Document ID: FAA-2007-0302-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 747-400 Series Airplanes
Posted Date: 2007-12-10T05:00Z

[Federal Register: December 10, 2007 (Volume 72, Number 236)]
[Rules and Regulations]               
[Page 69587-69589]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10de07-8]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0302; Directorate Identifier 2007-NM-161-AD; 
Amendment 39-15301; AD 2007-25-19]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-400 Series Airplanes

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

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 747-400 series airplanes. This AD requires 
repetitive inspections to detect discrepancies of the forward and rear 
heat exchanger shells of the air distribution system of the crew rest 
area, and applicable corrective actions. This AD also requires an 
inspection to identify the part number, shop code, and build date of 
the forward and rear heat exchanger shells of the air distribution 
system of the crew rest area, and applicable corrective actions, which 
end the repetitive inspections. This AD results from a report of an 
uncommanded up and down pitch movement of an airplane in flight and 
resistance in the elevator controls on the ground during taxi. We are 
issuing this AD to prevent cracking and buckling of the forward or rear 
heat exchanger shell of the air distribution system of the crew rest 
area, which could result in jamming of the rudder and/or elevator 
control cables and consequent reduced controllability of the airplane.

DATES: This AD becomes effective December 26, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of December 26, 
2007.
    We must receive comments on this AD by February 8, 2008.

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 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 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: Barbara Mudrovich, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 917-6477; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Background

    We previously issued AD 2001-18-04, amendment 39-12430 (66 FR 
46512, September 6, 2001), applicable to certain Boeing Model 747-400 
series airplanes. That AD requires repetitive inspections to detect 
damage or deflection of the crew rest heat exchanger (forward heat 
exchanger only), and follow-on actions if necessary. That AD also 
requires a one-time inspection to determine the part number and shop 
code of the shell of the crew rest area heat exchanger (forward heat 
exchanger only), and follow-on actions if necessary, which terminate 
the repetitive inspections.

Discussion

    Since issuance of AD 2001-18-04, we have received a report of 
uncommanded up and down pitch movement of an airplane in flight and 
resistance in the elevator controls on the ground during taxi on a 
Boeing Model 747-400 series airplane. An inspection revealed that the 
rear heat exchanger shell of the air distribution system of the crew 
rest area had expanded and deformed inboard and downwards, contacting 
the elevator control cables, which restricted their movements. Another 
inspection revealed that the thickness of certain forward heat 
exchanger shells of the air distribution system of the crew rest area, 
including forward heater exchanger shell subject to the requirements of 
AD 2001-18-04, was incorrect. The incorrect shells were manufactured 
from two-ply laminate instead of three-ply laminate.
    Cracking and buckling of the forward or rear heat exchanger shell 
of the air distribution system of the crew rest area, if not corrected, 
could result in jamming of the rudder and/or elevator control cables 
and consequent reduced controllability of the airplane.

Relevant Service Information

    Boeing has issued Service Bulletin 747-21A2439, Revision 2, dated 
May 24, 2007. The service bulletin describes the following procedures:
     Repetitive general visual inspections of the forward and 
rear heat exchanger shells of the air distribution system of the crew 
rest area for discrepancies (i.e., cracks, creases, deformation, 
deflection, and interference with the rudder and/or

[[Page 69588]]

elevator cables), and applicable corrective actions (Work Package 1).
     An inspection to identify the part number, shop code, and 
build date of the forward and rear heat exchanger shells of the air 
distribution system of the crew rest area, and applicable corrective 
actions (Work Package 2). Accomplishing these actions eliminates the 
need for the repetitive inspections.
    The corrective actions include replacing any discrepant forward or 
rear heat exchanger shell of the air distribution system of the crew 
rest area with a certain new heat exchanger shell, measuring the shell 
material thickness, repairing holes, re-marking the part number of the 
forward heat exchanger shell, and making sure the ten common fasteners 
are fully installed; as applicable.
    The compliance time specified in the service bulletin for 
accomplishing Work Package 1 is 1,200 flight hours or 90 days, 
whichever occurs first, and thereafter at intervals not to exceed 2,500 
flight hours. The compliance time specified in the service bulletin for 
accomplishing Work Package 2 is 24 months.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design that may be 
registered in the U.S. at some time in the future. Therefore, we are 
issuing this AD to prevent cracking and buckling of the forward or rear 
heat exchanger shell of the air distribution system of the crew rest 
area, which could result in jamming of the rudder and/or elevator 
control cables and consequent reduced controllability of the airplane. 
This AD requires accomplishing the actions specified in the service 
information described previously.

Differences Between This AD and Service Information

    For Work Package 1, Table 1 of paragraph 1.E. of Boeing Service 
Bulletin 747-21A2439, Revision 2, specifies a compliance time of 1,200 
flight hours or 90 days for accomplishing both the general visual 
inspections and replacement of the heat exchanger shells if necessary. 
We have determined that, because of the safety implications and 
consequences associated with cracking, any cracked heat exchanger shell 
must be replaced before further flight. Therefore, for Work Package 1, 
this AD requires that the applicable corrective actions for that work 
package, which include replacement of any discrepant forward or rear 
heat exchanger shell, be done before further flight. This difference 
has been coordinated with Boeing.

