[Federal Register Volume 71, Number 188 (Thursday, September 28, 2006)]
[Rules and Regulations]
[Pages 56861-56864]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-8227]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24865; Directorate Identifier 2005-NM-194-AD; 
Amendment 39-14771; AD 2006-20-02]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

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

ACTION: Final rule.

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

SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD), which applies to certain Boeing Model 747 airplanes. That AD 
currently requires inspections to detect disbonding, corrosion, and 
cracking at the longitudinal rows of fasteners in the bonded skin 
panels in section 41 of the fuselage, and repair, if necessary. This 
new AD adds airplanes to the applicability, and requires new 
inspections of airplanes that may have Alodine-coated rivets installed. 
This AD results from a report of cracking discovered in a skin lap 
joint that was previously inspected using the eddy current method. We 
are issuing this AD to prevent rapid decompression of the airplane due 
to disbonding and subsequent cracking of the skin panels.

DATES: This AD becomes effective November 2, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of November 2, 
2006.
    On November 27, 1996 (61 FR 57994, November 12, 1996), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Alert Service Bulletin 747-53A2409, dated September 26, 1996.

ADDRESSES: You may examine 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., Nassif Building, 
Room PL-401, Washington, DC.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this 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: 

Examining the Docket

    You may examine the airworthiness directive (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 street address stated in the ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 96-23-02, amendment 39-
9807 (61 FR 57994, November 12, 1996). The existing AD applies to 
certain Boeing Model 747 series airplanes. That NPRM was published in 
the Federal Register on May 25, 2006 (71 FR 30090). That NPRM proposed 
to continue to require inspections to detect disbonding, corrosion, and 
cracking at the longitudinal rows of fasteners in the bonded skin 
panels in section 41 of the fuselage, and repair, if necessary. That 
NPRM also proposed to add airplanes to the applicability of the 
existing AD, and require new inspections of airplanes that may have 
Alodine-coated rivets installed.

Comments

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

Support for the NPRM

    Boeing supports the NPRM.

[[Page 56862]]

Request To Clarify Inspection Applicability in Paragraph (g)(1) of the 
NPRM

    Northwest Airlines (NWA) requests that we use ``and/or'' in place 
of ``and'' in paragraph (g)(1) of the NPRM, as follows: ``* * * do 
initial inspections of Area 4 and repetitive inspections, as 
applicable, to detect disbonding, corrosion, and/or cracking of the 
skin; * * *.'' NWA explains that changing ``and'' to ``and/or'' 
provides clear instruction for accomplishing the inspection of Area 4 
using one of the inspection methods defined in Figure 18 or 20 of 
Boeing Alert Service Bulletin 747-53A2409, Revision 5, dated August 18, 
2005, which was referenced in the NPRM as the appropriate source of 
service information for accomplishing the required actions. NWA states 
that the requested change eliminates all possibility of interpreting 
the NPRM to require a specific inspection for disbonding, corrosion, 
and cracking using the applicable method for each inspection as defined 
in the service bulletin. NWA also states that this change would 
duplicate the inspection methods specified in paragraphs (b), (h), and 
(n) of AD 96-23-02, which used the words ``and/or'' in a similar 
context. This change would ensure the NPRM provides clear definition 
that an operator would accomplish one inspection using the applicable 
method to detect disbonding, corrosion, or cracks, rather than 
accomplishing three inspections for three specific and separate 
conditions.
    We agree that the paragraph should be clarified to provide clear 
instruction for accomplishing the inspection of Area 4 using one of the 
inspection methods defined in the service bulletin. We disagree with 
using the words ``and/or.'' Our recent policy has been to avoid using 
and/or, which can often be subject to misinterpretation. Therefore, we 
have changed paragraph (g)(1) of this AD by adding ``as applicable'' at 
the end of the phrase as follows: ``* * * do initial inspections of 
Area 4 and repetitive inspections, as applicable, to detect disbonding, 
corrosion, and cracking of the skin, as applicable; * * * .''

