
[Federal Register: March 12, 2008 (Volume 73, Number 49)]
[Rules and Regulations]               
[Page 13081-13084]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12mr08-6]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28662; Directorate Identifier 2007-NM-014-AD; 
Amendment 39-15415; AD 2008-06-03]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 
and -900 Series Airplanes; and Model 757-200, -200PF, -200CB, and -300 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing airplanes, identified above. This AD requires inspecting 
to determine if certain motor-operated shutoff valve actuators for the 
fuel tanks are installed, and related investigative and corrective 
actions if necessary. This AD also requires revising the Airworthiness 
Limitations (AWLs) section of the Instructions for Continued 
Airworthiness to incorporate AWL No. 28-AWL-21, No. 28-AWL-22, and No. 
28-AWL-24 (for Model 737-600, -700, -700C, -800 and -900 series 
airplanes); and No. 28-AWL-23, No. 28-AWL-24, and No. 28-AWL-25 (for 
Model 757-200, -200PF, -200CB, and -300 series airplanes). This AD 
results from a design review of the fuel tank systems. We are issuing 
this AD to prevent electrical energy from lightning, hot shorts, or 
fault current from entering the fuel tank through the actuator shaft, 
which could result in fuel tank explosions and consequent loss of the 
airplane.

DATES: This AD becomes effective April 16, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of April 16, 
2008.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Judy Coyle, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6497; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to certain Boeing Model 
737-600, -700, -700C, -800 and -900 series airplanes; and Model 757-
200, -200PF, -200CB, and -300 series airplanes. That NPRM was published 
in the Federal Register on July 10, 2007 (72 FR 37484). That NPRM 
proposed to require inspecting to determine if certain motor-operated 
shutoff valve actuators for the fuel tanks are installed, and related 
investigative and corrective actions if necessary. That NPRM also 
proposed to require revising the Airworthiness Limitations (AWLs) 
section of the Instructions for Continued Airworthiness to incorporate 
AWL No. 28-AWL-21, No. 28-AWL-22, and No. 28-AWL-24 (for Model 737-600, 
-700, -700C, -800 and -900 series airplanes), and No. 28-AWL-23, No. 
28-AWL-24, and No. 28-AWL-25 (for Model 757-200, -200PF, -200CB, and -
300 series airplanes).

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Revise References to Maintenance Planning Data (MPD) 
Documents

    Boeing requests that we revise the applicable areas in the NPRM 
that discuss the revision levels of the Boeing 737 and 757 MPD 
documents. Boeing states that the references in the NPRM should be 
clarified for the following reasons:
     Revision May 2006 of the Boeing 737-600/700/700C/700IGW/
800/900 MPD did not add AWLs (Airworthiness Limitations) 28-AWL-21, -
22, and -24. Instead, AWLs 28-AWL-21 and -22 were added at Revision 
January 2006; AWL 28-AWL-24 was added at Revision October 2006.
     Revision October 2006 of the Boeing 737-600/700/700C/
700IGW/800/900 MPD revised AWL 28-AWL-21.
     Revision October 2006 of the Boeing 757 MPD added AWL 28-
AWL-25; AWLs 28-AWL-23 and -24 were added at Revision February 2006 of 
the Boeing 757 MPD.
     Revision January 2007 of the Boeing 757 MPD revised AWL 
28-AWL-24.
    Boeing points out that the clarifications affect references in both

[[Page 13082]]

the ``Relevant Service Information'' section, and paragraph (h) of the 
NPRM, and requests that we revise the AD to make the clarifications.
    We agree that the references need to be clarified for the reasons 
Boeing stated. We have made the following changes to the AD as Boeing 
outlined in its comment:
     We have changed paragraph (h)(1) of the AD to refer to 
Revision November 2006 R1 of the Boeing 737-600/700/700C/700IGW/800/900 
MPD rather than to Revision May 2006.
     We have changed paragraph (h)(2) of the AD to refer to 
Revision January 2007 of the Boeing 757 MPD rather than to Revision 
October 2006.
    However, we have not changed the ``Relevant Service Information'' 
section of the NPRM because that section of the preamble does not 
reappear in the final rule.

Request To Change Wording in Note 1 of the NPRM

    Boeing requests that we change the wording in Note 1 of the NPRM as 
follows:
     Change ``new inspections and maintenance actions'' to 
include the words ``according to paragraph (h)'' after ``actions.''
     Change ``the operator must request approval for revision 
to the airworthiness limitations'' to ``the operator must request 
approval for deviation from the airworthiness limitations.''
     Remove ``as applicable'' from the last sentence of the 
note and change the paragraph reference from paragraph (h) to paragraph 
(i).
    Boeing explains that the current wording is difficult to follow.
    We partially agree. We have clarified the paragraph reference from 
paragraph (h) to paragraph (i). However, we do not agree to revise the 
note further. Boeing submitted a similar comment to another NPRM 
(Docket No. FAA-2006-26710), and the note in this AD is based on that 
comment. No additional change is necessary. In addition, we have used 
this note in several similar ADs and have not received any comments 
from operators requesting clarification. We have not changed this AD in 
this regard.

