Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP Series Airplanes Equipped with General Electric CF6-45 or -50 Series Engines, or Equipped with Pratt & Whitney JT9D-3 or -7 (Excluding -70) Series Engines

[Federal Register Volume 72, Number 8 (Friday, January 12, 2007)]
[Rules and Regulations]
[Pages 1427-1430]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-220]


=======================================================================
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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-26811; Directorate Identifier 2006-NM-262-AD; 
Amendment 39-14887; AD 2007-01-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP 
Series Airplanes Equipped with General Electric CF6-45 or -50 Series 
Engines, or Equipped with Pratt & Whitney JT9D-3 or -7 (Excluding -70) 
Series Engines

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

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) that applies to certain Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series 
airplanes. The existing AD currently requires repetitive inspections to 
detect cracks and fractures of the strut front spar chord assembly at 
each strut location, and repair if necessary. This new AD expands the 
inspection area by requiring repetitive inspections for any cracks or 
fracture of the strut front spar chord assembly in an area forward of 
the existing inspection area at each strut location, and repair if 
necessary. This AD results from a strut front spar chord assembly that 
was found fractured, forward of the inspection area required by the 
existing AD. We are issuing this AD to detect and correct cracks and 
fracture of the nacelle strut front spar chord assembly. Fracture of 
the front spar chord assembly could lead to loss of the strut upper 
link load path and consequent fracture of the diagonal brace, which 
could result in in-flight separation of the strut and engine from the 
airplane.

DATES: This AD becomes effective January 29, 2007.

[[Page 1428]]

    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of January 29, 
2007.
    On December 27, 2004 (69 FR 71349, December 9, 2004), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Alert Service Bulletin 747-54A2224, dated September 30, 2004.
    We must receive any comments on this AD by March 13, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., 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 service information identified in this AD.
    You may examine the contents of the AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-
401, Washington, DC. This docket number is FAA-2007-26811; the 
directorate identifier for this docket is 2006-NM-262-AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    On November 30, 2004, we issued AD 2004-25-05, amendment 39-13893 
(69 FR 71349, December 9, 2004). That AD applies to certain Boeing 
Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 
747-300, 747SR, and 747SP series airplanes. That AD requires repetitive 
inspections to detect cracks and fractures of the strut front spar 
chord assembly at each strut location, and repair if necessary. That AD 
resulted from a report of a fractured front spar chord assembly for 
strut No. 3, which resulted in the loss of the strut upper link load 
path. The actions specified in that AD are intended to prevent loss of 
the strut upper link load path and consequent fracture of the diagonal 
brace, which could result in in-flight separation of the strut and 
engine from the airplane.

Actions Since AD Was Issued

    Since we issued AD 2004-25-05, we have received a report that the 
front spar chord assembly for strut No. 3 was found fractured on a 
Boeing Model 747-200 series airplane equipped with General Electric 
(GE) CF6-50E series engines. The fracture was located forward of the 
inspection area required by AD 2004-25-05. The airplane had accumulated 
about 79,800 total flight hours and 15,100 total flight cycles. (Since 
strut modification, the airplane had accumulated about 9,800 flight 
cycles and 48,200 flight hours.) We have determined that the inspection 
area required by AD 2004-25-05 must be expanded to adequately detect 
and correct cracks and fracture of the nacelle strut front spar chord 
assembly. Fracture of the front spar chord assembly could lead to loss 
of the strut upper link load path and consequent fracture of the 
diagonal brace, which could result in in-flight separation of the strut 
and engine from the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-54A2224, 
Revision 1, dated November 16, 2006. The Accomplishment Instructions of 
the service bulletin are divided into two parts: Part 1--Aft Side 
Inspection and Part 2--Forward Side Inspection. Part 1 describes 
procedures for accomplishing detailed and high frequency eddy current 
(HFEC) inspections for any cracks or fracture of the front spar chord 
assembly for strut Nos. 1, 2, 3, and 4. For struts carrying Pratt & 
Whitney JT9D-3 or -7 (excluding -70) series engines and inboard struts 
carrying GE CF6-45 or -50 series engines, the inspection area is aft of 
the rear engine mount bulkhead. For outboard struts carrying GE CF6-45 
or -50 series engines, the inspection area is aft of the strut station 
270 bulkhead. (Part 1 contains the same procedures as those described 
in the original issue of the service bulletin, dated September 30, 
2006, which we referred to as the appropriate source of service 
information for AD 2004-25-05.) Part 2 describes procedures for 
accomplishing detailed and HFEC inspections for any cracks or fracture 
of the front spar chord assembly for strut Nos. 1, 2, 3, and 4, forward 
of the rear engine mount bulkhead or strut station 270 bulkhead, as 
applicable. The Part 2 inspections include inspecting in areas adjacent 
to the frame, around certain fasteners, and on the front spar chord 
radius. If any crack or fracture is found, Part 1 and Part 2 specify to 
contact Boeing for additional instructions and repair.