Costs of Compliance

    None of the airplanes affected by this action are on the U.S. 
Register. All airplanes affected by this AD are currently operated by 
non-U.S. operators under foreign registry; therefore, they are not 
directly affected by this AD action. However, we consider this AD 
necessary to ensure that the unsafe condition is addressed if any 
affected airplane is imported and placed on the U.S. Register in the 
future.
    The following table provides the estimated costs for U.S. operators 
to comply with this AD for any affected airplane that might be imported 
and placed on the U.S. Register in the future.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                          Average
                  Action                            Work hours           labor rate       Cost per airplane
                                                                          per hour
----------------------------------------------------------------------------------------------------------------
Inspection (Work Package 1)..............  Between 1 and 3 \1\........          $80  Between $80 and $240, per
                                                                                      inspection cycle.
Inspection (Work Package 2)..............  Between 1 and 3 \1\........           80  Between $80 and $240.
----------------------------------------------------------------------------------------------------------------
\1\ Depending on the airplane configuration.

FAA's Determination of the Effective Date

    No airplane affected by this AD is currently on the U.S. Register. 
Therefore, providing notice and opportunity for public comment is 
unnecessary before this AD is issued, and this AD may be made effective 
in less than 30 days after it is published in the Federal Register.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2007-0302; Directorate Identifier 2007-NM-161-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
AD. We will consider all comments received by the closing date and may 
amend this 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 AD.

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 the regulation:

[[Page 69589]]

    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 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):

2007-25-19 Boeing: Amendment 39-15301. Docket No. FAA-2007-0302; 
Directorate Identifier 2007-NM-161-AD.

Effective Date

    (a) This AD becomes effective December 26, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-400 series airplanes, 
certificated in any category; as identified in Boeing Service 
Bulletin 747-21A2439, Revision 2, dated May 24, 2007.

Unsafe Condition

    (d) This AD results from a report of an uncommanded up and down 
pitch movement of an airplane in flight and resistance in the 
elevator controls on the ground during taxi. We are issuing this AD 
to prevent cracking and buckling of the forward or rear heat 
exchanger shell of the air distribution system of the crew rest 
area, which could result in jamming of the rudder and/or elevator 
control cables and consequent reduced controllability 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.

Inspections and Corrective Actions

    (f) At the applicable times specified in the Table 1 of 
paragraph 1.E. of Boeing Service Bulletin 747-21A2439, Revision 2, 
dated May 24, 2007, except as provided by paragraph (g) of this AD, 
do the actions specified in paragraphs (f)(1) and (f)(2) of this AD 
by accomplishing all the actions specified in the Accomplishment 
Instructions of the service bulletin.
    (1) Do repetitive general visual inspections to detect 
discrepancies (i.e., cracks, creases, deformation, deflection, and 
interference with the rudder and/or elevator cables) of the forward 
and rear heat exchanger shells of the air distribution system of the 
crew rest area, and do the applicable corrective actions, until the 
actions required by paragraph (f)(2) of this AD are done. The 
applicable corrective actions must be done before further flight.
    (2) Do an inspection to identify the part number, shop code, and 
build date of the forward and rear heat exchanger shells of the air 
distribution system of the crew rest area, and before further 
flight, do the applicable corrective actions. Accomplishing these 
actions ends the repetitive inspections required by paragraph (f)(1) 
of this AD.
    (g) Where Boeing Service Bulletin 747-21A2439, Revision 2, dated 
May 24, 2007, specifies a compliance time ``after the release date 
of the service bulletin'' or ``after the date of Revision 02 of the 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.

Actions According to Previous Issues of Service Bulletin or Previously 
Accomplished Inspections

    (h) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 747-21A2439, dated 
November 3, 2005; or Boeing Service Bulletin 74721A2439, Revision 1, 
dated July 24, 2006; are acceptable for compliance with the 
corresponding actions specified in this AD.
    (i) If a forward heat exchanger shell, part number 65B41601-52, 
is found installed during the replacement required by paragraph (c) 
of AD 2001-18-04, amendment 39-12430, or was installed during the 
inspection required by paragraph (d)(2) of that AD (AD 2001-18-04 
refers to Boeing Alert Service Bulletin 747-21A2412, dated January 
20, 2000; or Revision 2, dated November 30, 2000; as the appropriate 
sources of service information for accomplishing the required 
actions): Actions required by paragraphs (f)(1) and (f)(2) of this 
AD are not required for that forward heat exchanger shell only.

 Parts Installation

    (j) As of the effective date of this AD, no person may install a 
heat exchanger shell having a part number identified in the 
``Existing Part Number'' column of the table specified in paragraph 
2.C. of Boeing Service Bulletin 747-21A2439, Revision 2, dated May 
24, 2007, on any airplane.

Special Flight Permits

    (k) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be done, except as provided by 
paragraphs (k)(1) and (k)(2) of this AD.
    (1) If any forward or rear heat exchanger shell of the air 
distribution system of the crew rest area is found deflecting or 
interfering with the rudder and/or elevator control cables (e.g., 
chafing, rubbing, or contacting) during any inspection required by 
paragraph (f)(1) of this AD, special flight permits are not allowed.
    (2) If any crack or crease is found on the forward or rear heat 
exchanger shell of the air distribution system of the crew rest area 
during any inspection required by paragraph (f)(1) of this AD, the 
air distribution system in the crew rest area must be inoperative 
during flight.

Alternative Methods of Compliance (AMOCs)

    (l)(1) The Manager, Seattle Aircraft Certification Office, 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

    (m) You must use Boeing Service Bulletin 747-21A2439, Revision 
2, dated May 24, 2007, 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 this 
document 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.

    Issued in Renton, Washington, on November 30, 2007.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
 [FR Doc. E7-23850 Filed 12-7-07; 8:45 am]

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