Document ID: FAA-2009-0865-0002
Agency: faa
Document Type: Rule
Title: 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 and Whitney JT9D-3 or -7 (Excluding -70) Series Engines
Posted Date: 2009-09-18T04:00Z

[Federal Register: September 18, 2009 (Volume 74, Number 180)]
[Proposed Rules]               
[Page 47897-47900]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18se09-9]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================

[[Page 47897]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0865; Directorate Identifier 2009-NM-023-AD]
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: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to supersede 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 (including the forward side) at each strut location, and 
repair if necessary. This proposed AD would add a one-time inspection 
for cracking of the forward side of the front spar chord assembly on 
the inboard and outboard struts, installation of a cap skin doublers 
for certain airplanes, and repair if necessary. These actions would 
terminate the repetitive inspections of the forward side of the strut 
front spar chord assembly; the inspections of the aft side assembly 
continue as specified in the existing AD. This proposed AD results from 
a report of a fractured front spar assembly for strut No. 3, which 
resulted in the loss of the strut upper link load path. We are 
proposing this AD to detect and correct cracks and fractures 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: We must receive comments on this proposed AD by November 2, 
2009.

ADDRESSES: You may send comments by any of the following methods:
     Federal rulemaking 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 proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; 
Internet https://www.myboeingfleet.com. You may review copies of the 
referenced service information at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information 
on the availability of this material at the FAA, call 425-227-1221 or 
425-227-1152.

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 proposed 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: Ken Paoletti, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6434; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2009-0865; 
Directorate Identifier 2009-NM-023-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed 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 proposed AD.

Discussion

    On December 26, 2006, we issued AD 2007-01-15, amendment 39-14887 
(72 FR 1427, January 12, 2007), for 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, 
including the forward side, at each strut location, and repair if 
necessary. That AD resulted from a strut front spar chord assembly that 
was found fractured, forward of the inspections that are required by AD 
2004-25-05, amendment 39-13893 (69 FR 71349), which was superseded by 
AD 2007-01-15. We issued AD 2007-01-05 to detect and correct cracks and 
fractures 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.

Actions Since Existing AD Was Issued

    The preamble to AD 2007-01-15 specifies that we consider the 
requirements ``interim action'' and that

[[Page 47898]]

the manufacturer is developing a modification to address the unsafe 
condition. That AD explains that we might consider further rulemaking 
if a modification is developed, approved, and available. The 
manufacturer now has developed such a modification only for the front 
spar chord assembly forward of the upper link attachment. Therefore, we 
have determined that further rulemaking is indeed necessary; this 
proposed AD follows from that determination.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-54A2230, dated 
October 30, 2008. The service bulletin describes the following 
procedures:
     A one-time open-hole high frequency eddy current (HFEC) 
inspection for cracking of the forward side of the front spar chord 
assembly on the inboard and outboard struts. For airplanes on which the 
cap skin doubler is not installed, the service bulletin also includes 
procedures for installing the cap skin doubler.
     For airplanes on which no crack is found, the service 
bulletin states that no further action is required.
     For airplanes on which any crack is found, the service 
bulletin specifies the corrective action of contacting Boeing for 
additional instructions and doing the repair before further flight. The 
service bulletin specifies that doing the repair ends the need for the 
repetitive inspections of the forward side of the strut front spar 
chord assembly.
    The service bulletin specifies doing the inspection, and the 
installation of the cap skin doubler for certain airplanes, within 48 
months after the date on the service bulletin for the outboard strut, 
and within 36 months after the date on the service bulletin for the 
inboard strut.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to develop on other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 2007-01-15 and retain the requirements of the 
existing AD. This proposed AD would also require accomplishing the 
actions specified in the service bulletin described previously, except 
as discussed under ``Difference Between the Proposed AD and the Service 
Bulletin.''

Difference Between the Proposed AD and the Service Bulletin

    Boeing Alert Service Bulletin 747-54A2230, dated October 30, 2008, 
specifies to contact the manufacturer for instructions on how to repair 
certain conditions, but this proposed AD would require repairing those 
conditions in one of the following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that has been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Changes to Existing AD

    This proposed AD would retain all requirements of AD 2007-01-15. 
Since AD 2007-01-15 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 proposed AD, as listed in 
the following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
                                             Corresponding  requirement
       Requirement in AD 2007-01-15             in this  proposed AD
------------------------------------------------------------------------
Paragraph (f).............................  paragraph (g).
Paragraph (g).............................  paragraph (h).
Paragraph (h).............................  paragraph (i).
Paragraph (i).............................  paragraph (j).
Paragraph (j).............................  paragraph (k).
Paragraph (k).............................  paragraph (l).
Paragraph (l).............................  paragraph (m).
Paragraph (m).............................  paragraph (q).
------------------------------------------------------------------------

Interim Action

    We consider the actions in this proposed AD to be interim actions 
for the strut front spar chord assembly at each strut location, 
excluding the forward side (the terminating action for the forward side 
is included in this proposed AD). If the manufacturer develops a 
modification for the remainder of the front spar chord assembly, we 
might consider additional rulemaking.

