

[Federal Register: December 28, 2007 (Volume 72, Number 248)]
[Rules and Regulations]               
[Page 73587-73589]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28de07-7]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28352; Directorate Identifier 2007-NM-037-AD; 
Amendment 39-15309; AD 2007-26-07]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-200B, 747-300, 747-
400, 747-400D, and 747-400F Series Airplanes Equipped with General 
Electric CF6-80C2 Engines

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 747-200B, 747-300, 747-400, 747-400D, and 747-400F 
series airplanes. This AD requires repetitive inspections of the left- 
and right-hand flipper door assemblies of the engine

[[Page 73588]]

core cowls for migrated pins and damaged flipper doors, and corrective 
actions if necessary. Modification of the hinge assemblies terminates 
the repetitive inspections. This AD results from two reports of missing 
flipper doors for the engine core cowls. We are issuing this AD to 
detect and correct migrated hinge pins and damaged flipper doors, which 
could allow the flipper door to fall off, resulting in the potential 
for an engine fire to propagate into the flammable leakage zone of the 
strut and for the amount of fire extinguishing agent reaching the fire 
to be diluted, and subsequent uncontained fire in the engine strut.

DATES: This AD becomes effective February 1, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of February 1, 
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: Sulmo Mariano, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6501; 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 
747-200B, 747-300, 747-400, 747-400D, and 747-400F series airplanes. 
That NPRM was published in the Federal Register on June 5, 2007 (72 FR 
31001). That NPRM proposed to require repetitive inspections of the 
left- and right-hand flipper door assemblies of the engine core cowls 
for migrated pins and damaged flipper doors, and corrective actions if 
necessary. That NPRM specified that the modification of the hinge 
assemblies would terminate the repetitive inspections.

Comments

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

Request to Clarify the Requirements Specified in Paragraph (f) of the 
NPRM

    Boeing requests that we revise paragraph (f) of the NPRM to clarify 
that the modification specified in Boeing Special Attention Service 
Bulletin 747-71-2310, dated October 13, 2005, is necessary only if 
hinge pins have migrated or flipper doors are damaged or missing. 
Boeing states that the instruction to do all applicable corrective 
actions could be interpreted to mean that the proposed modification is 
required, regardless of the inspection findings.
    We agree that modification is necessary only when hinge pins have 
migrated or the flipper doors are damaged or missing. Both Boeing 
Special Attention Service Bulletin 747-71-2310, and Rohr Service 
Bulletin TBC/80C2-NAC-71-035, dated October 10, 2005, clearly state 
that modification is necessary only when hinge pins have migrated or 
the flipper doors are damaged or missing. We have made no change to the 
AD in this regard.

Request to Clarify the Requirements Specified in Paragraph (g) of the 
NPRM

    Boeing requests that we revise paragraph (g) of the NPRM to clarify 
that accomplishing Rohr Service Bulletin TBC/80C2-NAC-71-035, as 
instructed in Boeing Special Attention Service Bulletin 747-71-2310, 
does not necessarily result in modification of the core cowl. Boeing 
points out that, if the hinge pin is properly installed, modification 
in accordance with Rohr Service Bulletin TBC/80C2-NAC-71-035 is not 
necessary.
    We agree with Boeing's comment. The actions specified in Rohr 
Service Bulletin TBC/80C2-NAC-71-035 do not require modification if the 
hinge pin has not migrated and is properly peened. We have changed 
paragraph (g) of this AD to say that accomplishment of the Rohr service 
bulletin terminates the repetitive inspection requirements (for non-
discrepant hinge pins) of paragraph (f) of this AD.

Conclusion

    We reviewed the relevant data, considered the comments received 
from the single commenter, and determined that air safety and the 
public interest require adopting the AD with the change described 
previously. We also determined that this change will not increase the 
economic burden on any operator or increase the scope of the AD.

Costs of Compliance

    There are about 297 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD.

                                                                     Estimated Costs
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                                                      Average labor                                            Number of U.S.-
               Action                  Work hours     rate per hour       Parts        Cost per airplane     registered airplanes        Fleet cost
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Inspection of flipper door                        1             $80              $0  $80, per inspection    42...................  $3,360, per
 assemblies, per inspection cycle.                                                    cycle.                                        inspection cycle.
Modification of hinge assemblies,                 1              80               0  80...................  Up to 42.............  Up to $3,360.
 if accomplished.
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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

[[Page 73589]]

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):

2007-26-07 Boeing: Amendment 39-15309. Docket No. FAA-2007-28352; 
Directorate Identifier 2007-NM-037-AD.

Effective Date

    (a) This AD becomes effective February 1, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-200B, 747-300, 747-400, 
747-400D, and 747-400F series airplanes, certificated in any 
category, equipped with General Electric CF6-80C2 engines.

Unsafe Condition

    (d) This AD results from two reports of missing flipper doors 
for the engine core cowl. We are issuing this AD to detect and 
correct migrated hinge pins and damaged flipper doors, which could 
allow the flipper door to fall off, resulting in the potential for 
an engine fire to propagate into the flammable leakage zone of the 
strut and for the amount of fire extinguishing agent reaching the 
fire to be diluted, and subsequent uncontained fire in the engine 
strut.

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.

Inspection of the Flipper Door Assemblies

    (f) Within 24 months after the effective date of this AD: Do a 
general visual inspection for migrated hinge pins and damaged 
flipper doors of the left- and right-hand flipper door assemblies of 
the engine core cowls, and do all applicable corrective actions, by 
accomplishing all the actions specified in the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 747-71-
2310, dated October 13, 2005. Do all applicable corrective actions 
before further flight. Repeat the inspection thereafter at intervals 
not to exceed 18 months for that flipper door assembly, until doing 
the actions specified in paragraph (g) of this AD.

    Note 1: Boeing Special Attention Service Bulletin 747-71-2310, 
dated October 13, 2005, refers to Rohr Service Bulletin TBC/80C2-
NAC-71-035, dated October 10, 2005, as an additional source of 
service information for accomplishing the actions specified in 
paragraph (f) of this AD.

Terminating Action for Repetitive Inspections

    (g) Accomplishing the inspection and applicable modification of 
a hinge assembly of a flipper door assembly of the engine core cowl 
in accordance with the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 747-71-2310, dated October 13, 2005; or 
Rohr Service Bulletin TBC/80C2-NAC-71-035, dated October 10, 2005; 
terminates the repetitive inspection requirements of this AD for 
that hinge assembly.

Parts Installation

    (h) As of the effective date of this AD, no person may install, 
on any airplane, a hinge assembly, part number 224-2335-69, for the 
flipper door of the engine core cowl unless it has been modified in 
accordance with the requirements of paragraph (g) of this AD.

Material Incorporated by Reference

    (i) You must use Boeing Special Attention Service Bulletin 747-
71-2310, dated October 13, 2005, 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 December 11, 2007.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-24520 Filed 12-27-07; 8:45 am]

BILLING CODE 4910-13-P