Request To Clarify Inspection Methods in Paragraph (g)(1) of the NPRM

    NWA also requests that we change the inspection methods in 
paragraph (g)(1) of the NPRM from ``Method 1 or 2'' to ``Method 2, 3, 
or 4'' as follows: ``If inspection Method 2, 3, or 4 is used and no 
disbonded doubler is found, no further action is required by this AD.'' 
NWA explains that changing the inspection methods from ``Method 1 or 
2'' to ``Method 2, 3, or 4'' would define the inspection methods 
necessary to inspect the fuselage skins. Inspection Method 1 is an 
external ultrasonic inspection that is not applicable to Area 4. 
Inspection Methods 2, 3, and 4 are inspections that apply to Area 4 and 
are defined in Figure 20 of the service bulletin.
    We partially agree. We agree that inspection Method 1 does not 
belong in the paragraph because the Method 1 inspection is applicable 
only to areas 1, 2, and 3. We disagree with including Methods 3 and 4 
in a statement that contains the words, ``no further action is required 
by this AD.'' Inspection Methods 3 and 4 are repetitive inspections. If 
we included these inspection methods in this statement, then the 
repetitive inspections would no longer be required. Therefore, we have 
changed the specified part of paragraph (g)(1) of the final rule as 
follows: ``If inspection Method 2 is used and no disbonded doubler is 
found, no further action is required by this AD.'' Furthermore, we 
eliminated all other references to Method 1 from the paragraph.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been 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 623 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. The average labor rate is $80 
per work hour.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                       Cost per
                                                     airplane, per       U.S.-       Fleet cost, per  inspection
              Action                  Work hours      inspection      registered                cycle
                                                         cycle         airplanes
----------------------------------------------------------------------------------------------------------------
Inspections (required by AD 96-23-             308         $24,640              79  $1,946,560.
 02, and continued in this AD).
New inspections (for airplanes                  42           3,360              96  Up to $322,560.
 with Alodine-coated rivets).
----------------------------------------------------------------------------------------------------------------

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.

[[Page 56863]]

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 
removing amendment 39-9807 (61 FR 57994, November 12, 1996) and by 
adding the following new airworthiness directive (AD):

2006-20-02 Boeing: Amendment 39-14771. Docket No. FAA-2006-24865; 
Directorate Identifier 2005-NM-194-AD.

Effective Date

    (a) This AD becomes effective November 2, 2006.

Affected ADs

    (b) This AD supersedes AD 96-23-02.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes, certificated in any 
category; as identified in Boeing Alert Service Bulletin 747-
53A2409, Revision 5, dated August 18, 2005.

Unsafe Condition

    (d) This AD results from a report of cracking discovered in a 
skin lap joint that was previously inspected using the eddy current 
method. We are issuing this AD to prevent rapid decompression of the 
airplane due to disbonding and subsequent cracking of the skin 
panels.

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.

Requirements of AD 96-23-02

Actions for Groups 1 Through 10, and 17 Through 36, as Specified in 
Boeing Alert Service Bulletin 747-53A2409, Revision 5

    (f) For airplanes identified as Groups 1 through 10 inclusive, 
and 17 through 36 inclusive, in Boeing Alert Service Bulletin 747-
53A2409, Revision 5, dated August 18, 2005: Do the inspections in 
paragraph (f)(1) of this AD; and do the corrective action in 
paragraph (f)(2) of this AD as applicable. Except as provided by 
paragraph (i) of this AD, do all actions in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2409, dated September 26, 1996; or Revision 5, dated August 18, 
2005. After the effective date of this AD, only Revision 5 of the 
service bulletin may be used.
    (1) At the applicable time in Figures 1, 2, 18, and 20 of 
Revision 5 of the service bulletin, do initial and repetitive 
inspections of Areas 1 and 4, as applicable, to detect disbonding, 
corrosion, and cracking of the skin; except any inspection using 
Method 1 or 2 must not be accomplished before the latest of the 
following, as applicable: Before the accumulation of 2,000 total 
flight cycles; 2,000 flight cycles since modification to the 
stretched upper deck (SUD) configuration; or 2,000 flight cycles 
since skin panel replacement in accordance with AD 90-26-10, 
amendment 39-6836. If inspection Method 1 or 2 is used and no 
disbonded doubler is found, no further action is required by this 
AD.
    (2) If any corrosion or cracking is found during any inspection 
required by paragraph (f)(1) of this AD: Before further flight, 
except as provided by paragraph (i) of this AD, repair and do any 
applicable related investigative actions in accordance with the 
Accomplishment Instructions of Revision 5 of the service bulletin.

New Requirements of This AD

Actions for Groups 11 Through 16 as Specified in Boeing Alert 
Service Bulletin 747-53A2409, Revision 5 (Airplanes Added to the 
Applicability of This AD)

    (g) For airplanes identified as Groups 11 through 16 inclusive 
in Boeing Alert Service Bulletin 747-53A2409, Revision 5, dated 
August 18, 2005: Do the inspections in paragraph (g)(1) of this AD; 
and do the corrective action in paragraph (g)(2) of this AD as 
applicable. Except as provided by paragraph (i) of this AD, do all 
actions in accordance with the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2409, Revision 5, dated August 18, 
2005.
    (1) At the applicable time in Figures 18 and 20 of the service 
bulletin, do initial inspections of Area 4 and repetitive 
inspections, as applicable, to detect disbonding, corrosion, and 
cracking of the skin, as applicable; except any inspection using 
Method 2 must not be accomplished before the latest of the 
following, as applicable: Before the accumulation of 2,000 total 
flight cycles; 2,000 flight cycles since modification to the SUD 
configuration; or 2,000 flight cycles since skin panel replacement 
in accordance with AD 90-26-10. If inspection Method 2 is used and 
no disbonded doubler is found, no further action is required by this 
AD.
    (2) If any corrosion, disbonding, or cracking is found during 
any inspection required by paragraph (g)(1) of this AD, before 
further flight: Repair and do any applicable related investigative 
actions in accordance with the Accomplishment Instructions of the 
service bulletin.

