirements of AD 2002-24-51, amendment 39-
12992.
Applicability
(c) This AD applies to Boeing Model 737-600, -700, -700C, -800,
and -900 series airplanes, certificated in any category; as
identified in Boeing Alert Service Bulletin 737-28A1248, dated
December 21, 2006.
Note 1: This AD requires revisions to certain operator
maintenance documents to include new inspections of the automatic
shutoff system for the center tank fuel boost pumps. 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 inspections, the operator may not be
able to accomplish the inspections described in the revisions. In
this situation, to comply with 14 CFR 91.403(c), the operator must
request approval for an alternative method of compliance according
to paragraph (p) of this AD. The request should include a
description of changes to the required inspections that will ensure
acceptable maintenance of the automatic shutoff system.
Unsafe Condition
(d) This AD results from fuel system reviews conducted by the
manufacturer. We are issuing this AD to prevent center tank
[[Page 37483]]
fuel pump operation with continuous low pressure, which could lead
to friction sparks or overheating in the fuel pump inlet or could
create a potential ignition source inside the center fuel tank;
these conditions, in combination with flammable fuel vapors, could
result in a center fuel tank explosion and consequent loss of the
airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Service Information References
(f) The term ``Revision December 2005 of the MPD,'' as used in
this AD, means the Boeing 737-600/700/700C/700IGW/800/900
Maintenance Planning Data (MPD) Document, D626A001-CMR, Section 9,
Revision December 2005. The term ``Revision May 2006 of the MPD,''
as used in this AD, means the Boeing 737-600/700/700C/700IGW/800/900
MPD Document, D626A001-CMR, Section 9, Revision May 2006. The term
``service bulletin,'' as used in this AD, means the Accomplishment
Instructions of the following service bulletins, as applicable:
(1) For installation of an automatic shutoff system required by
paragraph (g) of this AD: Boeing Alert Service Bulletin 737-28A1206,
dated January 11, 2006;
(2) For modification of the fuel control module assembly
required by paragraph (i) of this AD: Boeing Component Service
Bulletin 233A3202-28-03, dated January 12, 2006; and
(3) For installation of the secondary override pump control
relays required by paragraph (l) of this AD: Boeing Alert Service
Bulletin 737-28A1248, dated December 21, 2006.
Installation of Automatic Shutoff System for the Center Tank Fuel Boost
Pumps
(g) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1206, dated January 11, 2006: Within
36 months after the effective date of this AD, install an automatic
shutoff system for the center tank fuel boost pumps, by
accomplishing all of the actions specified in the applicable service
bulletin. If a placard has been previously installed on the airplane
in accordance with paragraph (h) of this AD, the placard may be
removed from the flight deck of only that airplane after the
automatic shutoff system has been installed. Installing automatic
shutoff systems on all airplanes in an operator's fleet, in
accordance with this paragraph, terminates the placard installation
required by paragraph (h) of this AD, for all airplanes in an
operator's fleet.
Placard Installation for Mixed Fleet Operation
(h) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1206, dated January 11, 2006:
Concurrently with installing an automatic shutoff system on any
airplane in an operator's fleet, as required by paragraph (g) of
this AD, install a placard adjacent to the pilot's primary flight
display on all airplanes in the operator's fleet not equipped with
an automatic shutoff system for the center tank fuel boost pumps.
The placard must read as follows (unless alternative placard wording
is approved by an appropriate FAA Principal Operations Inspector):
``AD 2002-24-51 fuel usage restrictions required.''
Installation of a placard in accordance with paragraph (e) of AD
2002-19-52, amendment 39-12900, is acceptable for compliance with
the requirements of this paragraph. Installing an automatic shutoff
system on an airplane, in accordance with paragraph (g) of this AD,
terminates the placard installation required by this paragraph, for
only that airplane. Installing automatic shutoff systems on all
airplanes in an operator's fleet, in accordance with paragraph (g)
of this AD, terminates the placard installation required by this
paragraph, for all airplanes in an operator's fleet. If automatic
shutoff systems are installed concurrently on all airplanes in an
operator's fleet in accordance with paragraph (g) of this AD, or if
operation according to the fuel usage restrictions of AD 2002-24-51
is maintained until automatic shutoff systems are installed on all
airplanes in an operator's fleet, the placard installation specified
in this paragraph is not required.
Concurrent Modification of P5-2 Fuel Control Module Assembly
(i) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1206, dated January 11, 2006, equipped
with any fuel control module assembly identified in paragraph 1.A.1.
of Boeing Component Service Bulletin 233A3202-28-03, dated January
12, 2006: Before or concurrently with accomplishing the actions
required by paragraph (g) of this AD, replace the left and right
center boost pump switches of the P5-2 fuel control module assembly
with new switches and change the wiring of the P5-2 fuel control
module assembly, by accomplishing all the applicable actions
specified in the applicable service bulletin.
Airplane Flight Manual (AFM) Revision
(j) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1206, dated January 11, 2006:
Concurrently with accomplishing the actions required by paragraph
(g) of this AD, do the actions specified in paragraphs (j)(1) and
(j)(2) of this AD.
(1) Revise Section 1 of the Limitations section of the Boeing
737-600/-700/-700C/-800/-900 AFM to include the following statement.
This may be done by inserting a copy of this AD in the AFM.
``Intentional dry running of a center tank fuel pump (low
pressure light illuminated) is prohibited.''