Request To Have AD Address Part Number (P/N) S343T003-39 Actuators

    AirTran Airways notes that the motor-operated shutoff valves are 
rotable parts which can be moved from airplane to airplane. AirTran 
states that the NPRM does not address P/N S343T003-39 actuators that 
may have been installed on airplanes outside of the applicability range 
of the service bulletins referred to in the NPRM.
    We infer that AirTran would like us to prohibit installation of P/N 
S343T003-39 actuators on any airplane. We disagree. No P/N S343T003-39 
actuator is approved to replace either a P/N S343T003-56 or P/N 
S343T003-66 actuator. Should we determine that P/N S343T003-39 is 
installed and unsafe on other airplanes, we might consider additional 
rulemaking. We have not changed the AD in this regard.

Request To Have AD Address P/N S343T003-56 Actuators

    AirTran requests that the AD allow for installation of either a P/N 
S343T003-56 or P/N S343T003-66 actuator in the AD. AirTran explains 
that Boeing considers P/N S343T003-56 fully interchangeable with P/N 
S343T003-66 and states that installing a P/N S343T003-56 actuator 
should meet the intent of the AD.
    We disagree; the two actuators are not fully interchangeable, but 
rather only in one direction. If an airplane currently has a P/N 
S343T003-56 actuator installed, then an operator can install a P/N 
S343T003-66 actuator; if an airplane has a P/N S343T003-66 actuator 
currently installed, then it is not possible to install a P/N S343T003-
56 actuator. However, if an operator has a P/N S343T003-56 actuator 
currently installed, no action is required by this AD. This AD 
addresses airplanes that currently have a P/N S343T003-39 actuator 
installed. The P/N S343T003-56 actuator has not been approved as a 
field replacement for the P/N S343T003-39. However, under the 
provisions of paragraph (i) of the AD, we will consider requests for 
approval of an alternative method of compliance if sufficient data are 
submitted to substantiate that the design change would provide an 
acceptable level of safety. We have not changed the AD in this regard.

Request To Reconsider Mandating Installation of P/N S343T003-66 
Actuators

    Boeing requested an ex parte meeting with the FAA to discuss the 
new motor-operated valves, which Boeing states have reliability issues 
in service. Boeing states that these issues could affect the FAA's 
decision to mandate the installation fleet-wide.
    During the meeting, held October 10, 2007, Boeing reviewed problems 
with the actuators and the design changes made since 2005. The Special 
Federal Aviation Regulation (SFAR) 88 review determined that the 
electrical switches for P/N S343T003-39 actuators were not isolated 
from the actuator shaft that enters the tank. During a lightning, hot 
short, or fault current event, it is possible that electrical energy 
could enter the fuel tank through the actuator shaft. The new P/N 
S343T003-56 actuator added an isolation feature, but created nuisance 
failure indications on the flight deck. Boeing then developed the P/N 
S343T003-66 actuator to correct the indication problem. The P/N 
S343T003-66 actuator reduced the number of events, but operators are 
still experiencing dispatch delays and unscheduled removals. Boeing 
also pointed out problems with the P/N S343T003-66 actuators on other 
Boeing airplane models, though not to the extent seen on Boeing Model 
737 airplanes. Boeing is in the process of re-designing the actuator, 
an effort that will take approximately 12 months. Boeing specifies that 
the isolation feature is not affected by the indication problems, and 
that the valves are opening and closing as commanded.
    We disagree with the request to reconsider mandating the 
installation of P/N S343T003-66 actuators. The problems with the P/N 
S343T003-66 actuators that Boeing pointed out do not constitute a new 
unsafe condition. We consider that to delay this particular AD action 
in order to wait for the re-designed actuator would be inappropriate, 
since we have determined that an unsafe condition exists and that 
replacement of certain parts must be accomplished to ensure continued 
safety. Therefore, no change has been made to the AD in this regard. 
However, when a new actuator is developed, approved, and available, we 
might consider additional rulemaking then.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 2,916 airplanes of the affected design in the 
worldwide fleet. This AD affects about 1,406 airplanes of U.S. 
registry. The average labor rate is $80 per work hour. The table titled 
``Estimated Costs'' provides costs to comply with this AD.