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. For this reason, we 
are issuing this AD to supersede AD 2004-25-05. This new AD retains the 
requirements of the existing AD. This AD also requires repetitive 
inspections for any cracks or fracture of the strut front spar chord 
assembly forward of the bulkhead at each strut location, and repair if 
necessary, except as discussed under ``Difference Between the AD and 
Service Bulletin.''

Difference Between the AD and Service Bulletin

    The service bulletin specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this AD requires 
repairing those conditions in one of the following ways:
    <bullet> Using a method that we approve; or
    <bullet> Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Change to Existing AD

    This AD retains all requirements of AD 2004-25-05. Since AD 2004-
25-05 was issued, the AD format has been revised, and certain 
paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this AD, as listed in the 
following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
                                          Corresponding  requirement in
     Requirement in  AD 2004-25-05                   this AD
------------------------------------------------------------------------
Paragraph (b)..........................  Paragraph (c).
Paragraph (c)..........................  Paragraph (d).
Paragraph (d)..........................  Paragraph (e).
Paragraph (e)..........................  Paragraph (f).
Paragraph (f)..........................  Paragraph (g).
Paragraph (g)..........................  Paragraph (h).
Paragraph (h)..........................  Paragraph (i).
------------------------------------------------------------------------


[[Page 1429]]

Explanation of Change Made to This AD

    Boeing Commercial Airplanes has received a Delegation Option 
Authorization (DOA). We have revised paragraph (i) of this AD to 
delegate the authority to approve an alternative method of compliance 
for any repair required by this AD to an Authorized Representative for 
the Boeing Commercial Airplanes DOA, rather than a Designated 
Engineering Representative (DER).

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised that it currently is developing a modification that will 
address the unsafe condition addressed by this AD. Once this 
modification is developed, approved, and available, the FAA may 
consider additional rulemaking.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD; therefore, providing notice and opportunity for public comment 
before the AD is issued is impracticable, and good cause exists to make 
this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2007-
26811; Directorate Identifier 2006-NM-262-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it.
    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 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 the 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 Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif 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.

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:
    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 part 39 of the Federal Aviation Regulations (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 
removing amendment 39-13893 (69 FR 71349, December 9, 2004) and adding 
the following new airworthiness directive (AD):

2007-01-15 BOEING: Docket No. FAA-2007-26811; Directorate Identifier 
2006-NM-262-AD; Amendment 39-14887.

Effective Date

    (a) This AD becomes effective January 29, 2007.

Affected ADs

    (b) This AD supersedes AD 2004-25-05.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series 
airplanes, certificated in any category, as identified in Boeing 
Alert Service Bulletin 747-54A2224, Revision 1, dated November 16, 
2006.

Unsafe Condition

    (d) This AD results from a strut front spar chord assembly that 
was found fractured, forward of the inspection area required by AD 
2004-25-05. We are issuing this AD to detect and correct cracks and 
fracture of the nacelle strut front spar chord assembly. Fracture of 
the front spar chord assembly could lead to loss of the strut upper 
link load path and consequent fracture of the diagonal brace, which 
could result in in-flight separation of the strut and engine from 
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.