Note 2: When a statement identical to that in paragraph (j)(1)
of this AD has been included in the general revisions of the AFM,
the general revisions may be inserted into the AFM, and the copy of
this AD may be removed from the AFM.
(2) Revise Section 3 of the Normal Procedures section of the
Boeing 737-600/-700/-700C/-800/-900 AFM to include the following
statements. This may be done by inserting a copy of this AD in the
AFM.
``Center Tank Fuel Pumps
Alternative Method of Compliance (AMOC) to AD 2001-08-24 and AD
2002-24-51 for Aircraft with the Automated Center Tank Fuel Pump
Shutoff
Center tank fuel pumps must not be ``ON'' unless personnel are
available in the flight deck to monitor low pressure lights.
For ground operation, center tank fuel pump switches must not be
positioned ``ON'' unless the center tank fuel quantity exceeds 1000
pounds (453 kilograms), except when defueling or transferring fuel.
Upon positioning the center tank fuel pump switches ``ON'' verify
momentary illumination of each center tank fuel pump low pressure
light.
For ground and flight operations, the corresponding center tank
fuel pump switch must be positioned ``OFF'' when a center tank fuel
pump low pressure light illuminates [1]. Both center tank fuel pump
switches must be positioned ``OFF'' when the first center tank fuel
pump low pressure light illuminates if the center tank is empty.
[1] When established in a level flight attitude, both center
tank pump switches should be positioned ``ON'' again if the center
tank contains usable fuel.
Defueling and Fuel Transfer
When transferring fuel or defueling center or main tanks, the
fuel pump low pressure lights must be monitored and the fuel pumps
positioned to ``OFF'' at the first indication of the fuel pump low
pressure [1].
Defueling the main tanks with passengers on board is prohibited
if the main tank fuel pumps are powered [2].
Defueling the main tanks with passengers on board is prohibited
if the center tank fuel pumps are powered and the auto-shutoff
system is inhibited [2].
[1] Prior to transferring fuel or defueling, conduct a lamp test
of the respective fuel pump low pressure lights.
[2] Fuel may be transferred from tank to tank or the aircraft
may be defueled with passengers on board, provided fuel quantity in
the tank from which fuel is being taken is maintained at or above
2000 pounds (900 kilograms).''
Note 3: When statements identical to those in paragraph (j)(2)
of this AD have been included in the general revisions of the AFM,
the general revisions may be inserted into the AFM, and the copy of
this AD may be removed from the AFM.
Airworthiness Limitations (AWLs) Revision for AWL No. 28-AWL-19
(k) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1206, dated January 11, 2006:
Concurrently with installing an automatic shutoff system in
accordance with paragraph (g) of this AD, revise the AWLs section of
the Instructions for Continued Airworthiness by incorporating AWL
No. 28-AWL-19 of Subsection F of Revision December 2005 of the MPD
into the MPD. Accomplishing the revision in accordance with a later
revision of the MPD is an acceptable method of compliance if the
revision is approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA.
[[Page 37484]]
Installation of Secondary Override Pump Control Relays
(l) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1248, dated December 21, 2006: Within
60 months after the effective date of this AD, install two secondary
override fuel pump control relays to each existing primary override
fuel pump control relay for the center fuel tank fuel boost pumps,
in accordance with the applicable service bulletin.
AWLs Revision for AWL No. 28-AWL-23
(m) For the airplanes identified in paragraph 1.A.1. of Boeing
Alert Service Bulletin 737-28A1248, dated December 21, 2006:
Concurrently with installing the secondary override pump control
relays in accordance with paragraph (l) of this AD, revise the AWLs
section of the Instructions for Continued Airworthiness by
incorporating AWL No. 28-AWL-23 of Subsection F of Revision May 2006
of the MPD into the MPD. Accomplishing the revision in accordance
with a later revision of the MPD is an acceptable method of
compliance if the revision is approved by the Manager, Seattle ACO.
Terminating Action for AD 2001-08-24
(n) Accomplishing the actions required by paragraphs (g), (h),
(i), (j), and (k) of this AD terminates the requirements of
paragraph (a) of AD 2001-08-24 for Model 737-600, -700, -700C, -800,
and -900 series airplanes that have the automatic shutoff system
installed. After accomplishing the actions required by paragraphs
(g), (h), (i), (j), and (k) of this AD, the AFM limitation required
by paragraph (a) of AD 2001-08-24 may be removed from the AFM for
those airplanes.
Terminating Action for AD 2002-24-51
(o) Accomplishing the actions required by paragraphs (g), (h),
(i), (j), and (k) of this AD terminates the requirements of
paragraph (b) of AD 2002-24-51 for Model 737-600, -700, -700C, -800,
and -900 series airplanes that have the automatic shutoff system
installed. After accomplishing the actions required by paragraphs
(g), (h), (i), (j), and (k) of this AD, the AFM limitations required
by paragraph (b) of AD 2002-24-51 may be removed from the AFM for
those airplanes.
Alternative Methods of Compliance (AMOCs)
(p)(1) The Manager, Seattle ACO, has the authority to approve
AMOCs for this AD, if requested in accordance with the procedures
found in 14 CFR 39.19.
(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 appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
Issued in Renton, Washington, on June 26, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-13326 Filed 7-9-07; 8:45 am]
BILLING CODE 4910-13-P