[[Page 13083]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                         Number of
                                                                             Cost per      U.S.-
                           Action                              Work hours    airplane    registered   Fleet cost
                                                                                         airplanes
----------------------------------------------------------------------------------------------------------------
Inspection for motor operated valve actuators...............            1          $80        1,406     $112,480
AWL revisions...............................................            3          240        1,406      337,440
----------------------------------------------------------------------------------------------------------------

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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2008-06-03 Boeing: Amendment 39-15415. Docket No. FAA-2007-28662; 
Directorate Identifier 2007-NM-014-AD.

Effective Date

    (a) This AD becomes effective April 16, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -700C, -800 
and -900 series airplanes; and Boeing Model 757-200, -200PF, -200CB, 
and -300 series airplanes; certificated in any category; as 
identified in Boeing Alert Service Bulletins 737-28A1207, dated 
February 15, 2007, and 757-28A0088, dated January 25, 2007.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections and maintenance 
actions. Compliance with these limitations 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 revision 
to the airworthiness limitations (AWLs) in the Boeing 737-600/700/
700C/700IGW/800/900 Maintenance Planning Data (MPD) Document 
D626A001-CMR and the Boeing 757 MPD Document D622N001-9, as 
applicable, according to paragraph (i) of this AD.

Unsafe Condition

    (d) This AD results from a design review of the fuel tank 
systems. We are issuing this AD to prevent electrical energy from 
lightning, hot shorts, or fault current from entering the fuel tank 
through the actuator shaft, which could result in fuel tank 
explosions 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 Bulletin Reference

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of the following service bulletins, as 
applicable:
    (1) For Model 737-600, -700, -700C, -800 and -900 series 
airplanes: Boeing Alert Service Bulletin 737-28A1207, dated February 
15, 2007; and
    (2) For Model 757-200, -200PF, -200CB, and -300 series 
airplanes: Boeing Alert Service Bulletin 757-28A0088, dated January 
25, 2007.

Inspection and Related Investigative/Corrective Actions

    (g) Within 60 months after the effective date of this AD: 
Inspect the applicable motor-operated valves (MOVs) to determine 
whether an MOV with the affected part number identified in the 
Accomplishment Instructions of the applicable service bulletin is 
installed. A review of airplane maintenance records is acceptable in 
lieu of this inspection if the part number of the part can be 
conclusively determined from that review. Do all applicable related 
investigative and corrective actions before further flight. Do all 
actions in accordance with the Accomplishment Instructions of the 
applicable service bulletin.

Revision of AWLs Section

    (h) Concurrently with the actions specified in paragraph (g) of 
this AD: Revise the AWLs section of the Instructions for Continued 
Airworthiness by incorporating the information specified in 
paragraphs (h)(1) and (h)(2) of this AD, as applicable. 
Accomplishing the revision in accordance with a later revision of 
the MPD document is an acceptable method of compliance if the 
revision is approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA.
    (1) Section F., ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEM AWLs,'' 
of Boeing 737-600/700/700C/700IGW/800/900 MPD Document D626A001-CMR, 
Section 9, Revision November 2006 R1, into the MPD to incorporate 
AWL No. 28-AWL-21, No. 28-AWL-22, and No. 28-AWL-24.
    (2) Section G., ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEM AWLs,'' 
of

[[Page 13084]]

Boeing 757 MPD Document D622N001, Section 9, Revision January 2007, 
into the MPD Document to incorporate AWL No. 28-AWL-23, No. 28-AWL-
24, and No. 28-AWL-25.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle ACO, FAA, 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.

Material Incorporated by Reference

    (j) You must use the service information listed in Table 1 of 
this AD to perform the actions that are required by this AD, unless 
the AD specifies otherwise. The Director of the Federal Register 
approved the incorporation by reference of these documents in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, 
for a copy of this service information. You may review copies at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington; or at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-
register/cfr/ibr-locations.html.

              Table 1.--Material Incorporated by Reference
------------------------------------------------------------------------
     Service information           Revision                Date
------------------------------------------------------------------------
Boeing 737-600/700/700C/       November 2006 R1  November 2006.
 700IGW/800/900 Maintenance
 Planning Data Document
 D626A001-CMR, Section 9.
Boeing 757 Maintenance         January 2007....  January 2007.
 Planning Data Document
 D622N001, Section 9.
Boeing Alert Service Bulletin  Original........  February 15, 2007.
 737-28A1207.
Boeing Alert Service Bulletin  Original........  January 25, 2007.
 757-28A0088.
------------------------------------------------------------------------


    Issued in Renton, Washington, on February 28, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-4486 Filed 3-11-08; 8:45 am]

BILLING CODE 4910-13-P