Costs of Compliance

    There are about 411 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                     Number of U.S.-
              Action                     Work hours        Average labor          Parts          Cost per airplane     registered         Fleet cost
                                                           rate per hour                                                airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspections (required by AD 2007-  17...................             $80  $0..................  $1,360 per                       85  $115,600 per
 01-15).                                                                                         inspection cycle.                    inspection cycle.
One-time inspection and cap skin   30 to 116 \1\........              80  $893 to $36,737 \1\.  $3,293 to $46,017                85  $279,905 to
 doubler installation (new                                                                       \1\.                                 $3,911,445.\1\
 proposed action).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Depending on airplane configuration.

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.

[[Page 47899]]

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, Incorporation by 
reference, 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 FAA amends Sec.  39.13 by removing amendment 39-14887 (72 FR 
1427, January 12, 2007) and adding the following new AD:

Boeing: Docket No. FAA-2009-0865; Directorate Identifier 2009-NM-
023-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by November 
2, 2009.

Affected ADs

    (b) This AD supersedes AD 2007-01-15.

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, equipped with General 
Electric CF6-45 or -50 series engines, or equipped with Pratt & 
Whitney JT9D-3 or -7 (excluding -70) series engines, as identified 
in Boeing Alert Service Bulletin 747-54A2224, Revision 1, dated 
November 16, 2006.

Subject

    (d) Air Transport Association (ATA) of America Code 54: 
Nacelles/Pylons.

Unsafe Condition

    (e) This AD results from a report of a fractured front spar 
assembly for strut No. 3, which resulted in the loss of the strut 
upper link load path. The Federal Aviation Administration is issuing 
this AD to detect and correct cracks and fractures 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

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Restatement of Requirements of AD 2004-25-05, Amendment 39-13893

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

    (g) Within 90 days after December 27, 2004 (the effective date 
of AD 2004-25-05, which was superseded by AD 2007-01-15), 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 January 29, 2007 (the effective date of AD 2007-01-15), only 
Part 1--Aft Side Inspection of the Accomplishment Instructions of 
Revision 1 of Boeing Alert Service Bulletin 747-54A2224, Revision 1, 
dated November 16, 2006, may be used.
    (h) 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 (g) of this AD.

Repetitive Inspections

    (i) For airplanes on which no crack or fracture is detected 
during the inspections required by paragraph (g) 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 
(g) of this AD.

                      Table 1--Repetitive Intervals
------------------------------------------------------------------------
   For airplanes identified in Boeing
  Alert Service Bulletin 747-54A2224,       Repeat the inspections at
 dated September 30, 2004; or Revision      intervals not to exceed--
    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

    (j) If any crack or fracture is found during any inspection 
required by paragraphs (g) and (i) of this AD, and Boeing Alert 
Service Bulletin 747-54A2224, dated September 30, 2004; or Revision 
1, dated November 16, 2006; specifies contacting Boeing for 
appropriate action: Before further flight, repair the crack or 
fracture using a method approved in accordance with the procedures 
specified in paragraph (q) of this AD.

Restatement of Requirements of AD 2007-01-15

Forward Side Detailed and HFEC Inspections

    (k) Within 90 days after January 29, 2007, 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. Doing the inspections required by paragraph (n) of 
this AD terminates the forward side detailed and HFEC inspection 
requirements of this paragraph.

[[Page 47900]]

Corrective Action for Forward Side Inspection

    (l) If any crack or fracture is found during any inspection 
required by paragraph (k) 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 (q) of this AD.

Credit for Inspections Done According to Boeing 747 Fleet Team Digest

    (m) Detailed and HFEC inspections done before January 29, 2007, 
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 (k) of 
this AD.

New Requirements of This AD

Inspection and Corrective Actions

    (n) At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-54A2230, dated 
October 30, 2008; except that where the service bulletin specifies a 
compliance time after the date on the service bulletin, this AD 
requires compliance within the specified compliance time after the 
effective date of this AD: Do an open-hole high frequency eddy 
current (HFEC) inspection for cracking of the of the forward side of 
the front spar chord assembly on the inboard and outboard struts; 
and, for airplanes on which the cap skin doubler is not installed, 
install the cap skin doubler; in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-54A2230, dated 
October 30, 2008.
    (o) If any crack is found during the inspection required by 
paragraph (n) of this AD: Before further flight, repair the crack 
using a method approved in accordance with the procedures specified 
in paragraph (q) of this AD.
    (p) Doing all applicable actions required by paragraphs (n) and 
(o) of this AD terminates the repetitive forward side detailed and 
HFEC inspection requirements of paragraph (k) of this AD. All aft 
side inspection requirements of this AD remain in effect.

Alternative Methods of Compliance (AMOCs)

    (q)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
ATTN: Ken Paoletti, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., 
Renton, Washington 98057-3356; telephone (425) 917-6434; fax (425) 
917-6590. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-
Requests@faa.gov.
    (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 principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (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.
    (4) AMOCs approved previously in accordance with AD 2007-01-15, 
are approved as AMOCs for the corresponding provisions of this AD.

    Issued in Renton, Washington, on September 11, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-22577 Filed 9-17-09; 8:45 am]

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