Actions for Airplanes With Alodine-Coated Rivets for Groups 1 
Through 10, and 17 Through 36 as Specified in Boeing Alert Service 
Bulletin 747-53A2409, Revision 5

    (h) For airplanes identified as Groups 1 through 10 inclusive, 
and 17 through 36 inclusive, in Boeing Alert Service Bulletin 747-
53A2409, Revision 5, dated August 18, 2005: Do the inspections in 
paragraph (h)(1) of this AD; and do the corrective action in 
paragraph (h)(2) of this AD if necessary. Except as provided by 
paragraph (i) of this AD, do all actions in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2409, Revision 5, dated August 18, 2005.
    (1) At the applicable time in Figures 21 and 22 of the service 
bulletin: Do initial and repetitive inspections of Areas 1 and 4, as 
applicable, to detect cracking of the skin.
    (2) If any cracking is found during any inspection required by 
paragraph (h)(1) of this AD, before further flight: Repair in 
accordance with the Accomplishment Instructions of the service 
bulletin.

Exceptions

    (i) Do all actions in accordance with the applicable service 
bulletin except as provided by paragraphs (i)(1), (i)(2), (i)(3), 
(i)(4), and (i)(5) of this AD.
    (1) For the action in paragraph (f)(1) of this AD: Where Boeing 
Alert Service Bulletin 747-53A2409, dated September 26, 1996; and 
Boeing Alert Service Bulletin 747-53A2409, Revision 5, dated August 
18, 2005; specify a compliance time after the issuance of any 
revision of the service bulletin, this paragraph requires compliance 
before the specified compliance time after November 27, 1996 (the 
effective date of AD 96-23-02).
    (2) For the actions in paragraphs (g)(1) and (h)(1) of this AD: 
Where Boeing Alert Service Bulletin 747-53A2409, Revision 5, dated 
August 18, 2005, specifies a compliance time after the issuance or 
receipt of any revision of the service bulletin, this paragraph 
requires compliance before the specified compliance time after the 
effective date of this AD.
    (3) For any repair or any inspection where Boeing Alert Service 
Bulletin 747-53A2409, Revision 5, dated August 18, 2005, specifies 
to contact the manufacturer for further instructions: Before further 
flight, repair or inspect using a method approved in accordance with 
the procedures specified in paragraph (k) of this AD.
    (4) If corrosion is found during any inspection required by this 
AD, before further flight: Repair in accordance with an FAA-approved 
method.
    (5) Where Boeing Alert Service Bulletin 747-53A2409, Revision 5, 
dated August 18, 2005, specifies that it is not necessary to count 
flight cycles at 2.0 psi or less cabin differential pressure, this 
AD does not allow for that adjustment factor.

Credit for Actions Accomplished Previously

    (j) Actions done before the effective date of this AD in 
accordance with the service bulletins specified in Table 1 of this 
AD are acceptable for compliance with the corresponding requirements 
of paragraphs (f) and (g) of this AD.

[[Page 56864]]



                   Table 1.--Credit Service Bulletins
------------------------------------------------------------------------
                                   Revision
        Service bulletin            level                Date
------------------------------------------------------------------------
Boeing Service Bulletin 747-              1  May 29, 1997.
 53A2409.
Boeing Service Bulletin 747-              2  August 6, 1998.
 53A2409.
Boeing Service Bulletin 747-              3  October 22, 1998.
 53A2409.
Boeing Service Bulletin 747-              4  February 17, 2000.
 53A2409.
------------------------------------------------------------------------

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office (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) AMOCs approved previously in accordance with AD 96-23-02, 
are approved as AMOCs for the corresponding provisions of paragraph 
(f) of this AD, except AMOCs for terminating action based upon 
inspection results using a sliding probe low frequency eddy current 
(LFEC), sliding probe high frequency eddy current (HFEC), or mid 
frequency surface eddy current (MFEC) inspection methods; and 
provided that any alternative method for future inspections did not 
incorporate a sliding probe LFEC, sliding probe HFEC, or MFEC 
inspection methods.
    (4) 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

    (l) You must use Boeing Alert Service Bulletin 747-53A2409, 
dated September 26, 1996; or Boeing Alert Service Bulletin 747-
53A2409, Revision 5, dated August 18, 2005, 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-
53A2409, Revision 5, dated August 18, 2005, in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) On November 27, 1996 (61 FR 57994, November 12, 1996), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Alert Service Bulletin 747-53A2409, dated 
September 26, 1996.
    (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 September 14, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-8227 Filed 9-27-06; 8:45 am]
BILLING CODE 4910-13-P