[[Page 1430]]

Restatement of Requirements of AD 2004-25-05

Aft Side Detailed and High Frequency Eddy Current (HFEC) 
Inspections With New Service Information

    (f) Within 90 days after December 27, 2004 (the effective date 
of AD 2004-25-05), perform detailed and HFEC inspections to detect 
any cracks or fractures of the front spar chord assembly for strut 
numbers 1 through 4 inclusive, in accordance with Boeing Alert 
Service Bulletin 747-54A2224, dated September 30, 2004; or in 
accordance with Part 1--Aft Side Inspection of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-54A2224, Revision 
1, dated November 16, 2006. As of the effective date of this AD, 
only Part 1--Aft Side Inspection of the Accomplishment Instructions 
of Revision 1 of the service bulletin may be used.
    (g) Accomplishment of the detailed and HFEC inspections in 
accordance with Boeing 747 Fleet Team Digest 747-FTD-54-04002, dated 
April 15, 2004, May 4, 2004, June 1, 2004, July 12, 2004, or July 
28, 2004; or Boeing Message 1-C6ELC (Service Request ID No.: 
218724992), dated April 14, 2004; before December 27, 2004, is 
considered acceptable for compliance with the requirements of 
paragraph (f) of this AD.

Repetitive Inspections

    (h) For airplanes on which no crack or fracture is detected 
during the inspections required by paragraph (f) of this AD: At the 
applicable times specified in Table 1--Repetitive Intervals of this 
AD, repeat the detailed and HFEC inspections required by paragraph 
(f) of this AD.

                                         Table 1.--Repetitive Intervals
----------------------------------------------------------------------------------------------------------------
 For airplanes identified in Boeing
Alert Service Bulletin 747-54A2224,
    dated September 30, 2004; or                 Repeat the inspections at intervals not to exceed--
   Revision 1, dated November 16,
             2006; as--
----------------------------------------------------------------------------------------------------------------
Group 1............................  1,000 flight cycles or 18 months, whichever occurs first.
Group 2 and Group 3................  1,200 flight cycles or 18 months, whichever occurs first.
Group 4 and Group 6................  1,500 flight cycles or 18 months, whichever occurs first.
Group 5............................  2,000 flight cycles or 18 months, whichever occurs first.
----------------------------------------------------------------------------------------------------------------

Corrective Action

    (i) If any crack or fracture is found during any inspection 
required by paragraphs (f) and (h) of this AD, and the bulletin 
specifies contacting Boeing for appropriate action: Before further 
flight, repair the crack or fracture according to a method approved 
by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or 
using a method approved in accordance with the procedures specified 
in paragraph (m) of this AD. For a repair method to be approved, the 
approval must specifically reference this AD.

New Requirements of This Ad

Forward Side Detailed and HFEC Inspections

    (j) Within 90 days after the effective date of this AD, do 
detailed and HFEC inspections for any cracks or fracture of the 
front spar chord assembly for strut numbers 1, 2, 3, and 4, in 
accordance with Part 2--Forward Side Inspection of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2224, Revision 1, dated November 16, 2006. If no crack or 
fracture is found, repeat the inspections thereafter at the 
applicable interval specified in Table 1 of this AD.

Corrective Action for Forward Side Inspection

    (k) If any crack or fracture is found during any inspection 
required by paragraph (j) of this AD, and Boeing Alert Service 
Bulletin 747-54A2224, Revision 1, dated November 16, 2006, specifies 
to contact Boeing for appropriate action: Before further flight, 
repair the crack or fracture using a method approved in accordance 
with the procedures specified in paragraph (m) of this AD.

Credit for Inspections Done According to Boeing 747 Fleet Team 
Digest

    (l) Detailed and HFEC inspections done before the effective date 
of this AD in accordance with Boeing 747 Fleet Team Digest 747-FTD-
54-06002, dated June 29, 2006; or October 16, 2006; are acceptable 
for compliance with the initial inspection required by paragraph (j) 
of this AD.

Alternative Methods of Compliance (AMOCs)

    (m)(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) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

Material Incorporated by Reference

    (n) You must use Boeing Alert Service Bulletin 747-54A2224, 
dated September 30, 2004; and Boeing Alert Service Bulletin 747-
54A2224, Revision 1, dated November 16, 2006; as applicable; to 
perform the actions that are required by this AD, unless the AD 
specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of Boeing Alert Service Bulletin 747-
54A2224, Revision 1, dated November 16, 2006, in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) On December 27, 2004 (69 FR 71349, December 9, 2004), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Alert Service Bulletin 747-54A2224, dated 
September 30, 2004.
    (3) 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 Docket Management Facility, U.S. Department 
of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif 
Building, Washington, DC; on the Internet at http://dms.dot.gov; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at the NARA, call 
(202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on December 26, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-220 Filed 1-11-07; 8:45 am]
BILLING CODE 4910-13-P

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